Antioxidant capacity of cultured mammalian cells estimated by ESR method

In the present study, the antioxidant capacity against hydrogen peroxide (H2O2), one of the stress-inducing agents, was investigated in two distinct cell lines: L-41 (human epithelial-like cells) and HLF (human diploid lung fibroblasts), which differ in tissue origin, life span in culture, proliferate activity, and special enzyme system activity. The cell antioxidant capacity against H2O2 was estimated by the electron spin resonance (ESR) spin-trapping technique in the Fenton reaction system via Fe+2 ion action with H2O2 resulting in hydroxyl radical generation. The effects of catalase inhibitors, such as sodium azide and 3-amino-1,2,4-triazole, on the antioxidant capacity of cells were tested. Based on our observation, it can be concluded that the defensive capacity of cells against H2O2 depends on the ratio between catalase/GPx/SOD and H2O2, especially at high-stress situations, and the intracellular balance of these enzymes are more important than the influence of the single component.