Title: Effects of Astragalus polysaccharide on expression of HSP70,PKB and P53 in rat cerebral cortex with cerebral ischemia and reperfusion
Abstract: AIM: To explore the molecular effects of Astragalus polysaccharide(AP) on improving nervous functions and preventing neuronal apoptosis in rat cerebral cortex with cerebral ischemia and reperfusion.METHODS: One hundred and twenty male Wister rats were randomly divided into sham operation group(SOG),model groups(MG-1 d,3 d and 7 d),low-dose AP treatment groups(L-APTG-1 d,3 d and 7 d),and high-dose AP treatment groups(H-APTG-1 d,3 d and 7 d).The right middle cerebral artery of the rats in MG and AGTG was intercepted by operation to induce ischemic brain injury.The rats in L-APTG and H-APTG were treated with AP at the doses of 5 mg/kg and 15 mg/kg by intraperitoneal injection,respectively.On the 1st day,3rd day and 7th day after operation,those animals were sacrificed to collect the brain specimens for the study after cerebral blood flow reperfusion and determination of neurological deficit scores.The structural changes of the neurons were observed under electron microscope.Apoptosis was analyzed by flow cytometry.The protein levels of heat-shock protein 70(HSP70),protein kinase B(PKB) and P53 in cerebral corical neurons were determined by immunohistochemical staining and Western blotting.RESULTS: The neurological deficit scores and the apoptotic rate of cerebral cortical neurons in H-APTG were significantly lower than those in MG and L-APTG(P0.05).The structures of the neurons in H-APTG,such as ribosome endoplasmic reticulum,nucleolus,Golgi complex,mitochondria,etc,were better than those in MG and L-APTG.On the 1st day,3rd day and 7th day,the protein levels of HSP70 and PKB in cerebral cortical neurons in H-APTG were significantly higher than those in L-APTG,which were significantly higher than those in MG(P0.05).However,the P53 protein level in H-APTG was significantly lower than that in L-APTG,which was significantly lower than that in MG(P0.05).CONCLUSION: AP improves nervous functions and inhibits neuronal apoptosis during ischemia and reperfusion.The molecular mechanisms are associated with variations of protein expression in cerebral cortical neurons,such as promotion of HSP70 and PKB and inhibition of P53.
Publication Year: 2012
Publication Date: 2012-01-01
Language: en
Type: article
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