EFFECT OF GINKGO BILOBA EXTRACT ON HIPPOCAMPAL ICAM-1 EXPRESSION IN RAT WITH DIABETIC ENCEPHALOPATHY

Objective To study the relation between diabetic encephalopathy and hippocampal ICAM-1 expression,and to investigate the therapeutic effect and mechanism of Ginkgo biloba extract on diabetic encephalopathy.Methods Sixty rats were assigned into control group,model group and EGb-treatment group randomly,and every group was further divided into 1 month and 3-month subgroups.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.The ICAM-1 expressions of mRNA and protein were evaluated by RT-PCR and immunohistochemistry method.Results(1) By maze water test,mild dysfunction of learning and memory was detected in model 1m group,and the dysfunction became worse in model 3m group.The matters were improved in EGb-treatment groups.(2) No expression of ICAM1 was spotted in control groups.In the model groups,the expressions of ICAM-1 were positive in hippocampus,and the expression were weaker in EGb-treatment groups.(3) Compared with control group,the ICAM-1 mRNA level of hippocampus was increased in model 1m group,and the level was obviously greater in model 3m group.In the EGb-treatment groups,the levels were dramatically reduced.Conclusion Diabetic encephalopathy may be closely related to hippocampal ICAM1 expression.EGb has an protective effect on diabetic encephalopathy and the mechanism may be attributed to its effects by down-regulating the ICAM-1 expression.