Segui questo link per vedere altri tipi di pubblicazioni sul tema: Medicinal plants – Research – South Africa.
Tesi sul tema "Medicinal plants – Research – South Africa"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Medicinal plants – Research – South Africa".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
1
Chadwick, Wayne. "Metabolic effects brought about by tricyclic antidepressants and the contribution of a medicinal plant in alleviating high fat diet induced insulin resistance in male wistar rats". Thesis, Nelson Mandela Metropolitan University, 2006. http://hdl.handle.net/10948/461.
Testo completoAbstract (sommario):
Type II diabetes is becoming a growing problem in developed countries worldwide. The median age for diagnosis was around sixty, but recent surveys have shown that the entire age distribution curve shifting left. The incidence of type II diabetes is thought to be parallel with the growing rate of obesity associated with an unhealthy western diet. Type II diabetes is an expensive disease to manage, it is for this reason that cheaper medication needs to be investigated in the form of traditional plants, such as Sutherlandia frutescens. Prescription medication, such as tricyclic antidepressants, may also increase body weight thereby playing a role in obesity. The cause of weight gain in such cases may go unrecognized or lead to cessation of the medication with or without the practitioner’s knowledge or approval. It is therefore necessary to investigate the causative agents responsible for the excessive weight gain. Drinking water containing extracts of S. frutescens or metformin was administered to two groups of eleven insulin resistant male Wistar rats. The insulin resistant control group received water without any medication. Rats were sacrificed after 8 weeks allowing for fasting blood glucose, insulin and tissue glycogen content determination. Glucose uptake was also determined using [3H] deoxyglucose. The effect of the medication and the diet on muscle post receptor insulin signaling proteins was determined through Western blots. Liver proteomics was also performed using 2-D electrophoresis. In a separate experiment 26 male Wistar rats were exposed to strepotozotocin toxin, 7 of these rats received intravenous insulin treatment, 7 rats received S. frutescens extract and 7 rats received a combination of both medications, the remaining 5 received no treatment and served as the control. Rats were sacrificed after 6 days allowing for fasting blood glucose, insulin and tissue glycogen content determination. Two groups of 14 male Wistar rats received amitriptyline or trimipramine (common tricyclic antidepressants) in their drinking water, the control group (30 rats) received water without any medication. The rats’ weight and food consumption was monitored throughout the trial and their oxygen consumption was also determined. Rats were sacrificed after 6 weeks or 14 weeks of medicinal compliance allowing for fasting blood glucose, insulin and tissue glycogen content determination. Glucose uptake was also determined using [3H] deoxyglucose. S. frutescens treatment normalized circulating serum insulin levels and significantly increased the rate of glucose clearance. Certain post receptor insulin signaling proteins were also significantly increased relative to the insulin resistant control group. 2-D electrophoresis identified the normalization of protein levels associated with the urea cycle. S. frutescens was also able to, independently; maintain normoglycaemic levels in the strepotozotocin treated group. The tricyclic antidepressants significantly increased blood glucose levels while significantly reducing tissue glycogen levels for both sacrifice periods. Serum insulin remained unchanged while a significant increase in insulin degradation and insulin degrading enzyme levels were found for both antidepressants. S. frutescens shows promise as a low cost antidiabetic medication for future use. Although the antidepressants did not promote weight gain, the increase in blood glucose levels may be cause for concern in patients with a pre-disposition toward developing diabetes.
2
Van, Huyssteen Mea. "Collaborative research with traditional African health practitioners of the Nelson Mandela Metropole : antimicrobial, anticancer and anti-diabetic activities of five medicinal plants". Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/663.
Testo completoAbstract (sommario):
The promotion and development of indigenous knowledge pertaining to the traditional African healing system is one of the prime objectives set out by the South African government. Despite excellent research opportunities and funding, the biggest problem with ethnopharmacological research is a lack of interaction with indigenous communities, which tends to dilute the benefits this research has to offer these communities. The primary aim of this study was thus to promote the traditional African healing system through collaborative medicinal plant research with local traditional health practitioners. The research collaboration aimed to validate some biological activities of traditional remedies used by collaborating traditional health practitioners and ensured interactive sessions where scientific literature, research practices, findings and relevant legislation were discussed and debated. The joint development of a medicinal garden was a valuable tool in realising these goals. Aqueous and ethanol extracts of Bulbine frutescens, Ornithogalum longibracteatum, Ruta graveolens, Tarchonanthus camphoratus and Tulbaghia violacea were selected for antimicrobial, anticancer and anti-diabetic screening, because of their sustainable utilisation potential. The ethanol extract of T. violacea produced the best antimicrobial activity on Bacillus subtilis (100% growth inhibition) and Candida albicans (89% growth inhibition) at 250 μg/ml. The EC50 for the ethanol extract of T. violacea against HT29 colon cancer cells was 101 μg/ml. The aqueous extracts of B. frutescens and T. camphoratus (0.5 and 50 μg/ml) produced the highest overall glucose uptake activity in Chang liver and C2C12 muscle cells. T. camphoratus was unanimously chosen by participating practitioners as the plant to be investigated further. The aqueous extract of T. camphoratus increased glucose uptake in C2C12 muscle cells through increased translocation of GLUT4 to the plasma membrane and activation of the PI3-kinase and AMP-kinase pathways. It produced some alpha-glucosidase inhibitory activity at concentrations of ≥ 200 μg/ml. Apart from interactive feedback seminars at which the findings were presented to participating practitioners, all scientific literature regarding the plants was summarised, translated, compiled and given to participating practitioners in written format. An indigenous knowledge agreement has been negotiated and will formalise the collaboration in future. It is recommended that future research focuses on plants with economic development potential that can be cultivated in the medicinal garden.
3
Lekganyane, Maleho Annastasia. "Isolation and characterization of antibacterial compounds from five selected plants used against bacteria which infects wounds". Thesis, University of Limpopo, 2015. http://hdl.handle.net/10386/1259.
Testo completoAbstract (sommario):
Thesis (M.Sc. (Microbiology)) --University of Limpopo, 2015Five plant species: Ziziphus mucronata, Senna italica, Lantana camara, Ricinus communis and Lippia javanica, were selected for this study based on their use in traditional medicine. In preliminary screening, crude extracts were prepared using hexane, dichloromethane (dcm), acetone and methanol. Phytochemical profiles on Thin Layer Chromatography plates of the extracts were obtained by developing the plates in mobile phases of varying polarity. Tests for compounds such as tannins, flavonoids, alkaloids, phlobatannins, terpenes, steroids, cardiac glycosides and saponins were carried out. Antibacterial activity of the extracts was carried out using microdilution assay for Minimum Inhibitory Concentration and bioautography against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis. Antioxidant activity of the extracts was performed using the 2, 2, diphenyl-1-picrylhydrazyl (DPPH) assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay and Phagoburst test were used to investigate the toxic effects and anti-inflammatory activity of the extracts on mouse Raw 264.7 macrophage cells, respectively. The presence of phytochemicals was observed on the chromatograms after the plates were sprayed with vanillin sulphuric acid reagent. The dcm extracts of the plants showed antibacterial activity against the selected bacterial species on the bioautograms. Senna italica and Z. mucronata showed the most activity bands on the bioautograms. Lippia javanica had the lowest MIC average of 0.56 mg/ml. Antioxidant activity was observed in the extracts of L. javanica and R. communis. The extracts promoted proliferation of the mouse macrophage cells Raw 264.7 at concentrations ranging from 0.31 mg/ml and 0.08 mg/ml. Senna italica leaves were selected for isolation of antibacterial compounds. The isolated compound was analysed on 1H and 13C nuclear magnetic resonance (NMR) and Mass Spectrometry (MS) for structural analysis. The structure could not be elucidated due to impurities in the compound but the tentative structure is a branched chain alkane with at least one ether linkage per repeating unit. Therefore the study shows that there are plant components with biological activities against wound infecting bacteria and a single lead compound was identified.
the National Research Foundation
4
Adams, Zanele. "Comparative phytochemical analyses of Aloe Ferox Mill. found in Eastern and Western Cape provinces in South Africa". Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1013114.
Testo completo
5
Faulconbridge, Steven Craig. "Propagating some commonly-used South African medicinal plants with compost and vermitea". Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1020316.
Testo completoAbstract (sommario):
The use of many of South Africa’s medicinal plants has shown marked increase with over 27 million users in South Africa alone. Most plants are still being unsustainably wild-harvested, a major concern for biodiversity conservation. Commercial interest in certain more commonly-used species has increased, with potential to cultivate medicinal plants on a more sustainable basis. Focus has shifted from conventional use of synthetic fertilisers, pesticides and fungicides to more organic methods of plant propagation. Aqueous extract derived from earthworm composted food waste (vermitea) was used to study the germination and rooting success of selected species. Also survival and growth performance of selected plants grown in a medium amended with commercial NPK fertiliser was compared to those grown in the same medium amended with compost and to those grown in the same medium amended with compost with weekly applications of vermitea. No change in germination success was noted. Vermitea showed promising results on the rooting of cuttings. The application of NPK improved growth performance (biomass) significantly for all species tested. However, they had lower root:shoot ratios as well as lower survival rates compared to plants under the compost and compost/vermitea treatments. The improved survival of these plants highlights the potential of these organic treatments on the propagation of selected medicinal plants.
6
Mathabe, Matlakala Christina. "Bioactivity of medicinal plants used for treatment of diarrhoea in selected villages in Limpopo Province, South Africa". Thesis, University of Limpopo (Turfloop Campus), 2006. http://hdl.handle.net/10386/925.
Testo completo
7
Pruissen, Megan Colleen. "Evaluation of plant extracts : artemisia afra and annona muricata for inhibitory activities against mycobacterium tuberculosis and human immunodeficiency virus". Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1019845.
Testo completoAbstract (sommario):
Mycobacterium tuberculosis and Human Immuno-Deficiency Virus (HIV) have a high prevalence in South Africa. The development and spread of drug resistant tuberculosis is a serious problem which is exacerbated by tuberculosis (TB) co-infection in HIV patients. Traditional medicinal plants like Annona muricata and Artemisia afra are used for respiratory ailments and antiviral therapies respectively. The aim of this study was to evaluate Annona muricata (ethanolic extract) and Artemisia afra (ethanolic and aqueous extracts) for inhibitory activities against M. tuberculosis and HIV. In vitro bioassays for anti-TB activity included: microplate alamar blue assay (MABA), flow cytometry and ρ-iodonitrotetrazolium chloride assays while anti-HIV activity was determined using an HIV-1 reverse transcriptase colorimetric ELISA kit and an HIV-1 integrase colorimetric immunoassay. Cytotoxicity of plant extracts were assessed by the MTT assay on Chang Liver and HepG2 cells. Potential synergistic effects were determined using the basis of Combination Index. Potential interactions of plant extracts with drug metabolic pathways were evaluated with the Glutathione-S-Transferase assay kit as well as the CYP3A4 assay kit. A. muricata ethanolic extract exhibited anti-TB activity with MIC 125 μg/mL. MABA was shown to be the most sensitive and effective method for the detection of anti-TB activity. Artemisia afra aqueous extract showed HIV-1 reverse transcriptase inhibition exhibiting ˃85 percent inhibition at 1 mg/mL while the ethanolic extracts of A. afra and A. muricata showed inhibition of HIV-1 integrase activity at ˃86.8 percent and ˃88.54 percent respectively at concentrations >0.5 - 4 mg/mL. The aqueous extract of A. afra displayed inhibition of HIV-1 integrase ˃52.16 percent at 0.5 mg/mL increasing to 72.89 percent at 4 mg/ml of the extract. A. muricata was cytotoxic at an IC50 of 30 μg/mL and 77 μg/mL on Chang Liver and HepG2 cells respectively, whilst A. afra aqueous and ethanol extracts were not cytotoxic to both cell lines. The ethanolic extract of A. muricata showed both antagonistic and synergistic properties at various IC values, when used in conjunction with rifampicin. A. afra ethanolic extract interrupted GST activity while aqueous extracts of A. afra and A. muricata had a slight effect. All extracts interrupted CYP3A4 activity, however the ethanolic extracts of A. muricata and A. afra showed greater inhibition than the aqueous extract of A. afra. These extracts should be investigated further as they could be an important source of compounds for treatment of M. tuberculosis and HIV respectively.
8
Malamule, R. J. "Mathyelo ya mavito ya misinya yo tshungula mavabyi eka Skhukhuza, eMpumalanga : maendlelo ya onomasitiki". Thesis, University of Limpopo, 2015. http://hdl.handle.net/10386/1771.
Testo completo
9
Chinyama, Robert Fred. "Biological activities of medicinal plants traditionally used to treat Septicaemia in the Eastern Cape, South Africa". Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1274.
Testo completoAbstract (sommario):
Over the past 25 years, there has been a resurgence of worldwide scientific research in the fields of ethnopharmacology. The Western world has acknowledged the continued use of traditional medicines by the majority of third world countries, and the need for novel drug development. Hence, much of the pharmaceutical research in recent years has focused on the ethnobotanical approach to drug discovery (Light et al., 2005). In South Africa, as in most developing parts of the world, traditional herbal medicine still forms the backbone of rural healthcare. The government health services in South Africa provide only western medical care although the majority of the population consult traditional healers for some or all of their healthcare needs (McGaw et al., 2005). Medicinal plants like Harpephyllum caffrum are used as blood purifiers or emetics (Watt and Breyer-Brandwijk, 1962), and also for treating acne and eczema. The antimicrobial activity of this plant can be used to treat septicaemia, which is ranked the sixth leading cause of death among neonates and the eighth leading cause of death for infants through the first year of life (Heron, 2007). In this study, the plants investigated for antimicrobial activity were Harpephyllum caffrum, Hermannia cuneifolia, Chironia baccifera, Rhigozum obovatum, Felicia muricata and Pentzia incana. These plants were tested against ATTC (American Type Culture Collection) strains and microorganisms isolated from clinical isolates of patients suffering from septicaemia. The assay methods used included the agar diffusion method using the Mast multipoint inoculator, the microtitre dilution method were used to determine the minimum inhibitory concentration, thin layer chromatography fingerprints accompanied by bioautographic assay were used to detect the inhibition of bacterial growth by active compounds separated from plant extracts and the Ames test was required to assess the possibility of bacterial mutagenesis upon the exposure to plant extracts which can lead to carcinogenicity. In agar diffusion method, extracts of Harpephyllum caffrum inhibited nine strains of Candida albicans, three species of Acinetobacter and four strains of E.faecalis. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus and three strains of Staphylococcus aureus. Extracts of Chironia baccifera inhibited one strain of Acinetobacter and five strains of E.faecalis. Extracts of plants Rhigozum obovatum, Felicia muricata, and Pentzia incana showed no antimicrobial activity. In the microtitre dilution method used to determine the minimum inhibitory concentration (MIC), the results were different from the agar diffusion method. More activity was observed. Extracts of Harpephyllum caffrum inhibited three strains of E.coli, six strains of S.aureus, three species of Acinetobacter and one strain of Klebsiella pneumonia. Extracts of Hermannia cuneifolia inhibited four strains of B.cereus, three strains of S.aureus, two strains of K.oxytoca and one species of Acinetobacter. Extracts of Chironia baccifera inhibited three strains of S.aureus, one strain of MRSA, one species of Acinetobacter and one strain of S.haemolyticus. The MIC values ranged from 0.049 to 6.25mg/ml. Using the thin layer chromatography fingerprints, bioautography showed the presence of various inhibitory chemical compounds. Methanol and acetone extracts of Harpephyllum caffrum, separated very well and showed various inhibition zones on exposure to Candida albicans, Enterococcus faecalis and Staphylococcus aureus. The different inhibition zones were recorded as Rf In the Ames test (Maron and Ames, 1983) the methanol and acetone extracts of Harpephyllum caffrum and Hermannia cuneifolia were negative which means they were devoid of any mutagenic properties. Methanol extracts of Harpephyllum caffrum showed similar results in the Ames assay as reported by Verschaeve and Van Staden (2008). values ranging from 0.25 to 0.95. The zones indicate the different inhibiting chemical compounds present in the plant. Petroleum ether, ethyl acetate, chloroform and formic acid were the solvents used in the assay in the ratio 8:7:5:1, respectively. Establishing the antimicrobial activity of these plants contribute to the systematic scientific investigation of indigenous South African medicinal plants.
