Protective effects of extracts of ginkgo biloba leaf on cerebral ischemia/reperfusioninduced oxidative injury in rats

Objective We tried to observe the protective effects of extracts of Ginkgo biloba leaf(EGB) on cerebral ischemia/reperfusion induced oxidative injury in rats.Methods Sixty male Wistar rats were randomly divided into following six groups(n=10for each):(a)normal control,(b) injury model,(c)sham operation,(d)low dose of EGB,(e)middle dose of EGB,(f) high dose of EGB.EGB dissolved in distilled in water at dosages of 25,50 and 100mg/kg was given to group d,e,f by gastric tube,continued for 14d;but group a,b,c was only given the equal volume of distilled water at dose of 10ml/kg.At 1 h after the last drug administration,the rats in group b,d,e,f were submitted to incomplete cerebral ischemia(1h)/reperfusion(30min) injury;but group c was only operated and not submitted to cerebral ischemia/reperfusion injury.The cerebral cortex tissue was taken and homogenized for following index assays:SOD and NOS activities,GSH,MDA content and total antioxidative catacity(T-AOC).Results Compared with the normal control,the SOD activity,GSH content and T-AOC in rat brain significantly decreased,but NOS activity and MDA content significantly increased in injury model group.Compared with the injury model,SOD activity,GSH content and T-AOC in rat brain significantly increased,but NOS activity and MDA content were significantly decreased after administration of EGB,especially at dosage of 50 mg/kg.Conclusions EGB has protective effects on cerebral ischemia/reperfusion induced oxidative injury in rats and shared the characteristic of dose-related effect.