OBJECTIVE To observe the effect of betulinic acid on CCl_4 induced liver injury in mice and its possible molecular mechanisms.METHODS Male ICR mice were randomly divided into 5 groups:normal control group,CCl_4 group(20 mg/kg),CCl_4+Silibinin group(200 mg/kg),CCl_4+betulinic acid group(20 mg/kg),CCl_4+betulinic acid group(40 mg/kg).Mice in the normal control group and CCl_4 group were given distilled water while other groups were given drugs in 7 days by gavage.2 hafter the last administration,0.1% CCl_4 wi...