IN-VITRO ANTIOXIDANT ACTIVITY OF VIETNAMESE GINSENG SAPONIN AND ITS COMPONENTS

To elucidate the antioxidant action of Vietnamese ginseng saponin agai nst free radial-mediated cellular damage, we examined the effect of Vi etnamese ginseng saponin on lipid peroxidation in the mouse brain, liv er, and liver microsomes by using two in vitro free radical generating systems (iron ferrous+ascorbic acid and iron ferrous+hydrogen peroxid e). Free radical-mediated Lipid peroxidation was determined by measuri ng the endogenous and stimulated accumulation of thiobarbituric acid r eactive substance (TBA-RS). Vietnamese ginseng saponin (0.05-0.5 mg/ml ), as well as vitamin E, significantly inhibited the formation of TBA- RS in tissue homogenates. Panax ginseng saponin, at the same concentra tion range as Vietnamese ginseng saponin, also had inhibitory action o n free radical-mediated lipid peroxidation. However, majonoside-R2, gi nsenoside-Rg(1) and ginsenoside-Rb-1, the main saponin components of V ietnamese ginseng saponin fraction, had no effect on lipid peroxidatio n. These results suggest that Vietnamese ginseng exerts a protective a ction against free radical-induced tissue injury and that this effect is attributable to minor components rather than the main saponin compo nents tested.