10
Essack, Magbubah. "Screening extracts of indigenous South African plants for the presence of anti-cancer compounds". Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8767_1210844967.
Testo completoAbstract (sommario):
Early man dabbled with the use of plant extracts to cure ailments. This practice has been passed down from generation to generation and today more than 50% of the world'sdrugs are natural products or derivatives thereof. Scientists have thus established a branch of research called natural product research. This branch of research involves the identification and purification of secondary metabolites with a specific biological activity. The methodology involves the screening of plant products for a specific biological activity, purification of the biologically active natural product by separation technology and structure determination. The biologically active natural products is then further scrutinized to serve as a novel drug or lead compound for the development of a novel drug. This research exploited this research methodology.
11
Matanzima, Yonela. "Quantitative and qualitative optimization of antimicrobial bioactive constituents of Helichrysum cymosum using hydroponics technology". Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/849.
Testo completoAbstract (sommario):
Thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Horticulture
in the Faculty of Applied Sciences
at the Cape Peninsula University of TechnologyThe high demand for medicinal plants has favoured over-exploitation of wild plants. The search for alternative and sustainable methods of medicinal plant cultivation is imperative and desirable. Biotechnological approaches particularly hydroponic technology has the potential for large scale plant cultivation and production of secondary metabolites. The current study aims at optimizing the production of antimicrobial secondary metabolites by an indigenous South African medicinal plant species (Helichrysum cymosum) through hydroponics N and K fertilization. In Chapter 1, the conceptual framework and justifications of the study are presented. In Chapter 2 the research objective was to discern the optimal potassium (K) supplement level for H. cymosum by evaluating the effects of different hydroponic K levels on growth, K-leaf content, and anti-Fusarium oxysporum f.sp.glycines (Ascomycota: Hypocreales) and total activities. Six weeks old seedlings of H. cymosum were treated with varied concentrations of K in the form of potassium chloride, potassium nitrate and monopotassium phosphate (58.75, 117.5, 235 and 470 ppm). These concentrations were based on a modification of Hoagland’s hydroponic nutrient formula. Plants were maintained under greenhouse conditions and growth parameters (plant height and number of leaves) were recorded weekly. At 8 weeks post treatment, plants were harvested and fresh weights were recorded and tissue nutrient content analysed. Sub-samples of the aerial parts of plants grown in the different treatments were air dried, extracted with acetone and tested against F. oxysporum. Plants exposed to 235 ppm K showed a marked increase in leaf number, plant height and fresh weight. Overall there was no significant difference (P > 0.05) among the treatments with respect to tissue nutrient content; K ranged from 3.56 ± 0.198 to 4.67 ± 0.29 %. The acetone extraction yield increased with increasing K fertilization: 58.75 ppm (16.67 ± 2.35 mg), 117.5 ppm (22.5 ± 4.79 mg), 235 ppm (210 ± 38.5 mg) but dropped to 40 ± 4.08 mg at 470 ppm K. Results from the anti-F. oxysporum bioassay showed that 58.75 and 235 ppm K treatments produced the most bioactive acetone extracts; MIC values of 0.49 and 0.645 mg/l, respectively. Acetone extracts obtained from plants exposed to 235 ppm K yielded the highest total activity, comparatively (P < 0.05). In conclusion, the optimum nutrient K level for growing H. cymosum hydroponically was 235 ppm. Chapter 3 focused on another important macro nutrient N and the objective was to determine the optimum nutrient requirements for growing the medicinal plant, Helichrysum cymosum (L.) (Asteraceae), hydroponically. Experiments were conducted to assess the effects of varied nitrogen (N) concentrations supplied as nitrate and ammonium on growth, tissue nutrient content, antimicrobial and total activities of acetone extracts of aerial parts. Treatments were based on a modified Hoagland’s nutrient formula. Six week old rooted cuttings were treated with 52.5 ppm, 105 ppm, 210 ppm and 420 ppm of N. Leaf number and stem height (cm) were recorded at weekly intervals and leaf analysis conducted. The effects of N treatments on plant growth parameters varied significantly among treatments; 52.5 ppm of N yielded the tallest plants (height) [19.4 ± 0.7 cm], while 105 ppm N yielded the maximum leaf number (68.1 ± 6.2) as well as maximum fresh weight of aerial parts was obtained with 105 ppm (15.12 ± 1.68 g). Nitrogen content of plant tissue ranged between 0.53 ± 0.03 and 4.74 ± 0.29% (d, f, 3, 12; f=14; P ≤ 0.002) depending on treatments. Powdered aerial parts (5 g) of H. cymosum obtained from the different N treatments were extracted with 100 ml of acetone. N treatment significantly affected the yield of crude extracts, which ranged from 87.5 ± 15.5 (52.5 ppm) to 230 ± 23.5 mg (105 ppm). Acetone extracts of plants that were exposed to varied N treatments were screened for anti-Fusarium oxysporum activity using minimum inhibitory concentration (MIC) method. The MIC value (0.073 ± 0.014 mg/ml) obtained with acetone extracts of plants exposed to 52.5 ppm N was significantly lower compared to the MICs of the other N treatments (105 [0.47 ± 0 and 0.705 ± 0.135 mg/ml], 210 [0.234 and 0.47 mg/ml] and 420 ppm [0.29 ± 0.101 mg/ml]) at 24 and 48 hours respectively. However, the total activities of extracts obtained among the four N treatments, which ranged from 0.062 ± 0.02 to 0.26 ± 0.06 ml/g was not statistically different at 24 or 48 hours (P > 0.05). LC-MS analysis of acetone extracts of H. cymosum plants obtained from the four treatments hinted that known anti-microbial agents such as apigenin, quercetin, kaempferol, helihumulone and quinic acids were present in the extracts and the quantity of helihumulone increased with increased nutrient N level. These results suggest that H. cymosum may be cultivated hydroponically and that the antimicrobial activity and/or the phytochemical profile of the crude acetone extracts is affected by nutrient nitrogen levels. Hydroponic cultivation of plants may be able to alleviate to an extent the pressure on wild medicinal plants.
12
Polori, Ketlareng Liza. "The medicinal properties of ipomoea oblongata E.Mey. ex Choisy". Thesis, Bloemfontein: Central University of Technology, Free State, 2014. http://hdl.handle.net/11462/671.
Testo completoAbstract (sommario):
Thesis (M. Tech. (Biomedical Technology)) -- Central University of Technology, Free State, 2014.Traditional medicine has been known by mankind since ancient times as a healthcare system. All cultures have used herbs throughout history and it was an integral part of the development of modern civilization. Primitive man observed and appreciated the great diversity of plants available to him. Plants provided food, clothes, shelter and medicine and still play a vital role in rural villages of South Africa. The medicinal uses of plants and animals have been developed through trial and error. Herbal plants produce and contain a wide variety of chemical substances that act upon the body’s immune system. The medicinal properties of Ipomoea oblongata (E.Mey.ex Choisy) in this study was to determine the phytochemical content, antioxidant, anti-cancer and anti-diabetic properties of I. oblongata (Mothokho), a medicinal plant used by traditional medical practitioners of Thaba-Nchu in the Free State. The study was carried out in order to validate the ethnomedicinal claims made by the traditional medical practitioners and to evaluate the plant’s potential as a novel therapeutic agent. Twelve traditional medical practitioners of the Kopanang Dingaka Association were interviewed on the knowledge and use of I. oblongata (Mothokho). The phytochemical constituents of the plant were determined using standard screening methods. Testing for antioxidant properties (free radical scavenging activity) was carried out by means of the 2, 2- diphenylpicrylhydrazyl (DPPH) assays. The Sulforhodamine B assay was used to screen for anti-cancer activity in breast (MCF7), colon (HCT116) and prostate (PC3) cancer cell lines. Glucose uptake in C2C12 muscle cells was used to evaluate the anti- iii diabetic potential of I. oblongata. Methanol extract was fractionated using Ultra-Pure Liquid Chromatography (UPLC) to identify active compounds. The traditional medical practitioners cited the plant roots as the main ingredient in the treatment of respiratory infections, sexually transmitted infections, postnatal womb treatments, inflammation, arthritis, wounds and cancer. The methanol extract of I. oblongata showed remarkable (99.03%, 98.39, 71.31%) antioxidant potential in all triplicates tested which explains its use in oxidative stress-related diseases such as arthritis and cancer. Phytochemical tests showed the presence of carbohydrates, glycosides, steroids, terpenoids, alkaloids, flavonoids and tannins. However, the extracts were inactive against the cancer cell lines used. Glucose uptake by the C2C12 muscle cells was increased by over 150% and was comparable to that of insulin and metformin, suggesting good anti-diabetic activity. Predicted compounds found were dihydroquercetin pentaacetate, actinorhodin and actinorhodine, using Chemspider analysis. These are possible compounds that could be found in the Ipomoea oblongata extracts when using nuclear magnetic resonance (NMR) to determine the structure and names of the active compounds. Ethnobotanical uses of Ipomoea oblongata were found to have a link with other ethnobotanical studies to capture the indigenous knowledge, culture and therapeutic uses. The phytochemical results of Ipomoea oblongata can contribute to the knowledge of new drug development as indicated by literature (Harbone; 1973, Soforowa, 1993; De et al., 2010) that plants contain phytochemical contents and phenolic compounds that are valuable as medicinal properties. Methanolic extract of Ipomoea oblongata presented high levels of antioxidant activity respectively, which can become a potential iv antimicrobial agent and remedy oxidative stress related diseases. The anticancer properties were inactive and the cytotoxicity levels were found to below in I. oblongata. Low levels of cytotoxicity allow medicinal plants to be consumed by humans with fewer side effects however doses must be standardized. High levels of glucose uptake in muscle cells were indicated from the aqueous extract of Ipomoea oblongata, therefore showing great potential as an antidiabetic agent. Many medicinal plants have been validated as antidiabetic therapeutic agents in South Africa and the world. New treatment of cancer, diabetes, bacterial and viral infections is required from natural products that are cost effective with minimal side effects that can be used in health care systems. There is a correlation between the medicinal properties found in I. oblongata and the ethnomedicinal uses cited by the traditional medical practitioners. The plant I. oblongata has six ethno-pharmaceutical uses. I. oblongata is a good source of anti-diabetic and antioxidant agents that can be developed further. However the plant is not a good source of anticancer properties. Future research will be into the isolation and identification of the active compounds.
13
Kellermann, Tracy. "A Pharmacological investigations of South Africa Lichens, Dessication-tolerant Plants and Medicinal Tree, Warburgia Salutaris". Doctoral thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/3284.
Testo completo
14
Fewell, William. "An assessment of the in vitro neuroprotective potential of selected Algerian and South African medicinal plant extracts". Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/8608.
Testo completoAbstract (sommario):
It is estimated by the World Health Organization (WHO) that by 2040 neurodegenerative disorders will collectively surpass cancer as the primary cause of death in industrialised countries (WHO,2006). Natural flora represents one of the most important therapeutic sources in modern drug discovery, however only a limited number of plant species have been screened for their neuroprotective value. The neuroprotective potential of eleven Algerian and two South African medicinal plant extracts were assessed in this study, aiming to identify promising candidates for future research. Neurodegenerative disorders such as Parkinson’s disease are characterised by distinct biochemical features, including protein misfolding/-aggregation, excessive oxidative stress and apoptotic cell death. As such, medicinal plant extracts were screened for biological properties directly relevant to neurodegeneration. The capacity to induce autophagy was also investigated as mounting evidence suggests that activation of this pathway may reduce abnormal protein aggregation and promote neuronal survival.
15
Venables, Luanne. "In vitro induction of cell death pathways by artemisia afra extract and isolation of an active compound, isoalantolactone". Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/d1021087.
Testo completoAbstract (sommario):
Artemisia afra is one of the oldest, most well known and widely used traditional medicinal plants in South Africa. It is used to treat many different medical conditions, particularly respiratory and inflammatory ailments. There is no reported evidence of its use for the treatment of cancer but due to its reported cytotoxicity, an investigation of the mode of cell death induced by an ethanol A. afra extract using two cancer cell lines was done. IC50 values of 18.21 and 31.88 μg/mL of ethanol extracts were determined against U937 and HeLa cancer cells, respectively. An IC50 value of the aqueous extract was greater than 250 μg/mL. The ethanol extract was not cytotoxic against confluent control cell lines, Chang Liver and Vero cells. The effect of the cytotoxic ethanol A. afra extract on U937 and HeLa cells and their progression through the cell cycle, apoptosis and mitochondrial membrane potential was investigated. After 12 hours of treatment with A. afra a delay in G2/M phase of the cell cycle was evident. Apoptosis was confirmed using the TUNEL assay for DNA fragmentation, as well as fluorescent staining with annexin V-FITC. Apoptosis was evident with the positive control and A. afra treatment at 24 and 48 hours. JC-1 staining showed a decrease in mitochondrial membrane potential at 24 hours. It was deduced that A. afra ethanol extract induces caspase-dependent apoptosis in a mitochondrial dependent manner. Plants harbour many compounds that are not only useful to the plants but also to mankind. Many metabolites have been isolated from A. afra and their biological activity characterised. Due to observed apoptosis induction, isolation of cytotoxic compounds was done and a new sesquiterpene lactone from A. afra was isolated. Structural elucidation of the compound was done by IR, 1D and 2D NMR, CD and mass spectrometry and it was identified as isoalantolactone. HeLa cancer cells were treated with isoalantolactone and cytotoxicity was exhibited in a dose-dependent manner. A low IC50 value of 8.15 ± 1.16 μM was achieved. This study showed that isoalantolactone is partly responsible for the observed A. afra cytotoxicity. Due to the evidence of G2/M arrest, the anti-mitotic potential and the possible onset of mitotic catastrophe by A. afra and isoalantolactone was investigated. It was evident from various flow cytometric analysis of cyclin B1 and phospho-H3 and confocal microscopy that A. afra does possess anti-mitotic activity by causing hyperpolymerisation of tubulin and cells progress into the mitotic phase where M arrest is experienced. The anti-inflammatory activity of sesquiterpene lactones is well documented; however, the anti-inflammatory activity of A. afra is not. Here, it is reported that the production of NO and COX-2 protein levels in RAW 264.7 cells decrease in the presence of A. afra and isoalantolactone after stimulation with LPS. The activated NF-κB subunit, p65 was also investigated. The results suggest that A. afra and isoalantolactone inhibit p65 activation as a decrease in the activated subunit was evident. Thus, the results indicate that exposure to A. afra and isoalantolactone induces an anti-inflammatory response. In conclusion, this study shows, for the first time, the mechanism of induced apoptosis, the anti-mitotic and anti-inflammatory activity of A. afra and its isolated compound, isoalantolactone. It also proves that although extensive research may have been done on a particular plant, as with A. afra, more can be discovered leading to the identification of new compounds and integration of signalling pathways that can be exploited for the treatment of various diseases and ailments.
16
Wilson, Katherine Leigh. "An investigation into the antibacterial activites of medicinal plants traditionally used in the Eastern Cape to treat lung infections in cystic fibrosis patients". Thesis, Nelson Mandela Metropolitan University, 2004. http://hdl.handle.net/10948/242.
Testo completoAbstract (sommario):
Lung infections in cystic fibrosis (CF) patients are very serious and are usually fatal. Prolonged antibiotic treatment can result in the development of antibiotic resistance. Thus, studies are required to determine if traditional medicinal plants have any significant effects (i.e. antibacterial effects in this case) on certain bacteria causing lung infections in CF patients, providing possible alternative treatment. The aim of this study was to test the effects of several Eastern Cape medicinal plants on specific bacteria causing lung infections in CF patients, for possible antibacterial activities. Four plants traditionally used to treat lung infections (Artemisia afra, Dodonaea angustifolia, Leonotis leonurus & Tulbaghia violacea), and different strains of four bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Pseudomonas species & Klebsiella pneumoniae), usually causing lung infections were investigated. Methanol, aqueous and acetone extraction methods were used to make extracts of the various plants chosen. A decoction of each plant was also investigated. An adapted microtitre plate method for testing the antibacterial activity of the plant extracts against the chosen bacteria was used. The minimum inhibitory concentration (MIC) of each plant extract was determined by means of this method.
