The effect and mechanism of albiflorin in alleviating hepatic fibrosis by mediating hepatocyte ferroptosis via the SLC7A11/GPX4 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Albiflorin(ALB), a key bioactive compound extracted from the traditional Chinese herb Paeonia lactiflora Pall., is a prominent ingredient in classical remedies like Xiaoyao Powder and Taohong Siwu Decoction. These formulations have a historical application in Chinese medicine for addressing liver fibrosis-related conditions. Functioning as a distinctive monoterpene glycoside, albiflorin exhibits anti-fibrotic properties attributed to its hepatoprotective and anti-inflammatory effects. Nonetheless, a comprehensive understanding of the precise molecular mechanisms responsible for its therapeutic efficacy necessitates further investigation.

OBJECTIVE: This study sought to validate the molecular mechanism of ALB against liver fibrosis, integrating both in vivo and in vitro experiments with molecular docking and molecular dynamics simulations.

METHODS: A liver fibrosis model was induced in mice using carbon tetrachloride (CCl4). ALB was administered at 5 and 20 mg/kg, with colchicine (0.1 mg/kg) serving as a positive control. The hepatoprotective effects of ALB were evaluated through serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and liver histopathology. ALB's anti-fibrotic efficacy was examined using Western blot, immunohistochemistry, and Quantitative Real-time Reverse Transcription PCR (qRT-PCR) for alpha-smooth muscle actin (α-SMA) and Collagen I (Col-I), along with Western blot for Fibronectin. Oxidative stress was assessed by measuring superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and glutathione (GSH) levels. Ferroptosis-related marker expressions were also analyzed. In vitro, an 20 μmol/L Erastin-induced ferroptosis model in AML12 hepatocytes was employed. Cell viability was determined via Cell Counting Kit-8 (CCK-8) assay, and intracellular reactive oxygen species (ROS) and Fe2+ levels were measured with the DCFH-DA fluorescent probe. Molecular docking and molecular dynamics simulations were used to assess the structural binding characteristics of ALB with Glutathione Peroxidase 4 (GPX4). Furthermore, the GPX4 inhibitor RSL3 was utilized to evaluate the expression of solute carrier family 7 member 11 (SLC7A11)/GPX4, iron metabolism-related proteins, and the levels of intracellular Fe2+.

RESULTS: ALB treatment significantly mitigated CCl4-induced liver fibrosis in mice, enhancing liver function, lowering serum ALT and AST levels, reducing liver injury, and restoring hepatic lobule architecture. It also effectively suppressed hepatic oxidative stress. Histological and analytical data showed that ALB treatment substantially decreased collagen deposition and α-SMA, Col-I and Fibronectin expression. Mechanistic studies indicated that ALB activated the SLC7A11/GPX4 signaling pathway, increasing the expression of SLC7A11, GPX4, Ferritin Heavy Chain 1 (FTH1), and Ferritin Light Chain (FTL), while decreasing Transferrin receptor protein 1 (TFRC) and Heme Oxygenase-1 (HO-1) levels, thus inhibiting ferroptosis. In vitro, ALB treatment improved cell viability, reduced oxidative stress and iron accumulation, and exerted anti-ferroptotic effects by modulating the SLC7A11/GPX4 pathway. Molecular docking and dynamics simulations have shown that ALB forms a stable complex with GPX4. The GPX4 inhibitor RSL3 partially diminished ALB's protective effects, suggesting that its activity might rely on the GPX4 pathway.

CONCLUSION: Our results demonstrate that Albiflorin mitigates CCl4-induced liver fibrosis in mice by inhibiting oxidative stress-induced ferroptosis, likely via modulation of the SLC7A11/GPX4 signaling pathway.