Qiliqiangxin reduced cardiomyocytes apotosis and improved heart function in infarcted heart through Pink1/Parkin -mediated mitochondrial autophagy

BACKGROUND: Qiliqiangxin (QLQX) is a preparation refined from a traditional Chinese medicine compound. It plays an important role in protecting cardiac function after myocardial infarction (MI). However, the underline mechanism of QLQX action is not clear. The purpose of this study was to detect the effects of QLQX on mitophagy after MI. METHODS: Male FVB/NJ mice aged 8–10 weeks were underwent left coronary artery ligation and were orally administered either QLQX (0.25 g/kg/d) or saline. Twenty-eight days after surgical operation, the cardiac function of mice was detected by echocardiography. Electron Microscopy was used to observe the microstructure of cardiomyocytes. Myocardial apoptosis was examined by TdT-mediated dUTP Nick-End Labeling (TUNEL) and western blot. H9c2 cells were cultured in a hypoxic incubator chamber (5% CO(2), 1% O(2), 94% N(2)) for 12 h and pretreated with or without QLQX (0.5 mg/mL). The cell apoptosis, reactive oxygen species (ROS), mitochondrial membrane potential and mitophagy were detected. RESULTS: When compared to sham group, the cardiac function of MI mice decreased significantly, and their cardiomyocyte apoptosis and mitochondrial damage were more serious. These MI-induced cardiac changes could be reversed by QLQX treatment. In vitro experiments also confirmed that QLQX could protect cardiomyocytes from hypoxia-induced apoptosis and mitochondrial damage. Further study indicated that QLQX could increase the expression of Pink1 and Parkin in cardiomyocytes. CONCLUSION: Qiliqiangxin could reduce cardiomyocytes apotosis and improved heart function in infarcted heart through Pink1-mediated mitochondrial autophagy.