Dose- and Organ-Specific Dual Effects of MitoTempo in Paracetamol-Induced Hepatorenal Toxicity in Mice.

Paracetamol (PAR) overdose is a major cause of drug-induced liver injury and is also associated with renal toxicity, both involving mitochondrial dysfunction and oxidative stress. This study investigated the dose- and organ-specific effects of the mitochondria-targeted antioxidant MitoTempo (MT) on PAR-induced hepatorenal toxicity in mice. Male C57BL/6J mice received a single toxic dose of PAR (600 mg/kg), either alone or combined with MT (20 or 40 mg/kg). Twenty-four hours after treatment, serum markers of liver and kidney injury were measured, and mitochondrial function was assessed in both organs. PAR administration caused severe liver injury and moderate renal dysfunction, accompanied by increased mitochondrial oxidative stress, glutathione imbalance, mitochondrial permeability transition pore opening, and disruption of electron transport chain (ETC) integrity. MT co-treatment attenuated several PAR-induced mitochondrial alterations in a dose- and tissue-dependent manner; however, MT did not consistently confer protection and, in some settings, exacerbated oxidative stress and bioenergetic dysfunction, particularly in the kidney. Notably, recovery of ETC protein levels by MT was not consistently associated with restoration of enzymatic activity. Overall, these findings demonstrate that MT exerts dual, dose- and organ-specific effects on PAR-induced mitochondrial dysfunction, highlighting that mitochondria-targeted antioxidants are not universally protective.