<正> Aim:To investigate and compare the antioxidant activities of salvianolic acid B（SalB）and Ginkgo biloba extract（EGb 761）in aqueous solution,rat microsomesand the cellular system.Methods:Superoxide anion（O2-）was generated usingxanthine/xanthine oxidase system and phenazine methosulate/NADH system,andthe effects of SalB and EGb 761 on the generation of O2- were achieved by spectro-photometric measurement of the product formed on reduction of nitro bluetetrazolium.Two different methods were used to assess the scavenging effects ofthe extracts on hydroxyl radical（.OH）:HPLC method was used for quantitation of.OH by oxy-radical trapping of 5,5-dimethyl- 1-pyrroline-N-oxide（DMPO）to formDMPO-OH adducts in Fe2+-EDTA-H2O2 system.To confirm the HPLC data,.OHwas also measured by spectrophotometry using a commercial detection kit.Theanti-lipid peroxidation effects of the extracts in microsomes of rat brain,liver andkidney induced by ascorbate-NADPH were determined by thiobarbituric acid（TBA）method.The protective effects of the extracts on peroxide hydrogen（H2O2）-induced oxidative damage in SH-SY5Y cells were investigated by assessing cellviability assay,the level of lipid peroxidation,and the lactate dehydrogenase（LDH）release.Results:Both SalB and EGb 761 were able to scavenge O2- and.OH,inhibit lipid peroxidation of microsomes,and protect SH-SY5Y ceils againstH2O2-induced oxidative damage.However,the concentration of SalB was far lowerthan that of EGb 761 when a similar effect was obtained.Conclusion:The antioxi-dant efficiency of SalB was greater than that of EGb 761.These results suggestthat SalB,like EGb 761,has promising potential in treating oxidative damage-derived neurodegenerative disorders.
