The present study was designed to evaluate genotoxic markers of mancozeb exposure and withdrawal in colon and liver tissues together with histological changes in the gastrointestinal tract of Sprague Dawley rats. Thirty rats were divided into three equal groups; group I: treatment, 250 mg/kg mancozeb dissolved in corn oil administered twice weekly for 7 weeks; group II: withdrawal, the same treatment as group I after which animals were untreated for 5 weeks; group III: control, administered corn oil on the same schedule as group I for 7 weeks. All administrations were by oral gavage. Serum samples were analyzed for biochemical parameters. The comet assay and histopathological examinations were done on liver and colon specimens. The results demonstrated that mancozeb exposure caused significant increases in triglycerides and total cholesterol accompanied by decreases in glucose levels, with extensive DNA damage in liver and colon together with pathological changes in stomach, colon, and liver. Mancozeb withdrawal for 5 weeks improved the lipid and glucose profiles and decreased the degree of DNA damage and changes in the architecture of the stomach, colon, and liver. We concluded that discontinuing exposure to mancozeb fungicide for 5 weeks could ameliorate the adverse effects induced by 7 weeks of exposure to mancozeb. A longer withdrawal time may further reduce the observed genotoxicity.
Keywords: DNA damage; Mancozeb fungicide; biochemical; colon; liver; stomach.