Forskolin alleviates cholestatic liver disease by inhibiting the Hippo/YAP-mediated ductular reaction and fibrosis progression.

Cholestatic liver disease (CLD) results from impaired bile flow, involving dysregulated Hippo/YAP signaling driving pathogenic ductular reaction (DR), inflammation, and fibrosis. Although ursodeoxycholic acid (UDCA) remains first-line therapy, most patients show inadequate response. Our computational screening identified forskolin (FSK), adenylate cyclases (ADCY1-10) activator, as a potential Hippo/YAP pathway modulator through cAMP elevation. Molecular docking confirmed FSK's stable binding across all human ADCY isoforms, supporting upstream cAMP's activation. Cholestatic injury was induced in rats via bile duct ligation (BDL). BDL-rats were treated with either FSK or UDCA. Relative to UDCA, FSK significantly improved liver function (ALT, AST, ALP, GGT) and cholestasis (bilirubin, bile acids) parameters. FSK markedly reduced inflammation markers (IL-6, IL-1β, CXCL1, and CXCL2) and attenuated fibrosis, as evidenced by restored Hydroxyproline levels, COL1A1, and α-SMA expressions. Histological analysis revealed that FSK preserved hepatic architecture, suppressed DR, and downregulated CK19/EpCAM expressions, whereas UDCA showed only partial improvement. Although UDCA significantly modulated Hippo/YAP signaling, FSK substantially activated the pathway through LATS1/2 and YAP1 phosphorylation, suppressing YAP/TEAD transcriptional activity, mediated through cAMP elevation. These findings indicate FSK's multi-target therapeutic actions, mitigating inflammation, DR, and fibrosis mediated by ADCY-cAMP-Hippo/YAP axis modulation. Given its superior efficacy over UDCA, FSK represents a promising therapeutic candidate for clinical translation in CLD.