Protective role of STVNa in myocardial ischemia reperfusion injury by inhibiting mitochondrial fission

It has been reported that isosteviol, a widely known sweeteners, can protect against myocardial ischemia-reperfusion (IR) injury in isolated guinea pig heart. Here, we aim to confirm the cardioprotective effect of its sodium salt, isosteviol sodium (STVNa), against IR injury and its potential molecular mechanism in H9c2 cardiomyocytes. STVNa significantly improved cell viability, restored mitochondrial membrane potential, decreased cellular reactive oxygen species generation, and inhibited cell apoptosis. Furthermore, STVNa treatment changed the morphology of mitochondria from fragmented, discontinuous forms to normal elongated, tubular forms. Cyto-immunofluorescence and western blot analysis revealed that STVNa inhibited mitochondrial fission proteins dynamin-related protein 1 (Drp1), and mitochondrial fission 1 (Fis1), thus plays a key role in cardioprotection. These findings, for the first time, suggest that STVNa can protect against myocardial IR injury through reverse mitochondrial fission.