Abstract:The antioxidation effect in vivo of Cordyceps sinensis for oxidative injury mice and its underlying mechanism were studied.Sixty mice were randomly divided into six groups：blank group，model group，vitamin E positive group，high，middle and low dose Cordyceps sinensis groups.The oxidative injury mice model of mice were established by back subcutaneous injection of D-galactose every day.The level of malondialdehyde（MDA），protein carbonyl（PC），glutathione （GSH），and the activities of superoxide dismutase（SOD），glutathione （GSH-Px）and total antioxidant activity （T-AOC）in serum，liver and brain were measured.The SOD and GSH-Px mRNA expression in liver were also detected by real time-polymerase chain reaction.Compared with the model group，Cordyceps sinensis could significantly reduce the content of MDA and protein carbonyl，increase the content of GSH and the activity of SOD，GSH-px and T-AOC in the serum of mice.It also could remarkably decrease MDA content and increase the activity of SOD and GSH-Px in liver and brain tissues of mice.In addition，Cordyceps sinensis could significantly increase SOD and GSH -Px mRNA expression in liver tissues of mice.Cordyceps sinensis could significantly improve the antioxidant capacity of mice with oxidative damage and the underlying mechanism might be associated with regulating the antioxidant enzyme gene expression.