Development and behavioural toxicity of deltamethrin on Rattus norvegicus following gestational exposure

Abstract

Deltamethrin, a synthetic type II pyrethroid was used at acceptable daily intake (ADI) levels to evaluate the embryo toxic risk in rat offsprings. Commercial formulation of deltamethrin (Decis 2.8 EC) at the level of ADI (0.01 mg/kg bw/day) and ten times ADI (0.1 mg/kg bw/day) was given orally to female rats (Rattus norvegicus) after mating until the end of pregnancy. The rats which did not breed were sacrificed for uterine examination, total implantations and resorptions. No toxicological symptoms were found in the rats treated with ADI level of deltamethrin, however rats treated with 10 times ADI dose of deltamethrin appeared weak and less active. Rats treated with 10×ADI did not breed and resorptions and cysts were observed in their uterus and ovary respectively. In rats treated with ADI dose of deltamethrin, litter size was reduced, pups gained less body weight and their developmental parameters and behavioural milestones were delayed as compared to control rats pups. The results suggested that gestational exposure of deltamethrin on growth and viability of rat offsprings at ADI level also affected the development and behaviour of rat offsprings.