Effect of Ginkgo biloba extracts on hippocampal apoptosis in diabetic encephalopathy rat / 中国糖尿病杂志

ABSTRACT

Objective To study the relation between diabetic rat encephalopathy and hippocampal apoptosis, and the therapeutic effect and mechanism of Ginkgo biloba extract. Methods Sixty rats were assigned into control group(NC), diabetic encephalopathy group (DM+B) and EGb-treatment group (EGb) randomly, and every group was further divided into two time points of 1 month (NC_1 ,DM+B_1, EGb_1 ) and 3 month(NC_3 ,DM+B_3, EGb_3 ). The behavioral abnormalities were investigated by water maze test and the apoptosis levels of brain tissue by ELISA. Immunohistochemistry and RT-PCR were performed to determine the protein and mRNA expressions of Bcl-2 and Bax. Results (1) Mild dysfunction of learning and memory was detected in DM+B_1 group, and the dysfunction became worse in DM+B_3 group. The matters were greatly improved in EGb-treatment groups. (2) The expressions of Bcl-2 protein and mRNA were increased in DM+B_1 and DM+B_3 groups, and were stronger in EGb_1 and EGb_3 groups. (3) The expressions of Bax protein and mRNA were obviously increased in DM+B_1 and DM+B_3 groups, and were dramatically reduced in EGb_1 and EGb_3 groups. (4) Compared with control group, the apoptosis level of brain tissue was increased in DM+B_1 group, and obviously greater in DM+B_3 group. In the EGb-treatment groups the levels were dramatically reduced. Conclusions Diabetic encephalopathy may be closely related to hippocampal apoptosis. EGb has an protective effect and the mechanism may be attributed to its effects inhibiting apoptosis.