银杏叶提取物对糖尿病所致脑部损害的影响

Effect of Ginkgo biloba extract on diabetic brain damage

目的观察糖尿病所致脑部损害与海马细胞凋亡的关系,并探讨银杏叶提取物(EGb)治疗的效果和机制。方法将60只大鼠随机分为对照组、糖尿病组和金纳多治疗组,各组再分为1个月和3个月2个时间点;以STZ制糖尿病大鼠模型,金纳多治疗组大鼠腹腔注射EGb;用水迷宫试验观察大鼠行为学变化;用免疫组织化学方法检测海马组织Bcl-2表达水平;用酶联免疫吸附法(ELISA)检测脑组织细胞凋亡水平。结果(1)水迷宫试验发现糖尿病1月组即已出现轻度学习和记忆功能障碍,3月组更加加重,金纳多治疗组则明显减轻;(2)对照组海马区未见Bcl-2表达,糖尿病组呈阳性表达,金纳多治疗组表达更强;(3)糖尿病1月组脑组织细胞凋亡水平升高,3月组更加明显,金纳多治疗组则显著减轻。结论海马细胞凋亡是糖尿病所致脑部损害的重要因素,银杏叶提取物可能通过上调Bcl-2来抑制细胞凋亡,而对糖尿病所致脑部损害有保护作用。

Objective To study the relation between diabetic brain damage and hippocampal apoptosis, and investigate the therapeutic effect and mechanism of Ginkgo biloba extract. Methods Sixty rats were assigned to control group, diabetes group and EGb-treatment group randomly, and every group was further divided into two time points of 1 month and 3 month. STZ was used to make the model of diabetes mellitus, and in EGb-treatment group EGb was abdominally injected every day. The behavioral abnormalities were investigated by water maze test and the apoptosis level of brain was evaluated by ELISA. The expression of Bcl-2 was determined by immunohistochemistry method. Results （1） By water maze test, mild dysfunction of learning and memory was detected in diabetes 1m group, and the dysfunction bacame worse in diabetes 3m group. In EGb-treatment groups the dysfunctions were greatly improved. （2） No expression of Bcl 2 was spotted in con trol group, but there was a moderate and strong expression in the diabetes group and EGb-treatment group, respectively. （3） Compared with control group, the apoptosis level of brain was increased in diabetes lm group, and the level was obviously greater in diabetes 3m group. In the EGb-treatment groups the level was dramatically reduced. Conclusions Diabetic brain damage may be closely related to hippocampal apoptosis. EGb has an protective effect on diabetic brain damage and the mechanism may be attributed to its effects by up- regulating the Bcl-2 expression and inhibiting apoptosis.