17
Monakisi, Charlotte M. "Knowledge and use of traditional medicinal plants by the Setswana-speaking community of Kimberley, Northern Cape of South Africa". Thesis, Stellenbosch : Stellenbosch University, 2007. http://hdl.handle.net/10019.1/18589.
Testo completoAbstract (sommario):
Thesis (MSc)--University of Stellenbosch, 2007.ENGLISH ABSTRACT: The majority of South Africans still depend on the use of traditional remedies, as these are sometimes the only types of health care systems available, especially within rural communities. South Africa comprises approximately 400 000 traditional healers and an estimated 60 to 80% of individuals consulting such traditional healers. As a result, the over-harvesting of many traditional medicinal plants has become a threat to the country’s species diversity and has resulted in the scarcity of certain medicinal plant species. The non-sustainable use of traditional medicinal plants stems from their intense harvesting from the wild to supply the high demands from urban and rural markets. As a result of the escalating population growth rate; high rural unemployment; and fundamental value attached to traditional medicinal plants (socio-economic factors), the national and regional trade of traditional medicines is currently higher than it has ever been. Another reason for the increased threat to traditional medicinal plants is the degradation and weakening of customary laws that have previously regulated such resources. This study focuses on the use of traditional medicinal plants by the Setswana-speaking community for self-medication and as a form of primary health care. Research was conducted in Kimberley, Northern Cape of South Africa and focuses on the issue of the sustainability of medicinal plant use in the area, specifically on use and users as well as the acquisition of material sold by a single trader and harvesting techniques. This is to determine whether harvesting of medicinal plants is a potential threat to plant communities in the area. To address the shortcomings of medicinal anthropology the study also investigates the impacts of relocation and resettlement of various communities in the area, on plant use, methods of collection, the sustainability of the natural resource, as well as the transmission of Setswana indigenous knowledge inter-generationally. most abundant under high disturbances. Certain species reacted positively to disturbance and were most abundant in disturbed habitats. These included Elephantorrhiza elephantina and a Helichrysum sp. To minimise destructive harvesting in the Kimberley area and to ensure the sustainable harvesting of plant material, it is important that local harvesters are educated on proper harvesting techniques and that local gatherers are educated on sustainability issues as well as other ecologically fundamental issues.
AFRIKAANSE OPSOMMING: Die meeste Suid-Afrikaners is steeds afhanklik van tradisionele geneesmiddels aangesien dit soms, veral in landelike gemeenskappe, die enigste beskikbare gesondheidsorg is. Suid-Afrika het sowat 400 000 tradisionele geneeshere wat deur ’n geraamde 60% tot 80% van individue geraadpleeg word. As gevolg hiervan hou die oorontginning van talle tradisionele medisinale-planthulpbronne ’n bedreiging vir die land se spesiediversiteit in en het dit reeds tot ’n skaarste aan sekere medisinale plante gelei. Tradisionele medisinale plante word tans nievolhoubaar aangewend aangesien dit op groot skaal in die veld geoes word om in die groot vraag van stedelike en landelike markte te voorsien. As gevolg van die stygende bevolkingsgroeikoers, hoë landelike werkloosheidsyfer en die grondliggende waarde wat aan tradisionele medisinale plante geheg word (sosio-ekonomiese faktore), is die nasionale en streekhandel in tradisionele geneesmiddels tans groter as ooit tevore. Nog ’n rede vir die toenemende bedreiging van tradisionele medisinale plante is die verslapping en versagting van gewoonteregwetgewing wat voorheen sodanige hulpbronne gereguleer het. Hierdie studie fokus op die gebruik van tradisionele medisinale plante deur die Setswanagemeenskap vir selfbehandeling en as ’n vorm van primêre gesondheidsorg. Die navorsing vir die studie is in Kimberley in die Noord-Kaapprovinsie van Suid-Afrika gedoen en fokus op die kwessie van volhoubare medisinale-plantgebruik in die gebied, met bepaalde klem op gebruik en gebruikers, die verkryging van middels wat deur ’n enkele handelaar verkoop word, en oestegnieke. Die doel van die navorsing was om te bepaal of die oes van medisinale plante ’n moontlike bedreiging vir plantgemeenskappe in die gebied inhou. Om die tekortkominge van medisinale antropologie aan te pak, ondersoek die studie ook die uitwerking van die verskuiwing en hervestiging van verskeie gemeenskappe in die gebied op plantgebruik, oesmetodes, die volhoubaarheid van die natuurlike hulpbronne, asook die oordrag van inheemse Setswana-kennis oor geslagte heen. Selfbehandeling en die gebruik van tradisionele medisinale plante speel steeds ’n groot rol in Kimberley, aangesien die meeste van die individue wat aan die navorsing deelgeneem het steeds tradisionele geneesmiddels as deel van hulle kultuur en tradisie gebruik. Daar word in ’n uiteenlopende verskeidenheid plantmateriaal handel gedryf. Hoewel sommige van die middels plaaslik ingesamel word, word die meeste van ander dele van die land, en in party gevalle van buurlande soos Lesotho en Swaziland, ingevoer. Hoewel die meeste van die materiaal dus nie plaaslik ingesamel word en dus nie bepaald op hierdie studie betrekking het nie, is dit steeds aanduidend van oes- en volhoubaarheidskwessies in ander dele van die land. Die kruiekenner dryf in sewentig tradisionele medisinale-plantsoorte handel, waarvan party beskermd en erg bedreig is, waaronder Prunus africana en Warburgia salutaris wat slegs in beskermde gebiede in die land voorkom. Prunus africana is ’n gelyste spesie in CITES, aanhangsel 2. Ander bedreigde spesies sluit Ocotea bullata, Bersama lucens, Curtisia dentata en ’n Eugenia-spesie in. Die meeste van die plante wat (in Kimberley) geoes word, is in die vorm van ondergrondse bergingsorgane (uitlopers en bolle). Hoewel hierdie plante van stingelskade en die skade aan ondergrondse bergingsorgane kan herstel, vat hulle swak pos indien hulle oorgebruik en oorontgin word, en kan hulle dus mettertyd al hoe minder voorkom. In hierdie studie word die mettertydse afname in plantbevolkings deur die toename in reisafstande na insamelingspunte aangetoon. Hierdie tendens is egter nie in die handelsprys en -materiaalhoeveelhede oor die afgelope eeu weerspieël nie. Die meeste van die studiedeelnemers het bevestig dat die prys en hoeveelheid van die handelsmateriaal deurentyd betreklik stabiel gebly het. Van die teikenspesies wat vir kwesbaarheid of sensitiwiteit vir ontwrigting ondersoek is, het Withania somnifera, Boophane disticha, Dicoma anomala en Bulbine natalensis die laagste oorlewingspotensiaal en die hoogste ontwrigtingsensitiwiteit getoon. Die meeste van hierdie spesies het in baie klein hoeveelhede op die gekose terreine voorgekom. In die geval van Withania somnifera kon die negatiewe resultate egter met die laereënvalseisoen gedurende daardie betrokke jaar in verband gebring word. Hierdie spesie word oor die algemeen as ’n onkruid in ontwrigte gebiede geklassifiseer en kom meestal onder erg ontwrigte toestande voor. Sekere spesies, soos Elephantorrhiza elephantina en ’n Helichrysum-spesie, het positief op ontwrigting gereageer en het volop in ontwrigte habitatte voorgekom. Om vernietigende oestery in die Kimberley-omgewing te minimaliseer en die volhoubare ontginning van planthulpbronne te verseker, is dit belangrik dat plaaslike plukkers in gepaste oestegnieke, en plaaslike insamelaars oor volhoubaarheidskwessies en ander ekologies belangrike sake opgelei word.
18
Kimbugwe, Francis Kambugu. "An investigation of factors which influence integrating indigenous knowledge of medicinal plants into the learning programme for Grade 9 General Science". Thesis, Rhodes University, 2001. http://hdl.handle.net/10962/d1003506.
Testo completoAbstract (sommario):
This study explores knowledge of some medicinal plants amongst the sub-urban community of and around a township in the Eastern Cape province. This qualitative interpretivist case study presents the prior knowledge of medicinal plants possessed by Grade 9 learners, which is used as a springboard toward interviewing traditional healers, herbal practitioners and lecturers at a university in the departments of Botany and Pharmacy. The data obtained from the informants reveals the factors that can influence integration of indigenous knowledge of medicinal plants in the learning programme for grade 9 General Science. These factors include: prior knowledge and enthusiasm of Grade 9 learners and teachers, support of the community which include parents, traditional healers, herbal practitioners and professionals who could introduce indigenous knowledge of medicinal plants into formal education, availability of resource materials and complexity of identifying pharmacologically tested plants from other indigenous medicinal plants. The analysis and discussion of the findings, have led me to conclude that the enthusiasm of learners who have a rich background of indigenous knowledge on medicinal plants is likely to be hampered by the unenthusiastic teachers as well as the reluctance of herbal practitioners in their communities to part with this knowledge. Hence I recommend that teachers be motivated through workshops and in-service training, conducted by goverr\ment paid herbal practitioners using the prior knowledge of learners as a stepping-stone.
19
Shai, LJ, JN Eloff, N. Boaduo, AM Mogale, SR Magano, MP Mokgotho e P. Masoko. "Yeast alpha glucosidase inhibitory and antioxidant activities of six medicinal plants collected in Phalaborwa, South Africa". Elsevier, 2010. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001248.
Testo completoAbstract (sommario):
Abstract
Recent decades have experienced a sharp increase in the incidence and prevalence of diabetes mellitus. One antidiabetic therapeutic
approach is to reduce gastrointestinal glucose production and absorption through the inhibition of carbohydrate-digesting enzymes such as α-
amylase and α-glucosidase and α-amylase. The aim of the current study was to screen six medicinal plant species, with alleged antidiabetic
properties for α-glucosidase inhibitory activities. Powdered plant materials were extracted with acetone, and tested for ability to inhibit baker's
yeast α-glucosidase and α-amylase activities. The largest mass (440 mg from 10 g) of the extract was obtained from Cassia abbreviata, while
both Senna italica and Mormordica balsamina yielded the lowest mass of the extracts. Extracts of stem bark of C. abbreviata inhibited baker's
yeast α-glucosidase activity with an IC50 of 0.6 mg/ml. This plant species had activity at low concentrations, with 1.0 mg/ml and above
resulting in inhibition of over 70%. The other five plant extracts investigated had IC50 values of between 1.8 and 3.0 mg/ml. Senna italica only
managed to inhibit the activity of enzyme-glucosidase at high concentrations with an IC50 value of 1.8 mg/ml, while Tinospora fragosa extracts
resulted in about 55% inhibition of the activity of the enzyme at a concentration of 3.5 mg/ml, with an estimated IC50 value of 2.8 mg/ml.
The bark extract of C. abbreviata was the most active inhibitor of the enzyme, based on the IC50 values (0.6 mg/ml). The bark extract of C. abbreviata
contains non-competitive inhibitor(s) of α-glucosidase, reducing Vmax value of this enzyme from 5 mM·s–1 to 1.67 mM·s–1, while Km remained
unchanged at 1.43 mMfor para-nitrophenyl glucopyranoside. Antioxidant activity of the extracts was also investigated. The C. abbreviata extract was
more active as an antioxidant than the positive control, trolox. The extracts did not inhibit alphaamylase activity more than about 20% at the highest
concentration tested.
20
Yengkopiong, P. J. "The assessment of the therapeutic and toxicological properties of carpobrotus acinaciformis and schkuhria pinnata used in traditional medicine in South Africa". Thesis, University of Limpopo (Medunsa Campus), 2005. http://hdl.handle.net/10386/846.
Testo completo
21
Tembeni, Babalwa. "Seasonal variations of essential oil composition and some biological evaluation of Pelargonium inquinans (L.) Ait. South Africa". Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/6281.
Testo completoAbstract (sommario):
Pelargonium inquinans which belongs to the family Geraniaceae, is an essential oil yielding plant. P. inquinans was collected from two different sites in Grahamstown (wild) and Alice, at the University of Fort Hare botanical garden. Authentication of the plant was done by Dr. T. Dold at Schonland herbarium, and the voucher specimen being T01. This study is focused at determining the chemical constituents and biological properties of the essential oils of wild and cultivated P. inquinans across different seasons, as the plant grows throughout the year. Seasonal collection of wild and cultivated P. inquinans was achieved in a duration of 12 months. 32 essential oil samples of P. inquinans were obtained by extraction using hydro-distillation technique for 3-4 hours. The chemical composition of the essential oils was determined using GC/MS and GC/FID. Amongst the 32 essential oils only 4 samples wild ( fresh stem and leaf) and cultivated ( fresh stem and leaf) from summer season were evaluated for analgesic activity using acetic acid induced writhings and hot plate nociception models in mice, anti-inflammatory activity was determined on the egg albumin- induced rat paw oedema in rats. The results obtained from GC-MS revealed a total of 169 components obtained from the leafstem, fresh/dry wild and cultivated P. inquinans. These essential oils showed a great deal of chemotaxonomic variation and similarity in the major and minor components along the season. In spring season the essential oils of wild and cultivated P. inquinans had abundance of hydrogenated sesquiterpenes (20.6percent-66.7percent). The major components were found to be α-caryophyllene (9.1percent-26.8percent), p-xylene (23.3percent-27.5percent), β-caryophyllene (11.4percent-30.9percent), o-xylene (6.3percent-39.4percent), β-thujene (8.7percent), isocaryophyllene (13.9percent), isoborneol (14.2percent), β-myrcene (5.7percent), geranyl acetate (13.8percent), toluene (7.9percent), β-gurjunene (18.5percent), α-cadinene (15.8percent), β-farnesene (14.2percent), 3-carene (12.1percent) and camphene (9.0percent). In summer season the essential oils of wild and cultivated P. inquinans were found to have abundance of hydrogenated sesquiterpenes (50.3percent- 63.0percent), oxygenated monoterpenes (30.4percent) and hydrogenated monoterpenes (20.8percent- 61.0percent). The major components were found to be α-caryophyllene (12.3percent-25.8percent), β-caryophyllene (15.1percent- 31.7percent), trans-caryophyllene (10.3percent- 17.8percent), phytol (14.2percent- 20.2percent), camphor (46.5percent), sabinene (27.8percent), elemol (18.1percent), z3-hexenyl isobutyrate (16.3percent), limonene (12.1percent), menthone (12.1percent)< E.E-β-farnesene (14.7percent), palmitic acid (9.6percent), eugenol (9.4percent), cis- β-ocimene (8.7percent), α-terpineol (8.7percent), geranyl acetone (7.8percent), β- humulene (7.5percent). linoleic acid (7.4percent), trans-linalool oxide (7.4percent), β-bisabolene (7.1percent), cis- linalool oxide (7.1percent), ionone (6.9percent), caryophyllene oxide (6.9percent) and germacrene d (6.3percent). In autumn season the essential oils of wild and cultivated P. inquinans were found to be rich in hydrogenated sesquiterpenes (29.3percent- 65.2percent) and oxygenated sesquiterpenes (22.8percent- 31.4percent). The major components were found to be α-caryophyllene (15.5percent- 23.4percent), β-caryophyllene (15.2percent- 17.2percent), β-myrcene (7.7percent-13.8percent), β-humulene (8.7percent- 15.2percent), caryophyllene oxide (9.8- 16.2percent), trans- caryophyllene (16.7percent- 23.3percent), α-humulene (11.8percent- 18.6percent), linoleic acid (11.2percent), palmitic acid (10.4percent), phytol acetate (8.5percent), -longipinene (8.3percent) and citronellol (7.8percent). In winter season the essential oils of wild and cultivated P. inquinans were found to have abundance of hydrogenated sesquiterpenes (25.1percent- 48.6percent), oxygenated monoterpenes (47.6percent), oxygenated sesquiterpenes (22.2percent- 28.0percent). The major components were found to be β-caryophyllene (14.6percent- 23.0percent), α-caryophyllene (9.4percent- 18.0percent), trans- caryophyllene (12.2percent- 14.6percent), α-cedrene (26.2percent), germacrene –d-4-ol (16.8percent), 2,6-dihydroxyacetophenone (15.6percent), (+) epibicyclosesquiphellandrene (15.3percent), E-β- farnesene (13.0percent), β-phellandrene (11.7percent), 2-nitrophenol (9.5percent), palatinol (8.4percent), geranyl acetate (7.7percent) and linoleic acid (7.4percent). The oils from the wild and cultivated sources showed significant (p<0.05-0.001) decrease in number of writhes induced by the acetic acid compared to vehicle; caused significant (p<0.05-0.001) delay in reaction time on the hot plate at 60 and 90 min post-treatment and significantly (p<0.05-0.001) reduced oedema size caused by the egg albumin injection compared to the vehicle. The oils from the wild plant showed more potency compared to the cultivated. The essential oils of wild and cultivated P. inquinans showed qualitative, quantitative and chemotaxonomic variation with analgesic and anti-inflammatory activity. These essential oils need to be explored for further biological analysis because of the major components they contain.
