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Radical-scavenging Ability (radical-scavenging + ability)
Selected AbstractsDISTRIBUTION AND ANTIOXIDANT ACTIVITY OF POLYPHENOLS IN RIPE AND UNRIPE TREE PEPPER (CAPSICUM PUBESCENS)JOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2007G. OBOH ABSTRACT Capsicum pubescens, commonly known as tree pepper with its distinctive thick-fleshed pungent fruit (ripe and unripe), is used as a vegetable condiment or made into a sauce. The present study sought to determine the distribution of polyphenols and antioxidant activity in its thick flesh and seeds. Free, bound and total phenol content of each extract was subsequently determined, while reducing power, Fe (II)-chelating ability, OH radical-scavenging ability and ability of the extracts to inhibit lipid peroxidation in basal and Fe (II)-induced lipid peroxidation in brain was used for antioxidant capacity. Unripe pepper had higher total phenol content than ripe pepper; however, there was no significant difference ( P > 0.05) in the total phenol content of flesh for both peppers (unripe [110 mg/100g], ripe [95 mg/100 g]) and the seed (unripe [110.0 mg/100 g ], ripe [90 mg/100 g]). Nevertheless, the free polyphenols in flesh and seed of the peppers were significantly higher ( P < 0.05) than the bound polyphenols. All the extracts inhibited lipid peroxidation in a dose-dependent manner, although free polyphenols from the flesh of ripe pepper caused the highest inhibition in malondialdehyde production in rat's brain. Free and bound polyphenols from the flesh of unripe pepper had the highest Fe (II)-chelating and OH radical-scavenging ability. While the free polyphenols from the flesh of ripe pepper had the highest reducing power, this may have accounted for its ability to reduce Fe (II)-induced lipid peroxidation. Therefore, by removing the seed from pepper, a 50% loss in the total phenol content would result, which will substantially reduce antioxidant activity. PRACTICAL APPLICATIONS Because many degenerative human diseases have been recognized as being a consequence of free radical damage, there have been many studies undertaken on how to delay or prevent the onset of these diseases. The most likely and practical way to fight against degenerative diseases is to improve body antioxidant status, which could be achieved by higher consumption of vegetables and fruits. Foods from plant origin usually contain natural antioxidants that can scavenge free radical. The inclusion of either ripe or unripe pepper in a diet is a common practice in Africa and some other parts of the world; our recent findings on the antioxidant properties of Capsicum pubescens clearly indicate that its inclusion in the diet will contribute greatly in the prevention of neuro-degenerative diseases associated with oxidative stress, by inhibiting lipid peroxidation. Moreover, removing the seeds of this pepper during food processing will reduce the total phenol content by 50%, and consequently reduce the antioxidant activity. [source] Antioxidative capacity produced by Bifidobacterium - and Lactobacillus acidophilus -mediated fermentations of konjac glucomannan and glucomannan oligosaccharidesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2008Cheng-Hsin Wang Abstract BACKGROUND: Konjac glucomannan (KGM) has been shown to stimulate the growth of bifidobacteria and lactobacilli in the human and rat colon. This study investigated the antioxidative effects produced after 48 h in vitro fermentation of unhydrolysed KGM and two hydrolysed KGM fractions (KH1 and KH2 with degree of polymerisation 10 and 5 respectively) by Bifidobacterium adolescentis, B. bifidum, B. breve, B. longum and Lactobacillus acidophilus respectively. The inhibitory effect on conjugated diene formation, ferric-chelating capacity, ,,,-diphenyl-,-picrylhydrazyl (DPPH) radical-scavenging ability and thiobarbituric acid-reactive substances (TBARS) concentration produced by these fermentations were compared with those of oligofructose (OF) fermentation. RESULTS: The fermentation of KGM by each bacterial strain produced higher ferric-chelating capacity of the culture supernatant compared with KH2 or OF fermentation. In contrast, the fermentation of KGM by each bacterial strain led to lower inhibition of conjugated diene formation and lower radical-scavenging ability compared with KH2 fermentation. The fermentation of KH2 produced the lowest amount of TBARS. CONCLUSION: The fermentation of unhydrolysed KGM by colonic lactic acid bacteria in vitro produced antioxidative capacity mainly by preventing the initiation of ferrous ion-induced peroxidation, whereas the fermentation of konjac oligosaccahrides did so by increasing the radical-scavenging ability and eliminating lipid peroxide formation. Copyright © 2008 Society of Chemical Industry [source] The Response of Articular Chondrocytes to Type II Collagen,Au NanocompositesARTIFICIAL ORGANS, Issue 12 2007Shan-hui Hsu Abstract:, The nanocomposites (denoted "CII,Au") of porcine type II collagen (CII) with 0.05, 0.1, 0.5, 1, or 2.5% (wt/wt) Au nanoparticles (,5 nm) were fabricated for potential use in cartilage tissue engineering. Au formed clusters on the surface of all nanocomposites and appeared to distribute along the collagen fibrils inside the matrix. The addition of Au at low concentrations (,0.5%) increased the modulus and viscosity, as well as the free radical-scavenging ability. These effects decreased at higher concentrations of Au. The chondrocytes on CII,Au became spindle-like with lamellipodia formation. Cell proliferation on CII,Au 0.1% was promoted. Nitric oxide (NO) in the culture medium was reduced by CII,Au 0.05% and CII,Au 0.1%. Type I collagen, aggrecan, and Sox 9 gene expressions increased with an increased Au content, but slightly decreased at 2.5% Au. There was no significant difference in the CII gene expression. The cellular uptake of Au was observed but less than that which occurred when 10 ppm of Au was added in culture medium. Chondrocytes cultured with ,10 ppm of Au nanoparticles showed neither cytotoxicity nor change in gene expression. Au at an appropriate amount could be well dispersed in CII, and enhanced the material modulus, antioxidant effect, as well as the chondrocyte growth and matrix production. 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