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McGinn, Jennifer Sarah. "The vasodilatory and antioxidant activities of polyphenolic substances." Thesis, University of Glasgow, 2002. http://theses.gla.ac.uk/1583/.
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This project was designed to determine the effect of a wide range of grape and tea based extracts and green tea catechins on vascular tension in vitro, further determine the relationship between their vasodilatory and antioxidant activities and identify the major polyphenols present in green and black tea. Grape and tea based extracts were examined for their vasodilator activity in vitro using standard organ bath pharmacology. All extracts evoked biphasic concentration-dependent relaxation in rabbit aortic vessels. Grape based extracts were significantly better vasodilators than tea based extracts. Previous work by others has shown that grape based products induce vascular relaxation via nitric oxide (NO) and endothelium-dependent mechanisms. This study demonstrated that a range of grape based extracts induced vasorelaxation responses via complex mechanisms including endothelium-dependent and independent mechanisms via vasodilating prostaglandins by way of prostacyclin and endothelial NO production. Tea based extracts on the other hand, induced vasorelaxation via the combined interactions of vasodilating endothelium-dependent prostaglandins. The relationship between the vasodilation capacity, antioxidant activity, based on the reduction of the free Fremy's radical and ferric reducing power, and total phenolic content of each extract was also determined. In general, a significant inverse correlation was identified between the vasodilator abilities of the grape and tea extracts in vitro and their antioxidants activities. This study demonstrates that grape and tea based extracts induce vasorelaxation in isolated rabbit aortic vessels and are effective antioxidants in vitro, within a concentration range that may be reached in vivo by moderate wine and tea consumption. The results presented here also indicate that consumption of green tea may have greater benefits than consumption of black tea in terms of their vasodilatory activity and antioxidant capacity in vitro.
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Jaishee, Nishika. "Phytochemical analysis of some ferns with reference to their antioxidant, hypoglycemic and antimicrobial activities." Thesis, University of North Bengal, 2016. http://ir.nbu.ac.in/hdl.handle.net/123456789/2747.
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Youdim, Kuresh Aaron. "Potential beneficial effects of thyme oil and thymol on aspects of ageing processes." Thesis, University of Strathclyde, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310179.
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Bonet, Sánchez Berta. "Antioxidant enzyme activities in fluvial biofilms as biomakers of metal pollution." Doctoral thesis, Universitat de Girona, 2013. http://hdl.handle.net/10803/110519.
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The present thesis aims to evaluate the use of antioxidant enzyme activities (AEA) of biofilm communities as biomarkers of metal pollution (mainly Zn) in fluvial ecosystems. In order to test AEA as biomarkers of metal pollution as well as their responses to environmental variables, several ecotoxicological experiments have been performed. A zoom from field studies (with high ecological realism) to microcosm experiments (under controlled conditions) has been done to fill the gap between both approaches and understand AEA responses under a multiple-stress (environmental and metallic) scenario. The field studies were carried out in the Riera d’Osor, a tributary of the Ter, located in the region of La Selva (Girona province)L’objectiu d’aquesta tesi és avaluar l’ús de les activitats enzimàtiques antioxidants (AEA) dels biofilms com a biomarcadors de contaminació metàl·lica (principalment per zinc (Zn)) en els ecosistemes fluvials. Per tal d’estudiar la resposta de les AEA a la contaminació metàl•lica, així com també la resposta a altres canvis ambientals (situacions d’estrès múltiple), s’han realitzat diversos experiments ecotoxicològics fent un zoom des d’estudis de camp (amb un elevat realisme ecològic) fins a un estudi de laboratori utilitzant microcosmos (amb condicions controlades). Els estudis de camp s’han dut a terme a la riera d’Osor, afluent del Ter, situada a la comarca de la Selva (província de Girona)
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Sadi, Gokhan. "Antioxidant Enzyme Activities In Rat Liver Tissues Of Diabetic Rats." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605254/index.pdf.
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Free radicals are the compounds having one or more unpaired electrons in their outer orbital and this unpaired electron make these compounds very reactive. Especially as their concentration increases, they initiate a chain oxidation reaction of lipids, proteins and nucleic acids. The condition, in which the production of free radicals exceeds their elimination or tissue defense mechanism decrease against them or both occur together, is called oxidative stress. In diabetes mellitus which is a glucose metabolism disorder, there occurs excessive non-enzymatic protein oxidation, glucose autoxidation and enhanced activity of polyol pathway enzymes, which are the possible sources of the oxidative stress in this disease.
In this study, the conditions of the activity measurements of major antioxidant enzymes, namely superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), glutathione peroxidase (GPx, 1.11.1.9) and glutathione S-transferase (GST, EC 2.5.1.18) were studied and the optimum conditions (pH, temperature and substrate concentrations) for each assay were determined.
Further objectives of the study were to characterize the enzymatic antioxidant systems (catalase, superoxide dismutase, glutathione peroxidase and glutathione S-transferase), tissue oxidation status (concentrations of TBARS, protein carbonylation, and lipid/protein ratios) and nonenzymatic antioxidant (reduced glutathione) levels of the diabetic rat liver tissues.
According to our results, the hepatic SOD and GPx activities significantly increased whereas CAT activity markedly decreased in diabetic rats compared to control group. Also, GST activities did not change in diabetes. As a result of oxidative stress, TBARS concentration, lipid/protein ratios and protein carbonylation increased and GSH levels decreased in diabetic rats compared to control rats. This increase in tissue damage, in spite of the increase in antioxidant enzyme activities, could have been due to the overproduction of reactive oxygen species that exceeded the capacity of the antioxidant enzymes during the eight week of diabetes.
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Talhi, Oualid. "Synthesis and biological activities of polyphenolic hybrids: evaluation of anti-cancer, anti-inflammatory and antioxidant activities." Doctoral thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/10132.
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Doutoramento em QuímicaOs compostos polifenólicos constituem uma classe de metabolitos secundários de plantas, mas existe também uma enorme quantidade de derivados sintéticos ou semi-sintéticos contendo múltiplas unidades fenólicas. Estes compostos apresentam importantes características biológicas, que dependem das suas estruturas básicas. Certos derivados desta família de compostos, tais como flavonoides, cromonas e cumarinas contribuem para os benefícios da dieta humana, e partilham o núcleo de benzopiran-(2 e 4)-ona ou benzofuran-3-ona. A presente dissertação inclui uma introdução geral e três capítulos que descrevem as novas rotas sintéticas estabelecidas para a preparação de novos híbridos de diversos compostos polifenólicos, assim como a sua elucidação estrutural e termina com a presentação dos resultados da avaliação biológica desses mesmos compostos. No segundo capítulo discute-se a preparação de híbridos de pirimidina- e imidazolidina-polifenóis, especialmente a síntese diastereoseletiva de novos híbridos benzofuran-3-ona-hidantoína e derivados de uracilo. A rota sintética envolve a ação de carbodiimidas sobre os ácidos cromona-(2- e 3)-carboxílicos num só passo ou em dois passos sequenciais, catalisada por uma base orgânica ou inorgânica. O terceiro capítulo descreve reações do tipo adições conjugadas 1,4 - hetero-ciclisações em cascata de compostos 1,3-dicarbonílicos em ácido cromona-3-carboxílico catalisadas por uma base orgânica, que originaram novas cromonas, cromanonas e flavonas polissubstituídas. As bispiranonas [bispiran-2 e 4)-onas] foram elaboradas numa reacção de acoplamento da 4-hidroxicumarina ou da lactona do ácido triacético com o ácido cromona-3-carboxílico ou precursores formil-funcionalizados (ω-formil-2’-hydroxy acetofenonas e cromona-3-carbaldeídos) utilizando organocatálise básica. Finalmente, alargou-se o estudo das adições conjugadas 1,4 para uma variedade de 4-hidroxipiran-2-onas e cetonas α,β-insaturadas para originar novos análogos de warfarina. Obteve-se uma variedade de estruturas complexas por hibridação das unidades de 4-hidroxicumarina ou da lactona do ácido triacético com os novos derivados de cromonas polissubstituídas. Todos as reações foram executadas em condições suaves e ambientalmente favoráveis, utilizando a 4-pirrolidinopiridina como organocatalisador básico. As estruturas dos novos híbridos polifenólicos foram caracterizados por técnicas espectroscópicas de alta resolução, incluindo espectroscopia de ressonância magnética nuclear (1D e 2D) e por difractometria de raios-X, que nos permitiram resolver o complexidade estrutural dos compostos sintetizados. O quarto capítulo apresenta os resultados da avaliação biológica obtidos com os híbridos polifenólicos sintetizados neste trabalho, mostrando a possibilidade de seu envolvimento na terapia do cancro. A maioria dos compostos foram avaliados quanto ao seu efeito sobre a citotoxicidade e proliferação de células leucémicas e ao seu envolvimento na regulação de via pró-inflamatória NF-kB, na qual, os híbridos de biscumarinas exibiram actividades elevadas (IC50 = 6-19 μM para inibição de NF-kB depois de 8 horas de incubação e IC50 = 15-39 μM para efeitos citotóxicos em células cancerosas, após 24 horas de incubação). Uma inibição moderada das enzimas HDAC e Cdc25 foi induzida pelos derivados de benzofuran-3-ona-hidantoína. Catorze dos novos derivados polifenólicos polissubstituídos, tendo como estrutura básica a benzopiran-4-ona, foram avaliados pela sua actividade quimiopreventiva do cancro mediada pela indução de sinalização citoprotectora Nrf2 (fator 2 relacionado com o fator nuclear da proteína E2) e capacidade para inibir a proliferação das células de cancro da mama. Os derivados da classe das cromanonas foram identificados como os indutores mais potentes da actividade Nrf2. As concentrações necessárias para aumentar a actividade de luciferase em 10 vezes (C10) foram de 2,8-21,3 μM. Todos os novos híbridos polifenólicos que apresentam atividade citotóxica e anti-proliferativa não afectam o crescimento de células saudáveis periféricas do sangue (PBMC) (IC50 > 50 μM), indicando a sua seletividade para as células cancerosas e sugerindo que alguns deles são estruturalmente interessantes para posteriores análises. A avaliação da atividade antioxidante utilizando os testes do radical livre DPPH e o poder redutor do ião férrico FRAP foram realizados em algumas estruturas híbridas polifenólicas.
