Gypenosides protect against cardiac ischemia-reperfusion injury by inhibiting mitochondria-dependent apoptosis

Purpose: To investigate the effect of gypenoside (Gyp) on myocardial ischemia-reperfusion (I/R), focusing on mitochondrial function and oxidative stress. Methods: A 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay was employed to measure the protective effect of Gyp pre-treatment against I/R injury. Flow cytometry was used to detect cellular reactive oxygen species (ROS) content and mitochondrial membrane potential (MMP) levels. Additionally, cytochrome C release was observed by laser scanning confocal microscopy. Finally, Annexin V staining and western blot were applied to analyse cell apoptosis. Results: MTT assay results showed that Gyp pre-treatment protected H9C2 cells against I/R injury in a Gyp concentration-dependent manner. Moreover, Gyp treatment inhibited intracellular ROS production, repressed cytochrome C transposition induced by I/R treatment, and recovered MMP to almost normal levels. Furthermore, the expression of apoptosis-related proteins included cleaved caspase-3, -9 and Bax which were decreased by Gyp treatment after I/R injury. Conclusion: These results suggest that Gyp treatment prior to injury can help maintain normal mitochondrial function and inhibit ROS production during I/R injury, ultimately leading to the suppression of I/R-induced cell apoptosis. Thus, Gyp may be a promising drug for the treatment of myocardial I/R.