Farnesoid X Receptor: Effective alleviation of rifampicin -induced liver injury.

Antituberculosis drugs induce pharmacologic cholestatic liver injury with long-term administration. Liver injury resulting from rifampicin is potentially related to the bile acid nuclear receptor Farnesoid X Receptor (FXR). To investigate this, cholestasis was induced in both wild-type (C57BL/6N) mice and FXR knockout (FXR-null) mice through administration of rifampicin (200 mg/kg) via gavage for 7 consecutive days. Compared with C57BL/6N mice, FXR-null mice exhibited more severe liver injury after rifampicin administration, characterized by enlarged liver size, elevated transaminases, and increased inflammation. Moreover, under rifampicin treatment, FXR knockout impairs lipid secretion and exacerbates hepatic steatosis. Significantly, the expression of metabolism molecules BSEP increased, while NTCP and CYP7A1 decreased following rifampicin administration in C57BL/6N mice, whereas these changes were absent in FXR knockout mice. Furthermore, rifampicin treatment in both C57BL/6N and FXR-null mice was associated with elevated c-Jun N-terminal kinase phosphorylation (p-JNK) levels, with a more pronounced elevation in FXR-null mice. Our study suggests that rifampicin-induced liver injury, steatosis, and cholestasis are associated with FXR dysfunction and altered bile acid metabolism, and that the JNK signaling pathway is partially implicated in this injury. Based on these results, we propose that FXR might be a novel therapeutic target for addressing drug-induced liver injury.