OBJECTIVETo investigate the effect of extract of Ginkgo Biloba(EGB) on nerve growth factor(NGF) and Neurotrophin-3(NT-3) expression of hippocampus neurons in streptozotocin-induced type I diabetic rats.

METHODSThirty male SD rats were divided into three groups (n = 10): the control group, diabetic group and EGB-treated group. Strepozotocin were injected intraperitoneally in the later two groups to induce diabetes. EGB-treated group was injected intraperitoneally with EGB, and the same volume of normal saline was injected to the other groups. Concentration of blood glucose and body weight and behaviour were dynamicly monitored. At the end of the 12th week, morphological changes of the hippocampus neurons were observed under microscopy by HE stain. The expression of NGF and NT-3 were assayed by Western blot and RT-PCR respectively.

RESULTSCompared with diabetic group, the behaviour and body weight (P < 0.05) and the concentration of blood glucose (P < 0.05) were significantly improved and the escape latency of Morris water maze test (P < 0.05) was significantly shortened, while the platform searching score was significantly increased (P < 0.01) in EGB treated group; The pathological changes of hippocampus neurons were significantly attenuate by EGB treated; The expression of NGF and NT-3 in hippocampus neurons were significantly increased which assayed by Western blotting and RT-PCR respectively (P < 0.05) in EGB treated group.

CONCLUSIONEGB may improve the learning and memory ability of diabetic rats the mechanism may be attributed to its improvement of the expression of NGF and NT-3 and reducing apoptosis in hippocampus neurons.