Monocrotophos Based Pesticide Alters the Behavior Response Associated with Oxidative Indices and Transcription of Genes Related to Apoptosis in Adult Zebrafish (Danio rerio) Brain

Abstract

Monocrotophos is one of the most widely used pesticides in India. The agricultural workers were exposed to high concentrations of these pesticides due to unsafe work practices, and also the individual exposed to these pesticides shows alterations in their neurobehavioral. The present study aimed to evaluate the toxic effects of Monocrotophos on the locomotor activity, antioxidant activity, lipid peroxidation, and expression of genes related to apoptosis using adult zebrafish (Danio rerio) as a model. The neurotoxic effects of sub-lethal concentration of the Monocrotophos on fish were evaluated. The locomotor activity of the fishes was determined, followed by an antioxidant activity, and lipid peroxidation assays were performed. The expression of genes related to apoptosis in the brain was also determined by qPCR. The Lethal Concentration for 96 hrs. was estimated to be 36.5 mg/L. When exposed to sub-lethal concentration, marked changes were observed in locomotor activity (distance traveled, swimming speed and meandering), acetylcholinesterase activity, oxidative stress markers (lipid peroxidation) and antioxidant defenses in the brain. Expression of apoptotic genes determined by qPCR revealed an increase in Bax, caspase-3, and caspase-9 expression and a decrease in Bcl-2 expressions. Data from this study suggest that Monocrotophos based pesticides induce cellular toxicity, and has the potential to alter the behavior and health.