There is a close relationship between the susceptibility to disease and nutritional state, in the sense that an adequate diet enhances resistance to disease. There is an increasing interest in this beneficial relationship among scientists, food manufacturers and consumers. The trend is moving towards functional foods and their specific health benefits. The results of numerous epidemiological studies and recent clinical trials provide consistent evidence that diets rich in fruits and vegetables can reduce the risk of chronic diseases. These protective effects are mediated through multiple groups of beneficial nutrients contained in the fruits and vegetables, one of these being polyphenol antioxidants. The intake of the polyphenols plays an important role in the reduction and prevention of coronary heart disease (CHD), cardiovascular disease and cancer, as a consequence of their associated antioxidant properties. Fruits contain an array of polyphenols with antioxidant capacity. Polyphenols may be classified in two broad groups namely: flavonoids and non-flavonoids. Flavonoid subgroups in fruits are further grouped as catechins, anthocyanins, procyanidins and flavonol among others. Phenolic acids occur as hydroxylated derivatives of benzoic acid and cinnarnic acid, and are classified as non-flavonoids. Polyphenols have redox properties allowing them to act as reducing agents, hydrogen donators and singlet oxygen quenchers, and thus contribute to the antioxidant capacity of fruits and vegetables. Because of the numerous beneficial effects attributed to these antioxidants, there is renewed interest in finding vegetal species with high phenolic content and relevant biological activities. In view of the importance of these substances towards health and food chemistry, this study will focus on the polyphenol and Vitamin C characterisation and quantification of an indigenous South African fruit, the Kei-apple (Dovyalis cafra), thought to have antioxidant properties. Due to the fact that polyphenol content influences the colour, taste and possible health benefits of the fruit / processed food product, this study will supply valuable information to industry in choosing the best fruit processing methods to attain the desired end product. The exploitation of indigenous South African fruits (Marula and Kei-apple) is receiving increasing prominence, not only due to their health benefits, but also the opportunities these present to rural based economics. Furthermore, this research will serve as a platform for further research on the Kei-apple and other indigenous South African fruits with possible health benefits. Aims: The overall aim of this study is the quantification and characterisation of various nutritionally important antioxidants (polyphenols and ascorbate) in the Kei-apple fruit in its entirety, as well as in its individual fruit components (peel, flesh and seeds). In addition, the total antioxidant capacity of the entire fruit and the various fruit components will be determined in the unfractionated and fractionated fruit extracts. Gas chromatography coupled mass spectrometry (GC-MS) characterisation of the individual polyphenol components will also be analyzed in order to speculate on possible specific health benefits which the Kei-apple may possess. Methods: The study was designed to ensure that a representative fruit sample was collected. Approximately 100 kg Kei-apples were picked in the month of November 2004 from the Bloemhof area in South Africa. A sample of 50 fruits was rinsed and separated into the various components (peel, flesh and seeds). An additional 50 fruits were randomly selected, cleaned and used in their entirety for data representative of the entire fruit. The sample extracts were prepared, after being grounded and lyophilized, by a method described by Eihkonen et al. (1999) using 70% aqueous acetone. The C18-fractionation on the fruit and separated fruit components resulted in four fractions containing (1) phenolic acids; (2) procyanidins, catechins and anthocyanin monomers; (3) flavonols and (4) anthocyanin polymers. The total polyphenol content of the fruit and fruit components as well as the above mentioned C18-fractions were determined by Folin-Ciocalteu's method (Singleton & Rossi, 1965). Both free and total ascorbate concentrations in these samples were determined as described by Beutler (1984), in addition to total sugar content of these via standard methods. Apart from their nutritional interest, both these measurements are necessary for the correction of the total polyphenol concentrations. The total antioxidant capacity of the entire fruit and various