22
Mintsa, Mi Nzue Agnan Pierre. "Use and conservation status of medicinal plants in the Cape Peninsula, Western Cape Province of South Africa". Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1590.
Testo completo
23
Louw, Melissa. "The social practices of cultivation and gathering of medicinal plants in Ebenhaezer, Matzikama, Western Cape, South Africa". Thesis, University of the Western Cape, 2016. http://hdl.handle.net/11394/5533.
Testo completoAbstract (sommario):
Magister Artium - MAThis study aims to investigate the extent to which the increasing demand for medicinal plant and the resulting pressure on local cultivators to meet the demand impact upon cultivation and gathering practices of such plants. The specific focus is on the social practices of cultivation and gathering of medicinal plants in Ebenhaezer, a small-scale peri-urban town in Matzikama in the Western Cape Province in South Africa. This study will utilize survey and in-depth interviews techniques complemented with a focus group discussion on observed cultivation and gathering practices.
24
Van, Gend Tania Anli. "Effect of a South African medicinal plant on antiretroviral drug induced abnormalities in rats". Thesis, Nelson Mandela Metropolitan University, 2008. http://hdl.handle.net/10948/1080.
Testo completoAbstract (sommario):
The worldwide AIDS epidemic is known to have had a profoundly negative social, economic and personal impact and has taken a heavy toll on existing health care systems, particularly in developing countries. South Africa is experiencing an HIV epidemic with enormous social and economic consequences. Lopinavir/ritonavir antiretroviral treatment has been accredited with having a significantly positive effect and is a key advance in controlling HIV morbidity and mortality. An indigenous South African medicinal plant, Sutherlandia frutescens, known for its anti-diabetic properties and immune-boosting effects, is used for treating HIV positive patients suffering from opportunistic infections. Despite the use of the medicinal plant extract as homeotherapeutic medication, there is little evidence of toxicity testing that identifies its potential for interaction with antiretroviral drugs. However, scientific data relating to the mechanism through which Sutherlandia frutescens acts on the immune system has not been comprehensively documented. The aim of this study was to investigate lopinavir/ritonavir induced metabolic abnormalities in rats and whether the introduction of a plant extract of Sutherlandia frutescens would counteract the side effects of ARV medication. The results indicated that the rodents did not become insulin resistant, however, biochemical analysis indicated that extended ARV drug treatment would have caused insulin resistance. Significant morphological changes were found in the livers, kidneys and pancreases of rats exposed to the lopinavir/ritonavir. Rats exposed to the Sutherlandia frutescens plant extract showed improved histopathology with minimal abnormalities.
25
Davison, Candice. "A biochemical study of the antidiabetic and anticogulant effects of Tulbaghia Violacea". Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1523.
Testo completoAbstract (sommario):
Secondary metabolites derived from plants, especially those used by traditional healers, are at the forefront of new drug development in combating diseases such as cancer and diabetes. Garlic is employed in indigenous medicine all over the world for the treatment of a variety of diseases. Dietary garlic has been recognized for its beneficial health effects. In particular, garlic consumption has been correlated with (i) reduction of risk factors for cardiovascular diseases and cancer, (ii) stimulation of immune function, (iii) enhanced detoxification of foreign compounds, (iv) hepatoprotection, (v) antimicrobial effects, (vi) antioxidant effects, and most importantly (vii) its hypoglycemic and anticoagulant properties. Due to these beneficial properties, garlic and its closely related genera which includes Tulbaghia violacea, may be useful as coadjuvant therapy in the treatment of type 2 diabetes and some of its physiological complications. The aim of this study was to determine if T. violacea has antidiabetic and anticoagulant properties. This was performed in vitro using both aqueous and organic extracts of the roots, leaves and bulbs. An organic extract was able to improve glucose-stimulated insulin secretion (GSIS) in INS-1 pancreatic β-cells and glucose uptake in Chang liver cells. The BO extract had no effect on the glucose uptake in 3T3-L1 an adipose cell line and reduced glucose utilisation in C2C12, a skeletal muscle cell line. Some of the properties displayed by T. violacea in this study are consistent with those found in similar studies with garlic extracts. It was observed that the BO extract increased the membrane potential and Glut-2 expression in INS-1 cells cultured at hyperglycemic levels, however, at normoglycemic levels a reduction was observed. The oxygen consumption increased at both glycemic levels due to treatment with the BO extract. Platelets were exposed to the extracts to determine their effects upon platelet aggregation, adhesion and protein secretion. Since the BO extract displayed the highest potential at inhibiting platelet aggregation and adhesion. A rat model was used in ex vivo studies to determine if the extract exhibited the same effect in a physiological model. It was noted that the BO extract exhibited a higher degree of inhibition on platelet aggregation and adhesion than the positive control, aspirin. The BO extract reduced clotting times in the prothrombin time (PT) test, but prolonged the clotting time in the actived partial thromboplastin time (APTT) assay in the ex vivo model; however, it had no affect on these clotting assays in the in vitro model using human blood. The BO extract increased the D-dimer and Fibrinogen-C levels in the in vitro model, but had no effect on the D-dimer concentrations and lowered the Fibrinogen-C levels in the ex vivo model. The active compounds in the extract remain to be elucidated.
26
Mgobozi, Vuyokazi. "Heavy metal content absorption and medicinal potential of Egeria densa (Planch.) Casp". Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1013121.
Testo completoAbstract (sommario):
The contamination of heavy metals in the environment is a looming concern worldwide. Egeria densa (Planch) (Submerged aquatic plant) from two ponds: Site A with co-ordinates (32º 48’22.04”S; 26°48’58.79” E) and Site B with co-ordinates (32°48’33.25”S; 26°48’33.25”S) in Alice (Eastern Cape) was evaluated for its ability to absorb heavy metals, phytochemical constituents, antimicrobial activity and ultra-structure using standard analytic procedures. Cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), and zinc (Zn) were measured in water, sediments and plant. The concentrations of these metal elements were determined with use of Inductively Coupled Plasma- Optical Emission Spectrometry (ICP-OES). In sediments, the heavy metals (mg/kg) decreased in the order of their average concentration as follows: Fe (40.320) > Zn (1.259) > Pb (0.564) > Mn (0.186) > Cu (0.037) in Pond 1 whereas in Pond 2 Fe (61.527) > Cd (0.999) > Mn (0.648) > Pb (0.586) > Zn (0.156) > Cu (0.045). The highest concentration of Fe was detected in both sites and Cu being the least. The concentrations of the metals in the plants sample (from Pond 1) were found in order of Mn > Pb > Cu > Fe whereas cadmium and zinc were not detected, while the concentration in Pond 2 decreases in order of Zn > Mn > Pb > Cd > Fe > Cu. In the water samples, concentrations of heavy metals (mg/L) decreased in the order of their average concentrations as follows: Pb (35.36) > Fe (3.07) > Mn (0.238) > Cu (0.104), both cadmium and zinc were below the limit of detection in Pond 1, whereas in Pond 2 the concentrations decreased as follows: Pb (13.033) >Fe (1.69) > Cu (0.270) > Mn (0.248) > Cd (0.004) and Zinc was not detected. Phytochemical analyses of the plant extracts revealed the presence of phenols, flavonoids, proanthocyanidin, flavonols, saponins, alkaloid and tannins in all the extracts (water, acetone and n-hexane). Both acetone and water extracts, showed high concentration of proanthocyanidin, while tannin was the lowest in acetone extract. Antimicrobial evaluation using, Gram positive (Staphylococcus aureus, Bacillus pumilus, Bacillus cereus, Streptococcus pyogenes, Enterococcus faecalis) and Gram negative (Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris and Serratia marcescens) bacteria showed negative results for all the strain, except Streptococcus pyogenes which was inhibited at MIC of 0.1 mg/ml. Scanning electron microscopy (SEM) of ultra-structure of Egeria densa, showed that certain bacteria attached to the leaf, However more work has to be done on E. densa to verify the mechanism by which it accumulates heavy metals. The study shows that E. densa has a potential of accumulating heavy metals especial Manganese in plant.
27
Appidi, Jaipal Reddy. "Evaluation of antidiarrhoeal and toxicological properties of Hermannia Incana cav.: a South African medicinal plant". Thesis, University of Fort Hare, 2010. http://hdl.handle.net/10353/259.
Testo completoAbstract (sommario):
Hermannia incana Cav. (Sterculiaceae), known as sweet yellow bells, is a medicinal plant used by the people of the Eastern Cape for the treatment of stomach-ache and diarrhoea. It has purgative and diaphoretic effects. It is a prostrate herb with yellow flowers and sparsely hairy and slightly glandular leaves, occurring in grassland and marshes in the Eastern Cape Province of South Africa. Based on the ethnomedical uses of this plant, the research project was designed to evaluate its antidiarrhoeal and toxicological properties. An ethnobotanical study of plants used for the treatment of diarrhoea in the Eastern Cape Province was carried out, using a questionnaire which was administered to herbalists, traditional healers and rural dwellers. This survey indicated a total of 17 plant species from 14 families. Elephantorrhiza elephantine (Burch.) Skeels, Hermannia incana Cav., Pelargonium reniforme Curt., Alepidea amatymbica Eckl. & Zeyh. and Bulbine latifolia (L.f.) Roem. et Schult. were the most frequently mentioned and highly recommended plants for the treatment of diarrhoea by both the traditional healers and rural dwellers. The root, bark and leaves are the common parts of plants used, while decoctions and infusions are the main methods of preparation. The agar dilution method was used to study the antimicrobial activity. The methanol extracts of the plant showed appreciable activity against Gram-positive and Gram-negative bacteria at concentrations ranging from 0.5 to 7.0 mg/ml. The acetone and water extracts of both the leaves and the roots showed moderate activity against Gram positive bacteria and less activity against Gram negative bacteria. All the extracts inhibited the growth of the fungi Aspergillus flavus, Aspergillus niger, and Mucor hiemalis with growth inhibition ranging from 54.31 percent to 96.67 percent at 0.1-10 mg/ml. None of the extracts suppressed the growth of Candida albicans at the maximum concentration (10 mg/ml) tested. iii In the in vivo antidiarrhoeal evaluation using Wistar rats, the aqueous extract at all the doses tested, significantly prolonged the time of induction of diarrhoea and also reduced the frequency of diarrhoeal episodes and fecal parameters (total number, number of wet, fresh and dry weight and water content of the faeces). The percentage inhibition of defecation and intestinal content (enteropooling) were increased in dose dependent manner. The doses also reduced the intestinal transit time of charcoal, masses and volumes of intestinal fluid (gastrointestinal motility). These results are indications of antidiarrhoeal property of H. incana leaf extract with the 600 mg/kg body weight of the extract being the most effective. In the toxicological evaluation using Wistar rats, the oral administration of the extract did not produce any significant effect on the liver and kidney body weight ratios, RBC, HB, PCV, MCV MCH, MCHC, RCDW, WBC, neutrophils, monocytes and basophils cholesterol, triacylglycerol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and atherogenic index. The extract also did not affect the levels of sodium, potassium, chloride, inorganic phosphorus, urea, creatinine, total protein, globulin, albumin, total and conjugated bilirubin. The activities of alkaline phosphatase, gamma glutamyl transferase and alanine aminotransaminase in the serum were increased by the extract whereas aspartate aminotransaminase was decreased. The levels of LUC, platelets, lymphocytes and eosinophils were significantly affected at 600 mg/kg body weight. The available evidence in this study suggests that the extract of H. incana leaf is mild, parameter and dose specific. The structure and distribution of foliar appendages on the leaves of this plant were investigated with the JEOL (JSM-6390LV) scanning electron microscope (SEM). Both glandular and non-glandular trichomes were observed. Long stalked glandular trichomes were present on both the abaxial and adaxial surfaces while short stalked glandular trichomes were present only on the adaxial surface. Glandular trichomes were capitate while nonglandular trichomes were stellate with many arms. Energy dispersive X-ray spectroscopyiv SEM showed that Al, Ca, K, Na, Ti and Si were the major constituents of the crystals analyzed from the leaf surfaces. The phytochemical screening of H. incana revealed the presence of bioactive antidiarrhoeal agents such as alkaloids, tannins, saponins, phenolics, triterpenes, cardiac glycosides, flavonoids, cardenolides and dienolides. Two flavonoids, epicatechin and 3, 5, 7, 2’ tetra-hydroxy flavone-3- O--D-glucopyranoside were isolated from the leaves of the plant through bio-active guided fractionation. Both these compounds were screened against diarrhoea causative organisms (Echerichia coli, Shigella flexneri, Bacillus cereus and Staphylococcus aureus) and exhibiting minimum inhibitory concentrations ranging from 12.5 to 100 μg/ml. The findings from this research have generally justified the traditional use of this plant for the treatment of diarrhoea in this province.
28
Emamzadeh-Yazdi, Simin. "Antiviral, antibacterial and cytotoxic activities of South African plants containing cardiac glycosides". Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/33163.
Testo completoAbstract (sommario):
South Africa has one of the richest and diverse floras in the world with over 30000 species of higher plants. There are approximately 3000 species of medicinal plants in South Africa. The discovery of active compounds in medicinal plants plays a strategic role in the phytochemical investigation of crude plant extracts. Secondary metabolites of medicinal plants are a major source of drugs for the treatment of various health disorders. Cardiac glycosides are one of the subgroups of steroids modified from terpenoids. The existence of cardiac glycosides in some plant species often indicates toxicity. Among the contagious elements, diseases caused by viruses are one of the major causes of death, disability, and social and economic disruption for millions of people. Viruses also cause many important plant diseases and are responsible for huge losses in crop production and quality in all parts of the world. According to literature, plants containing cardiac glycosides demonstrate potential for the discovery of more effective new drugs in the treatment of infection especially viral contagions. The main objectives of this study were to evaluate the antiviral (HSV-2 and PVYN), antibacterial and cytotoxic activities of South African plants containing cardiac glycosides. Furthermore, isolation and identification of compounds with an emphasis on cardiac glycosides was carried out. Eight plants known to contain cardiac glycoside compounds were selected. Leaves of Gomphocarpus fruticosus, Nerium oleander, Cotyledon orbiculata, the fruits and leaves of Strophanthus speciosus, the bulbs of Bowiea volubilis and Merwilla plumbea were selected to examine their antimicrobial activities, toxicity, antiviral and to isolate potential pure compounds.
The ethanol extracts of all selected plants were screened for antibacterial activity against two Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and two Gram-negative (Escherichia coli and Klebsiella pneumonia) pathogens. Plant extracts showed promising antibacterial action against Gram-positive bacteria. The most active extract against both Gram-positive bacteria was C. orbiculata with the MIC value of 1.25 mg/ml.
Cell toxicity was monitored by determining the effect of the ethanolic crude extracts on human embryonic kidney cell line (HEK 293) using the XTT method. All extracts exhibited high toxic effects with IC50 < 100 μg/ml on the tested cell line. The XTT assay was used to determine of the antiviral activity of crude ethanolic extracts on the kidney epithelial cells of African Green Monkey (Vero). The results revealed that the crude ethanolic extracts of all
iv
selected plants exhibited a cytotoxic effect on Vero cells at concentrations lower than their EC50. Consequently, the determination of antiviral activity of the selected plant extracts was not successful.
