STUDY OF CHRONIC TOXIC EFFECT OF DELTAMETHRIN AND DIMETHOATE ON BRAIN OF ADULT MALE ALBINO RATS

Abstract

organophosphate pesticides are being increasingly used in combination with Pyrethroids. The effects of single molecules are being studied, but the risk associated with pesticide mixtures is still to estimate. So, the purpose of the current study was to evaluate the individual and combined toxic effects of deltamethrin (DLM) and dimethoate (DM) on brain of adult male albino rats. For this purpose, 60 adult male albino rats were randomized into 5equal groups: Group I: negative control, Group II: positive control received 1ml corn oil once daily. Group III received deltamethrin (5 mg/kg b.w./orally ∕daily), Group IV received dimethoate (20 mg/kg b.w./ orally ∕daily), Group V received deltamethrin (5 mg/kg b.w) and dimethoate(20 mg/kg b.w)orally ∕daily . At the end of the study (12 weeks); Body weight was evaluated then blood sample were obtained for estimation of oxidative stress markers malondialdehyde (MDA) glutathione (GSH), total antioxidant capacity TAC) and plasma cholinesterase (PCHE) level then rats were sacrificed. The brains were excised, prepared for histopathological, immunohistochemical examination and DNA damage estimation by comet assay. Results revealed that single DLM and DM exposure significantly had adverse effects on adult male Albino rats in the form of decrease in the body weight, increase in brain &serum MDA, decrease in TAC &GSH and decrease in PCHE level. Pathological changes in brain of rats included, pychnosis, neuronal degeneration, neuropil vacuolization, hemorrhage and congested blood vessels beside positive immuoreaction for bax. Also they caused DNA damage compared to control group. In conclusion, chronic exposure to DLM and DM singly and in combination induced significant oxidative damage in rat brain, associated with marked perturbations in antioxidant defense system in addition to genotoxicity detected by comet assay. Also, the mixture of the two pesticides caused greater damage on the brain of male albino rats, than the individual pesticides.