Effects of soybean isflavones on mitochondrial damage and neuronal apoptosis induced by cerebral ischemia/reperfusion / 中国病理生理杂志

ABSTRACT

[ ABSTRACT] AIM:To study the effects of soybean isoflavones on mitochondrial ultrastructure, neuronal apopto-sis and expression of cytochrome C, caspase-9 and caspase-3 in the rats with cerebral ischemia/reperfusion.METHODS:Adult healthy SD rats ( n=60 ) were randomly divided into 3 groups sham group, ischemia/reperfusion injury ( I/R ) group and soybean isoflavone ( SI) pretreatment group.Soybean isoflavones (120 mg· kg-1 · d-1 ) were fed by gastric lav-age for 21 d.The global ischemia/reperfusion model of the rats was established by blocking 3 vessels, and then reperfused for 1 h after 1 h of ischemia.The morphological change of the cerebral cortex cells was observed under light microscope. The mitochondrial ultrastructure of the cerebral cortex cells was determined by transmission electron microscope.The apop-totic rate of the cerebral cortex cells was detected by flow cytometry.The expression of cytochrome C, caspase-9 and caspase-3 in the cerebral cortex cells was determined by semi-quantitative RT-PCR and immunohistochemical techniques. RESULTS:Disintegration of mitochondria membrane and disappearance of the mitochondrial cristae were seen in I/R group.Compared with I/R group, the change of ultrastructure of mitochondria was significantly improved by soybean isofla-vone pretreatment, and the neuronal apoptotic rate was also significantly decreased (P<0.01).The mRNA expression and protein content of cytochrome C, caspase-9 and caspase-3 in I/R group were obviously higher than those in sham group ( P<0.01).Compared with I/R group, the mRNA expression and protein content of cytochrome C, caspase-9 and caspase-3 in SI group were significantly decreased (P<0.01).CONCLUSION: Soybean isoflavones attenuate cerebral ischemia/reperfusion injury by stabilizing the structure of mitochondria, preventing cytochrome C release to the cytoplasm, inhibiting the activation of caspase-9 and caspase-3 and decreasing cell apoptosis.