Differences in early acetaminophen hepatotoxicity between obese ob/ob and db/db mice

Area of Science:

• Hepatology
• Toxicology
• Metabolic Disorders

Background:

• Obesity and nonalcoholic fatty liver disease may worsen acetaminophen (APAP) overdose-induced liver injury.
• Fat accumulation and CYP2E1 induction are proposed mechanisms for this increased susceptibility.

Purpose of the Study:

• To investigate the role of obesity and diabetes in APAP hepatotoxicity using mouse models.
• To explore the specific mechanisms contributing to liver injury in these conditions.

Main Methods:

• Experiments were conducted in obese diabetic ob/ob and db/db mice, alongside wild-type controls.
• APAP (500 mg/kg) was administered, and liver injury was assessed at various time points (0.5, 2, 4, 8 hours).
• Assessments included plasma transaminases, liver histology, glutathione levels, APAP-protein adducts, and gene expression.

Main Results:

• db/db mice exhibited significantly higher liver injury 8 hours post-APAP intoxication compared to wild-type and ob/ob mice.
• This increased injury in db/db mice occurred despite lower liver triglycerides and similar basal transaminase levels.
• Key injury markers like glutathione depletion and APAP-protein adducts were not elevated in db/db mice, but CYP2E1 activity was selectively increased.

Conclusions:

• Early APAP-induced hepatotoxicity is more severe in db/db mice than ob/ob mice.
• Hepatic CYP2E1 induction appears to play a critical pathogenic role in APAP liver injury within the context of obesity and metabolic disorders.
• Fat accumulation may not be the primary driver of enhanced APAP hepatotoxicity in this specific model.