Esculetin (6,7-dihydroxycoumarin), a natural coumarin compound extracted from natural plants, was reported to be involved in ischemiaireperfusion (I/R) injury. However, the role of esculetin in myocardial injury remains unclear. This study was designed to investigate the protective effects of esculetin on cardiomyocytes induced by hypoxiaireoxygenation (H/R), and explore the underlying mechanisms. Our results showed that esculetin improved the cell viability and decreased lactate dehydrogenase (LDH) release in HER-stimulated H9c2 cells. In addition, esculetin significantly suppressed oxidative stress and apoptosis in H9c2 cells exposed to HER treatment. Exploration of the underlying mechanisms of its action indicated that esculetin enhanced the activation of JAK2/STAT3 pathway in H/R-stimulated H9c2 cells. Taken together, these findings indicated that esculetin inhibits oxidative stress and apoptosis in H9c2 cardiomyocytes following H/R injury through the activation of JAK2/STAT3 pathway. (C) 2018 Published by Elsevier Inc.