Based on the chromatographic and bioassay results from the six plants selected for this study, the fruit extract of S. speciosus, belonging to the Apocynaceae family, was chosen for the isolation of compounds, particularly cardiac glycosides. All plant extracts were tested for antibacterial activity against E. coli (Gram-negative) and E. faecalis (Gram-positive) by using bioautography. The general TLC test showed more variety of compounds in the fruit extract of S. speciosus. The results of the bioassay showed promising activity of the fruit extract of S. speciosus and the bulb extract of B. volubilis against Gram-positive bacteria. The chromatographic investigation of the S. speciosus fruit extract led to the isolation of three pure compounds including a cardiac glycoside. The three compounds were identified based on NMR (1D and 2D) and HRMS. The isolated compounds were identified as: a triterpene (ursolic acid methyl ester), a sugar: myo-inositol methyl ester and an unidentified cardiac glycoside. According to literature, it is the first report of the isolation of ursolic acid methyl ester and myo-inositol-methyl ether from S. speciosus fruit extract.
The isolated cardiac glycoside exhibited no inhibitory activity at 1.25 mg/ml (the highest concentration tested) against all four tested bacteria (S. aureus, E. faecalis, E. coli and K. pneumonia). The cytotoxicity and anti-HSV-2 screening of the isolated cardenolide demonstrated the highly toxic effect of this compound on the HEK 293 cell line with 4.62 μg/ml IC50 value and < 25 μg/ml IC50 of Vero cell line. No evidence could be found in the literature of the cytotoxic activity of cardiac glycoside compounds on the HEK 293 cell line.
The ethanolic extracts of all plant extracts and isolated cardenolide were tested against the PVYN in vivo and in vitro. The results revealed that the high concentration (50 mg/ml) of M. plumbea, N. oleander, B. volubilis (fresh bulb), C. orbiculata and isolated cardenolide reduced the PVYN symptoms on tobacco plants in an in vivo experiment. In in vitro analysis, the high concentration (50 mg/ml) of S. speciosus (leaves & fruits), and especially M. plumbea (dry bulb) showed significant antiphytoviral activity. In vivo and in vitro results demonstrated that M. plumbea has potential antiphytoviral activity.Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Plant Science
Unrestricted
29
Gololo, Sechene Stanley. "Biological activity analysis of the crude extract of the Senna species : structure elucidation of a compound with antioxidant activity". Thesis, University of Limpopo, 2008. http://hdl.handle.net/10386/526.
Testo completoAbstract (sommario):
Thesis (M.Sc.) --University of Limpopo, 2008Senna species, a member of the Fabaceae family (subfamily Caesalpinaceae), is widely used traditionally to treat a number of disease conditions such as sexually transmitted diseases and some forms of intestinal complications. In this study the roots of Senna species, collected from Zebediela region of the Limpopo province (R.S.A), were ground to a fine powder and extracted with acetone by cold/shaking extraction method. The phytochemical composition of the extract was then determined by thin layer chromatography (TLC). The chromatograms were visualised with vanillin-sulphuric acid and p-anisaldehyde reagents. The total phenolic content of the extract was determined by Folin-Ciocalteu method and expressed as TAE/g of dry plant material. The extract was assayed for the in vitro anticancer activity using Jurkat T cells. The antioxidant activity was evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay and the antibacterial activity determined by both bioautographic and the microtiter plate methods. The acetone extract of the roots of Senna species inhibited the growth of Jurkat T cells in a dose- and time-dependent manner. The extract was shown to possess free radical scavenging activity and antibacterial activity against Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli and Staphylococcus aureus with MIC values of 0.16, 0.078, 0.078 and 0.16 mg/ml, respectively. A compound with free radical scavenging activity was isolated from the acetone extract of the roots of Senna species through bioassay-guided fractionation. The isolated compound was identified as 1, 3-diphenol-2-propen-1-one. Thus, the study has systematically shown the biological activity of the roots of Senna species and the isolation and identification of the bioactive compound.
30
Qodi, Noluntu. "In Vitro tests for immunomodulatory effects of medicinal plants used in the treatment of Malaria in South Africa". Master's thesis, University of Cape Town, 2001. http://hdl.handle.net/11427/3454.
Testo completoAbstract (sommario):
Bibliography: leaves 78-80.Using the ethno-medicinal data approach, nine South African plants used traditionally in the treatment of malaria were collected and evaluated for cytotoxic and lymphocyte-proliferating effects. These included Acokanthera oppositofolia, Zanthoxylum capense, Glycyrrhiza glabra, Harpephyllum caffrum, Lippia javanica, Pentanisia prunneloides, Psidium guajava, Typha capensis and Cannabis sativa. The cytotoxic effect of the aqueous, methanol and dichloromethane extracts of these plants was evaluated in vitro in Rat-1 fibroblasts there was no observable difference in cytotoxic activity between cold-and hot-water extracts of all the plants investigated. Cell proliferation greater than 80% was observed for aqueous extracts of A. oppositofolia, H. caffrum, L. javanica, P. prunneloides, P. guajava and T. capensis which would suggest are considered safe for consumption. However, high cytotoxic effect was exhibited by dichloromethane extracts of Z. capense, L. javanica, C. sativa and P. guajava at 100 μg/ml. These findings suggest that dichloromethane extracted compounds that are not normally extractable by traditional methods.
31
Freidberg, Ryno. "An investigation into the antimicrobial and anticancer activities of Geranium incanum, Artemisia afra and Artemisia absinthium". Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1045.
Testo completoAbstract (sommario):
It has been estimated that between 3000 and 4000 plant species are used for their medicinal properties throughout South Africa, with approximately 27 million South Africans making use of traditional medicines. Of this 27 million, 3 million South Africans rely on traditional medicine as their primary source of health care. Of the 250 000 to 500 000 known plant species, very few have been investigated for their pharmacological qualities, and compounds of significant medicinal value may still remain undiscovered in many plant species. The aims of this study included investigating the antimicrobial properties of Geranium incanum and Artemisia afra, both plants traditionally used for their medicinal properties, and comparing the antimicrobial activity of the latter to that of Artemisia absinthium, as well as investigating the anticancer properties of G. incanum and A. afra, and comparing the anticancer activity of the latter to that of A. absinthium. Infusions, aqueous-, methanol- and acetone extracts of the three plants were prepared and used for anticancer and antimicrobial screening. Plant specimens used to prepare extracts for antimicrobial activity were collected and extracted over three seasons, while extracts used for anticancer screening were prepared from plants collected during the summer only. Considerable variation existed in the percentage crude extract yields obtained when different extractants were used, while the season in which the plants were harvested and extracted also appeared to play a significant role in the amount of extract obtained. The plant extracts were screened for antimicrobial activity against various strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus and Bacillus cereus, using an agar dilution method. G. incanum and A. afra possessed activity for C. albicans, while all three plants showed activity for S. aureus and B. cereus. Activity was largely dependent on the extraction method used. iii The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was used to screen for anticancer activity of the respective extracts, at varying concentrations, against MCF-7 (human breast adenocarcinoma) cells, HT-29 (human colonic adenocarcinoma) cells and HeLa (human cervical cancer) cells. All of the extracts showed cytotoxic activity in all three cell lines to varying extents, depending on the extract used and cell line screened. The acetone extract of A. afra proved to be the most effective inhibitor with the lowest IC50 (2.65 ± 1.05 μg/ml) having been shown in MCF-7 cells. A. afra and A. absinthium showed similar inhibitory patterns, with the methanol- and acetone extracts having been the most potent inhibitors of each of the respective cell lines in general. Fluorescence microscopy employing 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) and propidium iodide (PI) staining indicated that the acetone extract of A. afra induces apoptosis in MCF-7 cells as apposed to necrosis, and the results were comparable to those obtained for cells exposed to cisplatin. Screening of the A. afra acetone extract for toxicity in normal human cells using the CellTiter-Blue® assay indicated the extract to be toxic to peripheral blood mononuclear cells (PBMC’s) at concentrations comparable to that for MCF-7 cells, while cell cycle analysis of MCF-7 cells exposed to the A. afra acetone extract indicated the extract’s ability to induce apoptosis comparable to that of cisplatin, with the extract exerting its activity at a point during or just prior to the S phase of the cell cycle.
32
Mtshali, Cynthia Sibongiseni. "An investigation of environmental knowledge among two rural black communities in Natal". Thesis, Rhodes University, 1995. http://hdl.handle.net/10962/d1003505.
Testo completoAbstract (sommario):
This study elicits and documents knowledge of the natural environment amongst two rural Black communities in Natal namely, the districts of Maphumulo and Ingwavuma.Twenty members of these communities who are older than 60 years of age were interviewed, as older people are considered by the researcher to be important repositories of environmental knowledge. This study records a variety of animals hunted in these communities and discusses various activities associated with this activity. It examines the gathering and the use of wild edible plants like fruits and spinach, and of wild plants alleged to have medicinal value. It reviews indigenous knowledge related to custom beliefs and prohibitions as well as traditional laws associated .with animals and trees. It also considers how this knowledge can contribute towards the development of Environmental Education in South Africa. The data was deduced from the responses elicited from semi-structured interviews. The data was analyzed qualitatively.
33
Bosch, Janine. "Production of biologically active recombinant HIV-1 protease and intehrase for the purpose of screening medicianl plant extracts". Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1056.
Testo completoAbstract (sommario):
Human immunodeficiency virus (HIV) and its gradual weakening of the immune system is an ever growing threat. Acquired immune deficiency syndrome (AIDS), the final stage of HIV, renders a person vulnerable to various opportunistic infections, which in the end lead to death. Apart from intensive vaccine studies, treatment research mainly focuses on preventing the individual HIV enzymes (reverse transcriptase, integrase and protease) from performing their functions. Entry inhibitors, however, block viral entry into the cell, while antisense drugs lock onto the viral genome to keep it from functioning. In this study production of active recombinant HIV-1 protease and integrase was attempted for future drug screening programs. HIV-1 protease was cloned into a pET28b(+) vector and expressed in ROSETTA(DE3)pLysS cells. The protein was purified using a nickel-affinity column utilizing the hexa-histidine tag encoded by the vector. Gel filtration chromatography was attempted after refolding of the protease, but protease yield seemed to decrease with the additional purification step. Partially purified protease was characterized with kinetic studies. Kinetic parameters of HIV-1 protease were determined to be Km = 592 μM, Vmax = 0.59 μM/min and kcat = 31 s-1. HIV-1 integrase, which was cloned into a pET15b vector, was expressed in E. coli BL21(DE3) cells. The coding sequence had been mutated to introduce the amino acid substitutions F185K and C280S, increasing solubility of the protein. The first step in purification of this protein was nickel-affinity chromatography, after which cation exchange chromatography was attempted. HIV-1 integrase concentration was low throughout experiments and no clear elution from the cation exchange column could be observed. A non-radioactive enzyme linked HIV-1 integrase assay failed to detect integrase activity. Modifications to future studies of the integrase are suggested in the chapter involved.
34
Harnett, Siobhán Margaret. "In vitro anti-HIV activities of Sutherlandia frutescens and Lobostemon trigonum extracts". Thesis, University of Port Elizabeth, 2004. http://hdl.handle.net/10948/347.
Testo completoAbstract (sommario):
Currently, the approved anti-HIV drugs on the market only target the three HIV enzymes: reverse transcriptase, protease and more recently, integrase. Due to the limited nature of the current therapy, it is possible that a multi-drug resistant virus can emerge. The main concerns in developing countries however, are the expense and availability of the drugs and because of this, it is essential to investigate all alternatives. Traditional medicine offers many advantages as compared to allopathic treatment in so far as being relatively cheaper, accessible and it is broadly accepted in the population groups of the developing countries. Little is known though, of the exact efficacy and toxicity of these remedies so it is vital that these possible leads be investigated thoroughly. For the purpose of this study, two plants, Sutherlandia frutescens and Lobostemon trigonum were studied to ascertain their potential anti-HIV activity. Sutherlandia has received international attention as a possible cheap herbal remedy to improve the health of AIDS sufferers. Anecdotal evidence from health workers claim that HIV- infected patients on Sutherlandia treatment have shown improved CD4 counts, decreased viral loads and a general improvement in well-being. Extracts were prepared from dried leaves and flowers in methanol, ethanol, acetone, methylene dichloride or distilled water. Sulphated polysaccharides have been described extensively in literature with regards to their anti-HIV activity, so as a form of dereplication; an ethanol precipitation was performed on the aqueous extracts to remove sulphated polysaccharides. A toxicity study was performed on all crude extracts using uninfected peripheral mononuclear blood cells (PBMCs) isolated from whole blood. To measure anti-HIV activity, HIV-infected PBMCs were cultured with each of the crude extracts and cell viability measured using the tetrazolium salt, XTT. HIV-infected CEM-NKR-CCR5 cells were also used and supernatant from the viral studies was tested for the HIV antigen p24. xii Results varied greatly between assays but with the inclusion of a point-scale system to evaluate the extracts it was clear that overall the organic extracts of the Sutherlandia flowers, especially the acetone extract (SFA), showed great anti-HIV potential. SFA in every case decreased p24 levels and in the toxicity study did not decrease cell proliferation. With the HIV-infected PBMCs SFA actually helped improve cell proliferation despite the infection. To determine the specific anti- HIV activity, all crude extracts were tested for inhibition of HIV-I reverse transcriptase, the glycohydrolase enzymes: a-glucosidase, ß-glucosidase, ßglucuronidase, HIV-I integrase and HIV-II protease. No significant inhibition was seen with these experiments except for the HIV-I RT assay. The aqueous extract of the Lobostemon leaves produced an inhibitor of HIV-RT with a very low IC50 value of 0.049mg/ml. Some inhibitory effect was lost with the removal of the sulphated polysaccharides and the addition of BSA to the assay, but still 64% inhibition of the HIVRT remained, which confirmed that the inhibitor could be something novel, and not of the polysaccharide or tannin compounds.
35
Chigor, Chinyere Blessing. "Development of conservation methods for gunnera perpensa l.: an overexploited medicinal plant in the Eastern Cape, South Africa". Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/d1019832.
Testo completoAbstract (sommario):
South Africa, many plants which are used in traditional medicines are collected from wild populations. The high demand for trade and use of these medicinal plants place an enormous pressure on their natural populations, especially because they are indiscriminately harvested. The most affected of these plant species are those harvested from their underground parts, among which is Gunnera perpensa L. Gunnera perpensa is of considerable ethnobotanical interest in traditional medicine because of its wide usage. The rhizomes are widely used and indiscriminately collected in large quantities from the wild to meet the ever increasing demand in traditional medicine markets. As a result, this valuable medicinal plant species is being endangered. According to the Red List of South African Plants, the conservation status of G. perpensa has been listed as ‘declining’. The ethnobotanical survey conducted as part of this research confirms the plant species as threatened. It is, therefore, important to develop propagation and conservation strategies for this medicinal plant. Clonal propagation of G. perpensa was conducted using varying lengths of the rhizome (1, 2, 3, 4 and 5 cm) segments as propagules. While regeneration was possible with all the rhizome lengths, most of the growth parameters were significantly higher in the 5 cm rhizomes than the other rhizome segments. The appropriate planting depth for the rhizomes was also determined and 4 or 5 cm planting depths were found appropriate. No significant difference was observed in the growth parameters amongst the planting depths; nevertheless, 4 cm depth gave higher growth and yield. The results of this study show that regenerating G. perpensa.
36
Kibiti, Cromwell Mwiti. "Evaluation of the medicinal potentials of Bulbine Abyssinica A. rich in the management of diabetes mellitus in the Eastern Cape, South Africa". Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/3077.
