A mixture of pyrethroids induces reduced fecundity and increased testicular genotoxicity in rats.

To achieve crop protection and higher agricultural yield, pesticides are used; and among them pyrethroid based ones are the most preferred choice because of their specificity on the pests. Uncontrolled use of pesticides resulted in contamination of food products. Presence of residual amounts of pyrethroids was reported in agricultural products sold in Indian market, indicating that humans are constantly exposed to these chemicals through food on a routine basis. Studies that determine the toxic effects of pyrethroids at doses equivalent to human exposure are rare. We orally administered a mixture of pyrethroids (detected in the rice and vegetables of Indian market) to male rats for 15 months to mimic the long-term exposure in humans. We observed reduced fecundity, sperm count and 13β-hydroxysteroid dehydrogenase enzyme activity. The serum concentrations of hormones involved in male reproductive function were altered. Further, testicular genotoxicity as reflected by perturbations in the expression pattern of genes involved in the molecular processes of gametogenesis was evident. Such toxic effects may also be occurring in humans who consume agricultural products that contain residual amounts of pyrethroids on a regular basis throughout their lifetime.