和厚朴酚对心梗小鼠的心肌保护作用研究

Study on myocardial protective effect of honokiol in mice after acute myocardial infarction

目的探讨和厚朴酚(Honokiolc,HKL)对急性心肌梗死(acute myocardial infarction,AMI)小鼠的心肌保护作用及其可能的调控机制。方法80只雄性C57BL/6J小鼠随机分为四组,每组20只:假手术(Sham)组、心梗模型+空白溶剂(Vehicle)(MI+V)组、心梗模型+和厚朴酚治疗(MI+HKL)组、心梗模型+和厚朴酚+沉默调节蛋白1(Sirtuin-1,SIRT1)抑制剂(selisistat,EX527)处理(MI+HKL+EX)组。造模后记录28 d内小鼠的死亡情况;术后第28天检测小鼠超声心动图后,处死动物留取血清标本,酶联免疫吸附剂(enzyme linked immunosorbent assay,ELISA)法检测血清炎症指标。留取心脏组织标本,活性氧荧光探针-二氢乙啶(dihydroethidium,DHE)法检测心肌组织氧化应激水平;末端DNA转移酶dUTP缺口末端标记(terminal-deoxynucleoitidyl transferase mediated nick end labeling,TUNEL)法检测心肌细胞凋亡率,蛋白质印迹法(Western Blot)检测目标蛋白的表达水平。结果与模型组比较,HKL口服治疗4周后可显著改善心梗小鼠的心功能,降低血清炎症因子水平和心肌细胞凋亡率,减轻心肌氧化应激水平,上调SIRT1表达并下调Ac-Foxo1表达。而使用SIRT1抑制剂EX527阻断SIRT1信号后,HKL的上述保护作用明显减弱(P<0.05)。结论口服HKL可以抵抗心梗引发的心肌损伤,并显著改善心梗小鼠心功能,其作用机制可能是SIRT1/Ac-Foxo1信号参与调节。

Objective To investigate the myocardial protective effect and possible regulatory mechanism of Honokiol(HKL)on Acute Myocardial Infarction(AMI)in vivo.Methods Eighty male C57BL/6J mice were randomly divided into the following groups:Sham(Sham)group,Myocardial Infarction model and Vehicle(MI+V)group,Myocardial Infarction model and HKL treatment(MI+HKL)group,Myocardial Infarction model,HKL treatment and Sirtuin-1(SIRT1)inhibitor(selisistat,EX527)(MI+HKL+EX)group,with twenty mice in each group.The mortality of the mice during modeling stage was recorded after the operation.The echocardiogram and serum samples of the mice were gathered on the 28th day after the operation.The inflammatory indexes in the serum were detected by enzyme linked immunosorbent assay(ELISA).Besides,dihydroethidium staining(DHE)was utilized to display the intensity of reactive oxygen species in myocardial tissue.Apoptosis ratio was evaluated by detection of terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL)and the expression of other target molecules was detected by Western Blot.Results Compared with the model group,the heart function of MI mice treated with oral HKL was significantly improved,the levels of inflammatory factors in serum were decreased.Additionally,cardiomyocyte apoptosis rate and reactive oxygen species in myocardial tissue were reduced.Simultaneously,the expression of SIRT1 was significantly up-regulated while the expression of Ac-Foxo1 protein was down-regulated,which were reversed by SIRT1 inhibitor(EX527)(P<0.05).Conclusions Oral HKL attenuate myocardial damage induced by myocardial infarction and significantly improve myocardial function,which may be regulated by the SIRT1/Ac-Foxo1 signal.