Testo completoAbstract (sommario):
Diabetes mellitus is a chronic physiological carbohydrate metabolic disorder with significant impact on the economy, quality of life and life expectancy in South Africa. Herbal medicine has become the alternative therapy in the management of this disease. However, their safety and effectiveness have not been investigated. To address this, one of the plants used in Eastern Cape Province, South Africa, Bulbine abyssinica A. Rich (Asphodelaceae), was evaluated. Bulbine abyssinica is one of the species used in the management of diabetes mellitus. This plant was mentioned during an ethnobotanical survey conducted in Nkonkobe municipality of the Eastern Cape Province. Though a decoction prepared from the whole plant is used in the treatment of diabetes mellitus, the mechanism of action and its safety has not been elucidated. Thus, this research work was designed to contribute to the understanding of the possible mechanism of action of B. abyssinica as an antidiabetic medicinal plant and its toxic potentials to the users. The aqueous extract exhibited remarkable inhibitory activity onα-amylase (estimated inhibitory concentration (IC)50 value of 3.28 μg/ml), while the acetone extract exhibited weak inhibitory activity. The acetone extract exhibited notable α-glucosidase inhibitory activity (IC50 value of 4.27 μg/ml) while aqueous extract had significantly weak activity. The Lineweaver-Burk double reciprocal plots revealed that the aqueous extract exerts noncompetitive inhibition on the α-amylase activity while the acetone extract exerts a near competitive inhibitory pattern on the α-glucosidase activity. The extracts from the plant possessed high free radical scavenging activities, with acetone extract exhibiting the highest activities in all assay models used except with ferric reducing power and nitric oxide (NO) scavenging ability. The aqueous extract exhibited the highest ferric reducing power and nitric oxide radical mopping strength while the essential oil exhibited the highest scavenging activities with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and relatively high ferric reducing power and nitric oxide scavenging ability. The acetone extract and the essential oil of this species exhibited higher albumin denaturation inhibition than the aqueous extract while the latter showed the greatest membrane lysis protection. The essential oil, acetone and aqueous extracts from this plant significantly inhibited the growth of Shigelle flexneri, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. Klebsiella pneumonia, Proteus vulgaris and Streptococcus pyogens growth were inhibited by acetone and aqueous extracts. The essential oil also showed inhibitory activity against Proteus vulgaris. However, the extracts were active against the growth of only three fungi species. The essential oil showed significant inhibitory activity against Trichophyton rubrum. The aqueous extract inhibited the growth of Microsporum gypseum while the acetone extract was active against Microsporum canis, and Microsporum gypseum. The carbohydrate, crude fibre, moisture, ash, crude protein and crude fat of approximately 74.8 percent, 8.9 percent, 8.8 percent, 8 percent, 7.7 percent and 0.6 percent, respectively, were detected in this plant. The species is characterized by moderate levels of oxalates, phytic acids, Vitamin A, Vitamin C and Vitamin E. Potassium and calcium were present in highest levels, while magnesium, iron, sodium, aluminium and phosphorus were moderately present. Manganese, zinc and copper where in low amounts. These vitamins and mineral elements were within their recommended daily allowance (RDA) in humans. The investigation also revealed appreciable amounts of total phenols, flavonoids, flavanols, proanthocyanidins and alkaloids in both acetone and aqueous extracts while saponins and tannins were in trace amounts. The essential oil was characterized by large quantities of terpenes (91.9 percent) and small fraction of esters (8.01 percent).
37
Ah, Goo Delia Felecia Stephanie. "The contribution of the trade in medicinal plants to urban livelihoods: a case study of the informal markets in Nelson Mandela Bay Municipality, Eastern Cape". Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1011601.
Testo completoAbstract (sommario):
The commercialisation of natural resources such as medicinal plants is a strategy that is increasingly being employed by poor people in developing countries such as South Africa, as a means of generating an income. Increasing economic hardship and a lack of employment opportunities in the formal sector of the economy has led to many urban dwellers seeking alternative means of meeting their everyday livelihood needs. Although the contribution of natural resources to subsistence economies is widely recognised, there are few studies that have examined the significance of the trade in medicinal plants to the livelihoods of poor and marginalised people. Thirty informal street traders were interviewed to investigate the role of the medicinal plant trade in sustaining the livelihoods of the traders who operate in the informal sector of the Nelson Mandela Bay Municipality, South Africa. The findings of the research indicate that the sale and collection of medicinal plants is an activity which is exploited by people with limited resources, few skills, little or no education and often without any other source of household income. Middle-aged women from impoverished, single income households dominated the trade. Although income from the trade is modest, it contributed substantially to the total household cash income of the traders. Other benefits of the trade included independence and having a sense of purpose in life, as the traders felt that they were not only helping their families but also the wider community. However, without the income from the trade, many of the traders and their families would be destitute and thus the medicinal plant trade is vital to the wellbeing of these people.
38
Njume, Collise. "Phytochemical analysis and bioactivity of selected South African medicinal plants on clinical isolates of Helicobacter pylori". Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/449.
Testo completoAbstract (sommario):
Medicinal plants have been used as traditional medicine in the treatment of numerous human diseases for thousands of years in many parts of the world. In the developing world, especially in rural areas, herbal remedies continue to be a primary source of medicine. Scientifically, medicinal plants have proven to be an abundant source of biologically active compounds, many of which have already been formulated into useful therapeutic substances or have provided a basis for the development of new lead molecules for pharmaceuticals. Antibiotic resistance, undesireable side effects and expences associated with the use of combination therapy in the treatment of Helicobacter pylori infections have generated a considerable interest in the study of medicinal plants as potential sources of new drugs against this organism. The high complexicity of bioactive compounds accumulated in plants coupled with their broad antimicrobial activity may make it difficult for pathogenic organisms, including H. pylori to acquire resistance during treatment. This study therefore evaluates the antimicrobial potential of selected South African medicinal plants employed in the treatment of H. pylori-related infections, and the subsequent isolation of the plant active principles. An ethnobotanical survey of plants used in the treatment of H. pylori-related infections was conducted in the study area. Crude extracts of Combretum molle, Sclerocarya birrea, Garcinia kola, Alepidea amatymbica and 2 Strychnos species were screened against 30 clinical strains of H. pylori and 2 standard control strains (NCTC 11638 and ATCC 43526). In the preliminary stages of this study, ethyl acetate, acetone, ethanol, methanol and water extracts of the plants were tested against H. pylori by agar well diffusion and micro broth dilution methods. The plant crude extracts that exhibited anti-H. pylori activity with a iv percentage susceptibility of 50 percent and above were considered for the rate of kill assays and the most active crude extracts selected for bio-assay guided isolation of the active ingredient. Preliminary fractionation of the crude extract was achieved by thin layer chromatography (TLC) using different solvent combinations; hexane/diethylether (HDE), ethyl acetate/methanol/water (EMW) and chloroform/ethyl acetate/formic acid (CEF) in order to determine the most suitable combination for column chromatography (CC) and subsequent testing by indirect bioautography. The extract was then fractionated in a silica gel column using previously determined solvent combinations as eluent. Active fractions obtained from column chromatography separations were further fractionated and the compounds identified by gas chromatography/mass spectrometry (GC/MS) analysis. All the plants exhibited antimicrobial activity against H. pylori with zone of inhibition diameters ranging from 0 - 38 mm and minimum inhibitory concentration (MIC) values ranging from 0.06 - 5.0 mg/mL. The most active plant extracts were the acetone extract of C. molle with a percentage susceptibility of 87.1 percent, acetone and aqueous extracts of S. birrea (71 percent each) and the ethanolic extracts of G. kola (53.3 percent). Except for the aqueous extract, these extracts also exhibited a strong bactericidal activity against H. pylori at different concentrations. TLC analysis revealed the presence of 9 components in the acetone extract of S. birrea with the EMW solvent system as opposed to 5 and 8 with HDE and CEF respectively. Bioassay-guided isolation led to the identification of 52 compounds from the acetone extract of S. birrea with n-octacosane being the most abundant (41.68 percent). This was followed by pyrrolidine (38.91 percent), terpinen-4-ol (38.3 percent), n-eicosane (24.98 percent), cyclopentane (16.76 percent), n-triacontane (16.28 percent), aromadendrene (13.63 percent) and α-gujunene (8.77 percent). Terpinen-4-ol and pyrrolidine demonstrated strong antimicrobial activity against H. pylori at all concentrations tested. These results may serve as preliminary scientific validation of the ethnomedicinal uses of the above mentioned plants in the treatment of H. pylori-related infections in South Africa. Terpinen-4-ol and pyrrolidine could be considered for further evaluation as therapeutic or prophylactic agents in the treatment of H. pylori-related infections. However, further investigations would be necessary to determine their toxicological properties, in-vivo potencies and mechanism of action against H.pylori
39
Dubeni, Zimasa Busisiwe. "Phytochemical screening and thin layer chromatographic profiling of aloe vera (l) burn. f growing in South Africa". Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1016169.
Testo completoAbstract (sommario):
The chemical profiling, characterization of Aloe products and phytochemical properties of Aloe vera were studied. The adulteration of commercial products derived from medicinal plants has been a major muddle for both the society and the pharmaceuticalindustry. Economically motivated adulteration includes the potential for contaminated, sub‐potent or counterfeit medication to enter the supply chain at several levels, from the production of raw ingredients through to the point of retail sale. Darwin’s theory of evolution states that, species undergo genetic variation with time to adapt to environmental changes. Therefore, the same species growing in widely different habitats may drift from the original genetic makeup as a mechanism of adaptation and that may result in them having different chemical profiles. Therefore this study aimed at investigating the phytochemical properties of Aloe vera growing in South Africa. Also, this study aims to utilize Thin Layer Chromatography to profile this plant, as well as use Infra Red spectroscopy to characterize commercial Aloe vera products. A large quantity of Aloe vera plant was collected from AloeWay, Iphofolo Game Farm, Polokwane in the Limpopo province of South Africa. The identity of the plant was confirmedrom literature and authenticated by Professor DS Grierson of Botany Department, University of Fort Hare, Alice. The plant leaves were divided into two portions. One portion was extracted fresh while the other was cut into pieces and oven dried at 400C then and milled to a homogenous powder once dried completely. The phytochemical composition of the gel and leaf extracts revealed the presence of alkaloids, flavonoids, saponins, tannins and phenols at different concentrations. Results showed that the dry plant material yielded more phytochemicals than the fresh plant material. In particular, it was found that the acetone extract showed much more amounts ofphychemicals than the dichloromethane and aqueous extracts. The percentage compositions of phenols (71.86), flavonols (36.61), proanthocyanidins (82.71), saponins (37.73) and alkaloids (13.29) were significantly high in the acetone extract, followed by the dichloromthane extract with values of 46.85, 37.73, 49.51, 89.0 and 11.11 respectively, while the least composition was found in the aqueous extract. Furthermore, flavonoids were somewhat high in composition in both the aqueous extract of the dried and of the fresh plant material while others were very low. Tannins levels were significantly very low in all the solvent extracts. It was found that the acetone extract showed great amounts of phytochemicals than dichloromethane and aqueous extracts. Since A. vera is used in the treatment of different ailments such as skin wounds and abrasions, eczema, constipation, rheumatoid arthritis etc, the medicinal uses of this plant could be associated to such analysed bioactive compounds. Acetone, hexane, ethanol, water and dichloromethane were used to extract the Aloe vera leaf and the best solvent extract was determined. Thin layer chromatography was used to profile the leaf extracts with the aim of documenting the main phytochemicals present in the Aloe vera growing in South Africa. The best spraying reagent was determined. Fourier transform infrared spectrophotometer was used to validate the presence of Aloe vera ingredients in commercial products. The yield extraction ability of the solvent was the order: water>ethanol> hexane >dichloromethane and acetone for the dry portion. However, for the plant extracted fresh, the order of yield produced was ethanol-acetone-dichloromethane > and water. The different solvent systems separated the compounds differently. Hexane: acetone: ethanol (20 : 5: 2) and Benzene: ethanol: ammonium (80): ethanol (10): ammonium solvent systems were noted to be the best mobile phase as they gave the best separation compared to other systems.EMW [ethyl acetate (81): methanol (11): water (8)] showed better separation than the other two separating solvent systems. Vanillin- sulphuric acid spray was seen to be the best spraying reagent as compared to vanillin- phosphoric acid. Fourier transform infrared spectrophotometer validated the presence aloe ingredients in aloe vera commercial products.
40
Stafford, Gary Ivan. "Storage of frequently used traditional South African medicinal plants". Thesis, 2003. http://hdl.handle.net/10413/5639.
Testo completoAbstract (sommario):
The post-harvest physiology of nine frequently used indigenous southern African
medicinal plants was investigated, in particular the effects of storage time and
accelerated ageing on the biological activity and chemical constituents of these plants.
Water, ethanol and hexane extracts of fresh plant material as well as material that had
been stored in dry form in paper bags at room temperature for 90 days (short-term)
were tested. Three bioassays, the COX-1 anti-inflammatory assay, nematode
anthelmintic assay and minimum inhibitory concentration anti-bacterial assay, were
used to determine biological activity. Thin layer chromatography of all the plant extracts
were used to determine changes in chemical composition. The plants tested were
Alepidea amatymbica Eckl. & Zeyh., Leonotis leonurus (L.) R. Br., Drimia robusta Bak.,
Vernonia colorata (Willd.) Drake, Scilla natalensis Planch., Eucomis autumnalis (Mill.)
Chitt. subsp. autumnalis, Bowiea volubilis Harv. ex Hook. f., Helichrysum cymosum (L.)
D. Don and Siphonochilus aethiopicus (Schweinf.) B. L. Burtt. Only those plants, which
are known to exhibit a particular biological activity either traditionally or scientifically,
were tested in the relevant bioassays. Of the plant extracts tested for anthelmintic
activity only the water extracts showed activity and very little change in activity was
observed after storage. Of the plant extracts tested for anti-inflammatory activity the
ethanol extracts generally yielded highest activity. S. natalensis and B. volubilis both
showed an increase in cyclooxygenase inhibition (anti-inflammatory) activity after
storage whereas S. aethiopicus, H. cymosum, D. robusta and V. colorata showed a
loss in activity after storage. The anti-inflammatory activity of E. autumnalis did not
change. The water extracts of plants tested for antibacterial activity showed no activity,
whereas the ethanol extracts generally showed an increase in activity. The TLC
fingerprints indicated that there was chemical break-down during storage in certain
species. These corresponded to the changes in biological activity.
Alepidea amatymbica, Eucomis autumnalis, Helichrysum cymosum, Leonotis leonurus,
Siphonochilus aethiopicus and Vernonia colorata were investigated further as to the
effect of one year's storage (long-term storage) on their chemical composition and
biological activity. Similar trends to that of the 90-day storage were observed. Activity
gained in plants that were stored for 90 days was retained after a year of storage.
Elevated temperature and humidity (55 C and 100% relative humidity) were used to
accelerate the ageing process of Alepidea amatymbica, Leonotis leonurus and
Vernonia colorata plant material. Again changes in the chemical composition and
biological activity were observed, and the extent of these changes was greater than
those in the stored material. The compounds responsible for the cyclooxygenase
inhibition in the ethanolic extracts of Alepidea amatymbica leaf material appear to be
stable and were not affected by the conditions of the accelerated ageing procedure
(55 C and 100% humidity for seven days), but the root material lost activity, as did the
leaf material of Leonotis leonurus. The leaf material of Vernonia colorata showed a
slight (8%) increase in cyclooxygenase inhibition activity. The response of the plant
material to accelerated ageing with respect to antibacterial activity varied with plant
species. Alepidea amatymbica root material and Vernonia colorata leaf material
appear to be stable whereas the other plant materials lost activity after prolonged (25
days) ageing.Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.
41
Duncan, Andrew Cameron. "An investigation of plants used in South Africa for the treatment of hypertension". Thesis, 1998. http://hdl.handle.net/10413/8559.
Testo completoAbstract (sommario):
In most countries, as many as 15 to 25% of the adult population have raised blood pressure. People with hypertension, and even those with mild elevation of blood pressure, are at an increased risk of cardiovascular disease, whether
or not the symptoms are present. The risk of serious cardiovascular disease varies greatly among individuals and is also determined by a variety of concomitant risk factors other than the level of blood pressure. Hypertension develops as a result of disturbances of the body's blood pressure regulating system. The biological activity of the renin-angiotensin systems results from a series of specific enzymatic cleavages leading to the
generation of angiotensin II, a potent vasoconstrictor. In the treatment of hypertension, inhibition of the angiotensin converting enzyme is established as one modern therapeutic principle. Angiotensin converting enzyme inhibitors act by inhibiting the conversion of angiotensin I to angiotensin II. The in vitro assay, developed by ELBL and WAGNER (1991) for the detection
of angiotensin converting enzyme inhibitors in plant extracts was successfully established during this study. Plants used by traditional healers in South Africa for the treatment of high blood pressure were investigated for their antihypertensive properties, utilizing the established angiotensin converting
enzyme assay. Twenty plants were investigated for their angiotensin converting enzyme inhibitory activity. The highest inhibition (97%) was obtained by Adenopodia spicata leaves. A further seven plants exhibited an inhibition greater than 70% and five more over 50%. Plants exhibiting inhibition levels greater than 50% were further tested for the
presence of tannins in order to eliminate possible false positives. The leaves of Tulbaghia violacea were chosen for bioassay-guided fractionation in an attempt to isolate the active compound(s).