fruit components was determined by measuring the oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) of the unfractionated and fractionated extracts. Using GC-MS analysis, the various individual polyhenol compounds contributing to the total polyphenol content of the Kei-apple was separated, identified and quantified. This quantitative data was captured and statistically analysed. The analysis of variation was performed using the Tukey Honest Significant Difference test for post-hoc comparison. ORAC, FRAP and polyphenol Pearson correlation analyses were performed using Statistics (Statsoft Inc., Tulsa, Oklahoma, USA) with significance set at P ≤ 0.05. Results and discussion: This study determined the presence of various nutritionally important antioxidants (polyphenols and ascorbate), the total antioxidant capacity in the entire fruit as well as in the individual fruit components (peel, flesh and seeds) and their polyphenol sub group fractions. Total phenol content: The Kei-apple, in its entirety, has a polyphenol concentration of 943 ± 20.3 mg GAE/100g dry weight. Comparison of the individual fruit components showed the seeds to have the highest total polyphenol concentration with 1990 ± 31.3 mg GAE/100g dry weight, followed by that of the peel, 1126 ± 45.8 mg GAE/100g dry weight and then that of the flesh, 521 ± 1.01 mg GAE/100g dry weight. Total, L-ascorbic (ASC) and L-dehydroascobic (DHA) concentration: The total ascorbate of Kei-apple fruit is 517 ± 0.92 mg/100g dry weight. In contrast to the polyphenol content, the flesh of the Kei-apple had significantly the highest concentration of total ascorbate 778 ± 1.20 mg/100g dry weight, Gascorbic 241 ± 21.0 mg/100g dry weight, as well as Gdehydroascobic 537 ± 22.2 mg/100g dry weight. The ratio of Lascorbic acidltotal ascorbate for the flesh, entire fruit, peel and seed is 0.31,0.43,0.49,0.95, respectively, indicating the seeds are the most stable source of biologically active Vitamin C, with 95% of the total ascorbate occurring as G ascorbate. This is also in line with the total polyphenol content of these components, confirming a polyphenol sparing effect on ascorbate. C18-fractionation extracts: Solid phase (C18) fractionation of the Kei-apple fruit and fruit components showed that the fruit, peels and seeds consist predominantly of phenolic acids, followed by procyanidin, catechin and anthocyanin monomers and thereafter varying amounts of anthocyanin polymers and flavonols. Antioxidant capacity: The antioxidant capacity of the entire fruit and individual fruit components as determined by ORAC, (r=0.76) and FRAP, (r=0.95) significantly correlated with the total polyphenol content, as well as to each other (r=0.88), indicating both to be good predictors of antioxidant capacity. GC-MS polyphenol characterisation of the Kei-apple: Caffeic acid and hydro-p-coumaric acid were seen to be the phenolic acids occurring in the highest concentrations in the Kei-apple fruit. The majority of these are concentrated in the flesh and in the case of caffeic acid, also in the peel. The order of predominance of other major non-flavonoid components in the whole fruit analysis are m-hydroxybenzoic acid > p-hydroxyphenyl acetic acid > 3-methoxy-4- hydroxyphenylpropionic acid > p-coumaric acid. The peel of the Kei-apple, apart from caffeic acid, has exceptionally high concentrations of ferulic acid and also serves as a source of protocatechuic acid. Syringic acid was most prominent in the seeds. Although the total flavonoid concentration in the Kei-apple was low, taxifolin and catechin were identified and the seeds almost entirely accounting for these. Conclusion: From this study it was concluded the Kei-apple is a rich source of antioxidant compounds (polyphenols and ascorbate), with a strong antioxidant capacity, and hence may be associated with health promotion properties, particularly in the prevention of cancer, cardiovascular disease, and neurodegeneration. Additionally, due to the increased scientific and commercial interest in this fruit, it is essential to take into consideration the various factors (agronomic, genomic, pre- and post harvest condition and processing) and tissues. This might affect the chemical composition of the final marketed product, which may play a significant role in determining the polyphenol and ascorbate composition and bioactivity of these compounds during food processing procedures. Hence, the polyphenol composition of the various fruit components should be taken into consideration when selecting a method of fruit processing into the desired end product. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2007.

