ABSTRACT
Hydrogen peroxide [H2O2] is a common reactive oxygen intermediate generated by various forms of oxidative stress. The aim of this study was to investigate the DNA damage capacity of H[2]O[2] in HepG2 cells. Cells were treated with H2O2 at concentrations of 25 micro M or 50 micro M for 5 min, 30 min, 40 min, 1 h, or 24 h in parallel. The extent of DNA damage was assessed by the comet assay. Compared to the control, DNA damage by 25 and 50 micro M H[2]O[2] increased significantly with increasing incubation time up to 1 h, but it was not increased at 24 h. Our findings confirm that H[2]O[2] is a typical DNA damage-inducing agent and thus is a good model system to study the effects of oxidative stress. DNA damage in HepG2 cells increased significantly with H2O2 concentration and time of incubation but later decreased likely due to DNA repair mechanisms and antioxidant enzymes