Wuling capsule modulates macrophage polarization by inhibiting the TLR4-NF-κB signaling pathway to relieve liver fibrosis.

BACKGROUND AND PURPOSE: Wuling capsule (WL) has good efficacy in the clinical treatment of chronic hepatitis B and liver injury. Liver fibrosis is a common pathological feature of chronic liver disease and may progress to irreversible cirrhosis and liver cancer. Accumulating evidence reveals that modulating macrophage polarization contribute to the therapy of liver fibrosis. However, the effects of WL on modulating macrophage polarization to relive liver fibrosis remain unclear. This study investigated the anti-liver fibrosis effects of WL in carbon tetrachloride (CCl4)-induced liver fibrosis in rats, and the modulation effects and underlying molecular mechanism on macrophage polarization. METHODS: A rat liver fibrosis model was constructed by intraperitoneal injection of 40 % CCl4 olive oil mixture. At 2, 4, 6, and 8 weeks, the histopathological status of the liver was assessed by hematoxylin-eosin (HE) and Masson staining; the liver biochemical indexes were measured in rat liver tissue. The expression levels of inflammatory cytokines in liver tissue were detected by ELISA. The mRNA levels and proteins expression of macrophage markers of different phenotypes, TLR4-NF-κB signaling pathway indicators were detected independently by ELISA, immunofluorescence, RT-PCR and western blotting. RESULTS: In vivo, WL treatment attenuated abnormal changes in weight, organ indices and biochemical indices, alleviated pathological changes, and reduced collagen fiber deposition as well as the expression of α-SMA in liver tissues. Further studies revealed that WL decreased the expression of the macrophage M1 polarization markers inducible nitric oxide synthase (iNOS), TNF-α, IL-6, and CD86, promoted the expression of the M2 macrophage polarization markers IL-10, CD206, and arginase-1 (Arg-1), and inhibited the activation of the TLR4-NF-κB signaling pathway via several key signaling proteins. In vitro, WL significantly suppressed macrophage M1 polarization, and promoted M2 polarization while boosted M1 polarization transform to M2 polarization in LPS-activated RAW264.7 cells. CONCLUSIONS: This study demonstrated that WL modulated macrophage polarization against liver fibrosis mainly by inhibiting the activation of the TLR4-NF-κB signaling pathway.

[Mechanism of Wuling Capsules against hepatic fibrosis based on network pharmacology and animal experiments].

The present study aimed to explore the underlying mechanism of Wuling Capsules in the treatment of hepatic fibrosis(HF) through network pharmacology, molecular docking, and animal experiments. Firstly, the chemical components and targets of Wuling Capsules against HF were searched from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), Traditional Chinese Medicines Integrated Database(TCMID), GeneCards, and literature retrieval. The protein-protein interaction(PPI) network analysis was carried out on the common targets by STRING database and Cytoscape 3.9.1 software, and the core targets were screened, followed by Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analyses. Enrichment analysis was conducted on the core targets and the "drug-core component-target-pathway-disease" network was further constructed. Subsequently, molecular docking between core components and core targets was conducted using AutoDock Vina software to predict the underlying mechanism of action against HF. Finally, an HF model induced by CCl_4 was constructed in rats, and the general signs and liver tissue morphology were observed. HE and Masson staining were used to analyze the liver tissue sections. The effects of Wuling Capsules on the levels of inflammatory factors, hydroxyproline(HYP) levels, and core targets were analyzed by ELISA, RT-PCR, etc. A total of 445 chemical components of Wuling Capsules were screened, corresponding to 3 882 potential targets, intersecting with 1 240 targets of HF, and 47 core targets such as TNF, IL6, INS, and PIK3CA were screened. GO and KEGG enrichment analysis showed that the core targets mainly affected the process of cell stimulation response and metabolic regulation, involving cancer, PI3K-Akt, MAPK, and other signaling pathways. Molecular docking showed that the core components of Wuling Capsules, such as lucidenic acid K, ganoderic acid B, lucidenic acid N, saikosaponin Q2, and neocryptotanshinone, had high affinities with the core targets, such as TNF, IL6 and PIK3CA. Animal experiments showed that Wuling Capsules could reduce fat vacuole, inflammatory infiltration, and collagen deposition in rat liver, decrease the levels of inflammatory cytokines TNF-α, IL-6, and HYP, and downregulated the expressions of PI3K and Akt mRNA. This study suggests that the anti-HF effect of Wuling Capsules may be achieved by regulating the PI3K-Akt signaling pathway, reducing the levels of TNF-α and IL-6 inflammatory factors, and inhibiting the excessive deposition of collagen.