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Rui Hai Liu - One of the best experts on this subject based on the ideXlab platform.
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cellular Antioxidant Activity of common fruits
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Kelly L Wolfe, Xinmei Kang, Mei Dong, Qingyuan Zhang, Rui Hai LiuAbstract:Measurement of Antioxidant Activity using biologically relevant assays is important in the screening of fruits for potential health benefits. The cellular Antioxidant Activity (CAA) assay quantifies Antioxidant Activity in cell culture and was developed to meet the need for a more biologically representative method than the popular chemistry Antioxidant capacity measures. The objective of the study was to determine the cellular Antioxidant Activity, total phenolic contents, and oxygen radical absorbance capacity (ORAC) values of 25 fruits commonly consumed in the United States. Pomegranate and berries (wild blueberry, blackberry, raspberry, and blueberry) had the highest CAA values, whereas banana and melons had the lowest. Apples were found to be the largest contributors of fruit phenolics to the American diet, and apple and strawberries were the biggest suppliers of cellular Antioxidant Activity. Increasing fruit consumption is a logical strategy to increase Antioxidant intake and decrease oxidative stress and may lead to reduced risk of cancer.
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structure Activity relationships of flavonoids in the cellular Antioxidant Activity assay
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Kelly L Wolfe, Rui Hai LiuAbstract:Chemical Antioxidant Activity assays are used extensively to evaluate the potential bioActivity of plant foods and their phytochemical constituents, but they do not mimic the complexity of biological systems. The cellular Antioxidant Activity (CAA) Activity assay was developed to be a more biologically relevant model to measure Antioxidant Activity. Structure−Activity relationships of flavonoids have been determined in many chemistry Antioxidant Activity assays, and they vary with the protocols. The objective of this study was to determine structure−Activity relationships of selected flavonoids in the CAA assay. The structures that conferred flavonoids with the most Antioxidant Activity in the CAA assay were a 3′,4′-o-dihydroxyl group in the B-ring, a 2,3-double bond combined with a 4-keto group in the C-ring, and a 3-hydroxyl group. Isoflavones had no cellular Antioxidant Activity. Flavanols with a galloyl moiety had higher Antioxidant Activity than those without, and a B-ring 3′,4′,5′-trihydroxyl group ...
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processed sweet corn has higher Antioxidant Activity
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Veronica Dewanto, Rui Hai LiuAbstract:Processed fruits and vegetables have been long considered to have lower nutritional value than the fresh produce due to the loss of vitamin C during processing. Vitamin C in apples has been found to contribute <0.4% of total Antioxidant Activity, indicating most of the Activity comes from the natural combination of phytochemicals. This suggests that processed fruits and vegetables may retain their Antioxidant Activity despite the loss of vitamin C. Here it is shown that thermal processing at 115 degrees C for 25 min significantly elevated the total Antioxidant Activity of sweet corn by 44% and increased phytochemical content such as ferulic acid by 550% and total phenolics by 54%, although 25% vitamin C loss was observed. Processed sweet corn has increased Antioxidant Activity equivalent to 210 mg of vitamin C/100 g of corn compared to the remaining 3.2 mg of vitamin C in the sample that contributed only 1.5% of its total Antioxidant Activity. These findings do not support the notion that processed fruits and vegetables have lower nutritional value than fresh produce. This information may have a significant impact on consumers' food selection by increasing their consumption of fruits and vegetables to reduce the risk of chronic diseases.
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nutrition Antioxidant Activity of fresh apples
Nature, 2000Co-Authors: Marian V Eberhardt, Chang Yong Lee, Rui Hai LiuAbstract:Vitamin C is used as a dietary supplement because of its Antioxidant Activity, although a high dose (500 mg) may act as a pro-oxidant in the body1,2. Here we show that 100 g of fresh apples has an Antioxidant Activity equivalent to 1,500 mg of vitamin C, and that whole-apple extracts inhibit the growth of colon- and liver- cancer cells in vitro in a dose-dependent manner. Our results indicate that natural Antioxidants from fresh fruit could be more effective than a dietary supplement.
George Paganga - One of the best experts on this subject based on the ideXlab platform.
