黄芩茎叶总黄酮对缺血再灌注心肌细胞凋亡及凋亡相关基因表达的影响

Effects of Total Flavonoid in Scutellaria Baiculensis Stem-leaf on Myocyte Apoptosis and Expression of Apoptosis-associated Genes in Rat Hearts with Acute Myocardial Ischemia and Reperfusion

目的观察黄芩茎叶总黄酮(Scutellaria Baiculensis Stem-leaf Total Flavonoid,SSTF)对缺血再灌注损伤大鼠心肌细胞凋亡及凋亡相关基因表达的影响。方法采用结扎大鼠左冠状动脉前降支30 min,然后松开再灌注2 h的方法,复制大鼠心肌缺血再灌注损伤模型。实验分为假手术组、缺血再灌注组(IR),SSTF不同剂量治疗组。采用原位缺口末端标记法(TUNEL)及免疫组化法,检测心肌细胞凋亡指数(AI),Bax和Bcl-2基因蛋白表达。结果与假手术组比较,缺血再灌注组AI增加,Bax阳性表达增强,Bcl-2阳性表达减弱(P<0.01);与缺血再灌注组比较,SSTF组AI、Bax阳性表达下降(P<0.05或P<0.01),Bcl-2阳性表达上调(P<0.05或P<0.01)。结论SSTF能明显抑制IR引起的心肌细胞凋亡,其作用机制可能与下调Bax蛋白表达和上调Bcl-2蛋白表达,提高Bcl-2/Bax比值有一定关系。

Objective To observe the effects of total flavonoid（SSTF） in Scutellaria Baiculensis Stem -leaf on myocyte apoptosis and the expression of apoptosis - associated genes in rat hearts with acute myocardial ischemia and reperfusion （IR）. Methods The left anterior descending branch of coronary artery was ligated for 30 min and reperfused for 2h to make a myocardial ischemia -reperfusion model in rats. The experiment rats were divided into five groups ：sham, ischemia -reperfusion（ IR）, SSTF （17.5,35,70 mg · kg^-1 · d^-1）group. Apoptosis index of（AI） of myocardium was detected by in situ end labeling method, and the protein expression of Bcl -2 and Bax genes cardiomyocytes was shown through immunohistochemistry method. Results In IR group, AI was significantly increased , a protein expression of Bcl - 2 gene was decreased and protein expression of Bax gene was increased. Compared with sham group, SSTF could decrease AI（ P 〈 0.05,0.01 ） ,up -regulate protein expression of Bcl -2 gene （P 〈0.05,0.01 ） ,and down - regulate protein expression of Bax gene （P 〈0.05,0.01 ）. Conclusion SSTF can significantly inhibit cardiomyocyte apoptosis in ischemia - reperfusion rat hearts. The possible mechanism is to raise the ratio of Bcl - 2/Bax proteins by increasing the expression of bcl -2 gene and decreasing the expression of bax gene.