Dissertations / Theses on the topic 'Phytochemicals - Therapeutic use'

Liver is one of the most important organs in the body that maintains the homeostasis of metabolism, immunity, detoxification and hematopoiesis. A large number of acute and chronic intoxications and diseases can influence the normal functions of the liver, leading to irreversible liver damage and even cancer. Currently, applying herbs or herbal derivatives in the prevention and therapy of acute and chronic liver injury receive numerous attentions since they hold great potentials as food supplements in the treatment strategy of liver injuries. There were two major hypotheses of this current work namely: a)In CCl4-inducedacute liver injury animal model, whether pre-treatment with garlic derived S-allylmercaptocysteine (SAMC)or Wolfberry derived Lycium barbarum polysaccharides (LBP)could reduce liver injury, oxidative stress and inflammation partly through a NF-κB-dependent pathway. SAMC or LBP could also promote liver regeneration after acute damage. b)In non-alcoholic steatohepatitis (NASH)-induced chronic liver injury animal model, whether administration of SAMC or LBP along with high-fat diet induction could attenuate liver injury, lipid metabolism dysfunction, fibrosis, oxidative stress, inflammation, apoptosis and transcription factors activities in the liver. In this study, SAMC and LBP were applied in a carbon tetrachloride (CCl4) induced mice acute liver injury model and a high-fat diet induced non-alcoholic steatohepatitis model. In the acute model, an eight-hour CCl4treatment induced severe acute liver injury. Pre-treatment with SAMC or LBP (1) attenuated hepatic histological injury; (2) reduced serum ALT level; (3) ameliorated oxidative stress; (4) reduced expression of inflammatory mediators and chemokines; (5) promoted liver regeneration; and (6) decreased NF-κB activity. Vehicle-treated SAMC or LBP did not exhibit obvious adverse effects on healthy mice. In the chronic NASH model, when compared with control rats, NASH rats showed typical clinical features of human NASH patients, including increased liver injury, lipid content, oxidative stress, inflammation, and apoptosis. In comparison, SAMC or LBP co-treated NASH rats showed (1) reduced fat accumulation, cellular necrosis, collagen formation, as well as reduced serum ALT and free fatty acids levels; (2) restored insulin resistance related kinase phosphorylation status which had been altered during NASH; (3) reduced pro-fibrogenic factors; (4) restored antioxidant enzymes, as well as attenuated end-products of lipid peroxidation and NO production through a cytochrome P450 2E1-dependent pathway; (5) reduced hepatic pro-inflammatory mediators and chemokines production; (6) diminished activities of nuclear transcription factors (NF-κB and AP-1); and (7) ameliorated hepatic cellular apoptosis through a p53-dependentpathwaywhich was under the regulation of LKB1/AMPK axis and PI3K/Akt axis. In conclusion, our data demonstrated that SAMC or LBP consumption protects the liver from acute injury caused by CCl4and chronic damages caused by a high-fat diet. These effects were mainly mediated by the amelioration of hepatic oxidative stress, inflammation, and cell death. In the NASH model, SAMC or LBP also improved hepatic lipid metabolism, fibrosis, and apoptosis. Therefore, the present study proposed that both garlic and Wolfberry, which are novel hepatoprotective herbal products, can be taken as part of the daily dietary supplements in the prevention of acute and chronic liver injury.
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Anatomy
Doctoral
Doctor of Philosophy

Chemical Characterization of Pseudognaphalium obtusifolium by Gas Chromatography – Mass Spectrometry (GC-MS) to Assess Potential Therapeutic Phytochemicals and Toxicological Concerns Using Simulated Use Conditions By Regina Ballentine Virginia Commonwealth University, 2019 Director: Sarah C. Rutan, Professor, Department of Chemistry Currently, there is an increasing demand for natural therapies and herbal products to treat various ailments. It is generally believed that natural therapies have fewer side-effects than traditional western medicine; however, they are often used in different strengths and formulations without consistency of the levels of target compounds or knowledge about toxicity. Due to this growing trend, a comprehensive chemical evaluation of plants used for medicinal purposes is necessary. Pseudognaphalium obtusifolium is a plant that has been used historically by Native Americans as an herbal medicine. It is a flowering plant belonging to the Asteraceae family indigenous to the Eastern United States. There are documented accounts of the Native Americans using the herb therapeutically. Reportedly, they used the plant to prepare tea and as filler for bedding. Additionally, they smoked the plant material. To date, there has been little research published on the chemical composition of this plant. Thus, the objective of this work was to conduct a chemical survey of P. obtusifolium using methodologies that would simulate the three historical routes of administration (tea, bedding material, and smoke inhalation). To determine the types of compounds that may be found in the plant, initial experiments using pressurized solvent extraction (PSE) with an ethanolic solvent were performed followed by analysis using gas chromatography – mass spectrometry (GC-MS) in scan mode. This extraction technique enabled a broad range of compounds to be identified. For the analysis of the tea, the leaves and the flowers were ground and analyzed separately. The “tea” simulation was then performed using a water extraction which was then back extracted into dichloromethane for GC-MS analysis in Selected Ion Monitoring (SIM) mode. Seventeen target compounds (terpenes, terpinoids, flavanoids, etc.) were quantified using this method. A bedding material simulation was performed using headspace solid phase micro-extraction (HS-SPME) to collect the volatile and/or semi-volatile components of the headspace. The compounds collected on the SPME fiber were then analyzed by GC-MS in scan and SIM modes to qualitatively and quantitatively determine the types of chemical compounds (most of which were terpenes) that may be off-gassed from bedding material. This analysis compared levels of compounds in two different crop years and four terpene compounds were quantified. To simulate smoking of the plant material, the leaves and flowers were fashioned into smoking articles. Sample collection was performed by a smoking machine and smoke condensate was collected. The smoke condensate was then analyzed by GC-MS in scan mode. As combustion and pyrolysis of plant material are known to produce toxic products, specific potentially harmful compounds were investigated and quantified. This chemical analysis of P. obtusifolium identified target compounds that can be found in the three simulated usage forms. Identification of these compounds gives insight on why the Native Americans may have used P. obtusifolium as an herbal medicine. Among the detected compounds, there were many unknowns. Elucidating these unknown compounds will be important in the effort to understand the full chemical profile of this plant.

