Effects of extract of Gingko biloba leaves on learning,memory and hippocampus HO-1 expression In diabetic rats

Objective To explore the effects of extract of Gingko biloba leaves (EGb) on learning, memory and hippoeampal heine oxygenase-1 (HO-1) expression in diabetic rats.Methods The behaviors of streptozotoein-induced diabetic rats were observed by Morris water maze for learning and memory after 6 months of diabetes.The HO-1 mRNA expression and protein expression in hippocampus of diabetic rats were detected by RT- PCR and immunohistochemistry respectively.Results The escape latency time in Morris water maze of diabetic rats was prolonged markedly.HO-1 mRNA and HO-1 protein expressions in hippocampus of diabetic rats were increased (1.635±0.326 vs 0.978±0.214,7.2±1.7 vs 1.9±0.5,respectively,both P＜0.01).The escape latency times in EGb (100,50 mg/kg) treated groups were shortened.HO-1 mRNA and HO-1 protein expressions in hippocampus were decreased at the same time as compared with diabetic group (100 mg/kg:0.954±0.144,2.0±0.8;50 mg/kg:0.988±0.154,2.5±0.6,all P＜0.01).Conclusion EGb can significantly inhibit HO-1 expression in hippocampus and improve learning and memory dysfunction in diabetic rats.