Evaluation of Neurotoxicity in SH-SY5Y Cells Caused by Chlorpyrifos Exposure and Its Usefulness in Terms of Cell Damage with Quercetin Application

Abstract Chlorpyrifos (CPF) exposure has been demonstrated to induce permanent damage to the nervous system, attributable to its toxic effect on the neuronal system and its inhibitory effect on acetylcholine esterase (AChE). Quercetin, a flavonoid found in numerous plant sources, has been shown to cross the blood-brain barrier and possesses the capacity to repair cellular damage. The present study sought to investigate the neurotoxicity that developed due to CPF exposure in SH-SY5Y cells and the changes in cellular functions such as DNA damage, apoptosis, and autophagy. It was observed that CPF increased DNA damage and induced apoptosis and autophagy in SH-SY5Y cells, while quercetin reversed this effect at low doses. The study determined that the lipophilic structure of quercetin, in addition to its capacity to block AChE activity at high doses by affecting membrane stability, hindered its ability to reverse cellular damage and counteract CPF neurotoxicity. The findings revealed that the combination of low doses of CPF and quercetin led to the suppression of DNA tail, caspase-3, and LC3B gene expression in cells, accompanied by an enhancement in cell viability. Consequently, the quantity of quercetin present in nutrients and the dosages to be ingested as supplements are pivotal for the restoration of cellular functions in reducing the damage that develops in the neuronal system due to CPF exposure.