Comparative Neuroprotective Evaluation of Mitochondria-Targeted Antioxidant MitoQ Versus Acetyl-L-Carnitine in Vincristine-Induced Peripheral Neuropathy: Electrophysiological and Structural Insights

Vincristine (Vin), a chemotherapeutic agent commonly used in clinical practice, frequently causes peripheral neuropathy (PN). The aim of this study was to compare the potential therapeutic effects of acetyl-L-carnitine (ALC) and the mitochondria-targeted antioxidant MitoQ, administered following the establishment of PN in rats. PN was induced in rats by administering Vin (0.1 mg/kg/day) for 5 consecutive days, followed by a 2-day break, and then for another 5 days (cumulative dose: 1 mg/kg). Animals were subsequently treated daily for 7 days with either 300 mg/kg/day of ALC or 2 mg/kg/day of MitoQ. At the end of the study, sciatic nerve function was assessed using ex vivo electrophysiological recordings, while morphological changes were examined via H&E, Klüver–Barrera, and MBP/MPZ immunohistochemical staining. Vin exposure caused significant impairments in sciatic nerve CAP amplitude, integral, and conduction velocity, and histopathologically led to myelin damage, axonal degeneration, and vacuolization. Both treatments administered after the injury significantly attenuated functional and structural impairments, restoring them toward baseline levels. Notably, MitoQ showed favorable numerical improvements across myelin sheath integrity, vacuolization scores, and CAP parameters. In conclusion, MitoQ demonstrates notable neuroprotective efficacy and promotes nerve structural recovery following Vin-induced PN.