Effects of Ginkgo Biloba Extract on Learning and Memory and Cytokines of Hippocampus in Senile Rats

Objective: To observe the effects of Ginkgo biloba extract (GBE50) on learning and memory impairment induced by D-galactose and contents of IL-1β,IL-6 and TNF-α in hippocampus of senile rats,in an attempt to study its mechanisms in improving learning and memory. Methods: SD rats were randomly divided into 3 groups: control group,model group and treatment group. In modeling,D-galactose was injected into abdomen according to 100mg/kg in the morning for 42 days. From the 21st day after modeling,GBE50 was given through gastric perfusion according to 150mg/kg in treatment group every day,and continuously for 21 days. Distilled water containing 1% CMC-Na was given in control and model groups. After treatment,Morris water maze tests were used to detect the change of rat behavior and the contents of IL-1β,IL-6 and TNF-α in hippocampus in all groups by radioimmunoassay. Results: The escape latency of the rats in model group was significantly longer than that in control group; the percentage of distance was lower(P 0.05,P 0.01); however,the escape latency of the rats in treatment group was significantly shorter than that in model group,and the percentage of distance was higher(P 0.05,P 0.01). The contents of IL-1β and TNF-α in hippocampus of model group were significantly higher than those of control group,but contents of IL-6 were lower (P 0.05,P 0.01). Compared with model group,the contents of IL-1β in treatment group were significantly decreased; and the contents of IL-6 were significantly increased (P 0.05,P 0.01). Conclusion: GBE50 can improve the impaired learning and memory of senile rats induced by D-galactose by regulating the contents of IL-1β and IL-6 in hippocampus,and inhibiting immune inflammatory reaction in central nerve system induced by D-galactose.