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2017.
The continued use and popularity of plant-based traditional medicine demands scientific validation of the therapeutic potential of the medicinal plants used in disease management and treatment. These medicinal plants are to be evaluated for phytochemical constituents and pharmacologically screened for their bioactivity and include the isolation and identification of their bioactive compounds. The diabetes tea and its eight individual plants constituents were collected from Sing Fefur Herbs in McGregor, Western Cape. The plant material was ground to a fine powder form using a milling machine. The powdered plant material was sequentially extracted with hexane, 1:1 DCM, DCM:MeOH, MeOH and water. The antioxidant activity of the tea and its plants was evaluated with comparison to the antioxidant activity of brewed rooibos tea in literature. The concentration of antioxidants in the plants and the tea were found to be significantly high. The ORAC assay results of the water extracts were significantly higher than that of rooibos tea in all plants. Salvia africana-caerulea water extract ORAC results were 14147.10±1.02 μmol TE/g and this is 10 times better than the brewed rooibos tea results of 1402±44.1 μmol TE/g. The alpha-amylase enzyme inhibition assay showed no significant results while the alpha-glucosidase enzyme inhibition assays showed significant results in some of the extracts. The highest inhibitory activity towards alpha-glucosidase was found in the Urtica urens hexane extract and the Thymus vulgaris hexane extract (69.66% and 68.43%, respectively). This observation suggests that alpha-glucosidase enzyme is inhibited mostly by the less polar or medium polarity chemical components of the plant extracts. The crude plant extracts that showed significant activity in the antidiabetic bioassays were further subjected to cytotoxicity assay to ascertain the safety of extracts. The T. vulgaris DCM extract, Salvia officinalis DCM extract and Salvia officinalis hexane extract showed a cell growth inhibition of 54.91%, 62.14% and 63.87% at 100 μg/ml, respectively. The Salvia africana-caerulea DCM extract showed a cell growth inhibition of 59.10% at 50 μg/ml and 62.14% at 100 μg/ml. In the cytotoxicity analysis Salvia africana-caerulea DCM extract is the only extract that showed cell viability below 50% for both concentrations. Phytochemical screening of selected methanolic and aqueous extracts of the diabetes tea and the Salvia africana-caerulea showed the presence of alkaloids, sugars, flavonoids, glycosides, proteins & amino acids, phenolics & tannins and saponins. Furthermore isolation, purification and analysis of two Salvia africana-caerulea crude extracts (DCM and DCM:MeOH) were done in order to try and obtain pure compounds. The compound characterization was done through the use of chromatographic techniques. Thin layer chromatography (TLC), flash chromatography and column chromatography resulted in the generation of 29 fractions. Spectroscopic techniques utilized for chemical structural elucidation for compounds of interest included Liquid chromatography mass spectrometry and Nuclear Magnetic Resonance Spectroscopy. Of all the fractions generated, DM 23 was the purest and its structural elucidation was attempted.

Pancreatic cancer is known to be one of the most life-threatening cancers characterized by aggressive local invasion and distant metastasis. The high basal level of autophagy in pancreatic cancer may be responsible for the low chemotherapeutic drug response rate and poor disease prognosis. However, the clinical application of autophagy inhibitors was unsatisfactory due to their toxicity and minimal single-agent anticancer efficacy. Hence, oncologists begin to consider the tumor microenvironment when exploring new drug targets. In the present study, the anti-tumorigenic mechanisms of two major phytochemicals derived from Chinese medicinal herbs had been investigated against pancreatic cancer development. Calycosin is a bioactive isoflavonoid of the medicinal plant Astragalus membranaceus. Our results have shown that calycosin inhibited the growth of various pancreatic cancer cells both in vitro and in vivo by inducing cell cycle arrest and apoptosis. Alternatively, calycosin also facilitated MIA PaCa-2 pancreatic cancer cell migration in vitro and increased the expression of epithelial-mesenchymal transition (EMT) biomarkers in vivo. Further mechanistic study suggests that induction of the Raf/MEK/ERK pathway and facilitated polarization of M2 tumor-associated macrophage in the tumor microenvironment both contribute to the pro-metastatic potential of calycosin in pancreatic cancer. These events appear to be associated with calycosin-evoked activation of TGF-β signaling, which may explain the paradoxical drug actions due to the dual roles of TGF-β as both tumor suppressor and tumor promoter in pancreatic cancer development under different conditions. Isoliquiritigenin (ISL) is a chalcone obtained from the medicinal plant Glycyrrhiza glabra, which can be a precursor for chemical conversion to form calycosin. Results have shown that ISL decreased the growth and EMT of pancreatic cancer cells in vitro, probably due to modulation of autophagy. ISL-induced inhibition of autophagy subsequently promoted reactive oxygen species (ROS) production, leading to induction of apoptosis in pancreatic cancer cells. Such phenomenon also contributed to the synergistic growth-inhibitory effect in combined treatment with the orthodox chemotherapeutic drug 5-fluorouracil. In addition, ISL-induced tumor growth inhibition in vivo was further demonstrated in a tumor xenograft mice model of pancreatic cancer. ISL promoted apoptosis and inhibited autophagy in the tumor tissues. Study on immune cells indicates that ISL could reduce the number of myeloid-derived suppressor cells (MDSCs) both in tumor tissue and in peripheral blood, while CD4+ and CD8+ T cells were increased correspondingly. In vitro test has revealed that ISL inhibited the polarization of M2 macrophage along with its inhibition of autophagy in M2 macrophage. These immunomodulating effects of ISL had reversed the pro-invasive role of M2 macrophage in pancreatic cancer.In conclusion, calycosin acts as a "double-edged sword" on the growth and metastasis of pancreatic cancer, which may be related to the dual roles of TGF-β and its influence on the tumor microenvironment. Alternatively, ISL consistently inhibited the growth and metastatic drive of pancreatic cancer through regulation of autophagy and reprogramming of the immune system. The differential modes of action of these compounds have provided new insights in the development of effective pancreatic cancer treatment adjuvants.

