Genotoxic effect induced by hydrogen peroxide in human hepatoma cells using comet assay

Abstract

Background: Hydrogen peroxide is a common reactive oxygen intermediate generated by various forms of oxidative stress. Aims: The aim of this study was to investigate the DNA damage capacity of H₂O₂ in HepG2 cells. Methods: Cells were treated with H₂O₂ at concentrations of 25 µM or 50 µM 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. Results: Compared to the control, DNA damage by 25 µM and 50 µM H₂O₂ increased significantly with increasing incubation time up to 1 h, but it was not increased at 24 h. Conclusions: Our Findings confirm that H₂O₂ 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. Key words: DNA damage, Hydrogen peroxide, HepG2 cells, Comet assay. (Published: 13 January 2010) Citation: Libyan J Med 2010, 5: 4637 - DOI: 10.3402/ljm.v5i0.4