Acta Pharmaceutica Sinica 2003,38(4):241-244Antioxidation properties and mechanism of action of dihydromyricetin from Ampelopsis grossedentata

Aim To assess the antioxidative properties and the mechanism of action of dihydromyricetin (DMY) from Ampelopsis grossedentata. Methods The antioxidative properties of DMY were measured by scavenging 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and inhibiting lipid peroxidation induced by FeSO₄-edetic acid in linoleic acid. The mechanism of antioxidative properties of DMY was tested by measuring the chelating activities of DMY for Fe²⁺ with ultraviolet spectrum (UV) method. Results The specific absorption of DPPH radical solution at 517 nm was reduced 73.3%-91.5% when DMY was added into the reaction solution in the concentration range from 0.01% to 0.04%. DMY was shown to greatly inhibit the increase of lipid peroxidation (LPO) values in linolei acid system catalyzed by FeSO₄-edetic acid. The reaction rates (A₅₃₂·min^-1) of lipid peroxidation were 0.002 1-0.000 4 in the concentration range from 0.01% to 0.04% and the inhibition activities of DMY was found to be in a concentration-dependent manner. The mechanism of antioxidative properties of DMY was chelating Fe²⁺ in the Fe²⁺-dependent lipid peroxidation system. Conclusion DMY showed great antioxidative effect and would be a good natural antioxidant.