栄研スタッフによる解説論文集 資料　作成日　98/01/21
	Flavonoids are scavengers of superoxide anions
	著者: Robak, J. and Gryglewski, R. J.
	出典: Biochem Pharmacol, 37, 837-841(1988)

要約

Seven flavonoids and three non-flavonoid antioxidants, i.e. butylated hydroxyanisole, chlorpromazine and BW755C, were studied as potential scavengers of oxygen free radicals. Superoxide anions were generated enzymatically in a xanthin-xanthine oxidase system and non-enzymatically in a phenazine methosulphate-NADH system, and assayed by reduction of nitro blue tetrazolium. The generation of malonaldehyde (MDA) by the ascorbate-stimulated air-oxidised boiled rat liver microsomes was considered as an index of the non-enzymatic formation of hydroxyl radicals. Flavonoids but not non-flavonoid antioxidants lowered the concentration of detectable superoxide anions in both enzymic and non-eazymic systems which generated these SOD-sensitive radicals. The most effective inhibitors of superoxide anions were quercetin, myricetin and rutin. Four out of seven investigated flavonoids seemed also to suppress the activity of xanthine oxidase as measured by a decrease in uric acid biosynthesis. All ten investigated compounds inhibited the MDA formation by rat liver microsomes. Non-flavonoid antioxidants were more potent MDA inhibitors than flavonoids. It is concluded that antioxidant properties of flavonoids are effected mainly via scavenging of superoxide anions whereas non-flavonoid antioxidants act on further links of free radical chain reactions, most likely by scavenging of hydroxyl radicals .

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