Liver fatty acid binding protein has been reported to possess antioxidant properties in the liver. The aim of this study was to investigate the effect of this protein in a nonalcoholic fatty liver disease (NAFLD) cell culture model. Rat hepatoma cells were treated with an oleate:palmitate (2:1) mixture for either 1 and 2 days, or further treated with 500 µM clofibrate to induce L-FABP expression. Intracellular lipid accumulation was quantitated by Nile Red. Lipotoxicity was determined using the WST-1 assay. Dichlorofluorescein (DCF) was utilized to assess intracellular reactive oxidative species (ROS) level. Measurement of lipotoxicity showed statistical decreases in cell viability as lipid concentrations increased in a dose-dependent manner. NAFLD cell cultures showed characteristic cellular damage from increased ROS levels in fatty acid treated cells. All groups treated with clofibrate showed statistically increased intracellular L-FABP levels and reduced ROS levels. The results lead to the conclusion that clofibrate induces L-FABP expression and in this manner suppresses hepatocellular ROS generation.

To determine the level of salt tolerance of the medicinal plant Echinacea, the physiological and biochemical characteristics of E. purpurea, E. pallida and E. angustifolia exposed to different NaCl levels (0, 50, 75, and 100 mM) were evaluated under hydroponic culture. Dry weights of shoots and roots were not affected by salinity; however E. purpurea and E. pallida exhibited higher survival rate than E. angustifolia, which also showed high salt injury index and electrolyte leakage compared to the other two species. Gas exchange (photosynthetic rate, stomatal conductance, and transpiration rate) showed a decline with increasing salt concentrations in all species with a more pronounced reduction in E. angustifolia. E. purpurea was able to retain more Na+ in the roots than the other two species showing its capacity to regulate Na+ translocation to shoots (Na+ exclusion). Moreover, the activities of two major antioxidant enzymes; superoxide dismutase (SOD) and ascorbate peroxidase (APX) were increased by salinity in E purperea, while the activities were decreased in E. angustifolia. The characteristic phytochemical profiles of caffeic acid derivatives (CADs) and alkamides/ketones were obtained for the three species, and quantitative changes were determined. Cichoric acid, the major CAD in E. purpurea, was increased with salinity up to 75 mM NaCl. A relative increase in alkamides and CADs was recorded in E. angustifolia, while in E. pallida, the level of echinacoside and major ketones (22 and 24) decreased, suggesting that the medicinal value of this species was compromised by salt stress. First evidence of salt-induced changes in alkamides and ketones in Echinacea was demonstrated in this study. Activity of phenylalanine ammonia-lyase (PAL), the major enzyme involved in the biosynthesis of CADs, was increased only in the roots of E. purpurea, further reflecting the differences in salt tolerance between species. It can be concluded that Echinacea species exhibited a limited degree of salt tolerance; however, E. purpurea showed a higher tolerance than E. pallida and E. angustifolia. This tolerance was mainly attributed to the increase in Na+ exclusion capacity, antioxidant activities and PAL activity.

There is a close relationship between the susceptibility to disease and nutritional state, in the sense that an adequate diet enhances resistance to disease. There is an increasing interest in this beneficial relationship among scientists, food manufacturers and consumers. The trend is moving towards functional foods and their specific health benefits. The results of numerous epidemiological studies and recent clinical trials provide consistent evidence that diets rich in fruits and vegetables can reduce the risk of chronic diseases. These protective effects are mediated through multiple groups of beneficial nutrients contained in the fruits and vegetables, one of these being polyphenol antioxidants. The intake of the polyphenols plays an important role in the reduction and prevention of coronary heart disease (CHD), cardiovascular disease and cancer, as a consequence of their associated antioxidant properties. Fruits contain an array of polyphenols with antioxidant capacity. Polyphenols may be classified in two broad groups namely: flavonoids and non-flavonoids. Flavonoid subgroups in fruits are further grouped as catechins, anthocyanins, procyanidins