Polyphenolic compounds represent a class of secondary metabolites of plants, but there are also a great number of synthetic or semi-synthetic derivatives characterized by the presence of multiples phenol moieties. Polyphenolic compounds underlie a number of biological characteristics such as the metabolic and therapeutic properties which depends on their basic phenolic structure. Certain members of this class, like flavonoids, chromones and coumarins contribute to the therapeutic benefits of the human diet, they all share the benzopyran-(2 or 4)-one or benzofuran-3-one nucleus. The present dissertation includes a general introduction and three main chapters describing the new synthetic methodologies established for the production of new polyphenolic hybrids, their fine structural elucidation and their biological application in cancer therapy involving redox-regulation and inflammation pathways The second chapter discusses the preparation of pyrimidine- and imidazolidine- based polyphenolic hybrids, especially the diastereoselective synthesis of new benzofuran-3-one-hydantoin hybrids and uracil derivatives. The organic synthetic route starts by the organic/inorganic base-catalyzed action of carbodiimides on chromone-(2 and 3)-carboxylic acids in a one-pot reaction or sequential steps. The third chapter describes the application of basic organocatalysis in the 1,4-conjugate additions / heterocyclisations tandem processes of 1,3-dicarbonyls on chromone-3-carboxylic acid leading to novel polysubstituted- chromones, chromanones and flavones. The bispyranone scaffold [bispyran-(2 and 4)-ones] have been elaborated in a one-step coupling reaction of 4-hydroxycoumarin or triacetic acid lactone with chromone-3-carboxylic acid or formyl-functionalized precursors (ω-formyl-2’-hydroxyacetophenones and chromone-3-carbaldehydes). Finally, the application of the 1,4-conjugate addition approach is extended to a variety of 4-hydroxypyran-2-ones reacting with α,β-unsaturated ketones, including chalcones, to give the new warfarin-analogues. Also a variety of complex structures have been obtained by hybridizing 4-hydroxycoumarin or triacetic acid lactone units with the newly synthesized poly-substituted- chromones. All the above organic reactions proceeds in mild and environmentally friendly conditions using 4-pyrrolidinopyridine as basic organocatalyst. The structures of the novel polyphenolic hybrids have been characterized by high resolution spectroscopic techniques including extensive 1D, 2D-NMR and single-crystal X-ray diffractometry which largely helped to solve the structural complexity. The fourth chapter briefly introduces the biological screenings performed on the novel synthesized polyphenolic hybrids showing their possible involvement in cancer therapy. Most of the newly obtained molecules have been evaluated for their effect on cytotoxicity and proliferation of leukemic cell lines and their involvement in regulation of NF-κB pro-inflammatory pathway, in which the biscoumarin hybrids exhibited high activities (IC50 = 6-19 μM for NF-κB inhibition after 8 hours of incubation and IC50 = 15-39 μM for cytotoxic effects on cancer cell after 24 hours of incubation). Moderate inhibitions of HDAC and Cdc25 enzymes are noticed for the previously mentioned benzofuran-3-one-hydantoin candidates. Fourteen polysubstituted benzopyran-4-one based polyphenolics were examined for their cancer chemopreventive activity mediated by induction of cytoprotective Nrf2 (nuclear factor E2-related protein 2) signalling and their ability to inhibit proliferation of breast cancer cells. Derivatives of the chromanone class were identified as the most potent inducers of Nrf2 activity. The concentrations required to increase luciferase activity by 10-fold (C10) were 2.8-21.3 μM. All the new cytotoxic and anti-proliferative polyphenolic hybrids did not affect the growth of healthy peripheral blood mononuclear cells (PBMC) (IC50 > 50 μM), indicating their selectivity for cancer cells, which make some of them interesting lead structure for further analyses. Antioxidant activity evaluations using DPPH free radical scavenging and ferric ion reducing FRAP tests have been carried out on some underlined polyphenolic hybrid structures.
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Shikanga, EA, S. Combrinck, and T. Regnier. "South African Lippia herbal infusions: Total phenolic content, antioxidant and antibacterial activities." Elsevier, 2010. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001254.
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Lippia javanica and Lippia scaberrima are used as herbal remedies and are commercially traded as health teas in southern Africa under the
brands “Mosukujane” and “Musukudu”, respectively. This study evaluates the relationship between the presence of phenolic compounds and the
antioxidant activities of infusions prepared from four Lippia species (L. javanica, L. scaberrima, L. rehmannii and L. wilmsii) indigenous to South
Africa. The antioxidant activities of the infusions, determined by the 2,2-diphenylpycrylhydrazyl (DPPH) method, were also compared to those of
popular black, green and herbal tea brands. Of the four indigenous species, infusions of L. javanica and L. wilmsii exhibited the highest
antioxidant activities (EC50: 358 and 525 μg/ml, respectively) and contained the most phenolic compounds (14.8 and 14.5 mg/ml of dry weight
gallic acid equivalent, respectively). Antibacterial activities of methanolic extracts of the four Lippia species were determined against four human
pathogens (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa). The extract of L. javanica was the
most active against all the pathogens tested. Those Lippia species (L. javanica and L. wilmsii) previously reported to produce higher levels of the
pharmacologically active phenylethanoid glycosides verbascoside and isoverbascoside, portrayed stronger antioxidant and antibacterial activities.
This study gives credence to the use of infusions of these Lippia species for their general health benefits.
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Alansari, Wafa S. "Antioxidant and angiotensin converting enzyme inhibitory activities from bovine serum albumin." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/810091/.
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Bioactive peptides represent an important source of health promoting food. Therefore, the objective of this study was to identify the in vitro antioxidant and ACE inhibitory peptides derived from bovine serum albumin (BSA) and to characterise them after further purification. To achieve this objective, BSA was hydrolyzed with pepsin enzyme, fractionated by ultrafiltration using a 10 kDa molecular weight cut off membrane, and purified by gel filtration chromatography prior to characterisation. The total antioxidant activity was evaluated in a linoleic acid model system using the ferric thiocyanate (FTC) and thiobarbituric acid reactive species (TBARS) methods. The results indicated that gel filtration fraction number 18 exhibited the highest FTC antioxidant activity (65.4 %) compared to the (< 10 kDa) ultrafiltration fraction (44.8 %) and BSA hydrolysate (34.9 %) using a concentration of 1mg peptide/ml. However, the peptide activities were lower than those of 0.01 % butylated hydroxyanisole (69.9 %) and 0.01 % trolox (78.5 %) (P ≤ 0.05). Likewise, TBARS inhibition values were 42.8, 54.8, 76.7 and 84.4 % for BSA hydrolysate, < 10 kDa, BHA and trolox, respectively. The antioxidant activity of the (Mw < 10 kDa) peptide was demonstrated by strong free radical scavenging using the 1, 1-diphenyl-2-picrylhydrazyl (DPPH•), hydroxyl (OH•) and superoxide anion (O2-•); ferric (Fe3+) reducing and ferrous (Fe2+) metal ion chelating capacity and reducing power activity. A second gel filtration fraction number 22 exhibited the highest ACE inhibitory activity (79.5%) compared to the (10 kDa) ultrafiltration fraction (44.7%) and BSA hydrolysate (33.2 %) at a concentration of 10 mg/ml, with corresponding low IC50 values of 0.32, 0.56 and 0.75 mg/ml respectively compared to captopril (88.5%, P ≤ 0.05). The peptide (GF 18) at 1 mg/ml had no cytotoxic effect in epithelial caco-2 cells. Moreover, the presence of the peptide showed high cell viability (99.7%) and reduced malondialdehyde formation (27.7 µg/ml) compared with cells treated with 3mM t-BHP alone, which showed low cell viability (54.6%) and high MDA (30.3 µg/ml) (P < 0.01). BSA peptides protected t-BHP treated cells from caspase-dependent apoptosis; inhibited intracellular ROS production and increased glutathione level and SOD activity. Similarly, the GF 22 peptides (1 mg/ml) protected the endothelial EA.hy 926 against 3mM t-BHP damage and showed reduced mROS production by both lucigenin-enhanced chemiluminescence and the DHE fluorescence techniques. Additionally, the peptides reduced nitrite concentration and inhibited the activity of angiotensin converting enzyme in a dose dependent manner. This study reports novel findings showing that BSA peptides have antioxidant and ACE inhibitory activities that could potentially be used as food supplements and pharmaceutical agents.
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Biler, Michal. "Molecular insights in tracking optical properties and antioxidant activities of polyphenols." Thesis, Limoges, 2017. http://www.theses.fr/2017LIMO0001/document.
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Les polyphénols sont abondamment trouvés dans de nombreux fruits, légumes, boissons etc. et ils possèdent de nombreux effets bénéfiques pour la santé. Les méthodes de calcul ont été utilisées dans le cadre de cette thèse pour rationaliser, décrire et prédire les propriétés physiques et chimiques des flavonolignanes et des pyranoanthocyanines pour la compréhension de leurs actions biologiques au niveau moléculaire. Tous les résultats des calculs théoriques ont été discutés par rapport aux données expérimentales. Les propriétés liées à l'activité antioxydante des flavonolignanes ont été étudiées par les méthodes de la théorie de la densité fonctionnelle (DFT). La dépendance au pH des propriétés d'absorption UV/Vis des flavonolignanes et des pyranoanthocyanines ont été évaluée par des méthodes DFT dépendante du temps (TD-), et les interactions non-covalentes ont été étudiées avec les méthodes de DFT incluant la correction de dispersion. Un bref aperçu est également donné sur l'interaction de ces composés avec des biomolécules. Le chapitre 6 présente des résultats non encore publiés de plusieurs systèmes non-covalents pigment: copigment. Cette partie des résultats constitue un bon point de départ pour la recherche du ‘meilleur copigment’Polyphenols are abundantly found in many fruit, vegetables, beverages, etc. and they possess many potential health benefits. Computational methods were thoroughly used through this thesis to rationalize, describe and predict physical chemical properties of flavonolignans and pyranoanthocyanins. Here, we aim at an understanding of polyphenol biological actions at a molecular level. All outcomes from the theoretical computations were discussed with respect to experimental data. The properties related to antioxidant activity of flavonolignans were investigated by density functional theory (DFT) methods. The pH dependence of ultraviolet/visible (UV/Vis) absorption properties of flavonolignans and pyranoanthocyanins were evaluated by time dependent (TD-) DFT methods, and noncovalent interactions were investigated within dispersion-corrected DFT methods. A short overview is also given on interaction of such compounds with biomolecules. Chapter 6 presents yet not published results of several noncovalent pigment: copigment systems. This part of the results serves as a good starting point to search for ‘the best copigment’
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Amiri, Negar. "Antioxidant and angiotensin converting enzyme inhibitory activities of soya protein extracts." Thesis, University of Surrey, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616923.
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Soy protein isolate was hydrolysed with gastrointestinal enzymes, pepsin and pancreatin. The hydrolysate (SPH) was sequentiaUy fractionated using ultrafiltration (UF), gel filtration (GF) and high performance liquid chromatography (HPLC) and tested at each stage to select the bioactive fractions. All fractions were tested for antioxidant activity by the peroxide value and TBARS methods in a linoleic acid containing system. Compared to the untreated control the GF fraction (GFF36) significantly decreased (p < 0.05) TBARS production to 0.02 /-lg/ml like synthetic BHT. Further purification with HPLC did not improve the antioxidant activity (TBARS 0.13 /-lg/rnl). Investigation of the mechanism of antioxidant activity showed that SPH and the 2 kD fraction scavenged superoxide, hydroxyl radical and DPPH free radicals and chelated iron. SPH showed hydrogen peroxide scavenging activity. The 2, 5 and 10 kD fractions demonstrated copper chelating activity in a copper-pyridine pyrocatechol system. The 2 kD fraction also formed complexes with copper and catalysed ascorbic acid oxidation. Affinity chromatography purified fraction (P4 fraction) from SPH chelated copper. Additionally, 300 /-lg/ml P4 prevented copper dependent LDL oxidation (antioxidant activity 54.57%); however, this was less effective than the GFF 36 fraction which had 56.84 % antioxidant activity at only 10 /-lg/ml. All soya fractions exhibited ACE inhibitory activity, especially the UF and GF fractions containing smaller peptides. However, further purification by HPLC to three fractions (HPF15, 16 and 17) showed less activity than the parent GFF 57 fraction. The ACE inhibitory activity values for the SPH, 10 kD, 5 kD, 2 kD, GFF 57 and HPFs 15, 16 and 17 fractions were 17.70, 29.50, 43.66, 58.87, 84.68, 32.18, 44.07 and 20.86 % respectively. Fractions from soy protein isolate comprising potent peptides and possibly polyphenols demonstrated antioxidant, antihypeliensive and anticancer properties in vitro; these fractions could be developed further as neutraceuticals.
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Eskandrani, Areej. "Antioxidant and antiotensin converting enzyme inhibitory activities of egg albumen proteins." Thesis, University of Surrey, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658625.
