黄芩素通过抗氧化及调节细胞内钙离子浓度抑制大鼠缺氧/复氧诱导的心肌细胞凋亡(英文)

Baicalein protects rat cardiac myocytes from hypoxia/reoxygenation induced apoptosis via antioxidant and modulation of intracellular calcium concentration

背景:黄芩素对缺氧复氧损伤的心血管有保护作,但机制至今不清。目的:探讨中药黄芩素对心肌细胞缺氧/复氧损伤导致心肌细胞凋亡的保护作用机制。方法:体外培养大鼠乳鼠心肌细胞培养。实验分3组:正常对照组为正常培养的心肌细胞未做处理;缺氧/复氧组为应用缺氧/复氧方法诱导心肌细胞凋亡损伤;黄芩素预处理组为经黄芩素预处理30min后经缺氧/复氧诱导的心肌细胞。通过检测培养基上清液中乳酸脱氢酶活力检测细胞损伤程度及黄芩苷保护作用;应用原位末端标记细胞法标记细胞后,流式细胞检测心肌细胞凋亡率;应用免疫印迹方法检测心肌细胞凋亡蛋白Bax与抗凋亡蛋白Bcl-2的蛋白表达水平;应用Fura-2-AM负载心肌细胞,实时检测心肌细胞内Ca2+浓度变化。结果与结论:与正常对照组相比,缺氧/复氧组上清液乳酸脱氢酶活性、心肌细胞凋亡率、Bax蛋白含量、心肌细胞Ca2+浓度均增加(P<0.05),Bcl-2蛋白含量降低(P<0.05)。与缺氧/复氧组相比,黄芩素预处理组乳酸脱氢酶含量、心肌细胞凋亡率、Bax蛋白含量及心肌细胞Ca2+浓度均降低(P<0.05),Bcl-2蛋白含量增加(P<0.05)。证实黄芩素能抑制缺氧/复氧导致的心肌细胞凋亡。

BACKGROUND：Protective mechanisms of baicalein against myocardial hypoxia/reoxygenation injury are still nuclear.OBJECTIVE：To investigate the protective role of baicalein in cardiomyocytes against hypoxia/reoxygenation induced apoptosis.METHODS：Neonatal rat cardiomyocytes were isolated and cultured in vitro,and the cells were randomly divided into three groups：normal control group with no treatment,hypoxia/reoxygenation group exposed to hypoxia/reoxygenation,and baicalein group pretreated with 10 μmol/L baicalein for 30 minutes followed by hypoxia/reoxygenation.The extent of cellular injury was determined by measuring activity of lactate dehydrogenase released in the supernatant,the number of apoptotic cardiomyocytes was detected by flow cytometry.To further study the mechanism,the myocardial Bcl-2 and Bax protein levels were determined by Western blot,the changes of intracellular calcium concentration was monitored by Fura-2-acetoxymethyl ester.RESULTS AND CONCLUSION：Compared with the normal control group,the activity of lactate dehydrogenase,the number of apoptotic cardiomyocytes,myocardial Bax protein level,intracellular calcium concentration were increased（P〈0.05）,as well as myocardial Bcl-2 protein level was decreased（P〈0.05）.However,pretreatment with baicalein could protect rat cardiomyocytes from hypoxia/reoxygenation induced apoptosis,increase anti-apoptotic protein level of Bcl-2,decrease the pro-apoptotic protein level of Bax,and down-regulate intracellular calcium concentration.These findings indicate that baicalein can inhibit the apoptosis of cardiomyocytes induced by hypoxia/reoxygenation injury,and its mechanism may be related to antioxidant and modulation of intracellular calcium concentration.