Ameliorative potential of quercetin nanoparticles against tolfenpyrad-induced subchronic toxicity in male Wistar rats

Tolfenpyrad, a pyrazole-derived pesticide, is widely used in agriculture. This study evaluated the median lethal dose (LD₅₀) of tolfenpyrad and protective efficacy of quercetin-loaded chitosan nanoparticles against tolfenpyrad-induced subchronic toxicity in male Wistar rats. The LD₅₀ was determined using ten rats. Subsequently, for the subchronic study, 42 animals were assigned to seven groups (six animals/group): Group I: distilled water control, Group II: vehicle control (Olive oil, 4 mL/kg), Group III: quercetin control (20 mg/kg), Group IV: quercetin-loaded chitosan nanoparticle control (20 mg/kg), Group V: tolfenpyrad (8.6 mg/kg), Group VI: tolfenpyrad (8.6 mg/kg) + quercetin (20 mg/kg), and Group VII: tolfenpyrad (8.6 mg/kg) + quercetin-loaded chitosan nanoparticles (20 mg/kg). Treatments were administered orally for 60 days. Clinical signs, biweekly feed and water intake, and body weight were recorded. Tolfenpyrad caused perioral inflammation, a coarse hair coat, and significant reductions in feed intake, water intake, and body weight. Co-administration of quercetin ameliorated these effects, while co-administration of quercetin-loaded nanoparticles significantly reduced inflammation and restored physiological parameters closer to normal levels. These findings highlight the therapeutic potential of quercetin-loaded chitosan nanoparticles against tolfenpyrad-induced physiological disruptions.