银杏叶提取物对糖尿病大鼠学习、记忆及海马血红素加氧酶1表达的影响

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

目的探讨银杏叶提取物(EGb)对糖尿病大鼠学习记忆及海马血红素加氧酶1(HO-1)表达的影响。方法大鼠腹腔注射链脲佐菌素建立糖尿病模型,6个月后以Morris水迷宫观察其学习记忆能力,以RT-PCR观察大鼠海马HO-1 mRNA的表达,以免疫组织化学法观察海马HO-1蛋白表达。结果大鼠糖尿病6个月后Morris水迷宫成绩下降,海马的HO-1 mRNA表达和蛋白表达水平升高(分别为1．635±0．326 vs 0．978±0．214,7．2±1．7 vs 1．9±0．5,均P＜0．01)；糖尿病EGb干预组(100、50 mg/kg)大鼠较糖尿病大鼠Morris水迷宫成绩提高,HO-1 mRNA表达和蛋白表达水平降低(100 mg/kg：0．954±0．144,2．0±0．8；50 mg/kg：0．988±0．154,2．5±0．6,均P＜0．01)。结论EGb可抑制海马的HO-1表达,提高糖尿病大鼠的学习记忆能力。

Objective To explore the effects of extract of Gingko biloba leaves （EGb） on learning, memory and hippocampal heme oxygenase-1 （ HO-1 ） expression in diabetic rats. Methods The behaviors of streptozotocin-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;50mg/kg：0.988±0.154,2.5 ±0.6, all P〈0.01）. Conclusion EGbcan significantly inhibit HO-1 expression in hippocampus and improve learning and memory dysfunction in diabetic rats.