Molecular hydrogen mitigates acetaminophen-induced liver injury and enhances the effects of N-acetylcysteine in diabetic mice

Abstract

Acetaminophen (APAP) overdose induces severe liver injury, especially in diabetic patients. N -acetylcysteine (NAC) is commonly used as an approved an- tidote for APAP toxicity; however, its narrow therapeutic window limits its clinical utility. This study investigated the protective effects of molecular hydro- gen (H2 ) against APAP-induced hepatotoxicity in diabetic mice. Diabetic db/db mice were provided with hydrogen-dissolved water (H2 -water) for two weeks prior to APAP administration. Consumption of H2 -water significantly attenuated APAP-induced liver injury, as evidenced by improved histological findings and decreased plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Using transgenic mice expressing redox-sensitive green fluorescent protein, H2 was shown to reduce both cytosolic and mitochondrial oxidative stress caused by APAP overdose. We observed that H2 modulated c-Jun N-terminal kinase (JNK) activation, inhibited mitochondrial translocation of Bax, and suppressed the release of mitochondrial endonucleases. Addi- tionally, H2 enhanced the expression of the hepatoprotective hormone fibroblast growth factor 21 (FGF21). These findings suggest that H2 protects against APAP-induced liver injury in diabetic mice by attenuating oxidative stress and upregulating FGF21 expression. Although NAC acts as an antioxidant, H2 was more effective in reducing mitochondrial oxidative stress. Importantly, co-treatment with H2 and NAC provided greater protection against APAP-induced hepatotoxicity than NAC alone. This synergistic effect may result from differences in the mechanisms by which NAC and H2 influence FGF21 expression and mitochondrial oxidative stress. The combination of H2 and NAC may offer an improved therapeutic strategy for treating APAP-induced liver injury in diabetic patients. © 2025 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

Study details

Article type

Original Research

Disease / injury model

Acetaminophen-induced liver injury in type 2 diabetic mice (db/db)

Duration

2 weeks

Dose comparison

The study compares the effects of different treatments (H2, NAC, and their combination) at fixed doses: H2-water (0.8 mM, ad libitum) and NAC (300 mg/kg, i.p.), both alone and in combination, on liver injury and oxidative stress outcomes.

Dose-dependent effect

No

Outcome

Positive

Findings

Molecular hydrogen (H2) administered as hydrogen-dissolved water significantly attenuated acetaminophen-induced liver injury in diabetic mice, as shown by improved liver histology, reduced plasma ALT and AST, decreased cytosolic and mitochondrial oxidative stress, inhibition of JNK activation, reduced Bax translocation, and increased FGF21 expression. H2 was more effective than NAC in reducing mitochondrial oxidative stress, and the combination of H2 and NAC provided synergistic protection against liver injury.