In Africa, the importance of medicinal plants in folklore medicine and their contribution to primary healthcare is well recognized. Across the continent, local herbal mixtures still provide the only therapeutic option for about 80% of the population. The vast floral diversity and the intrinsic ethnobotanical knowledge has been the backbone of localized traditional herbal medical practices. In Africa, an estimated 5400 of the 60000 described plant taxa possess over 16300 therapeutic uses. Similarly, with a therapeutic flora comprising of approximately 650 species, herbal medical practitioners in South Africa, make use of a plethora of plants to treat different human diseases and infections. Over the years, studies have identified numerous plant species with potential against chronic metabolic diseases including type 2 diabetes mellitus (T2DM). Globally, the incidence and prevalence of T2DM have reached epidemic proportions affecting people of all ages, nationalities and ethnicity. Considered the fourth leading cause of deaths by disease, T2DM is a global health crisis with an estimated diagnosis and mortality frequency of 1 every 5 seconds and 1 every 7 seconds respectively. Though the exact pathophysiology of T2DM is not entirely understood, initial peripheral insulin resistance in adipose tissue, liver, and skeletal muscle with subsequent pancreatic β-cell dysfunction resulting from an attempt to compensate for insulin resistance is a common feature of the disease. The current approach to treating T2DM is the use of oral antidiabetic agents (OAAs), insulin, and incretin-based drugs in an attempt to achieve glycaemic control and maintain glucose homeostasis. However, conventional anti-T2DM drugs have been shown to have limited efficacies and serious adverse effects. Hence, the need for newer, more efficacious and safer anti-T2DM agents. Sutherlandia frutescens subsp. microphylla is a flowering shrub of the pea family (Fabaceae/Leguminaceae) found mainly in the Western Cape and Karoo regions of Southern Africa. Concoctions of various parts of the plant are used in the management of different ailments including T2DM. However, despite extensive biological and pharmacological studies, few analyses exist of the chemical constituents of S. frutescens and no Triple Time of Flight Liquid Chromatography with Mass Spectrometry (Triple TOF LC/MS/MS) analysis has been performed. The initial aim of this study was to investigate the phytochemical profile of hot aqueous, cold aqueous, 80% ethanolic, 100% ethanolic, 80% methanolic and 100% methanolic extracts of a single source S. frutescens plant material using colorimetric and spectrophotometric analysis. The hot aqueous extractant was found to be the best extractant for S. frutescens, yielding 1.99 g of crude extract from 16 g fresh powdered plant material. This data suggests that application of heat and water as the extractant (hot aqueous) could play a vital role in extraction of bioactive compounds from S. frutescens and also justifies the traditional use of a tea infusion of S. frutescens. Colorimetric analysis revealed the presence of flavonoids, flavonols, tannins, and phenols in all extracts with varying intensity. The organic extracts 100% methanol, 80% and 100% ethanol exhibited high color intensity (+++) for flavonoids and flavonols respectively, while all the extracts exhibited a moderate color intensity (++) for tannins and phenols. Spectrophotometric analysis of S. frutescens extracts revealed that all the organic extracts contained a significantly higher concentration (in mg/g of extract) of flavonols and tannins when compared to the aqueous extracts. All extracts contained approximately equal levels of phenols. These data confirm the presence of all four groups of bioactive phytocompounds in the S. frutescens extracts used in this study, and also confirm that different solvent extractants possess the capability to differentially extract specific groups of phytocompounds. in individual extracts. Further comparison of these compounds with online databases of anti-diabetic phytocompounds led to the preliminary identification of 10 possible anti-diabetic compounds; α-Pinene, Limonene, Sabinene, Carvone, Myricetin, Rutin, Stigmasterol, Emodin, Sarpagine and Hypoglycin B in crude and solid phase extraction (SPE) fractions of S. frutesecens. Furthermore, using two hepatic cell lines (Chang and HepG2) as an in-vtro model system, the anti-T2DM properties of crude aqueous and organic extracts of S. frutescents was investigated and compared. Both aqueous and organic extracts of S. frutescens were found to decrease gluconeogenesis, increase glucose uptake and decrease lipid accumulation (Triacylglycerol, Diacylglycerol, and Monoacylglycerol) in Chang and HepG2 hepatic cell cultures made insulin resistant (IR) following exposure to high concentration of insulin and fructose. Using real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), the aqueous and organic extracts of S. frutescens were confirmed to regulate the expression of Vesicle-associated membrane protein 3 (VAMP3), Mitogen-activated protein kinase 8 (MAPK8), and Insulin receptor substrate 1 (IRS1) in insulin resistant hepatic cells. IR-mediated downregulation of VAMP3, MAPK8, and IRS1 mRNA in IR HepG2 hepatic cell cultures was reversed in the presence of aqueous and organic extracts of S. frutescens. The hot aqueous extract displayed the highest activity in all the assays, while all the organic extracts displayed similar potency. In conclusion, this study reports that aqueous and organic extracts of S. frutescens possess numerous anti-diabetic compounds that can be further investigated for the development of new, more efficacious and less toxic anti-diabetic agents. The presence of multiple compounds in a single extract does suggest a synergistic or combinatorial therapeutic effect. These findings support the burgeoning body of in-vivo and in-vitro literature evidence on the anti-diabetic properties of S. frutescens and its use in folklore medicine.

