Assessment of genotoxic effects of organophosphate and carbamate pesticides by comet assay

Abstract

Background and Aims: Pesticide poisoning is the most widespread occupational hazard for agricultural workers in the developing world, due to the extensive presence of pesticides in the environment. The aim of this study was to investigate the cytotoxicity and DNA damaging effects of organophosphosphate and carbamate pesticides. Methods: In the present study, the cytotoxicity of chlorpyrifos methyl, azinphos ethyl, [(O-Ethyl O-(p-nitrophenyl) pheriylphosphonothioate] (EPN), aldicarb sulfone, and ethiofencarb were assessed by the trypan blue dye exclusion method. An alkaline comet assay was performed to assess the genotoxic effects of applied pesticides in human peripheral blood lymphocytes. Results: We demonstrated the cytotoxic effect of EPN following 30 and 120 min exposure at 100 µg/mL concentration. Although chlorpyrifos-methyl and azinphos ethyl seem to be safer concerning cytotoxicity compared to other pesticides, significantly higher DNA damage levels were determined after exposure of these pesticides for 120 min at 100 µg/mL concentration by in vitro comet assay. The potential DNA-damaging effects of these pesticides were sorted from high to low, as chlorpyrifos-methyl, aldicarb sulfone, EPN, and azinphos ethyl after 30 min of exposure, and were sorted as chlorpyrifosmethyl, azinphos ethyl, aldicarb sulfone, and EPN after 120 min of exposure. Our results revealed that these pesticides tend to increase DNA damage in a dose- and time-dependent manner. Conclusion: The genotoxic effects of these widely used pesticides may cause prominent and serious health risks for human populations; hence, the DNA-damaging potential of pesticides can lead to genotoxic risk and adverse health effects like cancer.