Sniper-organophosphate pesticide exposure induces neurotoxicity and biochemical agitation in male Sprague-Dawley rats

Organophosphate poisoning as a result of exposure to Dichlorvos (Sniper) has remained a global health challenge with an estimated 220,000 deaths annually, especially in the developing nations of the world. The aim of this study was to determine the effect of acute exposure of organophosphate pesticide in male Sprague-Dawley rats and a possible effective antidote therapy. The LD50 in rats was determined in a pilot study to be 11.6mg/kg. Dichlorvos was injected intraperitoneally at 0, 4, 8, 12, 16, and 20 mg/kg respectively. Twenty rats divided into five groups of four rats per group were used for the study. Groups A, B, C, D, and E were administered 10mg/kg of Dichlorvos, 1 ml of normal saline, atropine sulphate (1.5mg/kg) after injection of Dichlorvos (10mg/kg), and diazepam (5mg/kg) after injection of Dichlorvos (10mg/kg). Acute poisoning symptoms of straub tail, restlessness, pupil constriction, respiratory distress, convulsion and death were observed. The blood chemistry and liver enzymes activities showed a significant decrease in the mean concentration values when compared to the control group. There was a dose dependent decrease (p< 0.05) in brain acetylcholine esterase activity but no significant difference in the hematological profile and cytochrome p450 in treated rats compared to the control. The brain histological examination showed that there were no visible abnormalities in the brain, liver and kidney tissues of rats in the groups. Atropine was the most effective antidote with a 100% survival rate, however, Diazepam significantly reduced symptoms like convulsion, pupil constriction and nervousness in the poisoned rats.