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The present study investigated the in vitro antioxidant and ACE-inhibitory activities of egg albumen hydrolysate (EAR) prepared with pepsin and pancreatin enzymes. The EAR and peptides were purified by ultrafiltration (UF), gel filtration (GF), and High Performance Liquid Chromatography (HPLC) and tested for" antioxidant and ACE-inhibitory activities. Antioxidant activity was assessed by lipid peroxidation inhibition in a linoleic acid system using the ferric thiocyanate (FTC) and thiobarbituric acid reactive species (TBARS) methods. The EAR, and 2, 5 and 10 kDa UP fractions, as well as the GF26 peptide fractions (I mg/ml) inhibited linoleic acid autoxidation, by 40, 76, 63, 53 and 79 % respectively, which was inversely related to peptide fraction size. However, 0.01 % butylated hydroxytoluene (BHT) and 0.01 % trolox had higher activity (95 and 82 %, respectively) compared with the peptide fractions (p<0.05). Similarly, inhibition of TBARS was in the order 29, 39, 27, 17, 70 and 78 % for EAR, 2 kDa, ' 5 kDa, 10 kDa, trolox and BHT respectively. The putative antioxidant mechanism of EAR involved scavenging activity based on the I, l-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl (OH") and superoxide anion (02") radical scavenging assays, and ferric (Fe3+) reducing and ferrous (Fe2+) ion chelating activities in a dose-dependent manner. All peptide fractions exhibited ACE-inhibitory activity, based on the ACE-catalyzed liberation of hippuric acid from the hippuryl-L-histidyl-L-Ieucine residue, which improved on further GF and HPLC purification. The 2, 5 and 10 kDa peptides exhibited % ACE inhibitory activities of 78, 71 and 62 %, respectively, compared to the positive control captopril (96 %). The 2, 5 and 10 kDa peptides had ICso values of 6.01, 6.86 and 7.93 mg/ml respectively. Further, GF and HPLC purification of the 2 kDa peptides improved the ICso values to 5.76 and 5.13 mg/ml, respectively. Cell viability of human colon carcinoma mono-layer (caco-2) cell line, assayed by the tetrazolium dye (MTT) colorimetric assay confIrmed that the 2 kDa peptides were not toxic. The 2 kDa peptides (0.1 mg/ml) reduced most of the endogenous antioxidant enzyme activities in a dose-dependent manner, indicating scavenging of ROS. It was evident that a significant proportion of the 2 kDa peptides were resistant to cellular aminopeptidases present in caco-2 cell epithelium and were therefore transported in their intact forms across the caco-2 cell epithelium. In addition, The 2 kDa peptides exhibited significant ROS scavenging activity evidenced by enhanced viability of the Ea.hy926 (HUVECs) cell lines, using the lucigenin-enhanced chemiluminescent and fluorescence methods. The results confirm that bioactive peptides derived from the EAH have significant antioxidant and ACE·inhibitory activities and potentially useful neutraceutical applications.
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Guo, Yafang <1991>. "Kinetic and mechanistic studies on unconventional antioxidant activities of natural compounds." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9950/1/Yafang_Guo.pdf.
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In chapter one, the autoxidation kinetics of natural oil substrates, including, triglyceric sunflower oil, olive oil, terpenic squalene, and p-cymene were calibrated through differential oximetry methods. Calibration allows their use as reference oxidizable substrates for further studies, e.g. for quantitative testing of antioxidants under biomimetic settings. Several essential oils samples, of different botanical species or different productions of same species were studied for their antioxidant activity in inhibited autoxidation kinetics. Their antioxidant activities were matched with their composition analyzed by GC-MS.
In chapter two, the molecular mechanism of the synergy between the common phenolic antioxidants such as tocopherol and catechols with widespread essential component gamma-terpinene was studied through lipid oxidation kinetics. Wherein, gamma-terpinene was able to disclose the key intermediacy HOO·, which acted as a reducing agent regenerating the phenolic antioxidant. This counterintuitive role of HOO· radicals was further investigated in detail and allowed to rationalize for the first time the purported antioxidant behavior of PDA melanin nanoparticles. It will also open to a deeper understanding of the redox biology of quinones.
Regarding melanin, its role is broadly important in living organisms and its control, including its inhibition, is of great importance with several relevant applications ranging from food preservation to control of human skin pigmentation. In chapter three, an oximetry method combined with the traditional UV-Vis spectroscopy was developed to study the tyrosinase inhibition kinetics, which allowed identifying Glabridin (from G. glabra, L.), as one of the most effective natural tyrosinase inhibitors.
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Ghosal, Mitali. "Evaluation of antioxidant activities of some locally available edible plants of Darjeeling Himalaya." Thesis, University of North Bengal, 2014. http://ir.nbu.ac.in/hdl.handle.net/123456789/978.
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Hosseini-Beheshti, Elham. "Characterization of antioxidant activities from fruits rich in delphinidin or malvidin anthocyanins." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/912.
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Anthocyanins have been shown to possess specific antioxidant capacities, which
may provide an underlying protective effect against many chronic diseases . Although the
antioxidant capacity of anthocyanins has been well established, less is known about the
extent to which specific anthocyanin composition affects total antioxidant capacity . The
aim of the present study was to compare the antioxidant capacity of two different soft
fruits, blackcurrant and grape, which have distinctly different anthocyanin profiles.
The anthocyanin profiles of grape and blackcurrant were characterized by
HPLC/MS coupled with a diode array detector. Results showed that blackcurrant
contained four predominant anthocyanins, cyanidin 3-glucoside, delphinidin 3-glucoside,
cyanidin 3-rutinoside, and delphinidin 3-rutinoside . In contrast, malvidin 3-glucoside,
delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, and peonidin 3-
glucoside were the major anthocyanins found in grape . The concentration of individual
anthocyanins in all berries was quantified with HPLC/UV using cyanidin 3-glucoside as
an external standard . Finally, results showed a greater (p<0.05) antioxidant capacity of
blackcurrant compared to grape. The total antioxidant capacity of crude extracts from
each was measured by Oxygen Radical Absorbance Capacity (ORAC) and ABTS assays.
Anthocyanin antioxidant capacity index (AACI), derived from the product of
antioxidant (ORAC) activity for each of major anthocyanin present in blackcurrant and
grape, was also used to determine whether the antioxidant capacity of crude anthocyanin
fractions represents either the sum total anthocyanin content or, alternatively, a synergy
between different anthocyanins components . Our results indicated that a plausible
potential synergy between anthocyanin components in regards to ORAC antioxidant
capacity existed in blackcurrant and grape semi-purified anthocyanin extracts.
Furthermore, it could be concluded that both total anthocyanin content as well as
the composition of individual anthocyanins in soft fruits is important to assess total
antioxidant capacity of different berry sources .
15
Hubbe, Michelle E. (Michelle Elzabet). "Evaluation of antioxidant and free radical scavenging activities of honeybush tea (Cyclopia)." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51749.
Full text
16
Tierney, Michelle. "Investigation of macroalgal polyphenols and peptides with potential antioxidant and antihypertensive activities." Thesis, Bangor University, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664510.
Full textAbstract:
Macroalgal phlorotannins and peptides are increasingly being investigated for their health-promoting properties; however in-depth research into the occurrence, bioactivity, profiling and molecular properties of these components in Irish species is limited. The process by which bioactives are extracted and purified from their original biomass must be efficient and food-friendly to be applicable to the food industry. Two different extraction methods, solid-liquid extraction (SLE) and pressurised liquid extraction (PLE), were compared for the extraction of polyphenols from three brown macroalgae, Ascophyllum nodosum, Pelvetia canaliculata and Fucus spiralis, and a green macroalga, Ulva intestinalis. SLE was deemed to be a more industrially relevant technique for generating food-friendly antioxidant extracts than PLE as it requires less capital investment, is food-safe, and can be scaled up. Molecular weight cut-off (MWCO) fractionation and reverse-phase flash chromatography techniques were employed to enrich the polyphenol content of brown macro algal SLE extracts by removing predominantly sugars from the extracts. Furthermore, the use of bioassay-guided fractionation indicated that the observed antioxidant activities of the extracts could be attributed to the polar, medium-to-high molecular weight phlorotannins. The analytical quality control and standardisation of naturally-sourced functional extracts has become a requirement for their use in the food industry. In this work, a rapid ultra-performance liquid chromatography® (UP LC®) method was presented for the profiling of low molecular weight phlorotannin isomers for polymers up to 16 monomers in length from the three brown species. The predominant size ranges of the phlorotannins found in A. nodosum, P. canaliculata and F. spiralis were 6-11, 6-13 and 4-6 monomers, respectively. The identification of bioactive peptides has been largely unexplored. In this work, various peptides were isolated from a trypsin-digested Ascophyllum nodosum protein extract. A selection of peptides were synthesised and their in vitro antioxidant and antihypertensive activities assayed. The polypeptide EKTGLLNVVETAEKFL displayed the highest renin enzyme inhibition of 56.12 ± 2.66 % and this is the first report of renin inhibitory peptides identified from brown macro algae Computational chemistry may act as a support to natural products experiment, through the provision of data on the molecular properties of individual components and also on potential binding interactions between mixtures of bioactive components. Density functional theory was employed to theoretically determine the radical scavenging potential of various 7-phloroeckol conformers through the calculation of their O-H bond dissociation enthalpies. Furthermore, a molecular dynamics simulation approach was proposed for the investigation of binding interactions between a selected macro algal phlorotannin and a bioactive peptide from A. nodosum.
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Gomes, Ana Maria de Carvalhais Mendes. "Evaluation of the antioxidant and anti-inflammatory activities of synthetic 2-styrylchromones." Doctoral thesis, Faculdade de Farmácia da Universidade do Porto, 2008. http://hdl.handle.net/10216/20815.
Full text
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Gomes, Ana Maria de Carvalhais Mendes. "Evaluation of the antioxidant and anti-inflammatory activities of synthetic 2-styrylchromones." Tese, Faculdade de Farmácia da Universidade do Porto, 2008. http://hdl.handle.net/10216/20815.
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Lorenzo, Mazzoli. "Bioactive peptides from Italian sourdough: characterization of antioxidant and anti-inflammatory activities." Doctoral thesis, Università di Siena, 2018. http://hdl.handle.net/11365/1059850.
Full textAbstract:
Degradation of cereal proteins in peptides during sourdough fermentation may have important
repercussions on functional features of leavened baked goods. Protein degradation is due both to the acidification by lactic acid bacteria (LAB), which activate the flour proteases, and to the peptidases synthetized by this microbial population. Recent studies demonstrated the existence of peptides in sourdough that have a positive impact on human health (bioactive peptides). In particular, antioxidant peptides, that are able to prevent oxidative stress associated with numerous degenerative aging diseases (cancer and arteriosclerosis) and anti-inflammatory peptides. With the aim of identifying the LABs more effective in producing bioactive peptides, 131 different strains from Italian sourdoughs have been screened for peptidase activities. Among these, 23 strains were selected and singly inoculated in liquid sourdoughs from which a Low Molecular Weight fraction containing peptides was obtained. Characterization of the antioxidant and anti-inflammatory activity of the extracts has been performed on cultured cells by assaying ROS content, NF-kB/IkB expression level and IL-1β production. Four of the tested strains show high level antioxidant and anti-inflammatory activity, so we decided to characterize their peptides components using the modern mass spectrometry techniques. LAB able to release bioactive peptides could be used to develop starter cultures with functional features. As a result, four LAB strains have shown a high antioxidant and anti-inflammatory ability thus enabling the setting up of model sourdoughs to increase bread qualities.
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MAZZOLI, LORENZO. "Bioactive peptides from Italian sourdough: characterization of antioxidant and anti-inflammatory activities." Doctoral thesis, Università di Siena, 2018. http://hdl.handle.net/11365/1046554.
Full textAbstract:
Abstract:
Degradation of cereal proteins in peptides during sourdough fermentation may have important repercussions on functional features of leavened baked goods. Protein degradation is due both to the acidification by lactic acid bacteria (LAB), which activate the flour proteases, and to the peptidases synthetized by this microbial population. Recent studies demonstrated the existence of peptides in sourdough that have a positive impact on human health (bioactive peptides). In particular, antioxidant peptides, that are able to prevent oxidative stress associated with numerous degenerative aging diseases (cancer and arteriosclerosis) and anti-inflammatory peptides. With the aim of identifying the LABs more effective in producing bioactive peptides, 131 different strains from Italian sourdoughs have been screened for peptidase activities. Among these, 23 strains were selected and singly inoculated in liquid sourdoughs from which a Low Molecular Weight fraction containing peptides was obtained. Characterization of the antioxidant and anti-inflammatory activity of the extracts has been performed on cultured cells by assaying ROS content, NF-kB/IkB expression level and IL-1β production. Four of the tested strains show high level antioxidant and anti-inflammatory activity, so we decided to characterize their peptides components using the modern mass spectrometry techniques. LAB able to release bioactive peptides could be used to develop starter cultures with functional features. As a result, four LAB strains have shown a high antioxidant and anti-inflammatory ability thus enabling the setting up of model sourdoughs to increase bread qualities.
