Electroacupuncture Pre-treatment Exerts an Anti-apoptotic Effect in Cerebral Ischaemia and Reperfusion Injury in Rats

Abstract

Background: Electroacupuncture (EA) pre-treatment can play a significant neuroprotective role in rats with cerebral ischaemia and reperfusion (CIR) injury, but the specific mechanism needs to be further elucidated. Objective: To investigate the effects of EA pre-treatment on apoptosis-related proteins Bax, Bcl-2, Cytochrome c (cyt c), cleaved caspase-9 and -3 in rats with CIR injury. Methods: CIR injury was induced using middle cerebral artery occlusion (MCAO) ischaemia-reperfusion. Thirty-six male Specific Pathogen Free (SPF) Sprague-Dawley rats were randomly divided into three groups: Sham (n=12), MCAO (n=12), and the EA+MCAO group (n=12). EA+MCAO group rats received electroacupuncture at DU20 for 2 consecutive weeks before MCAO model preparation. After 24 h of reperfusion, neurological deficits were evaluated by modified neurological severity scores. Brain infarct volumes were examined by 2,3,5-triphenyltetrazolium chloride staining. Expression of Bax, Bcl-2, cyt c, cleaved caspase-9 and -3 in the ischaemic penumbra were detected by Western blotting, and apoptosis evaluated by TUNEL staining. Results: After perfusion for 24 h, compared with the MCAO group, the neurological deficit scores and brain infarct volumes in the EA+MCAO group were significantly decreased (P <0.05), as was the level of Bax (P <0.05) or the Bax/Bcl-2 ratio (P <0.05), levels of cyt c, cleaved caspase-9 and -3 also decreased (P <0.05), like the number of TUNEL-positive cells (P <0.05), in contrast, the level of Bcl-2. Conclusion: EA pre-treatment exerts an anti-apoptotic effect through Bax-to-Bcl-2 ratio downregulation, blockage of mitochondrial cyt c release to the cytosol, and reduction of caspase-9 and -3 expression in rats with CIR injury.