Protective effects of radish (Raphanus sativus L.) leaves extract against hydrogen peroxide-induced oxidative damage in human fetal lung fibroblast (MRC-5) cells

Natural antioxidants play a critical role in the promotion of good health for its prevention of oxidative stress. The main purpose of this study is to investigate the protective effects of radish leaves extract on the oxidative damage in human fetal lung fibroblast (MRC-5) cells. F2, a fraction of radish leaves extracts, which was fractionated by different polarity solvents and AB-8 macroporous resins column shows the best free radical scavenging ability, the highest total polyphenol contents (TPC), and the most potent protective effects on H2O2-induced oxidative damage in MRC-5 cells. The results indicated that pretreatment with F2 before the exposure of cells to H2O2 led to a significant increase in cell viability and internal antioxidant enzyme activities, and a decrease in the content of malondialdehyde (MDA). Furthermore, F2 attenuated the increase in intracellular reactive oxygen species (ROS) level and restored the loss of mitochondria membrane potential (MMP) caused by H2O2. In addition, pretreatment of F2 down-regulated the pro-apoptosis protein (Bax) and up-regulated the anti-apoptosis protein (Bcl-2) suggested its preliminary mechanism of protective effect. In summary, F2 from radish leaves might be used as a source of antioxidant for protecting the oxidative damage of lung.