目的 探讨荭草苷对心肌缺血/再灌注损伤（MIRI）大鼠心肌细胞内线粒体质量的调控作用。方法 75只SD雄性大鼠随机分为假手术组、模型组、不同剂量（1.0、2.0、4.0 mg/kg）荭草苷预处理组。除假手术组外，其余各组大鼠均通过结扎冠状动脉左前降支致缺血30 min，再灌注120 min，制备MIRI模型。酶标仪检测线粒体膜电位（MMP）和线粒体通透性转换孔（mPTP）开放程度，分光光度法测定线粒体呼吸链酶复合物I～IV活性，TUNEL法检测心肌细胞凋亡水平，Western blotting法检测心肌细胞内凋亡与线粒体自噬相关蛋白的表达水平，免疫共沉淀法检测心肌细胞内Parkin与p62结合程度。结果 荭草苷可显著恢复MIRI诱导的MMP、mPTP开放阈值和粒体呼吸链酶复合物I～IV活性降低，减少心肌细胞凋亡；并能抑制心肌细胞内凋亡及线粒体自噬相关蛋白表达水平，减弱Parkin与p62的结合程度。结论 荭草苷对MIRI大鼠心肌细胞内线粒体具有明显保护作用，其机制可能通过Parkin依赖性和Parkin非依赖性信号通路抑制心肌细胞内线粒体自噬过度激活有关。

Objective To investigate the regulation effects of orientin on mitochondrial quality control in cardiomyocytes of rats with myocardial ischemia/reperfusion injury (MIRI). Methods A total of 75 Sprague-Dawley male rats were randomly divided into five groups:sham group, model group, and orientin preconditioning groups (1.0, 2.0, and 4.0 mg/kg). Except for sham group, all rats were exposed to modeling of MIRI with ligation of left anterior descending coronary artery (LADCA) for 30 min, and then releasing for 120 min. Mitochondrial membrane potential (MMP) and opening of mitochondrial permeability transition pore (mPTP) were detected by Microplate Reader; Activity of mitochondrial respiratory chain complexes I-IV was detected by Spectrophotometer; Cardiomyocyte apoptosis was detected by TUNEL method; Apoptosis and mitophagy related proteins were detected by Western Blot and the interaction between Parkin and p62 on mitochondria were detected by Co-IP. Results Orientin significantly restored MMP, mPTP opening threshold and activity of mitochondrial respiratory chain complexes I-IV, and reduced cardiomyocyte apoptosis. Additionally, orientin can dramatically inhibit the protein expression level apoptosis and mitophagy related proteins and weaken the interaction between Parkin and p62. Conclusion Orientin has a significant protective effect on cardiomyocyte mitochondria in MIRI rats. Its underlying mechanism is related to inhibition of hyperactivity of mitophagy in cardiomyocytes via Parkin-dependent and Parkin-independent signaling pathways.

国家自然科学基金资助项目（81470182）