and flavonol among others. Phenolic acids occur as hydroxylated derivatives of benzoic acid and cinnarnic acid, and are classified as non-flavonoids. Polyphenols have redox properties allowing them to act as reducing agents, hydrogen donators and singlet oxygen quenchers, and thus contribute to the antioxidant capacity of fruits and vegetables. Because of the numerous beneficial effects attributed to these antioxidants, there is renewed interest in finding vegetal species with high phenolic content and relevant biological activities. In view of the importance of these substances towards health and food chemistry, this study will focus on the polyphenol and Vitamin C characterisation and quantification of an indigenous South African fruit, the Kei-apple (Dovyalis cafra), thought to have antioxidant properties. Due to the fact that polyphenol content influences the colour, taste and possible health benefits of the fruit / processed food product, this study will supply valuable information to industry in choosing the best fruit processing methods to attain the desired end product. The exploitation of indigenous South African fruits (Marula and Kei-apple) is receiving increasing prominence, not only due to their health benefits, but also the opportunities these present to rural based economics. Furthermore, this research will serve as a platform for further research on the Kei-apple and other indigenous South African fruits with possible health benefits. Aims: The overall aim of this study is the quantification and characterisation of various nutritionally important antioxidants (polyphenols and ascorbate) in the Kei-apple fruit in its entirety, as well as in its individual fruit components (peel, flesh and seeds). In addition, the total antioxidant capacity of the entire fruit and the various fruit components will be determined in the unfractionated and fractionated fruit extracts. Gas chromatography coupled mass spectrometry (GC-MS) characterisation of the individual polyphenol components will also be analyzed in order to speculate on possible specific health benefits which the Kei-apple may possess. Methods: The study was designed to ensure that a representative fruit sample was collected. Approximately 100 kg Kei-apples were picked in the month of November 2004 from the Bloemhof area in South Africa. A sample of 50 fruits was rinsed and separated into the various components (peel, flesh and seeds). An additional 50 fruits were randomly selected, cleaned and used in their entirety for data representative of the entire fruit. The sample extracts were prepared, after being grounded and lyophilized, by a method described by Eihkonen et al. (1999) using 70% aqueous acetone. The C18-fractionation on the fruit and separated fruit components resulted in four fractions containing (1) phenolic acids; (2) procyanidins, catechins and anthocyanin monomers; (3) flavonols and (4) anthocyanin polymers. The total polyphenol content of the fruit and fruit components as well as the above mentioned C18-fractions were determined by Folin-Ciocalteu's method (Singleton & Rossi, 1965). Both free and total ascorbate concentrations in these samples were determined as described by Beutler (1984), in addition to total sugar content of these via standard methods. Apart from their nutritional interest, both these measurements are necessary for the correction of the total polyphenol concentrations. The total antioxidant capacity of the entire fruit and various fruit components was determined by measuring the oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) of the unfractionated and fractionated extracts. Using GC-MS analysis, the various individual polyhenol compounds contributing to the total polyphenol content of the Kei-apple was separated, identified and quantified. This quantitative data was captured and statistically analysed. The analysis of variation was performed using the Tukey Honest Significant Difference test for post-hoc comparison. ORAC, FRAP and polyphenol Pearson correlation analyses were performed using Statistics (Statsoft Inc., Tulsa, Oklahoma, USA) with significance set at P ≤ 0.05. Results and discussion: This study determined the presence of various nutritionally important antioxidants (polyphenols and ascorbate), the total antioxidant capacity in the entire fruit as well as in the individual fruit components (peel, flesh and seeds) and their polyphenol sub group fractions. Total phenol content: The Kei-apple, in its entirety, has a