Electroejaculation-guided analysis of sperm functional and biochemical parameters reveals ameliorative effects of...

Tolfenpyrad (TFP), a pyrazole carboxamide pesticide used on fruits and vegetables, raises concerns regarding male reproductive toxicity. This study investigated TFP-induced spermatotoxicity in Wistar albino rats and compared the protective effects of quercetin (QCT) versus chitosan-TPP encapsulated quercetin nanoparticles (QNP) in ameliorating the adverse effects of TFP on sperm. Rats were divided into seven groups (n = 6/group): normal control, vehicle (olive oil), QCT (20 mg/kg), QNP (20 mg/kg), TFP (8.6 mg/kg), TFP + QCT, and TFP + QNP, respectively. All treatments were administered continuously for a period of 60 days. Semen samples, obtained through electroejaculation on days 15, 30, 45, and 60, were assessed for motility, viability, concentration, morphology, acrosomal integrity, and hypo-osmotic swelling test (HOST) reactivity. The epididymis was harvested to assess oxidative stress, enzymatic, and metabolic markers. TFP induced an early decline in sperm motility from day 30, followed by significant deterioration in sperm concentration, viability, HOST reactivity, and acrosomal integrity, along with increased sperm abnormalities on days 45-60. TFP also induced oxidative stress and impaired antioxidant defence, accompanied by alterations in epididymal enzymatic and metabolic markers. Co-administration of QNP significantly improved motility from day 30 and mitigated sperm quality and biochemical indices (days 45-60), providing greater protection than free quercetin. These findings indicate TFP elicits spermatotoxicity during sub-chronic exposure and that chitosan-TPP quercetin nanoparticles offer superior mitigation via improved bioavailability.