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Antioxidant Activity of phytoestrogenic isoflavones
Free Radical Research, 1997Co-Authors: M B Ruizlarrea, George Paganga, Nicholas J Miller, A R Mohan, G P Bolwell, Catherine RiceevansAbstract:The aim of this work was to determine the Antioxidant activities of a range of phytoestrogenic isoflavones. The Antioxidant Activity in the aqueous phase was determined by means of the ABTS˙+ total Antioxidant Activity assay. The results show that the order of reActivity in scavenging the radical in the aqueous phase is genistein > daidzein = genistin = biochanin A = daidzin > formononetin = ononin, the latter displaying no Antioxidant Activity. The importance of the single 4′-hydroxyl group in the reActivity of the isoflavones, as scavengers of aqueous phase radicals, as well as the 5, 7-dihydroxy structure is demonstrated. Examination of their abilities to enhance the resistance of low density lipoproteins to oxidation supports the observation that genistein is the most potent Antioxidant among this family of compounds studied, both in the aqueous and in the lipophilic phases.
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Structure-Antioxidant Activity relationships of flavonoids and phenolic acids
Free Radical Biology and Medicine, 1996Co-Authors: Catherine A. Rice-evans, Nicholas J Miller, George PagangaAbstract:The recent explosion of interest in the bioActivity of the the flavonoids of higher plants is due, at least in part, to the potential health benefits of these polyphenolic components of major dietary constituents. This review article discusses the biological properties of the flavonoids and focuses on the relationship between their Antioxidant Activity, as hydrogen donating free radical scavengers, and their chemical structures. This culminates in a proposed hierarchy of Antioxidant Activity in the aqueous phase. The cumulative findings concerning structure-Antioxidant Activity relationships in the lipophilic phase derive from studies on fatty acids, liposomes, and low-density lipoproteins; the factors underlying the influence of the different classes of polyphenols in enhancing their resistance to oxidation are discussed and support the contention that the partition coefficients of the flavonoids as well as their rates of reaction with the relevant radicals define the Antioxidant activities in the lipophilic phase.
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structure Antioxidant Activity relationships of flavonoids and phenolic acids
Free Radical Biology and Medicine, 1996Co-Authors: Catherine Riceevans, Nicholas J Miller, George PagangaAbstract:The recent explosion of interest in the bioActivity of the flavonoids of higher plants is due, at least in part, to the potential health benefits of these polyphenolic components of major dietary constituents. This review article discusses the biological properties of the flavonoids and focuses on the relationship between their Antioxidant Activity, as hydrogen donating free radical scavengers, and their chemical structures. This culminates in a proposed hierarchy of Antioxidant Activity in the aqueous phase. The cumulative findings concerning structure-Antioxidant Activity relationships in the lipophilic phase derive from studies on fatty acids, liposomes, and low-density lipoproteins; the factors underlying the influence of the different classes of polyphenols in enhancing their resistance to oxidation are discussed and support the contention that the partition coefficients of the flavonoids as well as their rates of reaction with the relevant radicals define the Antioxidant activities in the lipophilic phase.
Dave B Oomah - One of the best experts on this subject based on the ideXlab platform.
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Antioxidant Activity in common beans phaseolus vulgaris l
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Anaberta Cardadormartinez, Guadalupe Loarcapina, Dave B OomahAbstract:Beans were pearled to evaluate the feasibility of increasing Antioxidant Activity and phenolic Antioxidants. Phenolics were concentrated mostly in the hull fraction at about 56 mg of catechin equivalents per gram of sample. The methanolic extracts of the pearled bean samples were screened for Antioxidant potential using the β-carotene−linoleate and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) in vitro model systems. The pearled material, also referred to as milled samples, exhibited Antioxidant Activity that correlated with phenolic content and inhibited DPPH significantly in a dose-dependent manner. Phenolics and Antioxidant activities were also examined in chromatographic fractions of methanolic extracts of manually obtained hulls that represented a model used previously to ascertain antimutagenic Activity. Fractions extracted with ethyl acetate/acetone and acetone displayed Antioxidant Activity, which implies potent free radical scavenging Activity with antimutagenic Activity. Keywords: Phenolics; antioxid...
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Antioxidant Activity in common beans phaseolus vulgaris l
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Anaberta Cardadormartinez, Guadalupe Loarcapina, Dave B OomahAbstract:Beans were pearled to evaluate the feasibility of increasing Antioxidant Activity and phenolic Antioxidants. Phenolics were concentrated mostly in the hull fraction at about 56 mg of catechin equivalents per gram of sample. The methanolic extracts of the pearled bean samples were screened for Antioxidant potential using the beta-carotene-linoleate and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) in vitro model systems. The pearled material, also referred to as milled samples, exhibited Antioxidant Activity that correlated with phenolic content and inhibited DPPH significantly in a dose-dependent manner. Phenolics and Antioxidant activities were also examined in chromatographic fractions of methanolic extracts of manually obtained hulls that represented a model used previously to ascertain antimutagenic Activity. Fractions extracted with ethyl acetate/acetone and acetone displayed Antioxidant Activity, which implies potent free radical scavenging Activity with antimutagenic Activity.
