β‐Carotene enhances hydrogen peroxide‐induced DNA damage in human hepatocellular HepG2 Cells

Abstract

In this study, the alkaline version of the comet assay has been used to determine the effect of beta-carotene supplementation (10 microM) on peroxide-initiated free radical-mediated DNA damage in human HepG2 hepatoma cells. In supplemented cells, beta-carotene failed to afford any protection against hydrogen peroxide-induced DNA strand breaks. Indeed, levels of strand breaks in supplemented cells were significantly higher than in cells exposed to hydrogen peroxide alone, especially after a long incubation period. In contrast, beta-carotene afforded significant levels of protection against DNA strand breaks when cells were treated with tert-butyl hydroperoxide. In this case, the level of protection increased as supplementation continued.