Protective effects of preconditioning with resveratrol on focal cerebral ischemia/reperfusion induced neuronal apoptosis in rat hippocampal CA1 region

Aim To explore the protective effects of the preconditioning with resveratrol on focal cerebral ischemia-reperfusion induced neuronal apoptosis in hippocampus CA1 region of rats.Methods Sixty Sprague-Dawley rats were randomly divided into sham group,ischemia-reperfusion group(I/R) and resveratrol preconditioning ischemia-reperfusion group(Res+I/R).Each group had 20 rats.The middle cerebral artery in rats was occluded for 90 min by an intraluminal filament and then reperfused to cause transient focal cerebral ischemia.In the Res+I/R group,the resveratrol(30 mg·kg-1) was injected intraperitoneally 1 h before ischemia.The apoptotic neurons in the CA1 region were measured by TUNEL staining at Day 5 after reperfusion.The expressions of PI3K,phospho-Akt proteins,and Caspase-3 proteins in the CA1 region were examined by immunohistochemistry staining.Results The results of TUNEL staining showed that,compared with I/R group,preconditioning with resveratrol significantly reduced the number of TUNEL-positive neurons in the hippocampal CA1 pyramidal layer induced by cerebral ischemia(P0.05).The results of immunohistochemistry showed that the expression of PI3K and phospho-Akt proteins in the hippocampal CA1 region of Res+I/R group was significantly higher than that of I/R group(P0.05).However,resveratrol pretreatment significantly reduced the expression of Caspase-3 protein(P0.05).Conclusion The results suggest that preconditioning with resveratrol 1 h before ischemia possesses neuroprotective effects on focal cerebral ischemia-reperfusion induced neuronal apoptosis.The neuroprotective mechanism of resveratrol may attribute to activating PI3K-Akt signal pathway and inhibiting the expression of Caspase-3 protein.