Ilhami Gulcin - One of the best experts on this subject based on the ideXlab platform.
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in vitro Antioxidant Activity of silymarin
Journal of Enzyme Inhibition and Medicinal Chemistry, 2009Co-Authors: Ekrem Koksal, Sevim Beyza, Ozturk Sarikaya, Ilhami Gulcin, Ercan BursalAbstract:Silymarin, a known standardized extract obtained from seeds of Silybum marianum is widely used in treatment of several diseases of varying origin. In the present paper, we clarified the Antioxidant Activity of silymarin by employing various in vitro Antioxidant assay such as 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH·) scavenging, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging Activity, total Antioxidant Activity determination by ferric thiocyanate, total reducing ability determination by Fe3+ − Fe2+ transformation method and Cuprac assay, superoxide anion radical scavenging by riboflavin/methionine/illuminate system, hydrogen peroxide scavenging and ferrous ions (Fe2+) chelating activities. Silymarin inhibited 82.7% lipid peroxidation of linoleic acid emulsion at 30 μg/mL concentration; butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), α-tocopherol and trolox indicated inhibition of 83.3, 82.1, 68.1 and 81.3% on peroxidation of linoleic acid emulsion ...
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Antioxidant Activity of cauliflower brassica oleracea l
Turkish Journal of Agriculture and Forestry, 2008Co-Authors: Ekrem Koksal, Ilhami GulcinAbstract:Recently, a number of studies on the health benefits associated with fruits, vegetables, herbs and spices demonstrated that they possess potent Antioxidant, anti-inflammatory, anti-mutagenic, and anti-carcinogenic Activity. The potential Antioxidant Activity of water and ethanol extracts of cauliflower (Brassica oleracea L.) were investigated to evaluate their potential value as a natural ingredient for foods or cosmetic application. In this study Antioxidant Activity was measured by 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH.) scavenging, N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD) radical scavenging, superoxide anion (O2.-) radical scavenging, total Antioxidant Activity, reducing Activity using Fe+3-Fe+2 transformation and CUPRAC assays, hydrogen peroxide (H2O2) scavenging, and ferrous metal chelating Activity assays. The water extract of cauliflower (WEC) and ethanol extract of cauliflower (EEC), as Antioxidants, neutralized the Activity of radicals and inhibited the peroxidation reactions of linoleic acid emulsion. Total Antioxidant Activity was measured according to the ferric thiocyanate method. a-Tocopherol and trolox, a water-soluble analogue of tocopherol, were used as the reference Antioxidant compounds. WEC and EEC showed 88.6% and 80.1% inhibition of lipid peroxidation of linoleic acid emulsion, respectively, at the concentration of 30 µg ml-1. On the other hand, at the same concentration, the standard Antioxidants a-tocopherol and trolox exhibited 68.1.4% and 81.3% inhibition of peroxidation of linoleic acid emulsion, respectively. In addition, WEC and EEC had effective DPPH., ABTS.+, DMPD.+, and superoxide anion radical scavenging, hydrogen peroxide scavenging, total reducing power, and metal chelating of ferrous ion Activity. Also, those various Antioxidant activities were compared to a-tocopherol and trolox as references Antioxidants.