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Antonini, Silvia. "Antioxidant Activities of Clovamide and Curcumin on Undifferentiated Cells from Different Origin." Doctoral thesis, Università del Piemonte Orientale, 2017. http://hdl.handle.net/11579/102509.
Full textAbstract:
Il trapianto di cellule staminali è uno degli approcci terapeutici maggiormente studiati. La bassa sopravvivenza, il ridotto attecchimento e la limitata capacità di migrazione rappresentano i principali limiti nel successo di questo metodo. Uno dei fattori principali che contribuiscono a questi insuccessi è lo sviluppo di stress ossidativo. Per questo motivo, il pre-trattamento ex-vivo delle cellule destinate al trapianto, al fine di aumentare l’attivazione di pathways citoprotettivi, potrebbe dimostrarsi una strategia vincente. Il cacao e la il tumerico contengono, rispettivamente, clovamide e curcumina, due molecole note per il loro potenziale antiossidante e antiradicalico. Abbiamo quindi valutato l’effetto protettivo della clovamide, amministrata dopo l’induzione dello stress ossidativo con perossido di idrogeno, sulla linea H9c2 e su cellule progenitrici cardiache (CPCs) isolate da biopsie cardiache. La clovamide è in grado di inibire la produzione di specie reattive dell’ossigeno a l’attivazione dell’apoptosi (saggi Annessina V/PI, TUNEL, attivazione delle caspasi, perossidazione lipidica). Abbiamo quindi testato gli effetti del pre-condizionamento con clovamide o curcumina su cellule staminali mesenchimali m17.ASC, prima dell’induzione dello stress ossidativo. Entrambe le molecole sono in grado di proteggere le cellule dall’apoptosi indotta da perossido di idrogeno (saggio AnnessinaV/propidio ioduro) inibendo la fosforilazione di p53 e l’attivazione delle caspasi 3 e 9 e regolando l’espressione di geni coinvolti nella progressione del ciclo cellulare, nell’apoptosi e nella riduzione del danno radicalico. Inoltre le due molecole sono in grado di mantenere il potenziale proliferativo delle cellule sottoforma di sferoidi. Queste molecole possono quindi essere considerate una buona strategia per attivare pathway citoprotettivi prima del trapianto, che possano permettere una maggiore sopravvivenza e resistenza allo stress ossidativo delle cellule staminali.
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Shai, LJ, JN Eloff, N. Boaduo, AM Mogale, SR Magano, MP Mokgotho, and 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.
Full textAbstract:
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.
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Li, Jumg-shuen, and 李榮憲. "The antibacterial and antioxidant activities of Cinnamomin." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/40823934171828049699.
Full textAbstract:
碩士義守大學
生物技術與化學工程研究所碩士班
97
The misuse of antibiotics in hospitals causes serious nosocomial infections by drug-resistant pathogens. The continued search for new, effective antibacterial agents is therefore very important. The use of Cinnamon as a preservative and for medicinal purposes has a long history. The aim of this study is to compare the antibacterial and antioxidation activity of supercritical fluid and ethanol extracts from different parts of the Cinnamon plant (branches, bark, buds, and leaves）, and to identify effective antibacterial and antioxidation constituents in the herbal medicine. The supercritical fluid extraction was performed at 600 bar and 45℃, with a separator pressure of 45 bar, and the extracts collected at different time intervals. The ethanol extracts were obtained by gently shaking with a 95％ ethanol solvent. After that, an antibacterial and antioxidation assay was conducted using each of the Cinnamon extracts. Based on the antibacterial results obtained by the disc diffusion method and the minimum inhibitory concentration (MIC), the supercritical fluid extracts displayed better antibacterial activity than the ethanol extracts. The supercritical fluid extracts exhibited good activities against the test microorganisms with minimal inhibitory concentrations of 0.3-0.6 mg/mL. Furthermore, the results from the time-kill assay revealed that the active extracts and (E)-cinnamaldehyde completely killed the test organisms within 4 hours. The exposure of the test strains to a sub-MIC level of the active extracts for ten consecutive subcultures did not induce resistance to the active components. The major active compound in the cinnamon extracts was determined by GC-MS analysis to be predominantly a volatile oil component, (E)-cinnamaldehyde. Based on the antioxidation results, each part of the Cinnamon supercritical fluid and ethanol extracts in DPPH scavenging effects assay of IC50 has shown 0.562-10.090 mg/mL and 0.072-0.208 mg/mL, respectively. The total flavonoid content (TFC) was shown to be 0.031-1.916 g/ 100g DW and 2.030-3.348 g/ 100g DW. The total phenolics contents (TPC) was 0.151-2.018 g/ 100g DW and 6.313-9.534 g/ 100g DW. The trolox equivalent antioxidant capacity (TEAC) was 6.789-58.335 mg trolox/g and133.039-335.779 mg trolox/g respectively. The results of this study indicate that the antioxidation constituents of Cinnamon are of a highly polar composition, and that extraction with ethanol is more suitable than supercritical fluid extraction.
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Young, Ya-Lu, and 楊雅露. "Antioxidant and Hypolipidemic Activities of Buckwheat Sprouts." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/33135498862967120259.
Full textAbstract:
碩士弘光科技大學
生物科技研究所
95
Buckwheat, a traditional carbohydrate food stuffs containing relatively high amount of rutin and quercetin, long has been known to be very beneficial to cardiovascular disease preventions. In this study, we examined the germination time vs. functionality profile of buckwheat with respect to contents of rutin, quercetin, total polyphenolics and ascorbic acid. The ethanolic extracts of non germinating seeds and sprouts (on day 4, 8, 10, and 14) were evaluated by their overall antioxidant abilities. The parameters included the DPPH radical scavenging capability (DRSC), the ferrous ion chelating capability (FICC), the thiobarbituric acid reacting substance (TBARS) and the peroxide values (POV). The sprouts on day 8 was found to be the most potent among all. Animal Model I intended to investigate the different effects between the non germinating seeds and the day 8-sprouts on serum and liver lipid profile in hamsters. While Animal Model Ⅱ was aimed at the effect of day–8 sprouts on the damages caused by high fat and high cholesterol in the male hamsters. The contents of total polyphenolics, rutin and quercetin were found to reach the peak contents 693.77 mg, 174.29 mg, and 4.39 mg/100g, respectively, in the day-8 old sprouts. The unsaturated linoleic and linolenic acid all increased with germination. As seeding days progressed, the contents of monosaccharide (fructose and glucose) in buckwheat sprouts were markedly increased, while disccaharides were rapidly decreased. In antioxidant tests using the ethanol extract of dry day-8-sprouts showed the highest capability: DPPH radical scavenging capability raching 89.27%; the malondialdehyde inhibitory effects 66.54%; with the ferrous ion chelating capability approaching 61.67%. In addition, the ferric thiocyanate method had revealed that the ethanol extract of dry day-8-sprouts had a higher peroxide inhibitory effects than the buckwheat seeds and day-4 , day-10 and day-14 sprouts with respect to linoleic acid peroxidation. Animal study Ⅰ was designed to investigate the difference of effect between the buckwheat seeds and the day-8-sprouts on serum lipids. Thirty-six hamsters were randomly divided into 6 dietary groups and fed on the following diets：the control group (C), the high-fat high-cholesterol (H), the buckwheat seed (2.5%) group, the buckwheat seed (25%) group, the buckwheat sprout (2.5%) group, and the buckwheat sprout (25%) group, all fed on a basic high-fat high cholesterol diet. Results demonstrated that ingestion of 2.5% or 25% buckwheat seeds, or sprouts all significantly reduced the levels of serum total cholesterol and low-density lipoprotein-cholesterol (LDL-C), with reduced the LDL-C/HDL-C and TC/HDL-C ratios. Apparently, buckwheat sprouts had more marked effect than the buckwheat seeds. However, levels of high-density lipoprotein-cholesterol was totally unaffected in this treatment. As contrast, 25% buckwheat day-8 sprout diet could have reduced the liver triglyceride levels, but not by the 2.5% and 25% buckwheat seed diets or 2.5% buckwheat sprout diets. Moreover, intake of 2.5% or 25% buckwheat seeds, and sprouts diet also reduced the ratio of the liver to body weight ratio. Supplementation with 2.5% or 25% buckwheat seeds, and sprouts diet could reduce liver cholesterol, at unlikely having any effect on triglyceride levels (p>0.05). Animal study Ⅱ was figured out to examine the effect of buckwheat the day-8-sprouts on serum lipids. Data revealed that 1%, 3%, and 5% buckwheat sprouts diets significantly reduced the levels of triglyceride and low-density lipoprotein-cholesterol (LDL-C) levels. High-density lipoprotein-cholesterol levels were not affected in this manner. As contrast, 3% or 5% buckwheat day-8 sprout diet could have reduced the blood total cholesterol levels（p<0.01）, but not by the 1% buckwheat sprout diets. Similarly, intake of 1%, 3%, and 5% of day-8 buckwheat sprout diet also reduced the levels of liver total cholesterol（p<0.05）, at unlikely having any effect on triglyceride levels and ratio of the liver to body weight ratio (p>0.05). . In conclusion, buckwheat exhibited rather potent antioxidant and lipemia-reducing activities. Day-8 buckwheat sprouts had a better effect than the non germinating seeds.
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Tsai, Jenn-Yi, and 蔡振義. "Antioxidant and anti-inflammatory activities of Physalis peruviana." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/50653715158142689655.
Full textAbstract:
碩士嘉南藥理科技大學
生物科技系暨研究所
94
Physalis peruviana L. (PP) is a medicinal herb widely used in folk medicine. Supercritical fluid extraction/carbon dioxide (SFE-CO2) method was employed to obtain three different PP extracts, namely SCEPP-0, SCEPP-4 and SCEPP-5. The total phenol and flavonoid concentrations, as well antioxidant and anti-inflammatory activities of these extracts were analyzed and compared them with aqueous and ethanolic PP extracts. Among all the extracts tested, SCEPP-5 demonstrated the highest total phenol (90.80±2.21 mg/g) and flavonoid (234.63± 9.61 mg/g) contents. At concentrations 0.1 to 30 μg/mL, SCEPP-5 also demonstrated the strongest superoxide anion scavenging activity and xanthine oxidase inhibitory effect. At 30 μg/mL, SCEPP-5 significantly prevented lipopolysaccharide (LPS)-induced cell cytotoxicity in murine macrophage (Raw 264.7) cells. At 10~50 μg/mL, it also significantly inhibited LPS-induced NO release and PGE2 formation in a dose-dependent pattern. SCEPP-5 at 30 μg/mL remarkably blocked the LPS induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. Taken together, these results suggest that SCEPP-5, an extract of SFE-CO2, displayed the most potent antioxidant and anti-inflammatory activities. It protection against LPS-induced inflammation could be through the inhibition of iNOS and COX-2 expression.
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"Antioxidant and antiproliferative activities of flower tea extracts." 2007. http://library.cuhk.edu.hk/record=b5896541.
Full textAbstract:
Leung, Yu Tim.Thesis submitted in: November 2006.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (leaves 103-128).
Abstracts in English and Chinese.
