Influence Of Ginkgo Biloba Extract On γ-Aminobutyric Acid Receptor A And N-methyl-D-aspartate Receptor Expression Of Kainic Acid Induced Epileptic Rats

Objective：To investigate the intervention effects of ginkgo biloba extract(GBE) pretreatment and the acute stage administration on epileptic ratsand its relationship with the expression of N-methyl-D-aspartate receptor2A (NR2A) andγ-Aminobutyric acid receptorA（GABAA）, in order toprobe the anti-epileptic mechanism of GBE.Methods：An epileptic animal model was established in rats by injectionof kainic acid.A total of108SD rats were randomly divided into shamoperation group, GBE control group, epilepsy model group, GBEpretreatment group, and GBE acute administration1groups, and GBEacute administration2groups. Each group was further divid into threesub-groups. Each group was further divided into three sub-groups.Morphologic changes of the hippocampal neurons were observed by HEstaining, while the expression of GABAA and NMDAR in hippocampal tissue was measured by in situ hybridizationResults：Seizure levels and neuronal damage of GBE pretreatment group,and GBE acute administration1groups. were lower than those ofepilepsy model group. In hippocampal tisse, NR-2AmRNA expression ofthree subgroups in epilepsy model group increased significantly thanthose in sham group(P<0.05)； NR-2AmRNA expressions of threesubgroups in GBE pretreatment group and GBE acute administration1groups. were lower than those in epilepsy model group(P<0.05), andGABA-ARmRNA expressions of three subgroups in GBE pretreatment groupand GBE acute administration1groups，increased significantly than thosein epilepsy model group (P<0.05). NR-2AmRNA expressions weredecreased and GABA-ARmRNA expressions were increased in GBEpretreatment group compared with those in GBE acute administration1groups (P<0.05). NR-2AmRNA expression of three subgroups in GBEacute administration2groups increased significantly than those in GBEacute administration1groups(P<0.05)； No statistically difference ofNR-2AmRNA and GABA-ARmRNA expression were found between GBEcontrol group and epilepsy model group (P>0.05). Downturns ofNR-2AmRNA expression and upturns of GABA-ARmRNA expression wereshowed from6h to24h time point after seisures in the same groups.Conclusion：GBE have some antiepileptic effects, and the effects ofpretreatment are better than that of acute stage administration. The anti-epileptic effects of GBE are concerned with lessen of neuronicdamage, the mitigation of seizure degree, the down-regulation ofNR-2AmRNA expression and the up-regulation of GABA-ARmRNAexpression.