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Background: Hepatic fibrosis is a dynamic process which ultimately leads to cirrhosis in almost patients with chronic hepatic injury. However, progressive fibrosis is a reversible scarring response. Activation of hepatic stellate cells (HSCs) is the prevailing process during hepatic fibrosis. Osthole is an active component majorly contained in the fruit of Cnidium monnieri (L.) Cusson. This present study investigated the therapeutic effects of osthole on rat liver fibrosis and HSC activation. Results: We established the thioacetamide (TAA)-model of Sprague-Dawley (SD) rats to induce hepatic fibrosis. Rats were divided into three groups: control, TAA, and TAA + osthole (10 mg/kg). In vivo, osthole significantly reduced liver injury by diminishing levels of plasma AST and ALT, improving histological architecture, decreasing collagen and α-SMA accumulation, and improving hepatic fibrosis scores. Additionally, osthole reduced the expression of fibrosis-related genes significantly. Osthole also suppressed the production of fibrosis-related cytokines and chemokines. Moreover, nuclear translocation of p65 was significantly suppressed in osthole-treated liver. Osthole also ameliorated TAA-induced injury through reducing cellular oxidation. Osthole showed inhibitory effects in inflammation-related genes and chemokines production as well. In vitro, we assessed osthole effects in activated HSCs (HSC-T6 and LX-2). Osthole attenuated TGF-β1-induced migration and invasion in HSCs. Furthermore, osthole decreased TNF-α-triggered NF-κB activities significantly. Besides, osthole alleviated TGF-β1- or ET-1-induced HSCs contractility. Conclusions: Our study demonstrated that osthole improved TAA-caused liver injury, fibrogenesis and inflammation in rats. In addition, osthole suppressed HSCs activation in vitro significantly. [ABSTRACT FROM AUTHOR]

Background: Non-alcoholic steatohepatitis (NASH) is associated with hepatic fibrogenesis. Despite well-known cholesterol-lowering action of statins, their mechanisms against NASH-mediated fibrogenesis remain unclear. This study aimed at investigating the in vitro and in vivo anti-fibrotic properties of fluvastatin (Flu). Methods: Palmitate (PA)-induced changes in intracellular hydrogen peroxide levels in primary rat hepatocytes (PRHs) and human hepatoma cell line (HepG2) were quantified by dichlorofluorescein diacetate (DCF-DA) dye assay, whereas changes in expressions of NADPH oxidase gp91phox subunit, a-smooth muscle actin (a-SMA), and NFB p65 nuclear translocation were quantified with Western blotting. Quantitative real-time polymerase chain reaction (q-PCR) was used to investigate mRNA expressions of pro-inflammatory genes (ICAM-1, IL-6, TNF-a). Conditioned medium (CM) from PA-treated PRHs was applied to cultured rat hepatic stellate cell line, HSC-T6, with or without Flu-pretreatment for 2 h. Pro-fibrogenic gene expressions (COL1, TIMP-1, TGF-ß1, a-SMA) and protein expression of a-SMA were analyzed. In vivo study using choline-deficient L-amino acid defined (CDAA) diet-induced rat NASH model was performed by randomly assigning Wistar rats (n = 28) to normal controls (n = 4), CDAA diet with vehicles, and CDAA diet with Flu (5 mg/kg or 10 mg/kg) (n = 8 each) through gavage for 4 or 8 weeks. Livers were harvested for histological, Western blot (a-SMA), and q-PCR analyses for expressions of pro-inflammatory (IL-6, iNOS, ICAM-1) and pro-fibrogenic (Col1, a-SMA, TIMP-1) genes. Results: In vitro, Flu (1-20 µM) inhibited PA-induced free-radical production, gp91phox expression, and NFB p65 translocation in HepG2 and PRHs, while CM-induced a-SMA protein expression and pro-fibrogenic gene expressions in HSC-T6 were suppressed in Flu-pretreated cells compared to those without pretreatment. Moreover, a-SMA protein expression was significantly decreased in HSC-T6 cultured with CM from PA-Flu-treated PRHs compared to those cultured with CM from PA-treated PRHs. Flu also reduced steatosis and fibrosis scores, a-SMA protein expression, mRNA expression of pro-inflammatory and pro-fibrogenic genes in livers of CDAA rats. Conclusions: We demonstrated PA-induced HSC activation through paracrine effect of hepatocyte in vitro that was significantly suppressed by pre-treating HSC with Flu. In vivo, Flu alleviated steatosis-induced HSC activation and hepatic fibrogenesis through mitigating inflammation and oxidative stress, suggesting possible therapeutic role of Flu against NASH. [ABSTRACT FROM AUTHOR]

