Aqueous extracts of Corni Fructus protect C2C12 myoblasts from DNA damage and apoptosis caused by oxidative stress

Although the various pharmacological effects of Corni Fructus are highly correlated with its antioxidant activity, the blocking effect against oxidative stress in muscle cells is not clear. The purpose of this study was to investigate the effect of aqueous extracts of Corni Fructus (CFE) against oxidative stress caused by hydrogen peroxide (H₂O₂) in murine skeletal C2C12 myoblasts.

MTT assay for cell viability, DCF-DA staining for reactive oxygen species (ROS) production, Comet assay for DNA damage, annexin V-FITC and PI double staining for apoptosis, JC-1 staining and caspase assay for monitor mitochondrial integrity, and western blotting for related protein levels were conducted in H₂O₂ oxidative stressed C2C12 cells. Our results showed that CFE pretreatment significantly ameliorated the loss of cell viability and inhibited apoptosis in H₂O₂-treated C2C12 cells in a concentration-dependent manner. DNA damage induced by H₂O₂ was also markedly attenuated in the presence of CFE, which was associated with suppression of ROS generation. In addition, H₂O₂ reduced mitochondrial membrane potential and caused downregulation of Bcl-2 and upregulation of Bax expression, although these were abrogated by CFE pretreatment. Moreover, CFE blocked H₂O₂-induced cytosolic release of cytochrome c, activation of caspase-9 and caspase-3, and degradation of poly (ADP-ribose) polymerase.

Taken together, the present results demonstrate that CFE could protect C2C12 cells from H₂O₂-induced damage by eliminating ROS generation, thereby blocking mitochondria-mediated apoptosis pathway. These results indicate that CFE has therapeutic potential for the prevention and treatment of oxidative stress-mediated myoblast injury.