Oxidative stress and superoxide dismutase activity in brain of rats fed with diet containing permethrin

Many pesticides have been reported to cause a lot of health problems in workers, users and non-target organisms in the environment. Permethrin containing insect pesticide has been reported to be toxic to non-target organisms. However, the underlying mechanism involved in the toxicity is not well understood. The present study was envisaged to investigate the possible role of oxidative stress in permethrin neurotoxicity and to evaluate the protective effect of superoxide dismutase (SOD) activity in brain homogenates of Wistar rats. Oxidative stress measured as thiobarbituric acid reacting substances (TBARS) was found to significantly increase (p < 0.05) in all the experimental groups compared with their parallel controls. Concomitantly, the activity of SOD was found to decrease or increase significantly (p < 0.05) in the experimental groups compared with their controls. Our result also showed that activity of SOD was aged and concentration dependent. Hence, the newly weaned rats appear to be more susceptible to the pesticide contaminated diet because the SOD activity decreased more in the brain homogenates compared with the middle aged rats or aged rats. Observed aggressive behaviour was noticed in the pesticide exposed rats, hence a possible neurobehavioral effect. The result demonstrated that the pyrethroid insect powder exerts its toxic effect by promoting oxidative stress in the brain and this may affect normal brain functioning and growth.

Keywords
pesticides, reactive oxygen species, superoxide dismutase, lipid peroxidation