Activation of hepatic stellate cells (HSCs) plays a crucial role in liver fibrogenesis. armepavine (Arm, C19H23O3N), an active compound from Nelumbo nucifera, has been shown to exert immunosuppressive effects on T lymphocytes and on lupus nephritic mice. The aim of this study was to investigate whether Arm could exert anti-hepatic 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. An in vivo therapeutic study was conducted in bile duct-ligated (BDL) rats. BDL rats were given Arm (3 or 10 mg/kg) by gavage twice daily for 3 weeks starting from the onset of BDL. Liver sections were taken for fibrosis scoring, immuno-fluorescence staining and quantitative real-time mRNA measurements. In vitro, Arm (1-10 μM) concentration-dependently attenuated TNF-α- and LPS-stimulated α-SMA protein expression and AP-1 activation by HSC-T6 cells without adverse cytotoxicity. Arm also suppressed TNF-α-induced collagen collagen deposition, NFκB activation and MAPK (p38, ERK½, and JNK) phosphorylations. In vivo, Arm treatment significantly reduced plasma AST and ALT levels, hepatic α-SMA expression and collagen contents, and fibrosis scores of BDL rats as compared with vehicle treatment. Moreover, Arm attenuated the mRNA expression levels of col 1α2, TGF-β1, TIMP-1, ICAM-1, iNOS, and IL-6 genes, but up-regulated metallothionein genes. Our study results showed that Arm exerted both in vitro and in vivo antifibrotic effects in rats, possibly through anti-NF-κB activation pathways. [ABSTRACT FROM AUTHOR]

Tumor necrosis factor-alpha (TNF-α) plays a central role in cellular necrosis, apoptosis, organ failure, tissue damage, inflammation and fibrosis. These processes, occurring in liver injury, may lead to cirrhosis. Thalidomide, α- N-phthalidoglutarimide, (C13H10N2)4, has been shown to have immunomodulatory and anti-inflammatory properties, possibly mediated through its anti-TNF-α effect. In this study, we investigated the in vitro and in vivo effects of thalidomide on hepatic fibrosis. A cell line of rat hepatic stellate cells (HSC-T6) was stimulated with transforming growth factor-β1 (TGF-β1) or TNF-α. The inhibitory effects of thalidomide on the NFκB signaling cascade and fibrosis markers including α-smooth muscle actin (α-SMA) and collagen, were assessed. An in vivo therapeutic study was conducted in dimethylnitrosamine (DMN)-treated rats, which were randomly assigned to 1 of 4 groups: vehicle (0.7% carboxyl methyl cellulose, CMC), thalidomide (40 mg/kg), thalidomide (200 mg/kg), or silymarin (50 mg/kg), each given by gavage twice daily for 3 weeks starting after 1 week of DMN administration. Thalidomide (100–800 nM) concentration-dependently inhibited NFκB transcriptional activity induced by TNF-α, including IKKα expression and IκBα phosphorylation in HSC-T6 cells. In addition, thalidomide also suppressed TGF-β1-induced α-SMA expression and collagen deposition in HSC-T6 cells. Fibrosis scores of livers from DMN-treated rats receiving high dose of thalidomide (0.89±0.20) were significantly reduced in comparison with those of DMN-treated rats receiving vehicle (1.56±0.18). Hepatic collagen contents of DMN rats were also significantly reduced by either thalidomide or silymarin treatment. Immunohistochemical double staining results showed that α-SMA- and NFκB-positive cells were decreased in the livers from DMN rats receiving either thalidomide or silymarin treatment. In addition, real-time PCR analysis indicated that hepatic mRNA expressions of TGF-β1, α-SMA, collagen 1α2, TNF-α and iNOS genes were attenuated by thalidomide treatment. In conclusion, our results showed that thalidomide inhibited activation of HSC-T6 cells by TNF-α and ameliorated liver fibrosis in DMN-intoxicated rats. [ABSTRACT FROM AUTHOR]

Fibrosis-related changes in livers of cirrhotic rats induced by dimethylnitrosamine (DMN) have not yet been fully clarified. The aim of this study was to investigate changes in molecular and biochemical markers in DMN-intoxicated rats. DMN was administered to Sprague-Dawley rats for 2 and 5 weeks to induce different degrees of hepatic fibrosis. Liver tissues were assessed for the degree of fibrosis and gene expression. Histological examination of the liver showed a progressive increase in fibrosis scores (1.33 ± 0.21 and 3.03 ± 0.29, respectively) and expansion of fibrous septa with collagen-staining fibers in rats after 2 and 5 weeks of DMN administration. Hepatic protein contents of α-smooth muscle actin (α-SMA) and total collagen were significantly higher in rats administered DMN for both 2 and 5 weeks compared with those in control rats. Hepatic mRNA expressions of α-SMA, transforming growth factor-β1 (TGF-β1), connective tissue growth factor, tissue inhibitor of metalloproteinase-1, and procollagen I and III were increased in DMN rats after 2 and 5 weeks. Abnormal increases in plasma alanine transaminase (ALT) and aspartate transaminase (AST) levels, plasma and mitochondrial MDA levels, and portal venous pressure were also noted in DMN rats. DMN administration to rats for 2 and 5 weeks induced progressive increases in hepatic fibrosis scores, hepatic mRNA expressions of TGF-β1 and procollagen I and III genes, plasma levels of ALT and AST, and portal venous pressure, as well as progressive decreases in both liver and body weights. Our results suggest that DMN administration in rats induces biochemical and molecular changes related to fibrogenesis in the liver. Copyright © 2004 National Science Council, ROC and S. Karger AG, Basel [ABSTRACT FROM AUTHOR]