中文摘要：

目的：探讨银杏叶提取物（EGB）对高糖环境中新生大鼠心肌细胞凋亡和线粒体凋亡途径中线粒体分裂蛋白1（Drp-1）、融合蛋白2（Mfn-2）、Bax、Bcl-2和Caspase-3表达的影响。方法：体外分离SD乳鼠心肌细胞,分别用低糖（LG组）、低糖＋EGB（LG＋EGB组）、高糖（HG组）和高糖＋EGB（HG＋EGB组）培养基培养心肌细胞。分别用流式细胞仪检测心肌细胞的凋亡率,用Western blot和/或RT-PCR分别检测心肌细胞Drp-1、Mfn-2、Bax、Bcl-2和Caspase-3的表达。结果：与LG组相比,HG组心肌细胞凋亡率、Drp-1、Bax、Caspase-3表达和Bax/Bcl-2比值均显著升高,差异均具有统计学意义（P〈0.05）,而Bcl-2、Mfn-2表达均降低,差异均具有统计学意义（P〈0.05）;与HG组相比,HG＋EGB组心肌细胞凋亡率、Drp-1表达、Bax、Caspase-3、Bax/Bcl-2比值均显著降低,差异均具有统计学意义（P〈0.05）,而Bcl-2表达升高,差异具有统计学意义（P〈0.05）,但Mfn-2的表达差异无统计学意义（P〉0.05）。结论：EGB通过上调高糖环境中心肌细胞Bcl-2的表达,同时下调Drp-1、Bax和Caspase-3的表达,从而减少心肌细胞的凋亡。这可能是EGB防治糖尿病心肌病的机制之一。

英文摘要：

Objective： To investigate the effects of Ginkgo biloba on apoptosis and the expression of Drp-1, Mfn-2, Bax, Bcl-2 and Caspase-3 in mitochondrial apoptotic pathway in neonatal rat myocardial cells induced by high glucose and underlying mechanism. Methods： Left ventricule myocardial cells of neonatal SD rats were isolated and cultured with low-glucose culture media（LG group）, low-glucose culture media added EGB（LG ＋EGB group）, high-glucose culture media（HG group） and high-glucose culture media added EGB（HG＋EGB group） in vitro respectively. The ratio of apoptosis of myocardial cells was analyzed by flow cytometry. The expression of Drp-1, Mfn-2, Bax, Bcl-2 and Caspase-3 were detected with western blot and/or RT-PCR respectively. Results： Compared to the LG group, the rate of apoptosis, the expression of Drp-1 and Bax, Caspase-3 and the ratio of Bax/Bcl-2 in ventricule myocardial cells were increased in HG group significantly（P〈0.05）, while the expression of Mfn-2 and Bcl-2 were decreased significantly（P〈0.05）. Compared to HG group, the rate of apoptosis, the expression of Drp-1 and Bax, Caspase-3 and the ratio of Bax/Bcl-2 in HG＋EGB group were decreased significantly（P〈0.05）, while the expression of Bcl-2 was increased significantly（P〈0.05）. But the expression of Mfn-2 had no significant difference（P〉0.05）. Conclusion： EGB plays an important role in attenuation cardiomyocyte apoptosis induced by high glucose via its upregulation the expression of Bcl-2 and down regulation of Drp-1 and Bax, Caspase-3 and the ratio of Bax/Bcl-2. It may be one of the underlying mechanisms for EGB to treat diabetic cardiomyopathy.