The study was aimed at evaluating the protective role of α-lipoic acid (ALA) on long-term exposure of rats to the combination of chlorpyrifos (CPF) and deltamethrin (DLT). Forty-two (42) male Wistar rats were divided into 6 exposure groups with 7 animals in each group: (I) soya oil (2 ml kg-1), (II) ALA (60 mg kg-1), (III) DLT (6.25 mg kg-1), (IV) CPF (4.75 mg kg-1), (V) (CPF + DLT) DLT (6.25 mg kg-1) and CPF (4.75 mg kg-1; 1/20th of the previously determined median lethal dose) and (VI) (ALA + CPF + DLT) pretreated with ALA (60 mg kg-1) and then co-exposed to CPF and DLT, 45 min later. The regimens were administered by gavage once daily for a period of 16 weeks. Sera obtained from blood collected at the end of the experimental period were used for the evaluation of serum glucose, total protein, albumin, urea, creatinine and the activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase and acetylcholinesterase. The liver homogenate was used to assay for the activities of superoxide dismutase and glutathione peroxidase and the concentrations of malondialdehyde, cytokine and tumour necrotic factor α. The result showed that the combination of CPF and DLT resulted in marked alterations of these biochemical parameters in most cases compared to either of the pesticides singly, supplementation with ALA ameliorated these alterations.
Keywords: Pesticides; alpha-lipoic acid; chlorpyrifos; deltamethrin; lipid peroxidation; oxidative stress.