Lymphocyte DNA damage in rats exposed to pyrethroids: effect of supplementation with Vitamins E and C.

Pesticides have been considered potential chemical mutagens. In fact, some studies show that various agrochemical ingredients possess mutagenic properties inducing mutations, chromosomal alterations or DNA damage. Experimental evidence shows a marked correlation between mutagenicity and carcinogenicity and indicates that short-term mutagenicity tests are useful for predicting carcinogenicity. The present study on rat exposed to two pyrethroids, cypermethrin and permethrin, showed different lymphocyte DNA damage depending on the type of pyrethroid, the dose, and the period of treatment. Data obtained from comet assay showed that oral treatment with 150 mg/kg body weight/day of permethrin (corresponding to 1/10 of LD50) for 60 days, induced a significant increase in all comet parameters. No lymphocyte DNA damage was measured after treatment with 25 mg/kg body weight/day of cypermethrin (corresponding to 1/10 of LD50) for the same period. A higher dose of permethrin (300 mg/kg body weight/day), for a shorter period (22 days), did not induce lymphocyte DNA damage, while supplementation with 200 mg/kg of Vitamins E and C protected erythrocytes against plasma membrane lipids peroxidation. Moreover, treatment with Vitamins E and C maintained the activity of glutathione peroxidase, which was reduced in the presence of permethrin, and reduced the osmotic fragility, which had increased following permethrin treatment.