EGCG-Zn对血管性痴呆大鼠学习记忆及抗氧化能力的影响

Effect of EGCG-Zn on the Learning,Memory and Antioxidant Abilities in Vascular Dementia Rats

目的:研究表没食子儿茶素没食子酸酯(EGCG)与锌离子螯合得到的EGCG-Zn对血管性痴呆(VD)大鼠的学习记忆及抗氧化能力的影响。方法:将大鼠随机分为假手术组、模型组、葡萄糖酸锌组(阳性对照,70 mg/kg)、EGCG组(5 mg/kg)和EGCG-Zn低、中、高剂量组(2、5、10 mg/kg),每组10只。采用大脑中动脉闭塞法制备VD模型,造模7 d后每天ig相应药物1次,连续28 d。采用Morris水迷宫实验评价各组大鼠的空间学习和记忆能力,分光光度比色法检测各组大鼠脑组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性及丙二醛(MDA)含量。结果:与假手术组比较,模型组大鼠逃避潜伏期延长,平台象限游泳距离百分比(d P/d T)降低(P<0.01);脑组织中SOD、CAT、GSH-Px活性降低,MDA含量增加(P<0.01)。与模型组比较,EGCG组和EGCG-Zn各剂量组大鼠记录第4天的逃避潜伏期明显缩短,d P/d T明显升高(P<0.05或P<0.01);脑组织中SOD、CAT、GSH-Px活性增强,MDA含量减少(P<0.05或P<0.01),且呈剂量依赖性。与EGCG组和葡萄糖酸锌组比较,EGCGZn各剂量组大鼠逃避潜伏期缩短,d P/d T升高;脑组织中SOD、CAT、GSH-Px活性增强,MDA含量减少,以高、中剂量组效果较明显(P<0.05或P<0.01)。结论:EGCG-Zn可以提高VD大鼠的学习记忆能力和抗氧化能力,且效果优于EGCG。

OBJECTIVE：To study the effect of EGCG-Zn chelated by epigallocatechin gallate（EGCG）and Zn ion on learning,memory and antioxidant abilities in vascular dementia（VD）rats. METHODS：Rats were randomly divided into sham group,model group,zinc gluconate group（positive control,70 mg/kg）,EGCG group（5 mg/kg）,and EGCG-Zn low-dose,middledose,high-dose groups（2,5,10 mg/kg）,10 in each group. The VD models were induced by middle cerebral artery occlusion.The rats were intragastrically given relevant medicines after 7 d of modeling,once a day,for 28 d. Morris water maze were used to evaluate learning and memory abilities of rats. Spectrophotometric method was adopted to detect the superoxide dismutase（SOD）,catalase（CAT）,glutathione peroxidase（GSH-Px）activities and malondialdehyde（MDA）content in brain tissue of rats.RESULTS：Compared with sham group,escape latency was extended in model group,percentage of platform quadrant swimming distance（d P/d T）was reduced（P〈0.01）;SOD,CAT,GSH-Px activities in brain tissue were reduced,and MDA content was increased（P〈0.01）. Compared with model group,escape latency on 4th d of recording was obviously shortened in EGCG group and EGCG-Zn dose groups,d P/d T was obviously increased and dose-depended（P〈0.05 or P〈0.01）;SOD,CAT,GSH-Px activities in brain tissue were increased,MDA content was decreased（P〈0.05 or P〈0.01）and dose-depended. Compared with EGCG group and zinc gluconate group,escape latency was obviously shortened in EGCG-Zn dose groups,d P/d T was increased;SOD,CAT,GSH-Px activities in brain tissue were increased,MDA content was decreased;and the effects in high-dose,medium-dose groups were more obvious（P〈0.05 or P〈0.01）. CONCLUSIONS：EGCG-Zn can improve the learning,memory and antioxidant abilities in VD rats,and the effect is superior to EGCG.