Effects of ginkgo biloba extract on the expression of inducible nitric oxide synthase and B cell lymphoma / lewkmia-2 associated X protein after focal cerebral ischemiareperfusion in rats

Objective To explore the protective effect and mechanism of extract of ginkgo biloba 761( EGb761) on brain tissue after focal cerebral ischemia-reperfusion injury in rats. Methods Eighty male Sprague Dawley rats were randomly divided into two groups: control group( group A,normal saline injected,n = 40),EGb intervention group( group B, EGb761 injected,n = 40),which were then divided into 4 subgrouops,namely,reperfusion after 1 h,3 h,6 h and 24 h groups,10 in each subgroup. The model of right middle cerebral artery occlusion( MCAO) and reperfusion of rats was made. Pathological changes in brain morphology were observed by HE staining; immunohitochemical method was used to detect the inducible nitric oxide synthase( iNOS) changes; changes of B cell lymphoma / lewkmia-2 associated X protein( Bax) mRNA expression was detected by reverse transcription-polymerase chain reaction( RT-PCR) method. All data were analyzad by SPSS 13. 0 software. Results( 1) Nerve cell necrosis,apoptosis and cytoplasmic vacuolatin were observed in group A,neuronal shape was difficult to identify,and most of the cell structure disappeared. While,the injury was relieved at the same time points in group B compared with that in group A.( 2) Immunohitochemical results showed that: there were a few iNOS expression positive cells 1 hour after reperfusion,which increased at 3 hours after referfusion and appeared nucler translocation. Analysis by Image-Pro Plus 5. 0 showed that iNOS expression levels in group B( 1851. 38 ± 242. 12,2005. 41 ± 290. 52,2625. 28 ± 385. 21, 3142. 5 ± 425. 72) were significantly lower than that in group A( 1950. 25 ± 298. 26, 2232. 45 ± 305. 28,3251. 22 ± 425. 26,3965. 36 ± 521. 62,P 0. 05). 3. RT-PCR results showed that bax mRNA expression in group B( 0. 26 ± 0. 02,0. 30 ± 0. 02,0. 42 ± 0. 03, 0. 53 ± 0. 05) was significantly higher than that in group A( 0. 33 ± 0. 02,0. 45 ± 0. 04, 0. 59 ± 0. 05,0. 73 ± 0. 05,P 0. 01 respectively). Conclusions iNOS and Bax increase significantly in rats after cerebral ischemia-reperfusion injury. EGb761 can significantly reduce the cerebral injury by regulating the expression of iNOS and Bax and effectively protect the ischemic cerebral tissue.