Resistance of human pathogenic bacterial strains results in selective pressure against known antibiotic. However, plant derived compounds that possess antibacterial potential are currently being investigated for treatment of wound infections in diabetic patients as they are inexpensive and non-toxic. Hence, this dissertation was designed to evaluate two medicinal plants (Brachylaena elliptica and Brachylaena ilicifolia) traditionally used in the treatment of various diseases such as diabetes, and its secondary complications in diabetic patients. The in vitro antioxidant activity of both plants were evaluated using DPPH (1, 1-diphenylhydrazl), ferric reducing power, ABTS (2, 2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), NO (nitric oxide) and H2O2 (hydrogen peroxide) techniques. The antibacterial test and Minimum inhibitory concentration (MIC) was determined by agar dilution method against 5 bacteria strains (Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogene, Proteus vulgaris and Proteus mirabilis) infecting wounds in diabetic patients using amoxicillin and ciprofloxacin as positive control. The phytochemical analyses were assessed using standard published methods. Identification of bioactive components in essential oils of both plants were assessed using GCMS. The aqueous and ethanol extracts of both plants were also evaluated to identify bioactive components using LC-MS. The results of the phytochemical analysis revealed the presence of phenols, tannins, flavanoids, flavanols, proanthocyanidins, saponins and alkaloids in both plants. Both plants indicated strong antioxidant activities which might be due to the presence of bioactive compounds. The aqueous and ethanol leaf extracts of both plants demonstrated appreciable broad spectrum activities against these wound pathogens with MIC ranging between 5 and 0.3 mg/ml. The GC-MS analysis of the essential oils of both plants revealed the presence of monoterpenes, oxygenated sesquiterpenes, phenolics and esters. The LC-MS analysis of the aqueous and ethanol leaf extracts of both plants showed that both plants are rich in alkaloids, terpenes, terpenoids, monoterpernoids, and flavanoids. Conclusively, this study has partially justified the ethnomedicinal use of B. elliptica and B.licifolia leaves for the treatment of various diseases, including diabetes and wound infections caused by bacteria in diabetic patients. These may be attributed to the presence of antioxidant compound such as phenols, flavanoids, saponins, tannins, alkaloids and other phytochemical compounds.

Thesis MTech (Food Technology))--Cape Peninsula University of Technology, 2017.
Bambara groundnut (Vigna subterranea) an indigenous legume cultivated in Sub-Saharan Africa has been proclaimed to have medicinal properties from communities and in rural areas. However, there is not enough scientific information to validate these claims. Therefore, this study aimed to identify possible medicinal properties of Bambara groundnut (BGN), by analysing the phytochemical and antimicrobial properties of BGN seed and product extracts from Mpumalanga province within South Africa. The BGN extracts (70% methanol, 70% ethanol, milli-Q water) from seeds and products (milk and yoghurt) were screened for the presence of alkaloids, flavonoids, phenols, riboflavin and thiamine using analytical laboratory methods for basic screening, high-performance liquid chromatography (HPLC) and gas chromatography (GC) for quantification. The antimicrobial activity involved direct bioautography and minimum inhibitory concentration (MIC) against six antibiotic-resistant microorganisms, Acinetobacter baumannii ATCC 19606T, Enterococcus faecalis ATCC 29212, Klebsiella pneumoniae subsp. pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus subsp. aureus ATCC 33591 and Candida albicans ATCC 24433. For the seed extracts, flavonoids and phenols were highly concentrated in the red and brown hulls of BGN compared to whole and dehulled BGN. Organic solvents in comparison to water yielded the highest concentration of flavonoids, whilst water yielded the highest concentration for phenols. Flavonoid compounds that were detected at the highest concentrations were rutin (24.458 ± 0.234 mg.g-1, brown hull extracted with 70% methanol), quercetin (0.070 ± 0.043 mg.g-1, red hull extracted with 70% methanol), kaempferol (0.391 ± 0.161 mg.g-1; brown hull extracted with 70% ethanol) and myricetin (1.800 ± 0.771 mg.g-1; red hull extracted with 70% methanol). For phenol compounds, gallic acid (0.009 ± 0.004 mg.g-1; brown hull extracted with milli-Q water), catechin (0.026 ± 0.041 mg.g-1; brown hull extracted with milli-Q water), methyl gallate (0.008 ± 0.013 mg.g-1; brown whole extracted with milli-Q water), chlorogenic acid (0.115 ± 0.199 mg.g-1; brown hull extracted with milli-Q water) and ellagic acid (0.105 ± 0.082 mg.g-1; red hull extracted with milli-Q water) were detected. Vitamins B1 and B2 (riboflavin and thiamine) were mostly present in milli-Q water extracts. Black-eye hull had the highest concentration of thiamine (vitamin B1) and riboflavin (vitamin B2) consisting of 0.072 mg.g-1 (extracted with milli-Q water) and 0.002 mg.g-1 (extracted with 70% ethanol and 70% methanol). Red and brown hull extracts from organic solvents (70% ethanol and 70% methanol) showed the highest antimicrobial activity, whereas the whole, dehulled and hulls (black-eye and brown-eye) extracts had no antimicrobial activity. As for BGN products extracts, flavonoid compounds that were detected at the highest concentrations were rutin (5.694 mg.g-1, whole BGN milk, milli-Q water), quercetin (0.703 mg.g-1, whole BGN yoghurt, milli-Q water) and myricetin (0.987 mg.g-1, whole BGN yoghurt, 70% ethanol).

