Platycodin D inhibits oxidative stress and apoptosis in H9c2 cardiomyocytes following hypoxia/reoxygenation injury.

Myocardial ischemia/reperfusion (I/R) injury is a complex pathophysiological process related to the occurrence of myocardial infarction (MI). Oxidative stress is known to play a crucial role in the pathogenesis of I/R injury. Platycodin D (PD) is an active natural saponin that possesses strong anti-oxidant activity. The aim of the present study was to investigate the effect of PD on myocardial I/R injury. An in vitro hypoxia/reoxygenation (H/R) model was established in cardiomyocyte H9c2 cells. The results showed that PD improved the cell viability in H/R-stimulated H9c2 cells. The H/R-induced increase in the production of reactive oxygen species (ROS) and malondialdehyde (MDA), and decrease in the activities of superoxide dismutase (SOD) and catalase (CAT) were reversed by PD pretreatment. The histone-associated DNA fragment was increased by H/R stimulation, while decreased after PD treatment. Besides, PD pretreatment reduced the expressions of Bax and cleaved caspase-3, while induced Bcl-2 expression in H/R-induced H9c2 cells. Furthermore, PD was found to induce the activation of Akt/Nrf2/HO-1 pathway. The inhibitor of Akt, LY294002, attenuated the effects of PD on H/R-induced H9c2 cells. These findings indicated that PD exerted its protective effect via inducing the activation of Akt/Nrf2/HO-1 pathway. Our work provided new insights into the potential therapeutic role of PD in myocardial I/R injury.