INHIBITORY EFFECTS OF ISOFLAVONES IN ROOTS OF ASTRAGALUS-MEMBRANACEUSBUNGE (ASTRAGALI RADIX) ON LIPID-PEROXIDATION BY REACTIVE OXYGEN SPECIES

Possible inhibitory effects were investigated of isoflavones in the ro ots of Astragalus membranaceus BUNGE (Astragali Radix), afrormosin, ca lycosin, formononetin and odoratin on lipid peroxidation by reactive o xygen species. Calycosin inhibited lecithin peroxidation which was ind uced by hydroxy radical-generation by interaction of haemoglobin and h ydrogen peroxide. Calycosin and formononetin inhibited lecithin peroxi dation which was induced by superoxide anion generation by xanthine-xa nthine oxidase. Other isoflavones had no inhibitory effects on lecithi n peroxidations. These results demonstrated that the antioxidant prope rties of isoflavones, which have a methoxy group at the 4' position, a re derived from hydroxy groups at the 7 and 4' position. (C) 1998 John Wiley & Sons, Ltd.