Chlorogenic Acid Attenuates Liver Fibrosis in Mice via HIF-1α Inhibition and M2 Macrophage Polarization

Abstract

Introduction: Liver fibrosis, a key pathological step preceding cirrhosis, is characterized by the abnormal accumulation of extracellular matrix (ECM) components, a process largely driven by hepatic stellate cell activation and persistent chronic inflammation. Chlorogenic acid (CGA), a natural polyphenolic compound, has exhibited promising anti-fibrotic activity. However, the precise mechanisms underlying its effects are still not fully elucidated. This study investigates CGA’s therapeutic effects and underlying pathways in carbon tetrachloride (CCl4)-induced liver fibrosis in mice. Methods: In this study, a mouse liver fibrosis model was established using CCl4. After treatment with different concentrations of CGA, the biochemical indicators related to liver fibrosis were detected. The pathological changes of liver tissues were examined by HE, Masson, and Sirius Red staining. The expression of related genes was analyzed by RNA-seq, immunohistochemistry, and immunofluorescence techniques to explore the molecular mechanism of CGA in anti-liver fibrosis. Results: CGA dose-dependently ameliorated liver fibrosis, as evidenced by reduced serum markers of liver injury and decreased collagen deposition in hepatic tissues. Histopathological examination confirmed that CGA treatment attenuated hepatocyte necrosis, inflammatory infiltration, and fibrotic lesions. At the molecular level, CGA inhibited Hepatic Stellate Cells (HSCs) activation, indicated by down-regulation of α-SMA, mitigated oxidative stress through restoration of SOD and GSH activities and reduction of MDA, and suppressed the expression of pro-inflammatory cytokines. Transcriptomic analysis identified 338 differentially expressed genes modulated by CGA, which were primarily enriched in immune regulation and metabolic pathways. Further mechanistic investigation revealed that CGA suppressed HIF-1α signaling, restored macrophage morphology, and promoted M2 polarization (up-regulation of CD206), thereby facilitating the clearance of activated HSCs. Discussion: This study found that CGA exerts multi-target anti-fibrotic effects by synergistically inhibiting HSC activation, reprogramming macrophage phenotypes, and alleviating oxidative stress. This synergistic mechanism provides a new basis for developing CGA-based targeted therapeutic strategies for liver fibrosis. Conclusion: This study demonstrates that CGA effectively reverses CCl4-induced liver fibrosis by promoting macrophage polarization toward the M2 phenotype, which in turn facilitates the elimination of HSCs. Its ability to reprogram macrophage function underscores its potential for clinical translation in treating chronic liver fibrosis.