Kanglexin, a new anthraquinone compound, attenuates hepatic fibrosis by regulating the TGF-β/SMADS signaling pathway and glutathione metabolism

Liver fibrosis, characterized by excessive extracellular matrix (ECM) accumulation, poses a significant threat to human health. This study synthesized a novel anthraquinone derivative, Kanglexin (KLX), and evaluated its protective effects against liver fibrosis while elucidating the underlying molecular mechanisms. Hepatic fibrosis was induced in mice via intraperitoneal carbon tetrachloride (CCl₄) injection, and an in vitro model of activated hepatic stellate cells (HSCs) was established using transforming growth factor-beta (TGF-β) stimulation. Transcriptomic analysis was employed to investigate KLX's mechanisms. In vivo, KLX significantly attenuated CCl₄-induced increases in serum fibronectin (FN), hyaluronic acid (HA), laminin (LN), collagen type IV (Col-IV), and TGF-β levels, alongside reducing collagen fiber deposition. KLX also reversed the CCl₄-induced imbalance in hepatic superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels. Transcriptomics revealed that retinol metabolism, glutathione metabolism, and cellular migration pathways are potentially pivotal for KLX's antifibrotic action. KLX mitigated CCl₄-induced upregulation of phosphoenolpyruvate carboxykinase 1 (PCK1) protein and downregulation of the cystine/glutamate antiporter (xCT), thereby modulating glutathione metabolism. In vitro, KLX suppressed the TGF-β/SMADs signaling pathway and regulated the expression of tissue inhibitors of metalloproteinases/matrix metalloproteinases (TIMPs/MMPs) to enhance ECM degradation balance. Furthermore, KLX downregulated cyclin-dependent kinase inhibitor 1 (Cyclin D1) and cyclin-dependent kinase 2 (CDK2) expression, inhibiting activated HSC proliferation. KLX also improved glutathione metabolism by modulating the expression of PCK1, xCT, and glutathione peroxidase 4 (GPX4)-related proteins. These findings demonstrate that KLX exerts potent antifibrotic effects by regulating glutathione metabolism and promoting ECM degradation, suggesting its potential as a therapeutic candidate for liver fibrosis.