Antioxidant Capacity of Cultured Mammalian Cells Estimated by ESR Method

Abstract

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.