Cytoprotective Mechanism of Cyanidin and Delphinidin against Oxidative Stress-Induced Tenofibroblast Death

Age-related rotator cuff tendon degeneration is related to tenofibroblast apoptosis. Anthocyanins reduce oxidative stress-induced apoptotic cell death in tenofibroblasts. The current study investigated the presence of cell protective effects in cyanidin and delphinidin, the most common aglycon forms of anthocyanins. We determined whether these anthocyanidins have antiapoptotic and antinecrotic effects in tenofibroblasts exposed to H(2)O(2), and evaluated their biomolecular mechanisms. Both cyanidin and delphinidin inhibited H(2)O(2)-induced apoptosis in a dose-dependent manner. However, at concentrations of 100 μg/ml or greater, delphinidin showed cytotoxicity against tenofibroblasts and a decreased antinecrotic effect. Cyanidin and delphinidin both showed inhibitory effects on the H(2)O(2)-induced increase in intracellular ROS formation and the activation of ERK1/2 and JNK. In conclusion, both cyanidin and delphinidin have cytoprotective effects on cultured tenofibroblasts exposed to H(2)O(2). These results suggest that cyanidin and delphinidin are both beneficial for the treatment of oxidative stress-mediated tenofibroblast cell death, but their working concentrations are different.