Cytochrome P450-Mediated Detoxification and NF-κB/NLRP3 Pathway-Driven Hepatotoxicity of Emodin: Multiomics and laboratory evidence

Emodin, a bioactive compound abundant in Chinese medicinal herbs, possesses broad therapeutic potential but raises safety concerns due to conflicting reports of hepatotoxicity. This study investigated the toxicological mechanisms underlying emodin-induced liver injury. Emodin (25-100 μM) elicited dose-dependent cytotoxicity in HepG2 cells, with the cytochrome P450 (CYP) enzymes CYP1A2 and CYP3A4 identified as the primary enzymes metabolizing emodin into hydroxylated products (M1-M3). The comparative cytotoxicity assay of emodin and its metabolites in HepG2 cells indicated that CYP-mediated metabolism functions as a critical detoxification pathway. Moreover, inhibition of CYP with 1-aminobenzotriazole (ABT, 500 μM) markedly enhanced emodin (12.5-100 μM) cytotoxicity in HepG2 cells. Similarly, ABT (50 mg/kg) markedly exacerbated emodin (400 mg/kg)-induced hepatotoxicity in mice following three weeks of co-administration. Transcriptomic profiling and validation experiments demonstrated that activation of the NF-κB/NLRP3 signaling axis contributes to emodin-induced hepatic injury. Metabolomic analyses further revealed perturbations in key pathways, including lipopolysaccharide (LPS) biosynthesis, sphingolipid metabolism, and cholesterol metabolism. Integrated multi-omics analysis identified a significant positive correlation between these metabolites (LPS, sphingosine, cholesterol) and NF-κB/NLRP3 pathway genes. These findings suggest that emodin-mediated upregulation of LPS, sphingosine, and cholesterol activates the NF-κB/NLRP3 pathway, subsequently triggering hepatic injury. Collectively, this study delineates the metabolic detoxification routes of emodin and provides mechanistic insight into its hepatotoxic potential.