Protective effects of black currant (Ribes nigrum L.) extract on hydrogen peroxide-induced damage in lung fibroblast MRC-5 cells in relation to the antioxidant activity

A black currant (Ribes nigrum L.) extract (BCE) was prepared to investigate its protective effects against damage to lung fibroblast MRC-5 cells induced by H2O2. BCE exhibited strong scavenging activities against hydroxyl (
- OH) and superoxide anion radicals (O2
- -) in vitro. Exposing MRC-5 cells to H2O2 reduced the cell viability, the activities of antioxidant enzymes, including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), and cell apoptosis while increasing the thiobarbituric acid reactive substances (TBARS) content. Pretreating cells with different concentrations of BCE (0, 2.5, 5 and 10 mg/ml) enhanced the cell viability and antioxidant enzyme activities while decreasing the TBARS content. Morphological observations and flow cytometric analysis revealed that BCE alleviated the cell apoptosis induced by H2O2. These protective effects of BCE on MRC-5 cells suggest that black currants may possess the ability to eliminate over-produced ROS in humans.