Detection of natural- and synthetic antioxidant-stimulated reduction of DNA damage in H2O2- and Mnng-treated mammalian cells with the comet assay

The possible protective effects of natural and synthetic antioxidants on DN A in hamster V79 cells exposed to hydrogen peroxide (H2O2) and N-methyl-N'- nitro-N-nitrosoguanidine (MNNG) were investigated. The levels of DNA damage were measured using single cell gel electrophoresis. It was assessed that natural antioxidants lignin biopolymer and vitamin E (alpha-tocoferol) and a synthetic antioxidant stobadine (STB) exhibited a protective effect again st the overall DNA damage induced after H2O2-treatment. In addition, it was observed that lignin NG. These findings suggest that the antioxidant natur e of lignin biopolymer enables a rbiopolymer and stobadine (but not vitamin E) also protected against DNA damaged by MNeduction of the levels of frank breaks and of oxidized DNA bases in H2O2-treated cells and its adsorptive capacity enables binding of N-nitroso compounds and reduction of alkylation in MNNG-treated cells. The reduced level of DNA damage in STB-pre-treated samples could be due to its antioxidant properties in the case of H2O2-trea tment and to a direct reduction of MNNG activity in the case of the alkylat ing agent.