Infection with Helicobacter pylori has been associated with the pathogenesis of numerous stomach and gastroduodenal diseases that pose threats to public health. Eradicaftion of this pathogen is a global challenge due to its alarming rate of multidrug resistance. Consequently, to find an alternative treatment, the search is increasingly focused on new antimicrobial product from natural sources including honey. Honey has been used as medicine in several cultures since ancient time due to its enormous biomedical activities. Its beneficial qualities have been endorsed to its antimicrobial, antioxidant, anti-inflammatory properties added to its phytocomponents. In this study, the anti-H. pylori activity of South African honeys and their solvent extracts as well as the phytochemicals present in the two most active honeys were evaluated. Agar well diffusion test was used to investigate the antimicrobial activity of six honey varieties obtained from different locations in the country. Subsequently, the honeys were extracted with four organic solvents viz n-hexane, diethyl ether, chloroform and ethyl acetate employed in order of increasing polarity. The antibacterial activity of the different solvent extracts of each honey was evaluated by agar well diffusion; broth micro dilution and time kill assays. Different chromatographic techniques (Thin layer & column chromatography) were employed to enumerate the phytochemical constituents in the most active solvent extracts of Pure Honey (PH) and Champagne Royal Train (CRT); and were identified by gas-chromatography linked mass-spectrometry. Linalool pure compound was equally evaluated for anti-H. pylori activity in a bid to trace the antibacterial agent among the variety of compounds identified. Data were analyzed by One-way ANOVA test at 95% confidence interval. Crude honeys and their solvent extracts demonstrated potent anti-H. pylori activity with zone diameter that ranged from [16.0mm (crude) to 22.2mm (extract)] and percentage susceptibilities of test isolates between 73.3% (crude) and 93.3% (extract). The chloroform extracts of PH and CRT were most active with MIC50 in the ranges 0.01- viii 10%v/v and 0.625-10%v/v respectively, not significantly different from amoxicillin (P> 0.05); and efficient bactericidal activity (100% bacterial cells killed) at 1/2MIC and 4xMIC over different time intervals, 36-72hrs and 18-72hrs respectively. The appearance of bands on the thin layer chromatography (TLC) chromatogram spotted with the chloroform extracts of PH and CRT; and developed with hexane: ethyl acetate: acetic acid (HEA) and methanol: acetic acid: water (MAAW) solvent systems indicated the presence of compounds. Purification of the compounds contained in these extracts over silica gel column yielded numerous fractions which were evaluated for antibacterial activity and purity. PHF5 was the most active fraction with a mean MIC50 value of 1.25mg/mL. Volatile compounds belonging to different known chemical families in honey were identified in all the active fractions obtained from PH. Conversely, only four compounds were identified in the active fractions obtained from CRT hence the non volatile constituents could be of prime relevance with respect to antibacterial activity of this honey. Of novelty was the presence of thiophene and N-methyl-D3-azirdine compounds, essential precursors used for the synthesis of natural products and pharmaceuticals with vital biomedical properties. Linalool demonstrated potent inhibitory (MIC95, 0.002- 0.0313mg/mL) and bactericidal activity (0.0039-0.313mg/mL) against the test isolates. On the other hand, a significant difference was recorded (P < 0.05) in comparing the activity of linalool compound to the fractions. PH could serve as a good economic source of bioactive compounds which could be employed as template for the synthesis of novel anti-H. pylori drugs. However, further studies are needed to determine the non volatile active ingredients in PH and CRT as well as toxicological testing

Abstract Medicinal plants have been for long remedies for human diseases because they contain components of therapeutic value. The growing problem of antibiotic resistance by organisms demands the search for novel compounds from plant based sources. The present study was aimed at evaluating the bioactivity and phytochemical analysis of Hydnora africana on clinical and standard strains of Helicobacter pylori (PE 252C and ATCC 43526), Aeromonas hydrophila ATCC 35654, and Staphylococcus aureus NCT 6571 in an effort to identify potential sources of cheap starting materials for the synthesis of new drugs against these strains. Ethyl acetate, acetone, ethanol, methanol, and water crude extracts of H. africana were screened for activity against the test organisms using the agar well diffusion assay. The Minimum Inhibitory Concentration (MIC50) and Minimum Bactericidal Concentration (MBC) of the most potent extracts were determined by the microdilution method, followed by qualitative phytochemical analysis. Results were analyzed statistically by ANOVA one - way test. Different concentrations (200,100, 50mg/mL) of the methanol, acetone, ethanol and ethyl acetate extracts showed activity against S. aureus and A. hydrophila while for H. pylori, only methanol and ethyl acetate extracts were active; water showed no activity for all studied bacterial pathogens. Mean zone diameter of inhibition which ranged from 0-22mm were observed for all test bacterial pathogens and 14-17mm for ciprofloxacin. The activity of methanol and ethyl acetate extracts were statistically significant (P< 0.05) compared to all the other extracts. MIC50 and MBC ranged from 0.078 – 2.5mg/mL, 0.78-25mg/mL respectively for all tested bacterial pathogens. For ciprofloxacin, the MIC50 and MBC ranged from 0.00976 – 0.078mg/mL and 0.098– 0.78mg/mL respectively. There was no statistically significant difference between extracts (methanol, acetone, ethanol, ethyl acetate) and the control antibiotic (ciprofloxacin) (P> 0.05). Qualitative phytochemical analysis confirmed the presence of alkaloids, saponins, steroids, tannins and flavonoids in the methanol, acetone,ethanol and ethyl acetate extracts. The results demonstrate that H. africana may contain compounds with therapeutic potentials which can be lead molecules for semi-synthesis of new drugs.

The distribution of anthocyanin pigments and polyphenolics of sweet (Prunus avium) and sour cherries (Prunus cerasus) were determined by Ultraviolet- Visible (UV-Visible) spectrophotometry and High Performance Liquid Chromatography with photodiode array detector (HPLC-DAD). Their antioxidant properties were determined by Oxygen Radical Absorbance Capacity (ORAC) and Ferric Reducing Antioxidant Power (FRAP). The effect of frozen storage, canning, and brining on those properties was measured. Experiments were conducted on three sweet cherry cultivars; Bing, Rainier, Royal Ann and one sour cherry cultivar; Montmorency. Cherries were separated into skins, flesh, pits, and pitted cherries for subsequent analyses. Bing had the highest anthocyanin pigments (60.6 mg/lOOg fw) while Montmorency had both the highest total phenolic content (5.6 mg GAE/g fw) and the highest antioxidant activities (ORAC 51.02 μmoles Trolox equivalent (TE) /g fw, FRAP 47.96 μmoles TE/g fw). Hydroxycinnamates predominated in sweet cherries (70-80%) while flavanols were the major class of polyphenolics in sour cherries (70%). The major anthocyanins in sweet and sour cherries were cyanidin-3-rutinoside and cyanidin-3- glucosylrutinoside, respectively. Skins contained the highest amount of anthocyanins, polyphenolics, and antioxidant activities. Anthocyanins and flavonol glycosides predominated in cherry skins. Bing cherries were different from the others in that it had substantial anthocyanins in flesh and pits. The proportion of flavanols increased from skins to pits. Pitted Bing cherries were frozen and stored at -23 and -70°C for 3 and 6 months. Pitted Bing cherries were also canned in light syrup and stored at 2 and 22°C for 5 months. Both Bing and Royal Ann cherries were brined in bisulfite for one year. In all processing experiments, polyphenolics were more stable than anthocyanins. Degradation of hydroxycinnamates occurred during frozen storage and canning while flavonol glycosides were relatively stable. With both canning and brining, anthocyanins and polyphenolics leached into syrup and brine. With brining, hydroxycinnamates and flavonol glycosides disappeared, and unidentified compounds with UV-Visible spectra similar to flavanols were formed. Unidentified compounds possessed antioxidant activity. Cherry skins are high in anthocyanins, polyphenolics and antioxidant properties. Cherry pits and spent brine solution may be a potential source for natural colorants, nutraceuticals, and natural antioxidants.
Graduation date: 2004