Thesis Committee --- p.i
Acknowledgements --- p.ii
Abstract --- p.iii
摘要 --- p.iv
Table of Contents --- p.v
List of Tables --- p.ix
List of Figures --- p.x
Abbreviations --- p.xiii
Chapter 1. --- Introduction
Chapter 1.1 --- Flower herbal teas --- p.1
Chapter 1.2 --- R. rugosa --- p.3
Chapter 1.2.1 --- The phytochemistry of R. rugosa --- p.3
Chapter 1.3 --- Secondary metabolites --- p.4
Chapter 1.4 --- Classification of secondary metabolites --- p.6
Chapter 1.5 --- Phenolic compounds --- p.6
Chapter 1.5.1 --- Phenylpropanoid compounds --- p.6
Chapter 1.5.2 --- Lignins --- p.7
Chapter 1.5.3 --- Coumarins --- p.7
Chapter 1.5.4 --- Stilbenes --- p.8
Chapter 1.5.5 --- Tannins --- p.8
Chapter 1.5.6 --- Flavonoids --- p.9
Chapter 1.6 --- Oxidative Stress --- p.13
Chapter 1.6.1 --- Diseases related to ROS --- p.13
Chapter 1.6.2 --- Significant chemical or biochemical conversion of ROS --- p.14
Chapter 1.6.3 --- Sources of ROS --- p.15
Chapter 1.7 --- Natural dietary antioxidants --- p.15
Chapter 1.7.1 --- Vitamin C --- p.15
Chapter 1.7.2 --- Vitamin E --- p.16
Chapter 1.7.3 --- Carotenoids --- p.16
Chapter 1.7.4 --- Phenolic compounds --- p.16
Chapter 1.8 --- Cancinogenesis --- p.17
Chapter 1.9 --- Cell cycle --- p.18
Chapter 1.9.1 --- Cell cycle of eukaryotic cells --- p.18
Chapter 1.9.2 --- Checkpoints of cell cycle --- p.18
Chapter 1.10 --- Cancer cell lines --- p.19
Chapter 1.11 --- The growth phases of cancer cell lines --- p.20
Chapter 1.12 --- Antiproliferative effects of phenolic compounds --- p.21
Chapter 1.13 --- Genotoxicity of phenolic compounds --- p.22
Chapter 1.14 --- Objectives --- p.23
Chapter 2. --- Methods and Materials
Chapter 2.1 --- Extraction of active substances --- p.40
Chapter 2.2 --- Determination of antioxidant activities TEAC assay --- p.40
Chapter 2.3 --- Determination of hydroxy 1 radical scavenging activity by the deoxyribose assay --- p.41
Chapter 2.4 --- Determination of phenolic contents by Folin´ؤCiocalteu assay --- p.43
Chapter 2.5 --- Determination of total flavonoid by aluminum chloride colorimetric method --- p.43
Chapter 2.6 --- Determination of oxidative DNA damage by comet assay --- p.44
Chapter 2.7 --- Cell lines propagation --- p.49
Chapter 2.8 --- Determination of antiproliferative activities by MTT assay (colorimetric) --- p.50
Chapter 2.9 --- Determination of antiproliferative activities by BrdU labeling assay --- p.52
Chapter 2.10 --- Cell cycle analysis by flow cytometry --- p.55
Chapter 2.11 --- Determination of genotoxicity by SOS chromotest --- p.57
Chapter 3. --- Results
Chapter 3.1 --- Dermination of antioxidant activities by TEAC assay --- p.59
Chapter 3.1.1 --- Trolox Standard Reference --- p.59
Chapter 3.1.2 --- TEAC of the seven flower extracts --- p.59
Chapter 3.2 --- Hydroxyl radical scavenging activity by deoxyribose assay --- p.60
Chapter 3.3 --- Determination of phenolic contents by Folin´ؤCiocalteu assay --- p.60
Chapter 3.4 --- Determination of total flavonoids by colorimetirc aluminium chloride assay --- p.61
Chapter 3.5 --- "The Inter-correlation between the antioxidant activities, total phenolic and flavonoid contents of flower extraction powders" --- p.61
Chapter 3.6 --- Determination of oxidative DNA damage by comet assay --- p.62
Chapter 3.7 --- Determination of antiproliferative activities by MTT assay --- p.63
Chapter 3.7.1 --- Antiporoliferative activities on HepG2 --- p.63
Chapter 3.7.2 --- Antiproliferative activities on MCF7 --- p.63
Chapter 3.7.3 --- IC50 of R. rugosa extract on both HepG2 and MCF7 --- p.64
Chapter 3.8 --- "The Inter-correlation between antioxidant activities, total phenolic contents, flavonoid contents, and the antiproliferative activities of flower extraction Powders" --- p.64
Chapter 3.9 --- Determination of DNA synthesis by BrdU labeling analysis --- p.65
Chapter 3.10 --- Cell cycle analysis by flow cytometry --- p.65
Chapter 3.11 --- Determination of genotoxicity by SOS chromotest --- p.66
Chapter 4. --- Discussions
Chapter 4.1 --- Extraction method --- p.90
Chapter 4.2 --- Comparison of TEAC of the dry flowers with other foods --- p.90
Chapter 4.3 --- Correlation between ABTS+ and hydroxyl scavenging ability of flower extraction powder --- p.91
Chapter 4.4 --- Comparison of phenolic contents of the fry flowers with other foods --- p.92
Chapter 4.5 --- Correlation between total phenolic contents and flavonoid contents of flower Eextraction powders --- p.92
Chapter 4.6 --- "Correlation between total phenolic, flavonoid content and antioxidant activities of flower extraction powders" --- p.93
Chapter 4.7 --- Factors affecting the antioxidant power besides total phenolic contents --- p.94
Chapter 4.8 --- Synergistic effect of phenolic compounds --- p.94
Chapter 4.9 --- Toxicity of drinking flower herbal tea --- p.95
Chapter 4.10 --- Recommended dose of flower herbal teas --- p.96
Chapter 4.11 --- Antiproliferative activities of flower extracts by MTT assay --- p.97
Chapter 4.12 --- Antiproliferation activities of flower extraction Powders by Brdu labeling assay --- p.98
Chapter 4.13 --- Protective effects of flower extraction powder on oxidative DNA damage determined by comet assay --- p.99
Chapter 4.14 --- Cell cycle analysis --- p.100
Chapter 4.15 --- Further Studies --- p.101
Chapter 5. --- Conclusion --- p.102
Chapter 6. --- References --- p.103
27
chang, cheng-mei, and 張婙梅. "Evaluating the antioxidant antityrosinase activities of Trachelospermum Jasminoides." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/00287733303751909274.
Full textAbstract:
碩士嘉南藥理科技大學
化妝品科技研究所
99
The antioxidant and antityrosinase activities of crude ethanolic extract and its fractions isolated by liquid-liquid extraction using ethyl acetate and water of Transchelospermum jasminoides were determined. The antioxidant activities were carried out using different in vitro assays including the inhibition of DPPH and ABTS radials, reducing power, and the inhibition of lipid peroxidation. Among these extracts, the ethyl acetate layer displayed the highest antioxidant and antityrosinase activities. In addition, these extracts were further fractionated by silica gel 60 and Diaion HP 20 columns into thirteen subfractions (EA1-EA6 and W1-W7). The third fraction of water (W3) is the most efficient in DPPH and ABTS inhibition assay. At 200 ppm, the scavenging activity in DPPH assay is 91.9% and ABTS is 90.1%. The reducing power of W3 at 200 ppm is equal to that of 34 ppm vitamin C. The total phenol content of W3 is equal to 158.8 mg gallic acid and the total flavonoid content is equal to 99.8 mg rutin. The most active sample in inhibiting lipid peroxidation and tyrosinase is the second fraction of ethyl acetate (EA2). At 200 ppm, the inhibitory effect on lipid peroxidation is 90.1%. At 1000 ppm, the inhibitory effect on tyrosinase is 86.8%. In conclusion, the antioxidant and antityrosinase activities in the extracts of Trachelospermum jasminoides can play an important role in antioxidation and whitening products.
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Chanbai, Chapiya, and 張萍亞. "Antioxidant activities of lactic acid bacteria fermentedlemon juice." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/38915206386301197941.
Full textAbstract:
碩士國立屏東科技大學
食品科學國際碩士學位學程
103
Lemon (Citrus limon (L.) Burms. f) juice containing phenolic compounds (10.75 mg garlic acid equivalent (GAE)/g) particularly flavonoids (0.57 mg/100g) have been reported to possess an important antioxidant activity toward radicals which can scavenge reactive oxygen species (ROS). In this study, lactic acid bacteria (LAB) stains were isolated and purified from Kimchi base on physiological characteristic and the phylogenetic of 16S rRNA sequence analysis and TA cloning sequences to typing stains. The results from analysis were identified as Lactobacillus plantarum, Lactobacillus casei, Lactobacillus acidophilus, Pediococcus pentosaceus by comparison in blast database with 100% similarity coefficient. Four different strains were used as starter cultures, change in pH, acidity, sugar consumption, viable cell count during fermentation and antioxidant properties were monitored. The amounts of glucose decreased significantly (P<0.05), meanwhile the fructose concentration did not change. All LAB strains were able to grow in the juice and their viable cell reached to 7.0 log CFU/ml after 72 h at 30oC. The results showed that pH were significantly decreased during the fermentation. Fermentation of lemon juice with LAB was reported higher the level of flavonoid and phenolic content. With regard DPPH radical scavenging activity, trolox equivalent antioxidant activity capacity and reducing power studied show that the fermentation of lemon juice using selected probiotic starters increased the antioxidant activity significantly, and the highest antioxidant activities were found in Lactobacillus plantarum fermentation. The results of this study showed that fermentation of Lemon juice by probiotic bacteria would enhance health benefit of the juice.
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YANG, SHU-TING, and 楊舒婷. "The antioxidant and whitening activities of Cistanchedeserticola Extract." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/15921893717820851378.
Full textAbstract:
碩士南臺科技大學
生物科技系
105
Cistanche deserticola is a worldwide genus of holoparasitic desert plant, and major distributed in Asian countries. The phenylethanoid glycosides (PhGs) are the major bioactive compounds of C. deserticola which showed the diverse pharmacological activities such as neuroprotective, anti-inflammatory, immunomodulatory, antioxidant, antibacterial and antitumor effects. In this study, we compared ultrasonic and general extraction with different concentrations of alcohol to extract PhGs and investigated the biological activities of PhGs including antioxidant and whitening capacity. The results showed that the highest concentration of PhGs that extract from dried C. deserticola with ethanol under mild condition was 29.8 mg PhGs/g cistanche deserticola extract. In the antioxidant capacity, the EC50 concentration of ABTS and DCFH-DA methods were 1.42 mg /mL and 6.39 mg /mL from the extract of C. deserticola, respectively. The IC50 concentration of inhibited melanoma cells and tyrosinase activity assay was 1.60 mg/mL and 11.47 mg /mL from the extract of C. deserticola, respectively. The 1.25 mg/mL extract of C. deserticola treated the melanoma cells can reduce 25% of the production of melanin during 72 hours. We confirmed that the extract of C. deserticola showed excellent whitening and antioxidant capacity.
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Hsu, Wei-Ning, and 許惟寗. "Anti-inflammatory and Antioxidant Activities of Dendropanax dentiger." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/54474722211379478022.
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碩士國立中興大學
森林學系所
101
14 species of Araliaceae plants grown in Taiwan were collected and studied on their antioxidant, anti-inflammation, anti adipogenesis and cytotoxic activities. The results indicated that the EtOH extracts of Eleutherococcus trifoliatus and Schefflera octophylla possesses the strongest antioxidant activity in DPPH scavenging assay, respectively；and the extract of Dendropanax dentiger is less active. Meanwhile, Aralia cordata possessed the strongest cytotoxicity among the examed plants. It exhibited potent cytotoxicity against human hepatoma and human breast cancer cell. As regarding to anti-inflammation activity, Dendropanax dentiger exhibited significant anti-inflammatory activity, which could totally inhibit the expression of NO production by microphages at the dosage of 20 μg/mL. One bioactivity compound named (9Z,16S)-16-hydroxy-9,17-octadecadiene-12,14-diynoic acid (HODA) was isolated from the leaves of Dendropanax dentiger by using bioactivity guided fractionation protocol. The structure of HODA was identified using spectral analysis. Meanwhile, our data indicated that HODA significantly inhibited the production of NO in LPS-induced RAW 264.7 murine macrophage cells. Consistent with these observations, the mRNA and protein expression levels of iNOS was also inhibited by HODA in a dose-dependent manner. HODA also reduced the translocation of NF-κB in to nuclear induced by LPS, which is associated with the prevention of the degradation of I-κB, and subsequently decreased p65/p50 protein levels in the nucleus. On the other hand, HODA enhanced Nrf-2 activation and its downstream antioxidant gene HO-1. The anti-inflammation compound, HODA, also revealed the antioxidant effect on RAW264.7 cell after alcohol-induced oxidative damage.
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Huong, Phuong Thi, and 芳氏香. "Antioxidant and α-Amylase Inhibitory Activities ofKombucha Tea." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/m47vc8.
