ETHNOPHARMACOLOGICAL RELEVANCE: The herb of Abrus cantoniensis Hance (AC) is an important Traditional Chinese Medicine (TCM) and is also used as an herbal tea with hepatoprotective action. Soyasaponin Bb is one of the pharmacodynamic substances of AC for the herb's effective pharmacological activity. This study aims to investigate the anti-fibrotic and hepatoprotective activities of soyasaponin Bb in vivo and in vitro experiments, mechanism by network pharmacology and quantification by HPLC.
MATERIALS AND METHODS: High-performance liquid chromatography (HPLC) was applied to evaluate the quality of the herb and determine the contents of soyasaponin Bb from different sources and parts of the AC. In vivo experiments were conducted to induce an acute liver injury model by injecting CCl4 into mice, and an in vitro hepatic fibrosis model was established by cultivating LX-2 cells with TGF-β1. These models were used to explore the anti-fibrotic and hepatoprotective effects of soyasaponin Bb and its underlying mechanisms. In addition, the potential target genes corresponding to soyasaponin Bb were identified using the Swiss Target Prediction database through network pharmacology methods. Meanwhile, hepatic fibrosis targets were screened using the GeneCards, TTD, and OMIM disease databases. The STING database was used to construct the protein-protein interaction (PPI) network of soyasaponin Bb-hepatic fibrosis. The soyasaponin Bb-hepatic fibrosis disease target-pathway network was constructed using Cytoscape 3.9.1 software. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to enrich and analyze the common targets of the drug and the disease, aiming to identify the potential targets and pathways involved in the anti-fibrotic and hepatoprotective effects of soyasaponin Bb.
RESULTS: The content of soyasaponin Bb varied across different sources, with the roots containing the highest concentration, up to 0.2480%. In vivo experiments showed that soyasaponin Bb had a protective effect against CCl4-induced acute liver injury, effectively inhibiting the increase in ALT and AST levels and slowing down the hepatocyte inflammatory damage caused by CCl4. Soyasaponin Bb also down-regulated MDA levels and up-regulated SOD levels, indicating a certain antioxidant capacity. In vitro cell experiments showed that soyasaponin Bb could effectively inhibit the proliferation of HSC-LX2 cells induced by TGF-β1 by regulating the TGF-β1/α-SMA pathway, significantly down-regulate the protein expression of TGF-β1 and α-SMA, while also reducing the levels of inflammatory cytokines IL-6 and IL-1β. Further network pharmacology analysis suggested that soyasaponin Bb can exert anti-fibrosis activity by regulating the IBD signaling pathway, Th17 signaling pathway, Hepatitis B signaling pathway, and JAK-STAT signaling pathway.
CONCLUSION: Soyasaponin Bb is primarily distributed in the root of AC, and it has a strong protective effect against CCl4-induced acute liver injury. It can reduce the level of inflammatory factors, relieve inflammation, and exert anti-fibrotic activity by regulating the TGF-β1/α-SMA pathway. Its potential anti-hepatic fibrosis mechanism has been investigated through network pharmacology.