Yeung Chung Man.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (leaves 83-97).
Abstracts in English and Chinese.
Abstract --- p.i
Abstract (Chinese) --- p.iv
Acknowledgements --- p.vii
Table of contents --- p.ix
List of figures --- p.xii
List of tables --- p.xiv
List of abbreviations --- p.xv
Chapter Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- General Introduction --- p.1
Chapter 1.2 --- Literature Review --- p.5
Chapter 1.2.1 --- Cancer and melanoma --- p.5
Chapter 1.2.2 --- Anticancer drugs from natural products --- p.6
Chapter 1.2.3 --- Challenges in treatment of melanoma --- p.9
Chapter 1.2.4 --- TCM - New source of natural products for cancer therapy --- p.10
Chapter 1.2.6 --- The genus Schefflera --- p.11
Chapter 1.2.7 --- Anticancer activities of triterpenoids --- p.16
Chapter 1.2.8 --- Cancer and apoptosis --- p.17
Chapter 1.2.8.1 --- The Apoptosis Pathways --- p.20
Chapter 1.2.9 --- Studies of anticancer molecules against melanoma --- p.26
Chapter 1.2.9.1 --- In vitro models for studying anticancer molecules --- p.26
Chapter 1.2.9.2 --- In vivo models for studying anticancer molecules --- p.30
Chapter Chapter 2 --- Materials and Methods --- p.34
Chapter 2.1 --- Phytochemicals --- p.34
Chapter 2.2 --- "Chemicals, Cell Lines and Culture Conditions" --- p.34
Chapter 2.3 --- Determination of in vitro antiproliferative effects of HLDA and the ethyl acetate fraction from S. heptaphylla on human cancer cells --- p.36
Chapter 2.3.1 --- MTT assay --- p.36
Chapter 2.4 --- Determination of the in vitro antiproliferative mechanisms of HLDA and the ethyl acetate fraction from S. heptaphylla in human melanoma A375 cells --- p.37
Chapter 2.4.1 --- Flow cytometric analysis --- p.37
Chapter 2.4.2 --- Western blot analysis --- p.38
Chapter 2.5 --- Determination of the in vivo anticancer effects of the ethyl acetate fraction from S. heptaphylla --- p.41
Chapter 2.5.1 --- Determination of cancer chemopreventive effect of the ethyl acetate fraction with DMBA/TPA-induced skin carcinogenesis model --- p.41
Chapter 2.5.2 --- Determination of cancer therapeutic effect of the ethyl acetate fraction with athymic BALB/c nude mice model --- p.42
Chapter 2.6 --- Statistical Analysis --- p.44
Chapter Chapter 3 --- Results --- p.45
Chapter 3.1 --- Effects of HLDA and the ethyl acetate fraction on viability and proliferation of different cancer cell lines by MTT assay --- p.45
Chapter 3.2 --- Effects of HLDA and the ethyl acetate fraction on cell cycle and apoptosis in A375 cells determined by DNA flow cytometry --- p.46
Chapter 3.3 --- Effects of HLD A and the ethyl acetate fraction on apoptosis induction in A375 cells determined by Western blotting --- p.53
Chapter 3.4 --- Effects of HLD A and ethyl acetate fraction on caspases in A375 cells --- p.55
Chapter 3.5 --- Effects of caspase inhibitors on the HLDA- and the ethyl acetate fraction-induced apoptosis in A375 cells --- p.57
Chapter 3.6 --- Effects of HLD A and the ethyl acetate fraction on the expression of Bcl-2 family proteins in A375 cells --- p.62
Chapter 3.7 --- Chemopreventive effect of the ethyl acetate fraction from S. heptaphylla on the DMBA/TPA-induced skin carcinogenesis model --- p.65
Chapter 3.8 --- Chemotherapeutic effect of the ethyl acetate fraction from S. heptaphylla on A375 xenograft in athymic nude mice --- p.70
Chapter Chapter 4 --- Discussion --- p.73
References --- p.83

A breast cancer cell line stably transfected with the CYP19 gene had been employed for aromatase inhibition. Among the phytochemicals tested, the major dietary flavonoids, such as genistein and daidzein, produced very weak inhibition. On the other hand, the red clover isoflavone biochanin A, the hydroxychalcone butein and the red grape phytoalexin resveratrol were found to be effective aromatase inhibitors. Cell proliferation assay had shown that they could inhibit ER-positive cell proliferation induced by testosterone, and the inhibitory effect was specifically attributed to the reduction of estrogen synthesis. In another breast cancer cell line SK-BR-3, resveratrol, biochanin A and genistein inhibited CYP19 both in enzyme and promoter I.3/II transcriptional levels. The element responsible for the inhibition of aromatase by these phytoestrogens should fall within the region between -556 to -446 by upstream of exon II.
Breast cancer is one of the most common cancers affecting women. Estrogen plays an important role in breast cancer initiation and development. The majority of breast tumors are initially dependent upon estrogen to support their growth. Most breast cancers occur in the postmenopausal period. However, the intra-tumoral estradiol (E2) is maintained at a high level equivalent to the pre-menopausal status. High intra-tumoral E2 level in postmenopausal women is sustained by the biosynthesis of estrogens in the tumorous tissue.
Genistein and Biochanin A, ranged from 0.1 to 10 muM, might act as estrogen agonist and induced aromatase activity and promoter I.1 transactivation in ERalpha-transfected SK-BR-3 cells. (Abstract shortened by UMI.)
The aromatase enzyme, CYP19, belongs to a family of P450 enzyme. As a final rate-limiting step in estrogen biosynthesis, it catalyzes the conversion of C 19 steroids to estrogens. The expression of CYP19 is tissue-specific, and is regulated by alternate promoter usage. The use of aromatase inhibitors for breast cancer treatment has become a major therapeutic approach.
The consumption of some phytochemicals protects against breast cancer. Yet the mechanisms are far from clear. In my present study, various phytochemicals, including phytoestrogens, monoterpenes and carotenoids, were evaluated for their effect on aromatase.
Wang Yun.
"July 2005."
Adviser: Lai-Kwok Leung.
Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3716.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references (p. 145-169).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract in English and Chinese.
School code: 1307.

