Ferulic Acid Protects Human Lens Epithelial Cells against Ionizing Radiation-Induced Oxidative Damage by Activating Nrf2/HO-1 Signal Pathway

Ionizing radiation- (IR-) induced oxidative stress has been recognized as an important mediator of apoptosis in lens epithelial cells (LECs) and also plays an important role in the pathogenesis of IR-induced cataract. Ferulic acid (FA), a phenolic phytochemical found in many traditional Chinese medicine, has potent radioprotective and antioxidative properties via activating nuclear factor erythroid 2-related factor 2 (Nrf2) signal pathway. The goals of this study were to determine the protective effect of FA against IR-induced oxidative damage on human lens epithelial cells (HLECs) and to elucidate the role of Nrf2 signal pathway. HLECs were subjected to 4 Gy X-ray radiation with or without pretreatment of FA. It was found that FA pretreatment protected HLECs against IR-induced cell apoptosis and reduced levels of ROS and MDA caused by radiation in a dose-dependent manner. IR-dependent attenuated activities of antioxidant enzymes (SOD, CAT, and GPx) and decreased ratio of reduced GSH/GSSG were increased by pretreatment of FA. FA inhibited IR-induced increase of Bax and cleaved caspase-3 and the decrease of Bcl-2 in a dose-dependent manner. Furthermore, FA provoked Nrf2 nuclear translocation and upregulated mRNA and protein expressions of HO-1 in a dose-dependent manner. These findings indicated that FA could effectively protect HLECs against IR-induced apoptosis by activating Nrf2 signal pathway to inhibit oxidative stress, which suggested that FA might have a therapeutic potential in the prevention and alleviation of IR-induced cataract.