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碩士國立虎尾科技大學
生物科技研究所
102
Kombucha tea (Kt) was made from black tea with sucrose addition fermented by local commercial tea fungi, actually a symbiosis of acetic acid bacteria and yeasts. The effects of bacterial cellulose pellicle volumes (3%, 5%, and 10% w/v defined as S-3, S-5, and S-10, respectively) and fermentation time (0, 3, 6, 9, 12, 15, 18, 21 days) on ethanol and sugar contents, organic acids, antioxidative and α-amylase inhibitory activities of Kts were investigated in this study. The pH value and total acidity of Kts decreased and increased, respectively, with increasing fermentation time. The highest ethanol contents for S-3, S-5, and S-10 were 0.83%, 0.63% and 1.02%, obtained from the 15th day, 12nd day and 18th day fermentation, respectively. The sucrose contents of Kts decreased with increasing fermentation time. The corresponding values for S-3, S-5, and S-10 after 21 days fermentation were 5.95, 4.88 and 5.34 g/L, respectively. Acetic acid was the major organic acid with values were 10.47, 9.51 and 6.93 g/L for S-3, S-5, and S-10, respectively, obtained from the last day fermentation. In addition, DPPH scavenging activity for all the Kts samples was over 90%. The total phenolic contents defined as GAE (gallic acid equivalent) were increased with fermentation ii time up to the highest values (0.93, 1.03 and 1.00 g GAE/L for S-3, S-5 and S-10, respectively) at the 21st day fermentation. The reducing power of Kts was increased with fermentation time at the first 9 days and then decreased. The highest reducing power (defined as vitamin C equivalent, Vit.CE) for S-3, S-5, and S-10 were 1.48, 1.57 and 1.55 g Vit.CE/L, respectively, obtained at the 9th day fermentation. Moreover, the highest values of α-amylase inhibitory activity for S-3, S-5, and S-10 were 67.55%, 69.69% and 65.41%, respectively, also obtained at the 9th day fermentation. Inclusion, addition of 5% (w/v) bacterial cellulose pellicle could be the most suitable starter for Kombucha tea made from black tea with sucrose addition fermented by tea fungi.
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Lin, Fong-Yun, and 林鳳芸. "Effect of Different Drying Methods on Antioxidant Compounds and Antioxidant Activities of Banana Inflorescence." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/81765896964753718025.
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碩士大仁科技大學
食品科技研究所
99
Banana (Musa sapientum) is one of important fruits in Taiwan. Because banana inflorescence will consume some nutrients during banana growth period, it is usually cut off as a fertilizer or a culinary ingredient. However, study on banana inflorescence is very rare so far. The aim of this study was to investigate the characteristics of anthocyanin in banana inflorescence and its stability after drying. The banana inflorescence was supplied by Taiwan banana research institute. The banana inflorescence was divided into two parts: bract and male flower. After different drying treatments, the pattern of anthocyanidins was determined by HPLC. The contents of β-carotene and lycopene were analyzed by LC/MS/MS. Total anthocyanin, monomeric and polymeric anthocyanins, caroteniod, polyphenol and flavonoid were measured by spectrophotometer. Antioxidant activities included DPPH radical-scavenging ability, reducing power, inhibition of lipid peroxidation and superoxide radical scavenging ability. The results showed that the contents of polyphenols and flavonoids in banana inflorescence decreased after drying treatments. The contents of polyphenols and flavonoids in banana bract treated by 55℃ hot-air and freeze drying were higher than that by 80℃. Both polyphenol and flavonoid contents of male flower obviously decreased by increasing drying temperature. It was found that more carotenoids and β-carotene remained in banana inflorescence after 55℃ hot-air drying than other drying methods. In this result, fresh banana inflorescence (bract and male flower) had higher content of total anthocyanins than dried inflorescence. The kinds of anthocyanidin in bract and male flower were different. The major anthocyanidin in bract and male flower was cyanidin and delphinidin, respectively. The color of banana bract was tending to dark red with increasing the total anthocyanin. The antioxidant activities of banana bract and male flower dried at 55℃ were better than that at high temperature (80℃). Scavenging activity of DPPH radical of banana inflorescence dried at 80℃ was lower than other drying treatments. Reducing power of bract treated by 55℃ hot-air and freeze-drying conditions was better than that by other drying temperatures. At high concentration (1000 ppm), male flower dried at 30℃ had the highest reducing power and the reducing power was the lowest at 80℃. Banana bract and male flower at 55℃ had better inhibition of lipid peroxidation. It was found that the contents of anthocyanins, polyphenols and carotenoids were significantly positive correlations with antioxidant activities. Between flavonoid content and antioxidant activities of male flower were significantly correlated. Since banana inflorescence has high moisture content, drying can extend its shelf life. This study suggests that either freeze-drying or 55℃ hot-air drying can be used as drying condition. Anthocyanin, antioxidant compound and antioxidant activity of banana inflorescence were obviously decreased by long time at low temperature (30 ℃) and short time at high temperature (80 ℃).
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Yu, Kuo-Hua, and 余國華. "The antioxidant and hepatoprotective activities of Terminalia chebula Retz." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/40534016571451404254.
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碩士高雄醫學大學
天然藥物研究所
88
英 文 摘 要 Kezi is a chinese crude drug, derived from the dried ripe fruits of Terminalia chebula Retz.(Combretaceae). In literature record, this crude drug has anti-microorganism, anti-atherosclerosis, anti-mutagenicity, anti-viruses, anti-diarrhea, and anti-inflammation. In the present study, it is believed that atherosclerosis, mutagenicity, inflammation is related with excess free radical in body. To evaluate the pharmacological effects of this crude drug, the following studies will be made: 1.Cytochrome C test 2.Xanthine Oxidase inhibition test (X. O. I. test) 3.FeCl2-Ascorbic acid test. 4.Electron spin resonance (ESR) Besides, we also evaluate the hepatoprotective activity of this crude drug. The results showed that Terminalia chebula Retz. has good antioxidation activity. In TBA test, the IC50 values for six fractions and three compounds were 4.05-8.97 mg/ml and 6.08×10-3-3.17×10-2 M, respectively. In X.O.I. test, the IC50 values for six fractions and four compounds were 4.77×10-1-2.42 mg/ml and 5.96×10-5-2.69×10-3 M, respectively. In cytochrome C test, the IC50 values for six fractions and four compounds were 4.49×10-3-2.11×10-2 mg/ml and 3.61×10-6-3.32×10-4 M mg/ml, respectively. In ESR test, the IC50 values for six fractions and four compounds were 3.01-30.11μM. In hepatoprotect test, the IC50 values for five fractions were 1.2-1.963 mg/ml. The results show that Terminalia chebula Retz. has free radical scavenge activity, free radical formation inhibition , anti-lipid peroxidation and hepatoprotective activity.
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Tseng, Ai-Lin, and 曾愛琳. "Analysis of the antioxidant activities of vegetable soybean varieties." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/18204752568647822800.
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碩士嘉南藥理科技大學
生物科技系暨研究所
94
Vegetable soybean is a rich source of vitamin , carbohydrates, protein and iron. The seeds of vegetable soybeans are larger, sweeter and more tender than grain soybean. Frozen vegetable soybeans are popular in supermarkets of Japan and Taiwan.The TNAV2 is a new vegetable soybean variety which has high yields and good quality . In this study，we used different species of soybean seeds and sprouts to analyze the antioxidant activities as compared with TNAV2。The antioxidant activities were evaluated by : 1)total phenolic compounds, 2) the 2-thiobarbituric acid （TBA）method 3)reducing power, 4)DPPH free radical scavenging metal, 5)chelating activities and 6) The ferric thiocyanate FTC method . Our results showed that both of the black bean seeds and sprouts of TN3 had the best antioxidant activity.The TNAV2 had good antioxidant activity in reducing power，TBA method and metal chelating activities. Selenium (Se) is incorporated into proteins to make selenoproteins, which are important antioxidant enzymes such as glutathione peroxidase (GPX). The antioxidant properties of selenoproteins help prevent cellular damage from free radicals. Selenium fertilizer with different concentration for foliar-applied to determine the effects of the antioxidant capability of selenium-enriched soybean seeds and sprouts，but these results were not dose-dependent.
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Chung, Te-Tsuen, and 鍾德村. "Study on Antioxidant Activities of Purple Rice Wine Dregs." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/90603807476523894795.
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碩士大葉大學
生物產業科技學系碩士在職專班
97
The purpose of this study is to investigate the effects of pretreatment and fermentation time on the Hunter's L, a, b, pH values and antioxidant capacity of the liquor dregs of purple wine produced in Yunlin, Taiwan. It is expected to improve the utilization of purple wine dregs. The results showed that the wine brewed from smashed purple rice produced higher ethanol concentration. The alcohol increased with the increase in fermentation time. Extraction rate of ethanol were 13.9% and 4.1% for smashed group and non-smashed group respectively. The pH values were lower for 0 and 10% ethanol extraction of non-smashed group. Hunter's L value (23.30± 0.19) for 70% ethanol extraction of the smashed group was significantly lower than that of other concentrations (0%, 10%, 95%) and non-smashed group. Hunter's a value (2.25 ± 0.30) for 70% ethanol extraction of the smashed group was significantly higher than that of other concentrations (0%, 10%, 95%) and non-smashed group. The b value of 95% ethanol extract of three weeks fermentation wine of smashed group showed the maximum of 1.99 ± 0.20. Antioxidant capacity in 70% ethanol extract had a better effect of 81.8％ scavenging rate at a low concentration (125 μg / mL). As for the non-smashed group, 70% ethanol extract also showed the best performance. of treatment group, in the concentration 125 μg / mL when to remove the best, The removal rate reached 80.9 ％ at the concentration 125 μg / mL. However, the rates for other concentrations (0,% 10%, 95%) were worse than the smashed group. The free radical scavenging effect increased with the amount of purple rice wine dregs extracts added.
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Hsu, Ting-Hung, and 徐定宏. "Antioxidant Activities and Related Compounds of Yam and Bulbils." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/15505325062827086073.
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碩士國立宜蘭大學
食品科學系碩士班
96
The purpose of this study was to evaluate the antioxidant activity and related compounds in yams and bulbils of three specis, I-Lan, Keelung, and Hualian. Furthermore, the changes of antioxidant activity and its constituents during cooking process were also investigated The results showed that the yield of different extracts from yams and bulbils were in the order of Water>MeOH> EtAc. The highest yield of extract from Hualian yams and bulbils were observed, The DPPH radical scavenging effect, reducing power, and chelating Fe2+ ability of yams and bulbils increased, while the concentration of extract increased also. However, inhibition of linoleic acid oxidation, in contrary, decreased during increasing concentration. The DPPH radical scavenging activities of extracts were MeOH>Water>EtAc, and the best effect was found in Ilan bulils. The analysis results of the constituents in yams and bulbils indicated that the total phenolic contents of yams and bulbils were between 235.45-1075.94 mg/100g dw.The content of total flavonoids in yams and bulbils were about 31.21-254.05 mg/100g dw. It was obviously, the contents of bulbils was higher than that in the yams. The contents of allantoin in water extract were higher than in methanol extract. The allantoin content of yams and bulbils were about 925.30-1382.33mg/100g dw.The content from Ilan’s were higher than other. Two sugars, rhamnose and sucrose, were found in the methanol extracts from yams and bulbils. The sucrose content of yams and bulbils were at the range of 2.88-14.40 mg/100g dw respectively. For the levels of rhamnose were 2.44-6.61 mg/100g for yams and bulbils. Ferulic acid and p-coumaric acid were identified in methanol extract of yams and bulbils. The contents in methanol extract of yams after alkali hydrolysis were 0.50-0.93 mg/100g dw and 0.39-1.07 mg/100g dw, respectively. However, no free form and acid hydrolysis form existed. For the bulbils, the contents of ferulic acid were 4.92-16.00mg/100g dw for alkali and acid hydrolysis. The contents of p-cumaric acid in bulbils were 2.46-9.62mg/100g dw for alkali and acid hydrolysis. The total ferulic acid and p-cumaric acid in bulbils were much more than that in yams. Acording to the DPPH addition assay, the ferulic acid and p-coumaric acid could react with DPPH free radical. The quantity of reactivity of both phenolic acids in bulbils were higher than that in yams, which implied that the ester form of phenolic acid might probably play an important role for DPPH radical scavenging effects. There were still many unknowns in methanol extracts of yams and bulbils and need to be elucidated in the future. The total phenolic contents and DPPH radical scavenging effect of yam and bulbils increased at the first, then decreased during cooking process. The correlation equation between total phenolic contents and DPPH radical scavenging effect was Y=0.4499X+2.3785，r2=0.8630. This indicated that the DPPH radical scavenging activity of bulbils might be affected by the contents of the total phenol in bulbils.
