N-butanol Extract Of Potentilla Anserinel Inhibits Apoptosis Of Cardiomyocytes With Ischemia And Reperfusion Injury

Objective: Recent years, more and more research considered that theSmall Heat Shock protein played important roles in heart disease, especially,αB-crystallin, one of the Small Heat Shock proteins, which can protect theheart subjected to ischemia-reperfusion injury. In our previous study, it hasbeen showed that the n-butanol extract of Potentilla anserine L (NP) canprotect the hearts from IR injury. But the understanding of the mechanism ofits effect still remains unclear. The aim of this project was to investigate themechanism of the beneficial effect of NP in rats IR model.Methods:The content of this study was divided into two parts.Part1: The variation of CryAB in different groups of rats subjectedto ischemia and reperfusion(1) The rats were grouped into sham-operation group,I-30min group,I-30min/R-1h group, I-30min/R-2h group and I-30min/R-4h group. They weresubjected to ischemia and reperfusion injury by ligation of LAD coronaryartery.(2) Cardiac injury was determined by H&E staining and Nagar-Olsen staining.The apoptosis of myocardial cells induced by IR was detected by TUNELstaining. We also observed the change of mitochondrion and glycogen inmyocardial cells by electron microscope.(3) The activities of LDH, CK, SOD, MDA and GSH in plasma were detected.(4) The expression of CryAB and pCryAB was measured byimmunohistochemisty staining and western-blot. Part2: N-butanol extract of Potentilla anserine L. inhibited theapoptosis of myocardial cells of rats subjected to ischemia andreperfusion injury(1) Rats were grouped into sham-operation group, I-30m/R-2h group,I-30m/R-2h+n-butanol extract of Potentilla anserine L. group (49.3mg.kg-1,98.6mg.kg-1,197.2mg.kg-1), I-30m/R-2h+compound recipe of Salviamiltiorrhiza group (328.6mg.kg-1). The rats were given intragastricadministration continuously for10days before the ischemia-reperfusionoperation.(2) The morphology change of myocardial cells was measured by H&Estaining. And TUNEL staining was used to observe the apoptosis ofmyocardial cells.(3) The activities of CAT, SOD, MDA and GSH in plasma were detected.(4) The expression of CryAB, pCryAB, Cyt C and caspase-3were analyzed byimmunohistochemisty staining and western-blot.Results:Part1: The variation of CryAB in different groups of rats subjected toischemia and reperfusion(1) A significantly increased in plasma activities of LDH, CK and MDA whilea decrease of SOD and GSH contents were observed in IR group as comparedto the sham group(P<0.05).(2) The apoptosis of myocardial cells was increased in IR group.(3) The αB-crystallin protein expression increased immediately when the heartwas subjected to reperfusion after ischemia for30min. But thephosphorylatedαB-crystallin increased notably only in I-30m/R-2h group andI-30m/R-4h group(P<0.01).Part2: N-butanol extract of Potentilla anserine L. inhibited theapoptosis of myocardial cells of rats subjected to ischemia andreperfusion injury(1) The NP can significantly increased the GSH, SOD and CAT productionwhich can clear the oxygen-derived free radicals induced by I/Rinjury(P<0.05). The NP also can reduced the plasma contents ofMDA(P<0.05).(2) Treatment of n-butanol extract of Potentilla anserine L (NP) showed that NP obviously reduced myocardial apoptosis.(3) The NP can increase the expression of phosphorylated αB-crystallinprotein with the decrease of cytochromeC and caspase3proteins expression ascompared with the model group, but not increase the expression ofαB-crystallin protein.Conclusion:1Ischemia and reperfusion injury induce the expression of CryAB.2The n-butanol extract of Potentilla anserine L (NP) is likely to protectmyocardial cells from IR injury not only against oxidative stress but also byincreasing the expression of phosphorylated αB-crystallin to inhibitmitochondrial apoptosis pathway.