Alleviating Effect of Phyllanthus niruri on Sensorimotor and Cognitive Changes Induced by Subacute Chlorpyrifos Exposure in Wistar Rats

Abstract

Objective: Studies in animal models and humans have shown that chlorpyrifos (CPF) causes sensorimotor and cognitive changes. Apart from inhibiting acetylcholinesterase (AChE), the induction of oxidative stress is one of the other molecular mechanisms implicated in OP-evoked toxicity. The present study evaluated the alleviating effect of Phyllanthus niruri, a flavonoid rich plant, on subacute CPF-evoked sensorimotor and cognitive changes in Wistar rats. Design: Thirty five adult male Wistar rats divided into five groups of seven rats were used for the study. Groups 1 and II were given soya oil (2 ml/kg) and CPF (10.6 mg/kg~1/8 th of LD50), respectively. Group III was administered methanol extract of Phyllanthus niruri (MEP) at 500 mg/kg only. Group IV was administered MEP (250 mg/kg) and CPF (10.6 mg/kg), 30 min later while group V was administered with MEP (500 mg/kg) and CPF (10.6 mg/kg), 30 min later. The regimens were administered by gavage once daily for 28 days during which periodic evaluation of sensorimotor and cognitive performances were carried out. Thereafter, the brain was evaluated for AChE activity and malonaldehyde (MDA) concentration. Results: CPF caused defi- cits in sensorimotor reflexes and cognition, increased brain MDA concentration and decreased AChE activity, which were all mitigated by MEPN. Conclusion: The study concludes that mitigation of sensorimotor and cognitive deficits elicited by CPF was mitigated by MEP partly due to the antilipoperoxidative and acetylcholinesterase restoration properties of its flavonoid constituent.