polyphenol concentration of 943 ± 20.3 mg GAE/100g dry weight. Comparison of the individual fruit components showed the seeds to have the highest total polyphenol concentration with 1990 ± 31.3 mg GAE/100g dry weight, followed by that of the peel, 1126 ± 45.8 mg GAE/100g dry weight and then that of the flesh, 521 ± 1.01 mg GAE/100g dry weight. Total, L-ascorbic (ASC) and L-dehydroascobic (DHA) concentration: The total ascorbate of Kei-apple fruit is 517 ± 0.92 mg/100g dry weight. In contrast to the polyphenol content, the flesh of the Kei-apple had significantly the highest concentration of total ascorbate 778 ± 1.20 mg/100g dry weight, Gascorbic 241 ± 21.0 mg/100g dry weight, as well as Gdehydroascobic 537 ± 22.2 mg/100g dry weight. The ratio of Lascorbic acidltotal ascorbate for the flesh, entire fruit, peel and seed is 0.31,0.43,0.49,0.95, respectively, indicating the seeds are the most stable source of biologically active Vitamin C, with 95% of the total ascorbate occurring as G ascorbate. This is also in line with the total polyphenol content of these components, confirming a polyphenol sparing effect on ascorbate. C18-fractionation extracts: Solid phase (C18) fractionation of the Kei-apple fruit and fruit components showed that the fruit, peels and seeds consist predominantly of phenolic acids, followed by procyanidin, catechin and anthocyanin monomers and thereafter varying amounts of anthocyanin polymers and flavonols. Antioxidant capacity: The antioxidant capacity of the entire fruit and individual fruit components as determined by ORAC, (r=0.76) and FRAP, (r=0.95) significantly correlated with the total polyphenol content, as well as to each other (r=0.88), indicating both to be good predictors of antioxidant capacity. GC-MS polyphenol characterisation of the Kei-apple: Caffeic acid and hydro-p-coumaric acid were seen to be the phenolic acids occurring in the highest concentrations in the Kei-apple fruit. The majority of these are concentrated in the flesh and in the case of caffeic acid, also in the peel. The order of predominance of other major non-flavonoid components in the whole fruit analysis are m-hydroxybenzoic acid > p-hydroxyphenyl acetic acid > 3-methoxy-4- hydroxyphenylpropionic acid > p-coumaric acid. The peel of the Kei-apple, apart from caffeic acid, has exceptionally high concentrations of ferulic acid and also serves as a source of protocatechuic acid. Syringic acid was most prominent in the seeds. Although the total flavonoid concentration in the Kei-apple was low, taxifolin and catechin were identified and the seeds almost entirely accounting for these. Conclusion: From this study it was concluded the Kei-apple is a rich source of antioxidant compounds (polyphenols and ascorbate), with a strong antioxidant capacity, and hence may be associated with health promotion properties, particularly in the prevention of cancer, cardiovascular disease, and neurodegeneration. Additionally, due to the increased scientific and commercial interest in this fruit, it is essential to take into consideration the various factors (agronomic, genomic, pre- and post harvest condition and processing) and tissues. This might affect the chemical composition of the final marketed product, which may play a significant role in determining the polyphenol and ascorbate composition and bioactivity of these compounds during food processing procedures. Hence, the polyphenol composition of the various fruit components should be taken into consideration when selecting a method of fruit processing into the desired end product. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2007.

Tyrimo tikslas: įvertinti bioaktyvių junginių kiekybinės sudėties bei antioksidantinio aktyvumo įvairavimą vienapiestės gudobelės žaliavų mėginiuose, rinktuose skirtinguose Lietuvos vietovėse. Tyrimo uždaviniai: Įvertinti suminio flavonoidų kiekio ir suminio fenolinių junginių kiekio įvairavimą vienapiestės gudobelės vaisių ir lapų mėginiuose, rinktuose skirtingose Lietuvos vietovėse; įvertinti chlorogeno rūgšties ir flavonoidų (epikatechino, hiperozido, izokvercitrino, viteksino-2“-O-ramnozido, rutino) kiekinį pasiskirstymą C.monogyna žaliavose efektyviosios skysčių chromatografijos metodu; ištirti gudobelių vaisių ir lapų žaliavų antioksidantinį aktyvumą ir įvertinti jo įvairavimą naudojant DPPH ir ABTS metodus; pritaikyti klasterinę analizę vienapiesčių gudobelių vaisių ir lapų mėginių grupavimui, iškiriant reikšmingai besiskiriančias antioksidantiniu aktyvumu grupes. Tyrimo