Serial extractions were made of ground Tulbaghia violacea leaves using polar to non-polar solvents to establish the solvent giving optimum extraction of the
active compound(s). Distilled H2O was selected as the extractant and a bulk extract was performed on 0.7 kg ground leaves. The extracted residue was
partitioned against butanol, fractionated using cation exchange resin chromatography, Sephadex ® LH-20 and high performance liquid chromatography. Fractions collected after each purification step were assayed using the angiotensin converting enzyme assay. Fractions exhibiting high levels of angiotensin converting enzyme inhibition were selected for further
purification. The active fraction from the final high performance liquid chromatography step used in this study requires further attention in order to
purify and identify the active compound(s). The chromatographic and chemical properties of the compound(s) present in the isolated active fraction are discussed.Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.
42
Ramalivhana, Naledzani Jeoffry. "Molecular characterization of Aeromonas hydrophila and antimicrobial activities of selected medicinal plants against pathogenic isolates from water and stool samples in the era of HIV/AIDS in Limpopo Province, South Africa". Thesis, 2010. http://hdl.handle.net/10500/4309.
Testo completoAbstract (sommario):
Aeromonas hydrophila is distributed widely in nature and is responsible for an array of
human infections. Several studies on the isolation and characterisation of the organism
abound. Although there are reports on the antibiotic resistance profiles of the organism,
these reports have not been updated in Limpopo province, South Africa despite the
established fact that antibiograms vary with time and geographical area. Antibiotic
resistance and pathogenesis of an organism are dependent on a host of factors such as the
production of extended spectrum beta-lactamases and the genetic profiles such as the genes
coding for resistance and possession of integrons and how these characteristics overach
with the phylogenetic inter-relatedness of isolates from different sources. In spite of the
aforementioned concerns on the efficacy of antibiotics due to the acquisition or endowment
of microorganisms with intrinsic and extrinsic factors , which enhances resistance to
antibiotics , medicinal plants are reportedly offering promise as alternative sources of
efficacious management of infections. Medicinal plants are employed by traditional healers
in the management of infections in developing countries especially in Africa. However, the
antimicrobial activities of medicinal plants against Aeromonas hydrophila have received only
a cursory attention.
In an endeavour to undertake a comprehensive study on the isolation, characterisation,
antibiograms, activities of medicinal plants as well as the genetic profiles, including
phylogenetics relatedness of Aeromonas isolates from different sources, stool and water
samples were collected over a two year period from designated places in Limpopo Province
and analysed using standard techniques applicable to the constituent research activity. The
research findings are presented in six chapters as presented hereunder.
The first chapter focussed on the literature review of the organism and reflects areas such as
the morphology, laboratory diagnosis, clinical manifestations, pathogenesis, antimicrobial
susceptibility profiles, antibacterial activities of medicinal plants as well as the genetic
aspects of Aeromonas hydrophila.Environmental Science
D.Phil. (Environmental Science)
43
Mankga, Ledile Thabitha. "DNA barcoding Medicinal plants of South Africa". Thesis, 2013. http://hdl.handle.net/10210/8532.
Testo completoAbstract (sommario):
M.Sc. (Botany)The market and public demand for medicinal plants over the past few decades has increased dramatically with more than 1 000 plant species actively traded for medicinal purposes throughout South Africa. Intensive harvesting of wild material is now acknowledged as a serious threat to biodiversity in this country. Also the substitution of a valuable commodity (medicinal plant) by a cheaper alternative (other plant species), either inadvertently due to misidentification, or deliberately to cheat consumers, raises some serious concerns as these adulterants may not be as effective or may even be toxic and cause harm to consumers. To add to the problem many species are either traded as dried leaf, root, bark products, or extracts and their identification becomes problematic. Therefore, DNA barcoding can help to provide a rapid and accurate identification tool for medicinal plants. In the current study I targeted the most commonly used medicinal plants in South Africa and produced a set of barcodes for fast and easy DNA-based species identification (rbcLa & matK). I tested the efficiency of core barcodes in the identification of medicinal plants using four main analyses, in the R package Spider 1.1-1. Here the extent of specific genetic divergence, DNA barcoding gap, BLAST test, and the ability to discriminate between species were assessed. Overall, the matK region was found to be a more useful tool for the species identification of medicinal plants in South Africa.
44
Ondua, Moise. "Antioxidative, analgesic and anti-inflammatory activities of Acokanthera oppositifolia, Plantago lanceolata, Conyza canadensis, and Artemisia vulgaris". Diss., 2015. http://hdl.handle.net/10500/19169.
Testo completoAbstract (sommario):
The anti-inflammatory properties of four medicinal plants were investigated. These plant extracts were subjected to screening for their possible effects as antioxidative, analgesic, and anti-inflammatory agents. In the antioxidant activity, the Plantago lancelota extracts resulted in an IC50 value of 0.4 mg/mL compared to the positive control quecertin with IC50 0.04 mg/mL Plantago lanceolata inhibited COX-2 activity with IC50 values of 0.41 mg/mL. However, the COX-1 inhibition indicated an IC50 of 68.99 mg/mL. The lipoxygenase assay indicated that Plantago lanceolata was the most active plant species with an IC50 value of 4.86 mg/mL compared to the positive control (quecertin) with an IC50<2mg/mL. The nitric oxide assay of the plant extracts indicates a dose-dependent activity of our plant extracts. Likewise the cell viability result indicated a good activity at dose 100 mg/mL.Life and Consumer Sciences
M. Sc. (Life Sciences)
45
Okem, Ambrose. "Pharmacological activities of selected South African medicinal plants". Thesis, 2011. http://hdl.handle.net/10413/8588.
Testo completoAbstract (sommario):
The use of traditional medicine is a popular practice in South Africa especially among rural dwellers due to several reasons such as availability of natural products, cultural beliefs, preference of natural products to synthetically derived drugs and the high cost of modern drugs. Traditional healers in South Africa play key roles in administering treatment for all sorts of ailments using plants. The aim of this study was to evaluate the efficacy of seven selected medicinal plants that are used in traditional medicine to treat stomach-related ailments for their pharmacological and phytochemical properties.
Plant material was extracted sequentially with ethyl acetate (EtOAc), ethanol (EtOH) and water. The extracts were evaluated for their antimicrobial activities using the microdilution technique against two Gram-positive (Enterococcus faecalis ATCC 19433 and Staphylococcus aureus ATCC 12600) bacteria and a Gram-negative (Escherichia coli ATCC 11775) bacterium. A modified microdilution technique was used to screen for antifungal activity against a yeast-like fungus (Candida albicans ATCC 10231). Only the EtOAc extract of Tetradenia riparia demonstrated good antibacterial activity against the Gram-negative E. coli, all the other extracts that were active only showed good antibacterial activity against the two Gram-positive (E. faecalis and S. aureus) bacteria with MIC values <1 mg/ml. None of the extracts that exhibited good inhibitory activity showed corresponding bactericidal activity against the bacterial test strains, suggesting that the observed activity were all inhibitory. Good antifungal activity with an MIC value <1 mg/ml was observed in only 5 extracts, and none of the extracts exhibited corresponding fungicidal activity. The in vitro colorimetric assay for anthelmintic activity against Caenorhabditis elegans revealed that almost all the extracts possessed moderate to high anthelmintic properties. The EtOAc extract of T. riparia had the best activity at MLC value of 0.004 mg/ml. The anti-inflammatory activity of the plant extracts was tested using the cyclooxygenase assays to determine their inhibitory potential against COX-1 and COX-2 enzymes. All the EtOAc extracts demonstrated both COX-1 and COX-2 inhibitory activity in the range of 50.7 ± 2.4 to 99.5 ± 0.5%. Apart from the EtOH extracts of C. multicava that showed high inhibitory activity against both COX-1 and COX-2, all the other EtOH extracts were COX-2 selective. Aqueous extracts exhibited poor inhibitory activity against both COX-1 and COX-2 enzymes with the exception of T. riparia and Coddia rudis that showed good inhibitory activity (69.1 ± 0.9 and 92.65 ± 0.7%) against COX-1 and COX-2 respectively. The standard plate incorporation assay for the Ames test was carried out to determine the potential genotoxic effects of the plant extracts and this revealed that all the extracts were non-mutagenic towards Salmonella typhimurium tester strains TA98, TA100 and TA1537 without metabolic activation. However, further studies incorporating metabolizing enzymes are needed to confirm the safe use of the studied plants.
Phytochemical analysis revealed relatively high amounts of total phenolics, gallotannins and flavonoids in all the evaluated plants. Total and steroidal saponins were detected in only two plant samples, Canthium spinosum and Cassinopsis ilicifolia (bark). These findings present useful information on the types of bioactive compounds that could be responsible for the pharmacological activities observed among some of the plant extracts. The results obtained in this study showed different levels of pharmacological activities among all the evaluated medicinal plants which provide scientific validation for their use in traditional medicine as antimicrobial agents. Phytochemical analysis provides valuable information for further study that will be aimed at isolation and identification of the bioactive principles in the evaluated plant species.Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
46
Street, Renée Anne. "Heavy metals in South African medicinal plants". Thesis, 2008. http://hdl.handle.net/10413/801.
Testo completoAbstract (sommario):
Plants are able to take up and accumulate certain environmental contaminants such as heavy metals. When the plants are ingested by man, these contaminants are transferred along the food chain. Due to the poorly regulated medicinal plant trade in South Africa, many opportunities exist for heavy metal contamination of medicinal plants namely contaminated harvest sites as well as poor drying, processing, storage, transport and manufacturing conditions. The concentrations of five heavy metals (As, Cd, Co, Ni, Pb) and six microelements (B, Cu, Fe, Mn, Mo, Zn) were determined in some commonly used South African medicinal plants obtained from street markets. Elemental content was determined using inductively coupled plasma optical emission spectrophotometry (ICP-OES). Some of the medicinal plant samples investigated contained As and Cd at levels exceeding the World Health Organization limits of 1 and 0.3 mg kg-1 respectively. Lead and Ni were detected in all the samples. Elevated Fe and Mn levels were recorded in certain plant species. The results revealed multiple metal contamination in some medicinal plant parts sold in local markets and is thus grounds for concern. The effects of Cd application on growth parameters of some medicinal plant species belonging to the Hyacinthaceae (Albuca setosa, Eucomis autumnalis, Eucomis humilis, Merwilla plumbea) gave insight into heavy metal accumulation and distribution in these species. Application of Cd at 5 mg l-1 over a 12 week period reduced growth in A. setosa. The medicinally used A. setosa bulbs accumulated 37 mg kg-1 Cd after 12 weeks. Cadmium application at 2 mg l-1 over a six week period had no effect on growth parameters of E. autumnalis or E. humilis. However, a substantial difference in total Cd accumulation was detected in the plants (40.2 and 15.3 mg kg-1 respectively). Cadmium application at 2 mg l-1 significantly reduced the fresh weight of leaves, bulbs and roots of M. plumbea. Although most of the Cd was stored in the roots, the medicinally used bulbs accumulated up to 11.6 mg kg-1 when applied at 10 mg l-1. The antagonistic effect between Cd and Zn treatments and their effect on micronutrient distribution in M. plumbea were investigated. Five treatments were evaluated: (1) Hoagland’s nutrient solution (HS) (control) (2) HS + Cd 2 mg l-1 (single) (3) HS + Cd 2 mg l-1 + Zn 50 mg l-1 (combination) (4) HS + Cd 2 mg l-1 + Zn 100 mg l-1 (combination) (5) HS + Cd 2 mg l-1 + Zn 150 mg l-1 (combination). Cadmium readily accumulated in leaves, bulbs and roots of M. plumbea when supplied at 2 mg l-1. Zinc at 50 mg l-1 led to increased Cd accumulation. However, further increases in Zn concentration showed an antagonistic effect of Zn on Cd uptake and accumulation. Thus, increasing Zn levels in soils may be favourable for reducing toxic Cd accumulation in M. plumbea plants. Boron was not significantly affected by the addition of Cd to the media. However, with an increase in Zn, leaf B content increased while the B content in the bulbs and roots decreased. Copper and Mo levels were not significantly affected by treatments with Cd or Cd/Zn combinations. Compared to the control, Cd and Cd/Zn applications caused an increase in Mn content in leaves, bulbs and roots. Iron levels of M. plumbea were not significantly affected by Cd in the media. However, with an increase of Zn in the Cd-containing media, Fe content in the leaves, bulbs and roots increased. Tulbaghia violacea is one of the few medicinal plants that is also frequently used as a leafy vegetable. Application of Cd at 2 and 5 mg l-1 to T. violacea of varying sizes (small 8 - 10 g, medium 16 - 20 g, large 80 – 95 g) elicited a difference in growth response, Cd accumulation and micronutrient distribution. Leaf length and fresh weight of leaves of the medium-size plants decreased with application of Cd at 2 mg l-1 whilst 5 mg l-1 Cd significantly decreased the number of leaves in small-sized plants. Small plants accumulated more Cd in the leaves than medium- or large-sized plants. Application of Cd at 2 mg l-1 and 5 mg l-1 lowered the leaf Cu, Fe, Mo and Zn contents in small- and medium-size plants. This study indicated that T. violacea has the ability to accumulate Cd. In addition, plant size plays an important role with regards to Cd accumulation and elemental distribution. The effect of various nutrient applications (10%, 50% and 100% Hoagland’s nutrient solutions (HS); and HS deficient in N, P or K) on growth parameters and micronutrient distribution in Dioscorea dregeana were investigated. Irrigating plants with 50% HS resulted in better growth performance, whereas a deficiency of either N, P or K negatively affected seedling growth. Plants grown in 10% HS contained higher total B, Fe and Mo levels compared to seedlings grown in 50% and 100% HS. Compared to the control, P deficiency resulted in a Fe increase in the leaves, tuber and roots while a lack of P and K significantly increased total Mn content in D. dregeana. The effect of excess Zn (100, 200 and 300 mg l-1) on growth performance, chlorophyll content and microelemental distribution on Dioscorea sylvatica was investigated. Growth parameters showed a significant decrease when supplied with Zn at 100 mg l-1. Zinc phytotoxicity was evident by the reduction in chlorophyll content. Highest Zn concentrations were detected in the roots. Certain micronutrients appear to be redistributed due to Zn toxicity. The effect of microelements (Cu, Zn) and heavy metals (Cd, Pb, Hg) on germination and seedling development of Bowiea volubilis, Eucomis autumnalis and Merwilla plumbea was investigated. Copper and Zn applied at 1 mg l.1 significantly reduced the percentage germination of E. autumnalis. Low concentrations (. 1 mg l.1) of Cu and Zn negatively affected the root growth of all three species. Mercury concentrations of 0.5 and 1 mg l.1 significantly decreased the percentage germination of B. volubilis and E. autumnalis respectively. Cadmium and Hg at 2 mg l.1 showed a negative effect on the root growth of B. volubilis. Concentrations of 0.5 mg l.1 of all heavy metals tested significantly decreased shoot length of M. plumbea. The effect of Cd on biological activity (anti-inflammatory, antibacterial and antifungal) of medicinal plants with previously confirmed activity was evaluated. When supplied with Cd at 2 mg l-1, Eucomis humilis bulbous extracts showed lower anti-inflammatory activity than the control for both COX-1 and COX-2 activity. Eucomis autumnalis bulbous extracts had greater COX-1 activity compared to the control. However, Cd suppressed the activity of COX-2. Compared with non-Cd-treated Merwilla plumbea plants (control), those supplied with Cd at 10 mg l-1 showed increased antibacterial activity against Bacillus subtilis, Klebsiella pneumoniae and Staphylococcus aureus. However, no change in activity against Escherichia coli was observed. Cadmium accumulation in the bulbs had no effect on antifungal activity of Tulbaghia violacea. Thus, optimized agricultural practices are essential for quality control of cultivated medicinal plants. The studies presented in this thesis collectively answer several questions related to heavy metal involvement in South African medicinal plants. The findings substantiate the need to regulate and monitor the South African medicinal plant trade against heavy metal contamination which will in turn provide a product of safety and quality to the consumer.Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
47
Hurinanthan, Vashka. "Anti-HIV activity of selected South African medicinal plants". Thesis, 2013. http://hdl.handle.net/10321/916.
