Genotoxicity of the organophosphorus compound methylparaoxon evaluated by the comet assay

Abstract

Pesticides are widely used in agriculture, food production and household. Due to the broad spectrum of their activity, their biological action is extensively investigated. We assessed the genotoxidty of methylparaoxon - the main metabolite of commonly used organophosphorus insecticide, methylparathion. Freshly isolated human peripheral blood lymphocytes were incubated for 1 h with methylparaoxon at 37° C, and then, were incubated in methylparaoxon-free medium to examine DNA repair. Alkaline single cell gel electrophoresis (the comet assay) was used to assess DNA damage and repair. Methylparaoxon induced moderate DNA damages that were almost completely repaired after 60 min. Obtained results suggest that methylparaoxon could induce single-strand breaks in DNA both directly and by methylathion of DNA bases.