In vitro and in vivo inhibitory effects of (S)-armepavine against hepatic fibrosis in rats

Activation of hepatic stellate cells (HSCs) plays a crucial role in liver fibrogenesis. (S)-armepavine (Arm, C₁₉H₂₃O₃N), an active compound from Nelumbo nucifera, has been shown to exert immunosuppressive effects. In this study we investigated whether Arm could exert anti-hepato-fibrogenic effects in vitro and in vivo. A cell line of rat HSCs (HSC-T6) was stimulated with tumor necrosis factor-α (TNF-α) or lipopolysaccharide (LPS) to evaluate the inhibitory effects of Arm. In vivo therapeutic studies were conducted in both bile duct-ligated (BDL) and thioacetamide (TAA)-intoxicated rats. BDL or TAA rats were given Arm (3 or 10mg/kg) by gavage twice daily for 3 or 4 weeks, respectively, starting from the onset of BDL or TAA. Liver sections were taken for fibrosis scoring, immuno-fluorescence staining and quantitative real-time mRNA measurements. One-way analysis of variance was used for comparison of parameters. In vitro, Arm (1–10µM) concentration-dependently attenuated TNF-α- and LPS-stimulated α-SMA protein expression and collagen deposition by HSC-T6 cells without adverse cytotoxicity. Arm also suppressed TNF-α-induced NFκB and AP-1 activation and MAPK (p38, ERK1/2, and JNK) phosphorylations. In vivo, Arm treatment significantly reduced (a) plasma AST and ALT levels, (b) hepatic α-SMA expression and collagen contents, (c) α-SMA- and NFκB-immuno-positive cells, (d) mRNA expression levels of IL-6, TGF-β1, TIMP-1, col 1α2, iNOS, and ICAM-1 genes, and (e) fibrosis scores of BDL and TAA rats as compared with vehicle treatment. Our study results showed that Arm exerted both in vitro and in vivo antifibrotic effects in rats, possibly through anti-NF-κB activation pathways.