metodai: Flavonoidų kiekiui įvertinti naudoti spektrofotometriniai ir efektyviosios skysčių chromatografijos metodai, suminis fenolinių junginių kiekis įvertintas spekrofotometriškai. Antioksidantinis aktyvumas nustatytas spektrofotometriniu metodu, naudojant DPPH ir ABTS testus. Tyrimo objektas: Lietuvos skirtinguose regionuose rinktos Crataegus monogyna Jacq. vaisių ir lapų žaliavos. Tyrimo rezultatai: Flavonoidų kiekis lapų žaliavose įvairavo nuo 0,47 iki 2,34 proc., vaisių žaliavoje nuo 0,12 iki 0,91proc.. Suminis fenolinių junginių kiekis lapų mėginiuose nuo 5,68 iki 11,80 proc., vaisių... [toliau žr. visą tekstą] / The aim of the research: to evaluate the variety of quantitative composition of bioactive combination and antioxidant activity in the samples of C. monogyna selected in different parts of Lithuania. The objectives of the research: to evaluate the variety of total amount of flavonoids and total amount of phenolic combinations in the samples of C. monogyna leaves and fruit; to evaluate the quantitative distribution of of chlorogenic acid and flavonoids in C. monogyna raw materials by the method of effective chromatography of liquid; to analyse the antioxidant activity of hawthorn leaves and fruit and evaluate the variety of it using DPPH and ABTS methods; to apply cluster analysis of sample grouping of monopistil howthorn leaves and fruit marking out groups having definetely different level of antioxidant activity. The methods of the research: the methods of spectrophotometry and efective liquid chromatography were used to evaluate the amount of flavonoids and the total amount of phenolic combinations. The antioxidant activity was established using DPPH and ABTS tests. The object the research: Crataegus monogyna Jacq. raw material of leaves and fruit selected in different parts of Lithuania. The results of the research: the amount of flavonoids in leaves differed from 0,47 to 2,34%; in fruit it difffered from 0,12 to 0,91 %. Total amount of phenolic combinations in the samples of leaves differed from 5,68 to 11,80 percent; in raw material of fruit differed from 1,03 to 2,78%... [to full text]

Maize genetic diversity includes an array of kernel colors (red, blue, purple) with blue concentrated in the aleurone and red primarily in the pericarp. Quality protein maize (QPM) is improved over normal maize in regards to grain concentration of the essential amino acids lysine and tryptophan but has not been widely adapted in part due to lower than conventional yields. These are minimally-utilized specialty corns when compared to the yellows and whites commonly grown. Red, blue, and purple pigments are antioxidant phytochemicals produced by the plant as secondary metabolites. Antioxidants have been linked to anti-cancer and other anti-inflammatory health benefits. QPM hybrids are desirable in developing countries where subsistent agriculture is commonly practiced and quality protein cereals are non-existent. These two diverse maize categories have been the subject of little breeding research compared to normal maize and the potential for high phenolic content as well as the characterization of these QPM hybrids has not been previously investigated. We evaluated 153 maize hybrids (84 colored, 69 QPM) across three locations. High heritability estimates were found for phenolic content (0.80), tryptophan (0.46), and endosperm opacity (0.82). It was encouraging that all three traits observed little genotype by environment (GxE) interaction across diverse environments. This proved the trait analysis procedure to be robust in detecting and separating genotypes for both total phenolic content in colored maize, and amino acids in QPM. Top combiners for phenolics were the purple maize "maize morado" and red lines, with blue, yellow and white maize performing in descending order. Within the tested hybrids, high per kernel antioxidants (measured by total phenolics) may be the answer for producing the most total phenolics, with the top hybrid yielding greater than twice the total phenolics as the top yielding yellow hybrid. The top QPM hybrid out yielded the top normal hybrid by 35 and 30% for lysine and tryptophan. Additionally, QPM endosperm opacity primarily followed an additive, mid-parent trend, with some hybrids (20%) from diverse germplasm backgrounds deviating from that trend displaying the complexity and recessive nature of multiple modifier loci. Additional agronomic and composition traits were minimally correlated with phenolics.