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Antioxidant Activity of cauliflower brassica oleracea l
Turkish Journal of Agriculture and Forestry, 2008Co-Authors: Ekrem Koksal, Ilhami GulcinAbstract:Recently, a number of studies on the health benefits associated with fruits, vegetables, herbs and spices demonstrated that they possess potent Antioxidant, anti-inflammatory, anti-mutagenic, and anti-carcinogenic Activity. The potential Antioxidant Activity of water and ethanol extracts of cauliflower (Brassica oleracea L.) were investigated to evaluate their potential value as a natural ingredient for foods or cosmetic application. In this study Antioxidant Activity was measured by 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH.) scavenging, N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD) radical scavenging, superoxide anion (O2.-) radical scavenging, total Antioxidant Activity, reducing Activity using Fe+3-Fe+2 transformation and CUPRAC assays, hydrogen peroxide (H2O2) scavenging, and ferrous metal chelating Activity assays. The water extract of cauliflower (WEC) and ethanol extract of cauliflower (EEC), as Antioxidants, neutralized the Activity of radicals and inhibited the peroxidation reactions of linoleic acid emulsion. Total Antioxidant Activity was measured according to the ferric thiocyanate method. a-Tocopherol and trolox, a water-soluble analogue of tocopherol, were used as the reference Antioxidant compounds. WEC and EEC showed 88.6% and 80.1% inhibition of lipid peroxidation of linoleic acid emulsion, respectively, at the concentration of 30 µg ml-1. On the other hand, at the same concentration, the standard Antioxidants a-tocopherol and trolox exhibited 68.1.4% and 81.3% inhibition of peroxidation of linoleic acid emulsion, respectively. In addition, WEC and EEC had effective DPPH., ABTS.+, DMPD.+, and superoxide anion radical scavenging, hydrogen peroxide scavenging, total reducing power, and metal chelating of ferrous ion Activity. Also, those various Antioxidant activities were compared to a-tocopherol and trolox as references Antioxidants.
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determination of Antioxidant Activity of lichen cetraria islandica l ach
Journal of Ethnopharmacology, 2002Co-Authors: Ilhami Gulcin, Munir Oktay, Irfan O Kufrevioglu, Ali AslanAbstract:The study was aimed at evaluating the Antioxidant Activity of aqueous extract of C. islandica. The Antioxidant Activity, reducing power, superoxide anion radical scavenging and free radical scavenging activities were studied. The Antioxidant Activity increased with the increasing amount of extracts (from 50 to 500 μg) added to linoleic acid emulsion. About 50, 100, 250, and 500 μg of aqueous extract of C. islandica showed higher Antioxidant Activity than 500 μg of α-tocopherol. The samples showed 96, 99, 100, and 100% inhibition on peroxidation of linoleic acid, respectively. On the other hand, the 500 μg of α-tocopherol showed 77% inhibition on peroxidation on linoleic acid emulsion. Like Antioxidant Activity, the reducing power, superoxide anion radical scavenging and free radical scavenging activities of C. islandica depends on concentration and increasing with increased amount of sample. The results obtained in the present study indicate that C. islandica is a potential source of natural Antioxidant.
Kelly L Wolfe - One of the best experts on this subject based on the ideXlab platform.
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cellular Antioxidant Activity of common fruits
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Kelly L Wolfe, Xinmei Kang, Mei Dong, Qingyuan Zhang, Rui Hai LiuAbstract:Measurement of Antioxidant Activity using biologically relevant assays is important in the screening of fruits for potential health benefits. The cellular Antioxidant Activity (CAA) assay quantifies Antioxidant Activity in cell culture and was developed to meet the need for a more biologically representative method than the popular chemistry Antioxidant capacity measures. The objective of the study was to determine the cellular Antioxidant Activity, total phenolic contents, and oxygen radical absorbance capacity (ORAC) values of 25 fruits commonly consumed in the United States. Pomegranate and berries (wild blueberry, blackberry, raspberry, and blueberry) had the highest CAA values, whereas banana and melons had the lowest. Apples were found to be the largest contributors of fruit phenolics to the American diet, and apple and strawberries were the biggest suppliers of cellular Antioxidant Activity. Increasing fruit consumption is a logical strategy to increase Antioxidant intake and decrease oxidative stress and may lead to reduced risk of cancer.
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structure Activity relationships of flavonoids in the cellular Antioxidant Activity assay
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Kelly L Wolfe, Rui Hai LiuAbstract:Chemical Antioxidant Activity assays are used extensively to evaluate the potential bioActivity of plant foods and their phytochemical constituents, but they do not mimic the complexity of biological systems. The cellular Antioxidant Activity (CAA) Activity assay was developed to be a more biologically relevant model to measure Antioxidant Activity. Structure−Activity relationships of flavonoids have been determined in many chemistry Antioxidant Activity assays, and they vary with the protocols. The objective of this study was to determine structure−Activity relationships of selected flavonoids in the CAA assay. The structures that conferred flavonoids with the most Antioxidant Activity in the CAA assay were a 3′,4′-o-dihydroxyl group in the B-ring, a 2,3-double bond combined with a 4-keto group in the C-ring, and a 3-hydroxyl group. Isoflavones had no cellular Antioxidant Activity. Flavanols with a galloyl moiety had higher Antioxidant Activity than those without, and a B-ring 3′,4′,5′-trihydroxyl group ...