by Lau Chun Hong.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 179-195).
Abstracts in English and Chinese.
Abstract --- p.i
Abstract in Chinese 摘要 --- p.iv
Acknowledgements --- p.vi
Table of Contents --- p.vii
List of Abbreviations --- p.xiii
List of Figures --- p.xvi
List of Tables --- p.xviii
Publications --- p.xix
Chapter Chapter1 --- Introduction --- p.1
Chapter 1.1 --- Epidemiology of Diabetes Mellitus --- p.1
Chapter 1.2 --- Definition of Diabetes Mellitus --- p.2
Chapter 1.3 --- Glucose Homeostasis and Diabetes Mellitus --- p.2
Chapter 1.4 --- Classification of Diabetes Mellitus --- p.5
Chapter 1.4.1 --- Type 1 Diabetes Mellitus --- p.5
Chapter 1.4.2 --- Type 2 Diabetes Mellitus --- p.6
Chapter 1.4.3 --- Other Specific Types --- p.7
Chapter 1.4.4 --- Gestational Diabetes --- p.9
Chapter 1.4.5 --- Clinical Stages of Diabetes --- p.9
Chapter 1.5 --- Diagnostic Criteria of Diabetes Mellitus --- p.10
Chapter 1.6 --- Complications of Diabetes Mellitus --- p.12
Chapter 1.7 --- Pharmacological Treatment of Diabetes --- p.13
Chapter 1.7.1 --- Treatment of Type 1 Diabetes --- p.13
Chapter 1.7.2 --- Treatment of Type 2 Diabetes --- p.14
Chapter 1.7.2.1 --- Sulphonylureas --- p.17
Chapter 1.7.2.2 --- Biguanides --- p.18
Chapter 1.7.2.3 --- α-Glucosidase Inhibitors --- p.19
Chapter 1.7.2.4 --- Thiazolidinediones --- p.20
Chapter 1.8 --- Diabetes and Traditional Chinese Medicine --- p.21
Chapter 1.9 --- Project Objective --- p.27
Chapter Chapter2 --- Botanical and Phytochemical Studies --- p.28
Chapter 2.1 --- Introduction --- p.28
Chapter 2.2 --- Materials --- p.31
Chapter 2.3 --- Authentication of Herbal Material --- p.41
Chapter 2.3.1 --- Materials --- p.41
Chapter 2.3.2 --- Phytochemical Studies --- p.43
Chapter 2.3.2.1 --- Sample Preparation --- p.43
Chapter 2.3.2.2 --- Thin Layer Chromatography --- p.46
Chapter 2.3.3 --- Results --- p.51
Chapter 2.4 --- Extraction of Herbal Material --- p.56
Chapter 2.4.1 --- Materials and Methods --- p.56
Chapter 2.4.2 --- Results --- p.46
Chapter 2.5 --- Quantification of Sugar Content in Herbal Extracts --- p.58
Chapter 2.5.1 --- Introduction --- p.58
Chapter 2.5.2 --- Materials and Methods --- p.58
Chapter 2.5.3 --- Results --- p.61
Chapter 2.6 --- Discussion --- p.65
Chapter Chapter3 --- In vitro Studies on Formula 2 and its Individual Herbs --- p.68
Chapter 3.1 --- Introduction --- p.68
Chapter 3.2 --- Intestinal Glucose Absorption Studies --- p.69
Chapter 3.2.1 --- Introduction --- p.69
Chapter 3.2.2 --- Materials and Methods --- p.70
Chapter 3.2.2.1 --- Preparation of BBMV --- p.71
Chapter 3.2.2.2 --- BBMV Glucose Uptake Assay --- p.72
Chapter 3.2.2.3 --- Bicinchoninic Acid (BCA) Protein Assay --- p.73
Chapter 3.2.2.4 --- Preparation of Herbal Chloroform Extract --- p.74
Chapter 3.2.2.5 --- Glucose Uptake Assay with Herbal Extracts --- p.75
Chapter 3.2.3 --- Results --- p.76
Chapter 3.3 --- Hepatic Gluconeogenesis Studies --- p.79
Chapter 3.3.1 --- Introduction --- p.79
Chapter 3.3.2 --- Materials and Methods --- p.82
Chapter 3.3.2.1 --- Cell Culture --- p.83
Chapter 3.3.2.2 --- Glucose Production Assay --- p.83
Chapter 3.3.2.3 --- PEPCK Assay --- p.85
Chapter 3.3.3 --- Results --- p.86
Chapter 3.4 --- Cellular Glucose Uptake Studies --- p.88
Chapter 3.4.1 --- Introduction --- p.88
Chapter 3.4.2 --- Materials and Methods --- p.89
Chapter 3.4.2.1 --- Cell Culture --- p.89
Chapter 3.4.2.2 --- Differentiation of 3T3-L1 --- p.90
Chapter 3.4.2.3 --- 2-Deoxy-D-glucose Uptake Assay --- p.91
Chapter 3.4.3 --- Results --- p.92
Chapter 3.5 --- Discussion --- p.96
Chapter 3.5.1 --- Intestinal Glucose Absorption Studies by BBMV --- p.96
Chapter 3.5.2 --- Hepatic Gluconeogenesis Studies by H4IIE Cells --- p.97
Chapter 3.5.3 --- Cellular Glucose Uptake Studies by Hs68 and 3T3-L1 Cells --- p.99
Chapter 3.5.4 --- Conclusions --- p.100
Chapter Chapter4 --- In vivo Studies on Selected Herbs --- p.103
Chapter 4.1 --- Introduction --- p.103
Chapter 4.1.1 --- Animal Models of Type 2 Diabetes --- p.103
Chapter 4.1.2 --- Chemically-induced Diabetic Models --- p.104
Chapter 4.1.3 --- Neonatal-STZ Diabetic Rats --- p.107
Chapter 4.2 --- Basal Glycaemia Test --- p.109
Chapter 4.2.1 --- Animals --- p.109
Chapter 4.2.2 --- Testing Method --- p.110
Chapter 4.2.3 --- Results --- p.112
Chapter 4.3 --- Oral Glucose Tolerance Test --- p.114
Chapter 4.3.1 --- Animals --- p.114
Chapter 4.3.2 --- Testing Method --- p.114
Chapter 4.3.3 --- Results --- p.116
Chapter 4.4 --- Discussion --- p.119
Chapter Chapter5 --- Bioassay-guided Fractionation of Cortex Moutan --- p.125
Chapter 5.1 --- Introduction --- p.125
Chapter 5.1.1 --- Phytochemical Studies of Cortex Moutan --- p.125
Chapter 5.2 --- Organic Extraction of Cortex Moutan --- p.128
Chapter 5.2.1 --- Extraction Method --- p.128
Chapter 5.2.2 --- Results --- p.129
Chapter 5.3 --- BBMV Glucose Uptake Assay with Fraction CM C --- p.131
Chapter 5.3.1 --- Materials and Methods --- p.131
Chapter 5.3.2 --- Results --- p.131
Chapter 5.4 --- In vivo Studies of Fraction CM-C --- p.133
Chapter 5.4.1 --- Materials and Methods --- p.133
Chapter 5.4.2 --- Results --- p.133
Chapter 5.5 --- Fractionation of Fraction CM-C --- p.137
Chapter 5.5.1 --- Materials and Methods --- p.137
Chapter 5.5.2 --- Results --- p.139
Chapter 5.6 --- BBMV Glucose Uptake Assay with CM-C Sub-fractions --- p.142
Chapter 5.6.1 --- Results --- p.142
Chapter 5.7 --- Isolation of Active Compound in Fraction CM-C4 --- p.144
Chapter 5.7.1 --- Materials and Methods --- p.145
Chapter 5.7.2 --- Results --- p.146
Chapter 5.8 --- Structure Elucidation of CM-C4a --- p.148
Chapter 5.8.1 --- Materials and Methods --- p.148
Chapter 5.8.2 --- Results --- p.149
Chapter 5.9 --- Effect of Paeonol in Oral Glucose Tolerance Test --- p.152
Chapter 5.9.1 --- Materials and Methods --- p.152
Chapter 5.9.2 --- Results --- p.153
Chapter 5.10 --- Discussion --- p.155
Chapter Chapter6 --- General Discussion --- p.163
Chapter 6.1 --- Introduction --- p.163
Chapter 6.2 --- Summary of Research Findings --- p.164
Chapter 6.3 --- Limitations and Improvements --- p.167
Chapter 6.4 --- Future Directions --- p.169
Chapter 6.5 --- Conclusion --- p.170
Appendices --- p.172
Appendix 1 Low Resolution EI Mass Spectrum of Paeonol Reference --- p.173
Appendix 2 Low Resolution EI Mass Spectrum of CM-C4a --- p.174
Appendix 3 High Resolution EI Mass Spectrum of Paeonol Reference --- p.175
Appendix 4 High Resolution EI Mass Spectrum of CM-C4a --- p.176
Appendix 5 1H-NMR Spectrum of Paeonol Reference --- p.177
Appendix 6 1H-NMR Spectrum of CM-C4a --- p.178
References --- p.179

