Objective To study the effect of alcohol extract of Qianghuo（Notopterygium root or rhizome）on antioxidase of liver tissues of rats with hepatic ischemia reperfusion injury（HIRI）and its mechanism.Methods Totally 100 rats were randomized into four groups

i.e.blank group

model group

Danshen（Salvia miltiorrhiza）pretreatment group（DS group）

and Qianghuo（Notopterygium root or rhizome）pretreatment group（QH group）.The latter three groups were subdivided into three groups respectively

namely

ischemia 45 min subgroup（I45）

ischemia 45 min reperfusion 30 min group（I45R30）and 60 min subgroups（I45R60）.The alcohol extract of Danshen or Qianghuo was given to DS group or QH group respectively by gastric perfusion 1 ml/d for 7 days.The level of alanine transaminase（ALT）in serum

content of malondialdehyde（MDA）

and activity of glutathione peroxidase（GSH-Px）of liver tissues of all rats in each time point were determined respectively and compared.Results In the I45R30 and I45R60 subgroups of model group

QH group

and DS group

the level of ALT in serum

the content of MDA

and the activity of GSH-Px were significantly higher than those of I45 subgroup（P<0.01）.In the I45R60 subgroup of DS group

the content of MDA of liver tissues was significantly lower than that QH group（P<0.05）.In the I45R60 subgroup of DS group

the activity of GSH-Px of liver tissues was lower than that of the model group and QH group（P<0.05）.Conclusion Qianghuo（Notopterygium root or rhizome）probably protects the liver through enhancing the GSH-Px activity

strengthening the ability of eliminating radical

and relieving the lipid peroxidation injury of liver tissue of HIRI model rats.