Objective: To study the antioxidative activity of the water-soluble extracts from Fructus Polygoni Orientalis.
Methods: Malondialdehyde and superoxide dismutase were measured by thiobarbituric acid assay, nitrite method, respectively. The activity of glutathione peroxidase was determined by 5,5'-dithionbis (2-nitrobenzoic acid) photometric method. Lipofuscin was determined by Sohal method in the brain of senile model mice induced by D-galactose. The extracts of 0.8, 1.6 and 3.2 g.kg(-1).d(-1) were administered to the mice separately through oral gavage daily for 7 weeks.
Results: Malondialdehyde content increased, activities of superoxide dismutase and glutathione peroxidase in the heart, liver and kidney decreased. Levels of lipofuscin in the brain of senile model mice induced by D-galactose increased. The three doses of the extracts could inhibit the levels of lipofuscin in the brain, malondialdehyde in the heart, liver and kidney. These results showed that there was a negative dose-effect relationship. The extracts also up-regulated the levels of superoxide dismutase and glutathione peroxidase in the heart, liver and kidney with a positive dose-effect relationship.
Conclusion: The water-soluble extracts exert its antioxidative activity by eliminating free hydroxyl radicals, increasing activities of superoxide dismutase and glutathione peroxidase.