Salvianolic Acid B Protects Against Myocardial Ischemic Injury Through Inhibiting Apoptosis and Promoting Autophagy
Abstract Aim of the study: Salvianolic acid B(Sal B) as a natural compound extracted from Salvia miltiorrhiza, has been extensively used to protect cardiomyocytes from myocardial ischemia. Although Sal B has shown evident effects on cardiovascular diseases, the detailed mechanism is still unclear as yet. Herein, we intended to explorethe protective effects of Sal B on myocardial ischemic injury and the underlying mechanism. Methods and Results: Western blotting, immunofluorescence assay, flow cytometry and lentiviral transfection were performed. The mice with myocardial ischemic injury were intravenously given 10 mg/kg Sal B once daily for seven days, and then H9c2 cells were treated with Sal B (20, 40, 80 μmol/L). Sal B treatment protected cardiomyocytes from myocardial ischemia through relieving apoptosis. Transmission electron microscopy and fluorescence microscopy exhibited that Sal B significantly increased autophagic lysosomes and vacuoles in H9c2 cells. Administration with Sal B significantly up-regulated the expressions of autophagy-related factors such as LC3, Atg5 and Beclin 1 in H9c2 cells and myocardial tissues. The beneficial autophagic changes induced by Sal B were abrogated through pharmacological inhibition. Conclusions: This study provides a molecular mechanism by which Sal B potently inhibits apoptosis and oxidative stress upon myocardial ischemia by activating the AMPK-autophagy pathway. Sal B is a potential agent for treating myocardial ischemia.