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Werawong, Napawan, and 翁佩雯. "Antioxidant and liver cell protective activities of onion wine." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/50820030026144930806.
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碩士國立屏東科技大學
食品科學國際碩士學位學程
103
Onion is a vegetable member of the genus Allium, have been shown to contain large amounts of flavonoids, and constitute one of the major sources of flavonoids in diets. Flavonoids, one group of bioactive compound which are mainly present as glucoside of quercetin in onions, have been identified as contribute a major part of the antioxidant and many health benefits. The aim of this research is to comparison the total phenol, total flavonoid and antioxidant activities of three onion varieties (red, white, yellow) fermentation by Saccharomyces cerevisiae bayanus for 30 days. The benefit affects of red, yellow and white fermentedonions have been investigated for its antioxidant activity, phytochemical components and hepatoprotective activity on ethanol injured mouse hepatocytes FL83B. The antioxidant activities was evaluated with 2,2-diphenyl-1-picrylhydrazyl (DPPH), TEAC (Trolox Equivalent Anti- oxidant Capacity) and reducing power assay. Quantitative and qualitative analysis of phytochemical compounds contained in fermented onion were carried out by Determination of total phenol, flavonoid and anthocyanin content method and RP-HPLCrevealedquercetin and phenolic compounds.It was found that fermented red onion had the highest antioxidant activity and phenolic compounds compare to all sample. The hepatoprotective of fermented onion on FL83B was investigated by ethanol induced injury, determination of lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate transaminase(AST). The results revealed that cell viability decreased while released LDH, ALT and AST value were increased with the increase of alcohol concentration. Keywords: Fermented onion, antioxidant activity, S. bayanus, FL83B
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HSU, FENG-YI, and 許逢逸. "Antigenic Properties and Antioxidant Activities of Fermented Soybean Products." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/02356652938402026983.
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碩士靜宜大學
食品營養學系
104
After fermentation of Soy products can improve human to digestion and absorption of nutrients it can also reduce the immunoreactivity and Increase the antioxidant capacity. In this study, fermentation Soy products were used to investigate the effects of different solvent extraction on the structure, immunoreactivity, and antioxidant capacity of proteins. The water, PBS, and denaturant extraction, centrifugation and the supernatant analyzed. Lowry, o-phthaldialdehyde, Tricine-SDS-PAGE, Western bolt analysis, and ELISA were used to elucidate the Changes in the protein after fermentation. The antioxidant capacity was analyzed by ABTS radical scavenging ability, ferrous ion chelating ability and reducing power methods. The results of Lowry showed that the highest concentration of protein extracted from the denaturant. The electrophoresis, Western blot and ELISA showed that propose using two different solvent extraction to observe more complete fermentation soybean meal hydrolyzate and immunoreactivity. Fermentation process antigenic protein is hydrolyzed into smaller fragments, such that the antibody and antigen binding protein immunoreactivity decreased. Different solvent extracts exhibit different antigen content, but are lower than non-fermented soybean. The results of antioxidant capacity showed that the ABTS inhibition is tempeh ≈ natto> fermented soybean meal, reducting power is fermented soybean meal > natto ≈ tempeh, Relative degree of hydrolysis is natto ≈ tempeh >fermented soybean meal. The chelating effect showed that compared to the control group showed lower values.
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Carlson, Joshua Steven. "Processing effects on the antioxidant activities of blueberry juices." 2003. http://www.lib.ncsu.edu/theses/available/etd-04162003-225442/unrestricted/etd.pdf.
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Wang, Chia-Lin, and 王家麟. "Antioxidant and anti-tyrosinase activities ofCyphomandra betacea Sendt. extracts." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/89359201067450993251.
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碩士嘉南藥理科技大學
生物科技系暨研究所
96
Tamarillo, Cyphomandra betacea Sendt. , is a subtropical fruit containing anthocyanins and carotenoids. To better understand whether tamarillo fruit could prevent oxidative stress and be used as a whitening agent in cosmetics, we analyzed the total phenol contents and investigated the biochemical properties of the ethanol extract and its partitioned fractions on free radical scavenging, anti-LDL oxidation and anti-tyrosinase activities. There is considerable evidence indicated that atherogenesis is initiated and promoted by oxidation of low-density lipoprotein (LDL). Dietary antioxidants might reduce the risk of atherosclerosis by scavenging free radical and reduction of LDL oxidation. Tyrosinase (EC 1.14.18.1) is a key enzyme involved in the synthesis of melanin, which plays a major role in human skin pigmentation. Compounds which inhibit tyrosinase activity could be effective as depigmenting agents. The ethanol extract of tamarillo fruit contained a high content of phenolic compounds [ 28.8 ± 0.05 mg catechin equivalents (CE)/g dry weight ] and showed a strong DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity [ IC50 = 189.1 ± 1.3 μg/mL ]. Further solvent partition of the ethanol extract yielded ethyl acetate (EA), n-butanol, and water layers. Among them, EA layer had the highest phenol content [ 61.1 ± 0.06 mg (CE)/g dry weight ], DPPH scavenging potential [ IC50 = 89.1 ± 4.2 μg/mL ] and TEAC [ 56.73 ± 4.5 mg/g ]. Tamarillo phenolics in EA layer also exhibited stronger or compatible inhibitory activity than DL-?tocopherol, at the same working concentration, Copper-induced LDL oxidation was suppressed by the tamarillo phenolics in EA layer more effectively or compatible to DL-??tocopherol, as measured by decreased formation of thiobarbituric acid-reactive substances assay（TBARS）, conjugated diene and electrophoretic mobility（REM）. Tyrosinase activity and enzyme kinetics was analyzed by Michaelis-Menten approach. The methanol fraction contained strong competitive inhibitors on mushroom tyrosinase with IC50 0.246 mg/mL. In conclusion, the tamarillo fruit may serve as a dietary antioxidant for prevention atherosclerosis and a whitening agent in cosmetics.
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Lin, Yu-Ru, and 林育如. "Comparison of antioxidant activities of commercial green tea beverages." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/39203499881488186208.
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碩士國立臺灣海洋大學
食品科學系
99
Six commercial green tea beverages were analyzed for their soluble solid content, total phenolic content, gallic acid, caffeine, vitamin C, and catechins. Their antioxidant capacities, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, ferrous ion chelating effect, and trolox equivalent antioxidant capacity (TEAC), were also evaluated and compared. The soluble solid content and total phenolic content in sample A1 were 27.46 mg/mL and 1.25 mg/mL, respectively. Its effective concentration (EC50) of DPPH radical scavenging capacity and chelating ability of ferrous ions were 104.13 and 949.92 g/mL, respectively. The trolox equivalent antioxidant capacity (TEAC) of A1 sample was 1.8 mmol/L trolox. Both total catechins (TC) and total ester type catechins (TGC) content of sample A1, which were 510.84 and 273.81 mg/L, respectively were the highest among the six samples. Its content of (-)-epigallocatechin-3-gallate (EGCG) was 2.7 times higher than sample A2, which was produced by the same manufacturer. Correlation tests between chemical contents and antioxidant capacities were also performed. TC (total catechins), TGC (total ester type catechins) and TP (total phenolic) showed a negative correlation with the EC50 of DPPH radical scavenging effect, a positive correlation with TEAC, and no correlation with the EC50 of chelating ability of ferrous ion. Vitamin C and caffeine showed no correlation with the three indices of antioxidant capacities mentioned above.
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SHUAN, LIN, and 林萱. "Preparation And Antioxidant Activities Of Djulis Extract-Zein Complexes." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/6cr36f.
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碩士輔仁大學
食品科學系碩士班
107
Preparation and antioxidant activities of djulis extract-zein complexes Abstract Djulis (Chenopodium formosanum Koidz.) has functional ingredients, such as phenolic acid, flavonoid and rutin which have an antioxidant effect. Zein can be conjugated with some therapeutic bioactive substances to function as a carrier for microcapsules. Therefore, the aim of this study was to form djulis extract-zein complex and to determine its corresponding antioxidant activity. Djulis powder was mixed with distilled water, 60%, 75% and 95% ethanol respectively to be extracted under 30oC for 4 hours. The contents of total polyphenol, flavonoid and antioxidant activity of djulis extracts were detected. Additionally, LC-MS was used to analyze extracts and djulis-zein complex. The results showed that the amount of total phenol in 60% and 75% ethanol extracts were 42.10 ± 1.26 μg/mg and 35.91 ± 1.50 μg gallic acid equivalent/mg, respectively. The scavenging effects on ABTS•+ radical showed the EC50 values of 60% and 75% ethanol djulis extracts were 1.08 ± 0.07and 1.33 ± 0.33 mg/mL, respectively. In addition, the phenolic acids and flavonoids including quinic acid, hydroxyphenylacetic acid pentoside, vanillic acid, quercetin-3-O-(coumaroyl)-rutinoside, and rutin (quercetin-3-O-rutinoside) in 60% ethanol extract were identified by LC-MS-MS. In the FTIR results, for vanillic acid-zein, quinic acid-zein and rutin-zein complexes, the main peaks of vanillic acid, quinic acid and rutin both were shifted. Thereafter, rutin-zein complex have the highest scavenging effects on DPPH and ABTS•+ radical, with the EC50 values being 0.04 ± 0.01 and 0.38 ± 0.01 mg/mL, respectively. In conclusion, these results indicated that zein could indeed be used as a carrier of djulis extract. The rutin-zein complex had the highest antioxidant activity and thus could be useful for functional foods. Keywords: djulis, zein, complexes, phenolic acid, flavonoids, antioxidant activity
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YONG, SHIN-YEE, and 楊欣怡. "Antioxidant and Neuroprotection Activities of Myrciaria Cauliflora Seed Extracts." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/vfc8rk.
Full textAbstract:
碩士靜宜大學
食品營養學系
108
An imbalance between production of reactive oxygen species and antioxidant system can cause oxidative stress and lead to neurodegenerative diseases. The objective of this study was to investigate antioxidant activity and neuroprotection effects of Myrciaria cauliflora (Jaboticaba) seeds extracts in vitro. Jaboticaba seeds were extracted with 95% ethanol, 50% ethanol and hot water, respectively. The extracts were vacuum-concentrated followed by lyophilizated. Antioxidant components in extracted powder, such as total polyphenol, total anthocyanins, total flavonoids, and resveratrol, were analyzed. Reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, and ferrous ion chelation ability were determined to evaluate the antioxidant capacity of extracts. To measure neuroprotection effect, oxidative stress was induced by H2O2 in N2a mouse neuroblastoma cells. The cell viability was analyzed with MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, while the amount of ROS production was assayed with H2DCF-DA stain, and the antioxidant status including the activities of cellular antioxidant enzymes and antioxidant contents were determined as well. The results showed that 50% ethanol extract contained the highest amount of total polyphenols (164.19 ± 4.46 mg gallic acid equivalent/g), total flavonoids (17.48 ± 0.01 mg rutin equivalent/g) and total anthocyanins (1.87 ± 0.04 mg/g). The EC50 of antioxidant properties of 50% ethanol extract expressed as DPPH radical scavenging ability, reducing power (reach OD 0.5 at 700nm) and ferrous ion chelation were 0.20 ± 0.00 mg/ml, 0.13 ± 0.00 mg/ml and 0.09 ± 0.00 mg/ml, respectively. Compare to untreated N2a cell line, N2a treated with 95% ethanol extract showed higher viability, lower ROS production and greater catalase activity. In conclusion, Jaboticaba seed extracts was proved to have neuroprotection effect by its antioxidant activity.
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CHIEN, SZU-CHIA, and 簡思嘉. "Studies on the Antioxidant Activities and Inhibitory Activities of Chitooligosaccharides on Acetylcholinesterase and α-amylase." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/58b9t7.