A number of recent research studies have been done on different species of the plants of the genus Phyllanthus. The plants are widely distributed in most tropical and subtropical countries and have long been used for the treatment of liver diseases in China and India.
Hepatitis B virus (HBV) is a major pathogen of human viral hepatitis. It has been estimated that 350 million people are chronic carriers of HBV throughout the world. Increasing evidence indicates that persistent viral infection of the liver is associated with cirrhosis and hepatocellular carcinoma. Hepatitis B virus belongs to a family of DNA viruses called hepadnaviruses. The current treatments of HBV infection with interferon or lamivudine have several disadvantages, and there appears to be much room for improvement in terms of medical treatment.
My project research focuses on two poorly characterized Indian Phyllanthus species called Phyllanthus nanus ("PN") and Phyllanthus niruri ("PI"). In my studies, random amplified polymorphic DNA ("RAPD") technique and high performance liquid chromatography ("HPLC") fingerprinting were used to authenticate different species of Phyllanthus. Both aqueous and ethanolic extracts of PN and PI were prepared to study their cytotoxicity in hepatoma cell lines. The effect of these extracts on hepatitis B virus was also examined in the HBV-genome integrated cell lines - PLC/PRF/5 (Alexander) and HepG2 2.2.15. Microparticle enzyme immunoassay ("MEIA") and enzyme-linked immunosorbent assay were used to measure the amount of hepatitis B surface antigen ("HBsAg") and hepatitis B e antigen ("HBeAg") secretion from the cell lines. RT-PCR was used to detect the change in HBsAg mRNA's expression level in the drug-treated cell lines. Real-time PCR was also employed to examine the effect of drug treatment on the level of HBV DNA replication and the amount of virions secreted into the medium. The experimental results showed that both the aqueous and ethanolic extracts of PN and PI exerted suppressive effect on HBsAg secretion and HBsAg mRNA level. The PN and PI ethanolic extracts also showed mild suppression of viral replication in vitro. The ethanolic extract of PN seemed to be more potent in suppressing HBV than the other extracts tested. (Abstract shortened by UMI.)
Lam Wai Yip.
"June 2005."
Advisers: Mary Waye; Vincent Ooi.
Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3594.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references (p. 217-234).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract in English and Chinese.
School code: 1307.

Lai, Kwok Kin.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2013.
Includes bibliographical references (leaves 229-251).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.