Clinico-Haematological and Histopathological Features of the Swiss Albino Mice Mus musculus L. in Response to Chronic Cypermethrin Exposure

Abstract

Cypermethrin is one of the widely used broad-spectrum pyrethroid insecticides because of their high insecticidal activities and lower mammalian toxicity. But indiscriminate and unregulated uses of this insecticide in agriculture and public health in Bangladesh have led to drastic effects on many non-target species including man. Using 0.1 to 0.25 LD50 dose equivalents, 25 healthy male mice were divided randomly into five groups viz., T0 (control), T1, T2, T3 and T4, each comprising five animals, which received intraperitoneally 0.0, 0.10, 0.15, 0.20, and 0.25 mL cypermethrin kg-1 body weight week-1 respectively for 28 days. Clinical signs and behavioral manifestations were monitored throughout the experiment, and vital hematological parameters and histopathological features were analyzed in the end. Compared to the control mice, repeated cypermethrin exposure elicited characteristic symptoms like decrease in feed intake, hind limb jerking, labored breathing, lesions, body weight loss, necrosis, startle response, hemorrhages, eye discharge and edema in the experimental mice. Owing to cypermethrin mediated oxidative stress on hematological profile, decreases in TEC, DLC, TTC, ESR and Hb concentration, but increases in TLC and lymphocytes, accompanied by lymphocytic infiltrations, congestion of vessels as well as inflammation of various tissues account for the degenerative changes in the hepatic and renal tissues. The present findings imply that cypermethrin is hazardous, which can affect the well-being of the non-target organisms including agricultural, industrial and household human workers who are liable to get cypermethrin toxicosis following its repeated dermal or aerial exposure, leading to anemia and/or hepatic and renal failure.