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碩士靜宜大學
食品營養學系
104
Low–molecular-weight chitosan and chitooligosaccharides are a non-toxic, biocompatible and biodegradable nature biopolymer, and have a variety of biological activities. The purpose of this study was to investigate the molecular size, antioxidant capacity and selected enzyme inhibitory activities of a commercial chitooligosaccharides preparation. The molecular mass of the chitooligosaccharides preparation was less than 10 kDa, and most in the range of 10 to 3 kDa, as estimated by ultrafiltration with different molecular weight cutoff membranes. However, it also consisted of some small size oligomers with chain length larger than 3, as analyzed by thin-layer chromatography. Antioxidant activities of the chitooligosaccharides preparation were evaluated with models of scavenging effect on ABTS, superoxide anion, hydroxyl and oxygen radicals. The trolox equivent scavenging values of the chitooligosaccharides toward ABTS, superoxide anion and oxygen radicals were 7.42 ± 0.17 mg trolox/ g COS，53.74 ± 0.002 mg trolox/g COS and 1140 ± 42.43 μmol trolox/ g COS, respectively. The half –effective concentration (EC50) of the chitoolgosaccharides preparation toward hydroxyl radicals was 412.87 ± 0.106 μg/mL. Reducing power of the chitooliosaccharides preparation was evaluated by a ferri-ferrocyanide and ferric chloride model. Its trolox and ascorbic acid equivalent reducing power values were 151.49 ± 0.015 mg trolox/g COS and 8.97 ± 0.011 mg ascorbic acid/g COS, respectively. Results of evaluation of selected enzyme inhibitory activities showed that the chitooligosaccharides preparation had inhibitory activities toward acetylcholinesterase and α-amylase. Its half-inhibitory concentration (IC50) values toward acetylcholinesterase and α-amylase were 18.82 ± 0.79 and 6.73 ± 0.28 mg/mL, respectively. Inhibitory kinetic analysis indicated that the chitooligosaccharides preparation was a noncompetitive inhibitor against α-amylase.
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Kartika, Henny. "Nutrients, polyphenols, and total antioxidant activities in Mamaki, Pipturus albidus." Thesis, 2006. http://hdl.handle.net/10125/20600.
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Huang, Chin Jung, and 黃靖容. "Antioxidant and anticancer activities of aqueous extracts from Toona sinensis." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/03993873343901730757.
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碩士中國醫藥大學
營養研究所
93
英文總摘要 Toona sinensis Roem belongs to the family Meliacceae.The leaves and young shoots are used as vegetable in Chin.In fact,the trees are also widely used medically.Previous phytochemical work on Toona sinensis had led to the isolation phenolic compounds. To further search for the novel bioactive agents from Meliaceae plants, Toona sinensis was chosen for phytochemical investigation and known compounds including, gallic acid, methyl gallate, kaempferol, quercitin, quercitrin, rutin and catechin, were isolated and identified from this plant. In this study, we have investigated the antioxidant properties of the aqueous extracts of whole fresh Toona sinensis were evaluated using different antioxidant tests, including reducing power ,free radical scavenging, superoxide anion radical scavenging, and metal chelating activities. The results showed that the aqueous extracts of whole fresh Toona sinensis had antioxidative activites in linoleic acid peroxidation system.Moreover, the aqueous extracts of whole fresh Toona sinensis had effective reducing power, free radical scavenging, superoxide anion radical scavenging, and metal chelating activities at the same concentrations. We have also investigated the effects (antioxidant properties) of Toona sinensis on the oxidative modification of human low-density lipoproteins (LDL), as induced by copper sulfate (CuSO4), 2,2-azobis-2-amidinopropane hydrochloride (AAPH), and sodium nitroprusside (SNP). Under such oxidant stress, Toona sinensis appear to possess antioxidant properties with respect to oxidation of LDL in a time- and concentration-dependent manner, as assessed by inhibition of thiobarbituric acid-reactive substances (TBARS) formation and cholesterol degradation of oxidized LDL. In addition , Toona sinensis exhibited a remarkable ability to rescue the relative electrophoretic mobility and fragmentation of the Apo B moiety of the oxidized LDL. Our findings suggest that the antioxidant properties of Toona sinensis may also provide effective protection from atherosclerosis. In this study, the ability of Toona sinensis to induce apoptosis was studied in cultured human premyelocytic leukemia HL-60 cells. Treatment of the HL-60 cells with a variety of concentrations of aqueous crude extracts of Toona sinensis (10-75 mg/ml) resulted in dose- and time-dependent sequences of events marked by apoptosis, as shown by loss of cell growth and viability,cell shrinkage. Furthermore, apoptosis in the HL-60 cells was accompanied by the release of cytochrome c, activation of caspase 3 and specific proteolytic cleavage of poly (ADP-ribose) polymerase (PARP). This increase in Toona sinensis induced apoptosis was also associated with a reduction in the levels of Bcl-2, a potent cell-death inhibitor, and an increase in those of the Bax protein, which heterodimerizes with and thereby inhibits Bcl-2. The data suggest that Toona sinensis exerts antiproliferative action and growth inhibition on HL-60 cells through apoptosis induction, and that it may have anticancer properties valuable for application in drug products.
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Hu, Ting-Hui, and 胡庭卉. "Effects of Trace Elements on Antioxidant Activities of Cordyceps militaris." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/81508012998344131759.
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碩士實踐大學
食品營養與保健生技學系碩士班
97
Cordyceps militaris（L.）Link, one of the best known traditional Chinese medicines and health foods, has been highly valued for the treatment of a wide range of diseases and reported to have antioxidant properties. In the present study, Cordyceps militaris were cultivated using the water containing trace elements (TEW) or de-ionized water (DIW) and then extracted with water. The objectives of this study are : 1) compared with these two groups of the antioxidant properties, including the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging activity, reducing power, ferrous ion chelating power, superoxide anions scavenging activity; 2) investigated the effects of Cordyceps militaris extracts on the intracellular activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase in human hepatoma cell line (Hep G2 cells). Our results showed that the TEW group contained significantly higher contents of mannitol, polysaccharide, adenosine and cordycepin than those of the DIW group. For antioxidant properties, the TEW group significantly increased DPPH radicals scavenging activity, ferrous ion chelating power and superoxide anion scavenging activity. When Hep G2 cells were treated with Cordyceps militaris extracts (1.0 mg/mL) for 24 hours, the intracellular activities of SOD, GPX and catalase significantly increased (activities of SOD increased 1.60~2.11-fold; activities of GPX increased 11.25~17.75-fold; catalase increased 1.66~2.71-fold), and the TEW group were significantly higher the activities of antioxidant enzymes than those of the DIW group. Therefore, supplemented with the trace elements obviously increased the functional ingredient content and promoted the activities of antioxidant enzymes, thereby achieving the increase of antioxidant properties.
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Chang, Shun-Hsien, and 張順憲. "Antibacterial and antioxidant activities of chitosan with various molecular weights." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/hfvwek.
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碩士國立臺灣海洋大學
食品科學系
97
Chitosan with deacetylation degree of 95% (DD 95) was degraded by cellulase at 55oC for various periods, and the low-molecular-weight chitosan (LMWC) in the hydrolysate at each period was separated. The antibacterial and anti-oxidant activities of DD95 and LMWC with various molecular weights were investingated. The molecular weights (MW) of DD95 and LMWC from 0, 1, 3, 6, 9, 18, 24 hours-samples were 300, 156, 72, 29.2, 7.1, 3.3, 2.2 kDa, respectively. The oligosaccharides content of each period contain monomer to pentamer. Activities of antibacterial activities of DD95 and LMWCs at pH 6.0 and 7.0 against with two Gram positive strains of Saphylococcus aureus BCRC 10780 and Listeria monocytogenes BCRC 14845, and 2 Gram negative strains of Escherichia coli BCRC 10675 and Pseudomonas aeruginosa BCRC 10944. At pH 6.0 the antibacterial activity of chitosan increased with increasing of molecular weight of chitosan, with DD95 being highest. The minimal lethal concentrations (MLC) of chitosan with MW of 300, 156, 29.2, 7.1, and 2.2 kDa against S.aureus were 50, 100, 200 and 500 ppm, respectively, against E. coli being 100, 100, 200 and 500 ppm, respectively. Among 4 tested stains, P. aeruginosa was most resistant to chitosan. Except 2.2 kDa LMWC, the MLC of the rested 6 chitosan samples against P. aeruginosa was 500 ppm. However, at pH 7.0 the antibacterial activities of chitosan samples with 300, 156 and 72 kDa were greatly decreased; while chitosan samples with MW less than 30 kDa (29.2, 7.1, 3.3 and 2.2 kDa) were less affected by this pH change. Accordingly, these 4 smaller MW chitosan samples have much higher antibacterial activity at pH 7.0. Activities of scavenging DPPH, superoxide anion, ABTS+, and the Fe2+-chelating effect for LMWC samples were significantly increased with the decreasing MW of LMWC, and dose-dependence was observed, with 2.2 kDa LMWC being highest. The superoxide anion scavenging activity for 2.2 kDa LMWC at 5000 ppm was 86.76 ± 0.26%, and equal to 176.92 ± 6.27 ppm Quercetin; while its DPPH scavenging activity at 2000 ppm was 63.40 ± 0.46%, and equal to 113.64 ± 0.66 ppm Vit. C. Compared to other anti-oxidant activities, both DD95 and LMWC have weaker activity of chelating Fe2+ ion and scavenging ABTS+. The Fe2+-chelating and ABTS+ scavenging activity for 2.2 kDa LMWC at 5000 ppm were 47.33 ± 1.44 and 25.28 ± 0.55%, and equal to 76.13 ± 1.39 ppm EDTA and 20.75 ± 0.68 mM Trolox.
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Lin, I.-Hwa, and 林宜樺. "Study of surface and antioxidant activities of chemically modified chitosan." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/67p66w.
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Sun, Nai-Yun, and 孫乃云. "Study of Gelidium water extracts on antioxidant and anticancer activities." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/14656996261582682294.
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碩士國立臺灣海洋大學
水產養殖學系
94
The aim of this study was to compare the difference in antioxidant ability and anticancer activity between Gelidium species, and also to check the effects of post-harvesting process in respect to the effective compositions. The Gelidium species used in this work are Pterocladiella capillacea, Gelidium amansii, and Gelidium japonicum, in which they are lyophilized immediately, or subjected to oven drying at 80℃, or half-sun-dry plus washing. The antioxidant activities (DPPH and ABTS), total phenolic compounds and flavonoid content, MAA (mycosporine-like amino acids) content and its antioxidant activities, and human brain cancer GBM8401 and human cervix cancer HeLa cell inhibition of cold water extracts taken from the crude product were investigated. In the antioxidant activities assay, it was found that Pterocladiella capillacea had the highest DPPH and ABTS radical-scavenging activities, followed by Gelidium amansii and Gelidium japonicum. Total phenolic compounds had no significant differences between all species. Total flavonoid content had no significant differences between Pterocladiella capillacea and Gelidium amansii, and higher than Gelidium japonicum. The highest amount of total MAA contents was found in Pterocladiella capillacea, followed by Gelidium amansii and Gelidium japonicum. The MAA of lower concentration had no antioxidant activity. The antiproliferative activities of cold water extracts were studied in vitro using human brain cancer GBM8401, and the following results were found: Pterocladiella capillacea and Gelidium amansii had no significant differences, and higher than Gelidium japonicum. The data from the antiproliferative activities of GBM8401 by MAA found that porphyra-334 had the highest inhibition, followed by shinorine and palythinol. The antiproliferation activities in human cervix cancer HeLa of cold-water extracts and MAA had no effect. The species difference in total MAA contents is consistent with the species difference in the activity of antiproliferation of GBM8401. It suggests that total MAA contents are related to inhibition of GBM8401 cell growth. MAA of low concentrations had no antioxidant activity, but exhibits marked anticancer activity on GBM8401, it suggests MAA has another anticancer pathway. In summary, Gelidium species had the potential for healthy foods and their cold water extract can be developed as a potential anticancer chemical.