水飞蓟宾对大鼠心肌缺血再灌注损伤后心肌细胞凋亡的影响

The Effects of Silibinin on the Cardiomyocyte Apoptosis in the Rats with Myocardial Ischemia-reperfusion Injury

目的研究水飞蓟宾(Silibinin,SIL)对大鼠心肌缺血再灌注损伤后心肌细胞凋亡的影响及其机制。方法取100只实验用大鼠随机分为假手术组,模型组和SIL低(100mg/(kg·d))、中(200mg/[kg·d))、高(400mg/(kg·d))剂量预处理组(n=20),术前7d开始灌胃给药;采用结扎冠状动脉30min的方法建立大鼠心肌缺血再灌注损伤模型;再灌注6h后,通过高分辨率超声影像系统检测舒张末期左室内径(IVIDd)和收缩末期左室内径(LVIDs)、短轴缩短率(FS)、射血分数(EF)、每搏输出量(SV);TTC染色法计算心肌梗死面积,TUNEL法观察心肌细胞凋亡状况,RT-PCR法测定心肌组织bcl-2 mRNA、Bax mRNA表达,Western blotting法测定心肌组织caspase-3、NF-kB蛋白表达;比色法测定心肌组织中抗氧化酶活性和丙二醛(MDA)含量。结果与模型组比较,发现经SIL中、高剂量预处理能够显著降低急性心肌梗死大鼠LVIDd并显著提高FS、EF和SV,其中SIL高剂量预处理组LVIDs显著降低;显著降低心肌组织梗死面积,明显改善心肌细胞凋亡状况、显著降低心肌细胞凋亡指数(Apoptosis index,AI),显著上调bcl-2 mRNA表达并下调Bax mRNA表达、显著提高‘bcl-2/Bax比值,显著降低caspase-3、NF-kB蛋白表达量,显著提高抗氧化酶(SOD、CAT)活性并显著降低MDA含量,差异均具有统计学意义(P<0.05,P<0.01)。结论SIL具有抑制心肌缺血再灌注损伤大鼠心肌细胞凋亡的作用,其机制可能与SIL改善心功能、调节凋亡相关基因和蛋白表达以及抑制氧化应激损伤有关。

Objective To investigate the effects of Silibinin（SIL） on the cardiomyocytes apoptosis in the rats with myocardial ischemia- reperfusion injury. Methods Selected 100 rat models were randomly divided into sham operation group, model control group and SIL low- dose （100mg/（kg·d）, medium-dose（200mg/（kg·d）, high-dose（400mg/（kg·d） pre-treated group（n=20）, the drugs were given by intragastric administration before operation; the rat models with acute myocardial infarction were made by clamping the artery. 6h after reperfusion, the LVIDd, LVIDs, FS, EF, SV were detected by high frequency ultrasound imaging system; the areas of myocardial infarction was analysed by TTC staining, the cardiomyoeyte apoptosis was observed by TUNEL; the expression of bcl-2 mRNA, Bax mRNA were determined, the expression of caspase-3, NF-kB were examined by Western blotting; the activity of antioxidase and the content of MDA in myocardial tissue were determined. Results Compared with model control group, the LVIDd, LVIDs in SIL medium- and high-dose per- treated groups were significantly decreased, the FS, EF, SV were significantly increased; the myocardial infarction areas was significantly decreased, the myocardial cardiomyocyte apoptosis were significantly improved and the AI were significantly decreased, the expression of bcl-2 mRNA was significantly up-regulated and the Bax mRNA was significantly down-regulated, the ratio of bcl-2/Bax was significantly increased, the expression of caspase-3 and NF-kB protein were significantly decreased; the activity of SOD, CAT in myocardial tissue were significantly increased and the activity of MDA was significantly decreased, all of the difference above were significant（P〈0.05, P〈0.01）. Conclusion SIL has inhibitive effects on the cardiomyocytes apoptosis in the rats with myocardial ischemia- reperfusion injury, which perhaps related to its effects of improving heart function, altering the expression of apoptosis-related genes, proteins and depressing oxidative stress.