EGCG对血管性痴呆Wistar大鼠学习记忆功能及Bax、Bcl-2蛋白表达的影响

Effect of EGCG on ethology and expression of Bax and Bcl-2 in vascular dementia rats

目的探讨(-)表没食子儿茶素没食子酸酯(epigallocatechin-3-gallate,EGCG)对血管性痴呆大鼠学习记忆能力及Bax、Bcl-2蛋白表达的影响。方法 3-4月龄Wistar大鼠70只,用线栓法建立血管性痴呆(VD)动物模型,随机分为5组:假手术组,模型组、对照组、EGCG高剂量治疗组(6mg/kg/d)、EGCG低剂量治疗组(2mg/kg/d)。水迷宫实验检测动物的学习记忆能力,免疫组化、Wstern Blot方法检测Bax、Bcl-2蛋白表达。结果水迷宫结果显示:模型组动物水迷宫潜伏期较假手术组明显延长(P<0.05),EGCG高低剂量治疗组VD动物的水迷宫潜伏期较模型组明显缩短(P<0.05)。免疫组化和Western Blot结果显示:与假手术组相比模型组动物Bax蛋白表达上升(P<0.05),Bcl-2(P<0.05)蛋白表达下降,EGCG治疗组Bax蛋白表达下降(P<0.01),Bcl-2蛋白表达升高(P<0.01)。结论 EGCG明显改善VD动物模型的学习记忆能力,可能与诱导脑组织Bcl-2蛋白表达及降低Bax蛋白表达量有关。

Objective To study the effect of EGCG on vascular dementia（VD） rats in ethology and expression of Bax and Bcl-2 proteins.Methods 3-4 month old Wistar rats were randomly divided into 5 groups：sham group,model group （by occlusion of MCAO to establish VD model,control group（injexction normal saline）,EGCE high dose group （6mg/kg/d）,EGCG low dose group （2mg/kg/d）.Learning and memory ability was determined by Morris water maze,the expressions of Bax and Bcl-2 were assessed by immunohistochemistry and Wstern blot.Results The results of water maze test showed that the escape latency and frequency of crossing platform decreased in EGCG treatment groups compared with model group （P〈0.05）,but increased in model group than in sham （P〈0.05）.Immunohistochemistry and Western Blot results showed that the expression level of Bax was lower in EGCG group than in model （P〈0.05）,but higher for the expression level of Bcl-2.The expression of Bax was significantly higher in model group than in sham （P〈0.05）,but lower for expression of Bcl-2 （P〈0.01）.Conclusion EGCG significantly improved cognitive function and memory capabilities in VD rat,which might be related to the induction of Bcl-2 protein and decrease Bax expression.