Chronic bisphenol A exposure at LOAEL induces hepatic metabolic remodeling associated with NAFLD-related pathways and hepatocarcinogenic susceptibility.

Abstract

Introduction: Bisphenol A (BPA) is a widely distributed endocrine-disrupting chemical with documented metabolic effects in experimental models. Although hepatic transcriptional alterations following BPA exposure have been reported, the extent to which these changes translate into functional metabolic remodeling remains unclear.

Objectives: This study aimed to characterize global hepatic metabolomic alterations following chronic exposure to BPA at the lowest observed adverse effect level (LOAEL) in mice and to determine whether the affected metabolic networks overlap with pathways implicated in non-alcoholic fatty liver disease (NAFLD) progression and early events associated with hepatocarcinogenic susceptibility.

Methods: Untargeted liquid chromatography-mass spectrometry (LC-MS)-based metabolomics was performed on liver samples from BPA-exposed (n = 8) and control (n = 6) mice. Differential metabolite analysis and pathway enrichment analysis were conducted to identify significantly altered metabolites and metabolic pathways.

Results: BPA exposure induced marked hepatic metabolic remodeling involving polyunsaturated fatty acids, arachidonic acid-derived eicosanoids, lysophospholipids, retinoid metabolism, and phase II detoxification pathways. Dysregulation of omega-3 and omega-6 fatty acids and altered prostaglandin and thromboxane derivatives indicated disruption of inflammatory lipid mediator balance. Changes in retinol- and retinoic acid-related metabolites suggested impaired differentiation-associated signaling, while increased sulfated and glucuronidated metabolites reflected enhanced xenobiotic metabolism. Pathway enrichment analysis highlighted biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, and retinol metabolism as significantly affected pathways.

Conclusion: Chronic BPA exposure at a LOAEL dose induces coordinated hepatic metabolic reprogramming characterized by pro-inflammatory lipid remodeling, disruption of retinoid signaling, and activation of detoxification mechanisms. These alterations may represent metabolic features associated with pathways relevant to NAFLD progression and hepatocarcinogenic susceptibility.