Exposure of cells to hydrogen peroxide can cause oxidative damage to cellular constituents including lipids, protein, and DNA. At elevated concentrations, hydrogen peroxide can trigger cell death by apoptosis or necrosis. Apoptotic cell death can be prevented by overexpression of the oncoprotein Bcl-2. The exact mechanism by which Bcl-2 blocks cell death is controversial. Some researchers believe that Bcl-2 possesses antioxidant properties that protect cells from apoptosis. The purpose of this thesis was to assess oxidative stress and apoptosis following hydrogen peroxide exposure in Jurkat T cells overexpressing Bcl-2. One of the major objectives was to ascertain whether or not Bcl-2 overexpression elevated the antioxidant capacity of Jurkat T cells to provide protection from oxidant-induced cell death. Hydrogen peroxide treated Jurkat cells became apoptotic at moderate levels of oxidant (25-100 uM H2O2), and necrotic at higher doses (greater than 200 uM H2O2). Bcl-2 overexpression prevented caspase activation and cell death at the apoptotic doses of H2O2, but not the necrotic doses. Caspase inhibition studies demonstrated that Bcl-2 overexpression provided a greater level of resistance from H2O2-induced cell death than the broad-spectrum caspase inhibitor z-VAD.fmk. A systematic study was carried out examining the antioxidant status of Jurkat cells overexpressing Bcl-2. Several Bcl-2 transfectants were utilised for the study, so that any differences seen could be correlated to the level of Bcl-2 expression. Surprisingly, there were no statistically significant differences among the Bcl-2 transfectants for any of the antioxidant enzymes. Jurkat cells overexpressing Bcl-2 exhibited the same level of oxidative damage to lipids and protein in response to H2O2 exposure as the parental Jurkat cells. Interestingly, Jurkat cells overexpressing Bcl-2 continued to grow in culture after H2O2 exposure, despite harboring damage to cellular constituents. Consistent with these results, H2O2 treated Jurkat cells overexpressing Bcl-2, which failed to undergo apoptosis, were more prone to genomic instability. Together, these findings suggest that Bcl-2 overexpression protects Jurkat cells from H2O2-induced cell death by blocking apoptosis. Jurkat cells overexpressing Bcl-2 were no better at detoxifying oxidants and showed the same level of oxidative damage following H2O2 exposure. As a result, the overexpression of Bcl-2 considerably enhanced the mutagenicity of H2O2.

No description available.

Made available in DSpace on 2014-12-17T14:07:03Z (GMT). No. of bitstreams: 1 FranciscoCF_DISSERT_PARCIAL.pdf: 2286379 bytes, checksum: af4524a1a3287e34f13eef34d1f6e39b (MD5) Previous issue date: 2009-08-06 / Biodiesel is a fuel obtained from vegetable oils, such as soy, castorbean, among others. The monoester of fatty acid of these oils have chains with mono, di and tri double connections. The presence of these insaturations are susceptible to oxidization. Antioxidants are substances able to prevent oxidization from oils, fats, fat foods, as well as esters of Alquila( biodiesel). The objective of this work is to summarize a new antioxidant from the Cashew Nut Shell Liquid (CNSL) using the electrolysis technique. A current of 2 amperes was used in a single cell of only one group and two eletrodos of stainless steel 304 in a solution of methanol, together with the eletrolits: acetic acid, sodium chloride and sodium hydroxide, for two hours of agitation. The electrolysis products are characterized by the techniques of cromatography in a thin layer, spectroscopy of infrared and gravimetric analysis. The material was submitted to tests of oxidative stability made by the techniques of spectropy of impendancy and Rancimat (EN 14112). The analyses of characterization suggest that the polimerization of the electrolytic material ocurred. The application results of these materials as antioxidants of soy biodiesel showed that the order of the oxidative stability was obtained by both techniques used / Biodiesel ? um combust?vel obtido a partir de ?leos vegetais como soja, mamona, etc. Os monos ?ster de ?cidos graxos desses ?leos possuem cadeias com com mono, di e tri liga??es duplas. A presen?a destas insatura??es s?o suscept?veis a oxida??o. Antioxidantes s?o subst?ncias capazes de inibir oxida??o l?p?dica de ?leos, gorduras, alimentos gordurosos, bem como ?steres de alquila (biodiesel). O objetivo deste trabalho foi sintetizar um novo antioxidante a partir do l?quido da castanha de caju (LCC), utilizando a t?cnica da eletr?lise. Fez-se passar uma corrente de 2 ?mperes em uma ?nica c?lula de um s? compartimento e dois eletrodos de a?o inoxid?vel 304 em solu??o de metanol, na presen?a