Risk reduction of ethyl acetate fraction of Empetrum nigrum var. japonicum via antioxidant properties against hydrogen peroxide-induced cell damage.

Reactive oxygen species (ROS) produce damage to all major cellular constituents. The antioxidant properties of the ethyl acetate fraction of Empetrum nigrum was assessed against hydrogen peroxide (H(2)O(2))-induced cell damage. Empetrum extract was found to scavenge (1) intracellular ROS in cell system, (2) hydroxyl radicals generated by the Fenton reaction (FeSO(4) + H(2)O(2)), and (3) superoxide radicals generated by xanthine/xanthine oxidase in a cell-free system as detected by electron spin resonance (ESR) spectrometry. Cell damage was produced by H(2)O(2) treatment as evidenced by DNA damage, lipid peroxidation, and increased protein carbonyl formation; however, Empetrum extract prevented H(2)O(2)-induced damage to these parameters. Empetrum extract increased viability of Chinese hamster lung fibroblast (V79-4) cells exposed to H(2)O(2), as evidenced by decreased apoptotic nuclear fragmentation, and lower sub G(1) cell population. Further, Empetrum extract restored the cellular antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and heme oxygenase-1 (HO-1), which were reduced by H(2)O(2) treatment. In conclusion, Empetrum extract protected cells against H(2)O(2)-induced cell damage via antioxidant properties by scavenging ROS and enhancing antioxidant enzyme activities.