Abstract: Objective To elucidate the underlying mechanisms of periplocin-induced hepatotoxicity using a zebrafish model, combined with cytochrome P450 (CYP) inhibitor interventions and transcriptomics. Methods Zebrafish larvae at 4 days post-fertilization (4 dpf) were used as the experimental model. Hepatotoxicity was evaluated by analyzing liver phenotypes in transgenic zebrafish and performing hematoxylin-eosin (H&E) staining following combined exposure to periplocin and CYP inhibitors. Subsequently, transcriptome sequencing and real-time quantitative PCR (RT-qPCR) were employed to uncover and validate the molecular mechanisms. Results Periplocin exposure caused a dose-dependent decrease in liver fluorescence intensity and induced pathological damage, including hepatocyte vacuolization and disordered arrangement. Notably, co-treatment with CYP inhibitors exacerbated these toxic effects, suggesting that the hepatotoxicity of periplocin was closely associated with its metabolic clearance. Transcriptomic analysis revealed significant alterations in the hepatic gene transcription profile, characterized primarily by the suppression of pathways related to CYP-mediated xenobiotic metabolism, lipid metabolism, and bile acid synthesis. RT-qPCR confirmed the significant downregulation of the key transcription factor hnf4a and its downstream phaseⅠmetabolic enzymes (cyp3a65, cyp2p6), phaseⅡmetabolic enzyme (gstp1), as well as the lipid metabolism regulator pparab and the bile acid regulator cyp8b1 (P<0.05). Conclusion Periplocin can induce severe liver injury by suppressing the expression of the upstream core transcription factor-hepatocyte nuclear factor 4α (HNF4α). This suppression triggers a transcriptional inhibition cascade affecting downstream CYP detoxification systems and the PPARα lipid metabolism pathway, leading to disrupted hepatic homeostasis, diminished detoxification capacity, and metabolic disorders.

Key words: Periplocin, Hepatotoxicity, Zebrafish, Transcriptomics, Cytochrome P450