dos eletr?litos: ?cido ac?tico, cloreto de s?dio e hidr?xido de s?dio, por duas horas sob agita??o. Os produtos de eletr?lise foram caracterizados pelas t?cnicas de cromatografia em camada delgada, espectroscopia de infravermelho e an?lise termo gravim?trica. O material caracterizado foi submetido a testes de estabilidade oxidativa realizados pelas t?cnicas de espectroscopia de imped?ncia e de rancimat (EN 14112). As an?lises da caracteriza??o sugerem que ocorreu a polimeriza??o do material eletrolisado. Os resultados da aplica??o desses materiais como antioxidantes de biodiesel de soja mostraram que a ordem de estabilidade oxidativa foi: LSAL > LELET > LCC T?CNICO > KEROBIT > LACAC > LSODA, obtida pelas duas t?cnicas utilizadas

Orientador: Taís maria Bauab / Banca: Luis Vitor Silva do Sacramento / Banca: Carlos Henrique Gomes Martins / Resumo: A família Eriocaulaceae é amplamente distribuída no Brasil, popularmente são conhecidas como "sempre viva" porque, mesmo após o corte e secagem, conservam a cor e forma por vários anos. O objetivo deste trabalho foi determinar o potencial biológico de P. geniculatus, estudando a atividade antimicrobiana, antioxidante e a motilidade intestinal dos extratos diclorometânico, metanólico e hexânico. Para determinação da atividade antimicrobiana foram utilizadas as técnicas de difusão em ágar e microdiluição. Para determinação do potencial antioxidante foram realizados os ensaios espectrofotométricos: radical ABTS●+, DPPH, determinação dos teores de fenóis e flavonóides totais, utilizando como padrões a quercetina e ácido gálico. Na técnica de difusão em ágar, 100\L de suspensão bacteriana a concentração de 108 UFC/mL foram semeadas em ágar Muller Hinton e ágar Sabouraud. Discos de papel foram embebidos com 25\L das amostras vegetais e dispostos na superfície das placas de Petri. Após incubação a 37ºC por 24 horas em aerobiose foram feitas as leituras dos halos de inibição de crescimento ao redor dos discos (mm). No teste de microdiluição os orifícios das microplacas foram preenchidos com 80\L de caldo de Muller Hinton, 100\L de soluções da amostra vegetal diluída seriadamente de 1000 a 7,81\g/mL e 20\L da cultura a concentração de 107 células/mL para as bactérias e 103 células/mL para as leveduras. As microplacas foram incubadas a 37ºC durante 24 horas sob condições de aerobiose e posteriormente determinou se a CBM e CFM. Na avaliação da motilidade intestinal, foram utilizados os extratos de escapos e capítulos no solvente diclorometano e metanólicos (250mg/kg), um controle positivo (cloridrato de loperamida, 5mg/kg), controle negativo (solução fisiológica), controle do solvente (Tween 80 a 20% de metanol). Após 45 minutos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The family Eriocaulaceae is distributed over several parts of Brazil, are popularly known as "evergreen" because even after cutting and drying, retain their color and shape for many years. This work was to determine the biological potential of P. geniculatus, studying the activity antimicrobial, antioxidant and assess the motility of the extracts dichloromethanic, methanolic and hexanic. For activity determination as techniques were used antibacterial ágar diffusion and microdilution against Gram positive and Gram negative bacterium and yeasts. To determine the potential antioxidant spectrophotometric assays were performed: radical ABTS●+ , DPPH, determining the levels of phenolics and flavonoids, using standards as quercetin and gallic acid. In the diffusion technique , 100 mL of bacterial suspension concentration of 108 CFU/mL were seeded in Muller Hinton ágar and Sabouraud broth with Drigalski loop. Discs paper with 10 mm in diameter soaked with 25\L of vegetation samples were arranged on the surface of the plates. After incubation at 37 ° C for 24 hours under aerobic conditions were the readings of the inhibition of growth around the disks, measured in millimeters. In test microdilution holes of the microplate were filled with 80\L Muller Hinton broth , 100 mL of sample solutions of serially diluted plant 1000 to 7,81 \g/mL and 20\L of bacterial culture concentration of 107 cells/mL and 103 cells/mL for yeasts. The microplates were incubated at 37 ° C for 24 hours under aerobic conditions and subsequently became the technique of CBM and CFM. In the evaluation of intestinal motility, were used extracts of scapes and chapters in dichloromethane solvent and methanol (250mg/kg), a positive control (loperamide hydrochloride, 5mg/kg), negative control (saline solution), control of the solvent (Tween 80 to 20% methanol). After about 45 minutes the animals received a suspension activated... (Complete abstract click electronic access below) / Mestre