Herpetrione alleviates ANIT-induced cholestatic liver injury by targeting FXR to suppress NF-κB signaling

Ethnopharmacology relevance Herpetrione, an active lignan isolated from Herpetospermum pedunculosum , a traditional Tibetan medicinal plant renowned for its use in hepatobiliary diseases, has been long applied in the treatment of jaundice, hepatitis, hepatic fibrosis and other conditions, demonstrating remarkable hepatoprotective efficacy. Aim of the study Based on the traditional efficacy of Herpetospermum pedunculosum as well as the hepatoprotective activity of herpetrione, we aim to investigate the therapeutic effects and molecular mechanisms of herpetrione against α-naphthylisothiocyanate (ANIT)-induced cholestasis in mice. Materials and methods Therapeutic effects of herpetrione were evaluated in ANIT-induced cholestatic mice and Fxr knockout mice. Molecular interactions with FXR were validated using CETSA, SIP, ITC, and SPR assays, with binding sites confirmed via molecular docking and amino acid mutation analyses. FXR-regulated signaling was explored in HepG2 cells treated with guggulsterone/lithocholic acid, using Co-IP, yeast one-hybrid, and dual-luciferase assays to clarify mechanisms. Results Herpetrione significantly alleviated ANIT-induced cholestatic liver injury, evidenced by reduced serum biomarkers of bile acid accumulation and liver damage, improved hepatobiliary pathology, and decreased hepatic inflammatory infiltration. Mechanistically, it directly bound the ligand-binding domain (Glu467/Ile317/Leu464) of FXR, then ligand-bound FXR recruit coactivator SRC-1 to trigger transcriptional upregulation of BSEP/MRP2/SHP to enhance bile acid excretion while inhibiting synthesis, thereby restoring hepatic and bile acid homeostasis. Notably, herpetrione-activated FXR directly binds the promoter region of NFKB1 to inactivate NF-κB signaling and suppress inflammation. Importantly, the therapeutic effects of herpetrione were abrogated in Fxr knockout mice. Conclusion This dual regulation of bile acid homeostasis and inflammatory signaling through targeting the FXR highlights the therapeutic potential of herpetrione in cholestatic injury.