Testo completoAbstract (sommario):
Submitted in complete fulfilment for the Degree of Doctorate of Technology (Biotechnology)--Durban University of Technology, 2013.South Africa has the largest number of people infected with HIV/AIDS. It also has more than 30 000 species of plants and many of these have a long tradition of medicinal use. It is highly likely that the treatment for HIV will come from this traditional knowledge. The need for effective preventative and therapeutic agents for HIV remains an urgent global priority. The aim of this study was to screen selected South African medicinal plants for anti-HIV activity and to identify and characterise an active compound from a plant that can be used for HIV treatment. The aqueous and methanolic extracts of the roots, leaves, flowers and stems of thirty eight plant species (108 extracts) were screened for anti-HIV activity. The plants which had anti-HIV activity were further screened for anti-reverse transcriptase activity. Thirty-two extracts exhibited varying degrees of anti-HIV activity. Cleome monophylla, Dichrostachys cinerea and Leonotis leonurus aqueous leaf extracts had anti-HIV-1 reverse transcriptase activity. The aqueous extracts of D. cinerea showed the best anti-HIV activity with a Selectivity Index of 43.5 and significant anti-HIV-1 reverse transcriptase activity. Crude phytochemical screening of D. cinerea showed that it had tannins, saponins, flavonoids and alkaloids but did not contain any phlobatannins, terpenoids, steroids or phenols. D. cinerea displayed a high degree of free radical scavenging activity with an IC50 of 25 μg/ml, therefore the anti-HIV activity could be attributed to the flavonoids present in the plant. Bio-guided fractionation was used to isolate and purify the active compound from the D. cinerea extract. Compounds were isolated by thin layer chromatography and were tested for anti-HIV-1 and anti-reverse transcriptase activity. From these results the active compound was identified, and purified using preparative TLC. The active compound was characterised by High Performance Liquid Chromatography, Ultraviolet-visible spectrophotometry, and Ultra Performance liquid chromatography coupled to MS/MS. Structural elucidation was performed using Nuclear Magnetic Resonance. From these results, it was deduced that the compound isolated from D. cinerea was a catechin. In this study we show that the catechins present in D. cinerea are responsible for the anti- HIV-I activity and inhibits the reverse transcriptase activity which is a key factor in the progression of HIV. Potentially, these results can be used to develop a new drug for the treatment of HIV or as a cost effective therapeutic agent in treating HIV-infected individuals with oxidative stress.
48
Ncube, Bhekumthetho. "Seasonal pharmacological and phytochemical properties of medicinal bulbs". Thesis, 2010. http://hdl.handle.net/10413/8585.
Testo completoAbstract (sommario):
Medicinal bulbs form part of the diversified flora in South Africa. The plants are used extensively in South African traditional medicine in the treatment of various ailments. Due to the ever-increasing demand and the unrestricted collection of medicinal plants from the wild, many of these slow growing bulbous plant species are driven into over-exploitation and extinction. The main parts collected for use are the underground bulbs, leading to the destructive harvesting of the whole plant. This form of plant harvesting poses threats to the long term sustainability of these plant resources from their natural habitats. Sustainable harvesting of these plants should be within the limits of their capacity for self-renewal. However, this seldom occurs with the often inconsiderate medicinal plant gatherers. Conservation of these plants is therefore necessary. A strategy that would take into consideration the sustainable harvesting and perhaps simultaneously provide similar medicinal benefits, would be the substitution of bulbs with leaves of the same plant. This study was aimed at evaluating the seasonal pharmacological and phytochemical properties in bulbs/corms and leaves of medicinal bulbs with a view of promoting the substitution of bulbs with leaves in traditional medicinal use. Four medicinal bulbous plants, Tulbaghia violacea, Hypoxis hemerocallidea, Drimia robusta and Merwilla plumbea were evaluated for the pharmacological and phytochemical properties in their bulbs/corms and leaves in spring, summer, autumn and winter seasons, with a view of promoting the use of leaves as a conservation strategy. Dried plant materials were sequentially extracted with petroleum ether (PE), dichloromethane (DCM), 80% ethanol (EtOH) and water in each season. The extracts were tested for activities against Gram-positive (Bacillus subtilis and Staphylococcus aureus), Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria and the fungus Candida albicans using the in vitro microdilution assays to obtain minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC). The four plant species were also evaluated for their ability to inhibit cyclooxygenase (COX-1 and COX-2) enzymes. Spectrophotometric methods were used to evaluate saponin and phenolic contents of samples from the four plant species in each season.
Antibacterial activity was fairly comparable between bulbs/corms and leaves of H. hemerocallidea, T. violacea, and M. plumbea, with at least one extract showing some good activity (MIC < 1 mg/ml) in most of the seasons. Bulb extracts of D. robusta did not show good antibacterial activity while the leaf extracts showed good activity (0.78 mg/ml) against B. subtilis in spring, summer, and autumn and S. aureus (0.78 mg/ml) in autumn. The best antibacterial activity was recorded in winter, with MIC values as low as 0.195 mg/ml from the DCM bulb extracts of T. violacea against K. pneumoniae and S. aureus and PE corm extracts of H. hemerocallidea (0.195 mg/ml) against B. subtilis. Good antibacterial activity from water extracts were only recorded from corm extracts of H. hemerocallidea in summer, autumn and winter, H. hemerocallidea leaf extracts in autumn and winter, and M. plumbea bulb extracts in autumn. The leaf extracts of all the screened plant species demonstrated good fungicidal activity in autumn, with H. hemerocallidea corm water extracts recording an MFC value as low as 0.39 mg/ml. The leaf extracts of H. hemerocallidea (water), D. robusta (DCM) and M. plumbea (DCM) had good MFC values of 0.78 mg/ml each, in spring. The DCM leaf extracts of T. violacea also showed good fungicidal activity (0.78 mg/ml) in summer, while corm water extracts of H. hemerocallidea had an MFC value of 0.39 mg/ml in winter. There were no fungicidal activities recorded from all the bulb extracts in all the seasons. All the PE and DCM extracts in all the tested plant samples recorded between moderate (40-70%) and high (> 70%) COX-1 and COX-2 inhibition levels across all seasons. The EtOH corm extracts of H. hemerocallidea also demonstrated moderate to high inhibitory activity against COX-1 enzyme across all seasons. Bulb and leaf extracts of T. violacea showed selective inhibitory activity for COX-2 enzyme in all the seasons. The highest COX inhibitory levels were recorded in COX-2 from the PE leaf (spring) and bulb (autumn) extracts of T. violacea, with both recording 100% inhibitory activity.
Phytochemical analysis revealed higher total phenolic compounds in bulbs/corms and leaves of all the analysed plant species, to be either higher in spring or winter. Plant material collected in autumn had the least levels of total phenolics. An almost similar trend to that of total phenolics was observed for flavonoids, gallotannins and condensed tannins in most plant samples, with higher levels either in spring or
winter. Total saponins were consistently higher in winter than in the other seasons in all the screened plant species. There were in some cases, relationships between the peaks in the levels of some phytochemical compounds and the observed levels of bioactivity in different assays. The results obtained from this study demonstrate that the leaves of the screened plant species may substitute or complement bulbs in the treatment of certain ailments in traditional medicine. Thus, plant part substitution can be sustainably utilised in the conservation of these plant species while retaining the same medicinal benefits.Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.
49
Steenkamp, P. A. "Chemical analysis of medicinal and poisonous plants of forensic importance in South Africa". Thesis, 2014. http://hdl.handle.net/10210/12377.
Testo completoAbstract (sommario):
Ph.D. (Chemistry)The Forensic Chemistry Laboratory of Johannesburg (FCL JHB) is tasked with the chemical analysis of a variety of samples to assist in determining the cause of death where unnatural cause is suspected. Some of the samples submitted to the laboratory have a herbal or muti connotation, but a large portion of these cases turn out to have no herbal components present as only pharmaceutical or agricultural products are detected in these samples. This study combined, for the first time, forensic investigation, chemistry and botany to create a unique platform needed for the identification of poisonous plants and their components in forensic exhibits and viscera. The research was focussed on the poisonous plants previously detected at the laboratory, as well as the requests received for the analysis of muti/toxic plant components. The selection of plants included Nicotiana glauca, Datura stramonium / Datura ferox, Callilepis laureola, Boophone disticha / Ammocharis coranica, Abrus precatorius, Ricinus communis, Nerium oleander / Thevetia peruviana and Bowiea volubilis. All these species are known to have caused fatalities, hence their choice. Nicotiana glauca has been implicated in the deaths of at least 15 people since 2001. It was previously detected by GC-MS (EI) in plant exhibits, but could not be detected in a viscera matrix. A selective extraction method for alkaloids was used to extract botanical and viscera samples. Anabasine was successfully detected on the HPLC-MS (EI) system but this detection technique was not considered sensitive enough. A very sensitive HPLC-MS method was developed on the ZMD detector by using electrospray technology. This method outperformed both electron impact detectors (GC and HPLC) and could detect 1ng/ml anabasine with relative ease in full scan mode. Datura stramonium and D. ferox have not been previously positively linked to any human poisoning or death due to exposure to botanically derived products at the FCL JHB. Atropine and scopolamine were successfully ionised in ESI positive mode and could be detected at 10 pg/ml and 100 pg/ml level respectively. The identities of the compounds were confirmed by characteristic ISCID fragmentation patterns. The developed method was successfully applied to a suspected heart attack case. The results proved conclusively that the deceased was given D. ferox seeds as part of his meal and an overdose of atropine and scopolamine contributed to his death...
50
Hartzell, James Francis. "Response of the endangered medicinal plant : Siphonochilus aethiopicus (Schweif) B.L. Burt. to agronomic practices". Thesis, 2011. http://hdl.handle.net/10413/10037.
Testo completoAbstract (sommario):
This study examines field cropping constraints for domestication of an endangered, wild medicinal plant, Siphonochilus aethiopicus, (Schweif.) B.L. Burt. Extensive literature review and careful observations of plant growth behavior during two years of crop trials overturned several long-held but erroneous claims that have consistently appeared in the scholarly literature, and revealed previously undocumented plant growth characteristics. S. aethiopicus (Schweif.) B.L. Burt. is a rhizomatous corm, not a rhizome. Field growth observations demonstrated clearly that the false stem and leaves grow continuously from emergence in September to senescence in April-May; the corm retains its tuberous roots during winter senescence, and is genetically preprogrammed to shoot in September. Flowers may emerge throughout the growing season (not only initially prior to shoot emergence), typical leaf count is 11-15, not 6-8 as previously reported, numbers that remain constant even when the plant height increases by 20-30% under shade, and leaf distichy is independent of the sun’s course and is unaffected by mother corm orientation. S. aethiopicus proved to be unusually resistant to common field diseases and pests, and resilient to severe hail.
The responses of S. aethiopicus were tested in a series of field trials to the effects of levels of compost, field spacing, size of planting material, addition of biocontrol agents, different degrees of shading, and factorials of the macronutrients Nitrogen, Phosphorous and Potassium. Spacing-Composted chicken litter combinations were tested in 2005-2006 in factorial combination with Spacing at 15 cm-4.5 kg ha-1, 20 cm-7.5 kg ha-1, 30 cm-10 kg ha-1, and 40 cm-15.5 kg ha-1, and these treatments were randomized with 4 Corm planting sizes (height by base diameter in mm): Small (S, 12.38 mm x 12.6 mm), Medium Small (MS, 29.65 mm x 27.93 mm), Medium Large (ML, 38.48 mm x 37.78 mm) and Large (L, 52.37 mm x 44.10 mm). 2005-2006 ANOVA tests showed significant differences between Spacing-Compost and Corm Size for the total harvest biomass measure, with 30 cm and 40 cm spaces better than 15 cm spacing, and Corm Size MS, ML and L all better than S, and ML better than MS. Total Corms harvested per block and
ii
Survival Percentage were similarly significant for Corm Size, but not Spacing. Corms smaller than the Small criteria were raised separately, under optimal conditions in a nursery. In a separate 2005-2006 Compost-only trial ANOVA tests did not find significant differences between compost levels.
In 2006-2007 we tested Spacing separately at 5, 10, 15, 20, 30 and 40 cm between planted corms in each plot. We tested Compost levels separately, with 0, 5, 10 and 15 kg ha-1 compost per plot. In 2006-2007 only the ML and L sizes were used in an even mix. There were no significant differences between treatments due to high experimental error, but measurement across all production parameters showed a clear trend towards best performance at spacing between 20 and 40 cm. Overall the results from the Spacing, Compost-level and Corm Size trials suggest that 30 cm is perhaps the optimal field spacing, higher compost levels tend to give better results, and the ML and L corm sizes perform better in open-sun field trials. These parameters are recommended for further field studies and production.
The effects of two commercial strains of Trichoderma spp were tested at recommended doses applied to S. aethiopicus. T. harzianum Strain B77 was used as a drench at planting in comparison with a Control and a fungicide in 2005-2006. There were no significant differences between treatments for Harvested Biomass or Survival Percentage. B77 did perform significantly better than the Fungicide in the Total Corm measurement, but neither treatment was significantly different from the Control. In sum, there was a weak trend towards a greater number of output corms as a result of the application of the biocontrol agent. In both 2005-2006 and 2006-2007 we tested T. harzianum Strain kd applied as a drench at planting, with a second drench at 4 weeks. In 2006-2007 there were no significant differences between treatments, but the trend was towards better performance as a result of the drench at planting only.
In 2005-2006 open field trials had shown that S. aethiopicus is susceptible to sunburn and Erwinia soft rot when grown in the full sun. Therefore, we tested the effect of various shadecloth densities and colours on production performance in 2006-2007. Treatments were Control (full sun), 40% White (TiO2) (23% shade), 40% Grey (28-30% shade), Light Black (40%), Medium Black (50%), Dark Black (80%), and Red (40%).
There were no significant differences between treatments, but the trends indicated that the Control (full sun) and Dark Black (80% shade) performed the worst. Colour of shade did not appear to be important, and plants under all the shadecloths with 40-50% shade grew best. In a factorial trial different levels of Nitrogen, Phosphorous, and Potassium (NPK)were tested, over two seasons. Four levels of each input were used: N at 0 (Control), 40 kg ha-1 (N1), 80 kg ha-1 (N1), and 120 kg ha-1 (N3). P levels were 0 (Control) 60 kg ha-1 (P1) ,120 kg ha-1 (P2) and 200 kg ha-1 (P3). K levels were 0 (Control), 100 kg ha-1 (K1), 200 kg ha-1 (K2), and 400 kg ha-1 (K3). In 2005-2006 there were no significant differences between treatments. In 2006-2007 data there were significant results for Nitrogen only within each repetition. However, significance disappeared when combining across repetitions. We then ran a Bootstrap re-sampling analysis of both 2005-2006 and 2006-2007 data (data were analyzed separately because of different plot sizes and corm numbers in the two years), looking at the optimal level of each macronutrient tested against all combinations of the other two. Though significant results were obtained for each individual level of each macronutrient against the others in combination, the difference between the confidence intervals was not significant. However, there was a clear trend: the optimum N levels were between 40 and 80 kg ha-1; optimum P level was 0 (the Control) and optimum K levels were between 100 and 200 kg ha-1.
Tests of handling during harvest, storage, and planting yielded additional useful information for small scale commercial farmers. The optimal harvest time is May, when the false stem and leaves are senescing and yellow, but still upright and visible. Harvest is facilitated by moistening the soil to minimize breaking off of tuberous roots, with simple field washing to remove compacted soil highly recommended. Harvested corms and tuberous roots should be stored under air-restricted, cool conditions because the tuberous roots contain high moisture and will shrivel quickly when left exposed to air, and excessively dried corms will eventually die. Senesced mother corms should be discarded at harvest. Corms are genetically preprogrammed to shoot, so should be planted in September in soft soil, with 1-2 cm of soil coverage.
The studies provide a framework for developing the basic agronomy for the domestication and commercial crop production of an endangered medicinal plant species.Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.