Evaluation of the protective effect on exogenous melatonin in adult rats and their offspring exposed to insecticides methomyl and cypermethrin during pregnancy

Exposure of pregnant women to pesticides in an occupational or incidental manner has been pointed out as a possible cause of health problems in newborns. Cypermethrin and methomyl are insecticides whose active compounds and metabolites can cause harm to the health of pregnant women and their offspring. Both contribute to increases in the concentrations of oxidizing agents that damage DNA, causing mutations. Thus, the use of antioxidant substances, such as melatonin, could serve as protection against genetic damage, reducing the problems caused by insecticides. Here, we evaluated the protective effect of exogenous melatonin in adult rats and their offspring exposed to methomyl and cypermethrin during the gestational period. Thirty adult rats were divided into five groups from the first day of pregnancy: NC - negative control, Mth received 0.02 mg/kg/day of methomyl, Cyp received 0.05 mg/kg/day cypermethrin, MthMl received 0.02 mg/kg/day methomyl combined with 10 mg/kg/day melatonin, and CypMl received 0.05 mg/kg/day cypermethrin combined with 10 mg/kg/day melatonin. Blood and liver samples were collected from the dams; blood, liver, and brain samples were collected from the offspring. All tissues were used for comet assay; blood was used for micronucleus test. Our results demonstrate that cypermethrin and methomyl induce significant genetic damage in the tissues of dams and offspring. Treatment with melatonin significantly reduced cypermethrin-induced genetic damage in dams and pups; however, melatonin was not effective against the genetic damage caused by methomyl. Thus, melatonin may be considered a promising agent for the reduction of genotoxic effects induced by cypermethrin but appears to be inefficient against the genotoxic effects caused by methomyl, probably due to differences in the metabolism of each pesticide.