Effects of ginkgo biloba extract on the expression of bax, GFAP after local cerebral ischemia/reperfusion in rats

Abstract

Objective To explore the protective action of ginkgo biloba extract (GBE) after local cerebral ischemia and reperfusion in rats.Methods 80 male Sprague-Dawley rats were randomly divided into two groups:control group ( group A,saline injected,n =40 ),GBE intervention group ( group GBE injected,n =40),which were divided into 4 subgroups,namely,reperfusion after 1,3,6 and 24 h groups,10 in each subgroup.The animal model of right middle cerebral artery occlusion (MCAO) and reperfusion was established; pathological changes in brain morphology were observed by Hematoxylin and Eosin (HE) staining; serum glial fibrillary acidic protein (GFAP) was detected by enzyme linked immunosorbent assay (ELISA) method; changes of bax mRNA expression was detected by reverse transcriptionpolymerase chain reaction (RT-PCR) method.Results (1) Nerve cell necrosis,apoptosis were observed,neuronal shape was difficult to identify,and most of the cell structure disappeared in group A.While,the injury was milder at same time points in group B compared with group A.(2) ELISA results showed that serum GFAP levels increased after ischemia-reperfusion,the levels in group B (275.29 ±112.72,308.72 ± 124.11,372.56 ± 185.62,452.12 ± 145.26) ng/L were significantly lower than those in group A (437.17 ± 152.26,490.27 ± 198.37,583.45 ± 201.42,656.26 ± 256.36) ng/L,respectively( P ＜ 0.05 ).3.RT-PCR results showed that bax mRNA expression in group B (0.256 ± 0.018,0.302 ±0.023,0.417 ±0.034,0.527 ±0.052) was significantly higher than that in group A (0.333 ±0.021,0.452 ±0.037,0.587±0.052,0.726±0.046,respectively) (P＜0.05).Conclusion GFAP and bax change significantly after cerebral ischemia-reperfusion which may involve in cerebral isehemia reperfusion injury mechanism.GBE can significantly reduce the cerebral injury by down regulating the expression of GFAP and bax.GBE is effective on prevention of cerebral ischemia-reperfusion injury. Key words: Ginkgo biloba extract; Cerebral ischemia-reperfusion injury; Apoptosis; bax; Glial fibrillary acidic protein