Chlorpyrifos-induced DNA damage in rat liver and brain.

Chlorpyrifos (O,O'-diethyl-O-3,5,6-trichloro-2-pyridyl phosphorothionate, CPF) is a broad spectrum organophosphate pesticide used to control a variety of pests. The present study was undertaken to test the in vivo genotoxic potential of CPF in rats, using the single cell gel electrophoresis (or comet) assay. The rats were administered 50 mg and 100 mg CPF/kg body weight daily for 1, 2, and 3 days as well as 1.12 mg and 2.24 mg CPF/kg body weight for 90 days. The level of DNA damage was estimated by scoring 100 cells per animal, dividing into five types: types 0, I, II, III, and IV. The results clearly indicate that exposure to CPF, acutely or chronically, caused a dose-dependent increase in DNA damage in the liver and brain of rats. From the present study, it can be concluded that CPF exhibits genotoxic potential in vivo.