Objective To investigate the chemical compositions of the ethyl acetate (EtOAc) fraction of Sophora flavescens and evaluate their anti-liver fibrosis activity. Methods The EtOAc extraction of S. flavescens was separated and purified by various column chromatography methods, including silica gel, polyamide, Sephadex LH-20 and C₁₈reversed-phase column chromatography. The structures of the isolated compounds were elucidated based on modern spectroscopic techniques and physical and chemical identification method. Transforming growth factor beta-1 (TGF-β1)-induced LX-2 cells were used as an in vitro model of hepatic fibrosis, and the anti-fibrotic activities of the compounds were evaluated using the CCK-8 assay. Additionally, cell wound scratch assay, real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, and flow cytometry assays were employed to investigate the anti-liver fibrosis activity and mechanism of compound 14 (kushenol T). Results A total of 28 compounds were isolated from the EtOAc of S. flavescens, and they were identified as follows: ethyl 2,4-dihydroxybenzoate (1), trifohrhizin (2), 2,4- dihydroxybenzoic acid (3), kuraridin (4), kushenol N (5), kurarinol A (6), kushenol C (7), 8-isopentenyl-5-methoxy-7,2′,4′-trihydroxy flavanonol (8), 2′-hydroxy-isoxanthohumol (9), kurarinone (10), methyl 2,4-dihydroxybenzoate (11), sophoflavescenol (12), umbeliferone (13), kushenol T (14), sophophenoside B (15), 6′′-β-D-xylosegenistin (16), 3′,4′-methylenedioxyisoflavone-7-O-β-D-apiofuranosyl-(l→6)-β-D-glucopyranoside (17), ambocin (18), kushenol O (19), 4′-hydroxy-3′-methoxyisoflavone-7-O-β-D-xylopyranosyl-(l→6)-β-D-glucopyranoside (20), 3′-hydroxy-4′-methoxyisoflavone-7-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (21), genistein (22), isoxanthohumol (23), 8-isopentenyl-5-methoxy-7,4′-dihydroxyflavanonol (24), 2-(2¢,4¢-dihydroxyphenyl)-5,6-methylenedioxy- benzofuran (25), calycosin (26), daidzein (27), narirutin (28). Bioactivity screening revealed that compounds 9, 11—14, 17, 20, 23—25 and 28 exhibited significant inhibitory effects on LX-2 cells. Among these, 14 demonstrated the most potent activity, markedly downregulating the expression of hepatic fibrosis markers, such as α-smooth muscle actin (α-SMA), fibronectin (FN) and Collagen I, at both the gene and protein levels. Furthermore, 14 promoted cell apoptosis and suppressed TLR4 in the Toll-like receptors 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling pathway, myeloid differentiation primary response 88 (MyD88), and TGF-β-activated kinase 1 (TGF-β-activated kinase 1), tumor necrosis factor α (TNF-α), and interleukin-1β (IL-1β). Conclusion Compounds 18, 25 and 28 were isolated from this species for the first time. Compounds 9, 11—14, 17, 20, 23—25 and 28 significantly inhibited LX-2 cell proliferation. Among them, compound 14 had the most significant activity and exerts an anti-liver fibrosis effect through the TLR4/NF-κB signaling pathway.

Sophora flavescens Ait.  /  hepatic fibrosis  /  kushenol T  /  LX-2 cells  /  TLR4/NF-κB signaling pathway  /  ambocin  /  narirutin