Abstract: Cordyceps militaris fruiting bodies were extracted by using the method of systematic solvent extraction, and three different extracts were prepared named chloroform extract, acetic ether extract and ethanol extract, respectively. In vitro, the antioxidant activities of different extracts were investigated by using chemiluminescence measurements, and the activities of oxidative injury protection were assessed by using PC12 oxidative injury model induced with H₂O₂. The superoxide free radical (O₂^-) system and H₂O₂ system assays showed that the acetic ether extract had notable antioxidant activity, their scavenging rate for both H₂O₂ and O2- were highest among the three extracts, whose IC₅₀ were 88.5 µg/mL and 190 µg/mL, respectively. Moreover, the oxidative injury protection for PC12 assay showed that the acetic ether extract had significant rehabilitation effect in comparison with chloroform extract and ethanol extract, and it rehabilitated PC12 cell treated with H₂O₂ in a dose-dependent manner. Therefore, it was concluded that the acetic ether extract was the principal extract of both antioxidant and the activity of oxidative injury rehabilitation among three extracts from C. militaris fruiting bodies.

Key words: Cordyceps militaris, antioxidant activity, PC12 cell, oxidative injury, systematic solvent extraction