Antifibrotic effect of silymarin in rat secondary biliary fibrosis is mediated by downregulation of procollagen alpha1(I) and TIMP-1

Department of Gastroenterology and Hepatology, Friedrich-Alexander University, Erlangen-Nuernberg, Erlangen, Germany.
Journal of Hepatology (Impact Factor: 11.34). 09/2001; 35(3):392-8.
Source: PubMed


Silymarin reduces hepatic collagen accumulation by 35% in rats with secondary biliary cirrhosis. The aim of the present study was to explore its antifibrotic mechanism.
Thirty female adult Wistar rats were allocated to (1) bile duct occlusion, (2) bile duct occlusion and oral silymarin at 50 mg/kg per day, and (3) sham operation and oral silymarin at 50 mg/kg per day. Steady-state mRNA levels for procollagen alpha1(I), tissue inhibitor of metalloproteinases-1 (TIMP-1), and transforming growth factor (TGF) beta1 were determined by multi-probe ribonuclease protection assay.
After 6 weeks of bile duct occlusion, liver collagen content was increased 12-fold, when compared with the sham-operated controls. These animals displayed 17-, 6.5- and 16-fold higher transcript levels for procollagen alpha1(I), TIMP-1 and TGFbeta1 (P < 0.01). Silymarin downregulated elevated procollagen alpha1(I), TIMP-1 and TGFbeta1 mRNA levels by 40-60% (P < 0.01). These lowered hepatic profibrogenic transcript levels correlated with decreased serum levels of the aminoterminal propeptide of procollagen type III.
Silymarin suppresses expression of profibrogenic procollagen alpha1(I) and TIMP-1 most likely via downregulation of TGFbeta1 mRNA in rats with biliary fibrosis. The serum procollagen type III propeptide level mirrors profibrogenic mRNA expression in the liver.

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Available from: Detlef Schuppan, Sep 30, 2015
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    • "Liver transplantation is currently the only therapeutic option for liver cirrhosis or tumor, but such method is risky and painful for the patient. Antifibrotic agents, such as silymarin, are widely accepted for the treatment of liver diseases and can downregulate TIMP-1 and TGF-␤1 expression, as well as suppress collagen synthesis (Jia et al., 2001); however, the treatment effect of silymarin is not outstanding. Therefore, the search for more effective antifibrotic agents with fewer side effects remains an active area of research. "
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    ABSTRACT: Fibrosis results from excessive accumulation of extracellular matrix (ECM), and hepatic stellate cell (HSC) plays a central role in hepatic fibrosis. Thus, removal of excess ECM and promotion of apoptosis in HSC are two antifibrotic approaches. Ethyl acetate fraction (EF) of Terminalia bellirica fruit has long been used in liver diseases, but little scientific evidence exists for EF mechanisms in such illnesses. EF has demonstrated both antiproliferative and proapoptotic activities in HSC-T6. The present study investigated the effects of EF on cellular proliferation, ECM removal, cellular signaling pathways, and apoptosis of a rat HSC line (HSC-T6). HSC-T6 cells were incubated with EF, and their proliferation was assessed by MTT assay. Expression of Smad2, platelet-derived growth factor receptor (PDGFR), alpha-smooth muscle actin (␣-SMA), matrix metalloproteinase-2 (MMP-2) was determined by real-time polymerase chain reaction (PCR) and western blot analysis. Expression of tissue inhibitor of metalloproteinase (TIMP)-1, and TIMP-2 mRNAs was determined by real-time PCR. Collagen I, collagen III, TGF-␤1, and hydroxyproline levels were assessed by ELISA. Apoptosis was measured and confirmed by Annexin V-PI staining using fluorescence microscopy and flow cytometry. Apoptotic pathways involving Fas/FasL expression and Bcl-2/Bax family were investigated by real-time PCR. Results showed that 31.25–250 ␮g/mL EF exhibited cytotoxic and antiproliferative effects on HSC-T6 cells. EF at 50 ␮g/mL significantly decreased the levels of collagen I, collagen III, TGF-␤1, and hydroxyproline. EF suppressed the gene expression of Smad2, PDGFR, ␣-SMA, TIMP-1, and TIMP-2 but elevated that of MMP-2. These events consequently facilitated ECM removal and fibrosis resolution. The highest potency of EF promoting HSC-T6 apoptosis was detected at 50 ␮g/mL concentration. This finding was associated with upregulation of Fas/FasL and Bax, as well as downregulation of Bcl-2 in HSC-T6. These results indicate that EF demonstrates antifibrotic activity, and its mechanism of action can be ascribed to inhibition of collagen synthesis, cytokine secretion, and TGF-␤1/Smad pathway. Furthermore, EF facilitates apoptosis in HSCs.
    Industrial Crops and Products 01/2015; 76:364-373. DOI:10.1016/j.indcrop.2015.07.007 · 2.84 Impact Factor
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    • "Silymarin, a mixture of flavonoids extracted from the seeds of Silybum marianum containing three structural isomers (silybin, silydianin, and silychristin), has exhibited hepatoprotective effects both in vivo and in vitro [4]. Silymarin suppresses the expression of both profibrogenic procollagen alpha (I) and Timp1, most likely via downregulation of Tgfb1, in rat models [6]. It is also used to protect liver cell membranes against hepatotoxic agents and has been shown to improve liver function in both experimental animals and humans [7]. "
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    ABSTRACT: The incidence of cirrhosis is rising due to the widespread occurrence of chronic hepatitis, as well as the evident lack of an established therapy for hepatic fibrosis. In the search for hepatoprotective therapeutic agents, Graptopetalum paraguayense (GP) showed greater cytotoxicity toward hepatic stellate cells than other tested herbal medicines. Histopathological and biochemical analyses suggest that GP treatment significantly prevented DMN-induced hepatic inflammation and fibrosis in rats. Microarray profiling indicated that expression of most of metabolism- and cell growth and/or maintenance-related genes recovered to near normal levels following GP treatment as classified by gene ontology and LSM analysis, was observed. ANOVA showed that expression of 64% of 256 liver damage-related genes recovered significantly after GP treatment. By examining rat liver samples with Q-RT-PCR, five liver damage-related genes were identified. Among them, Egr1 and Nrg1 may serve as necroinflammatory markers, and Btg2 may serve as a fibrosis marker. Oldr1 and Hmgcs1 were up- and down-regulated markers, respectively. A publicly accessible website has been established to provide access to these data Identification of 44 necroinflammation-related and 62 fibrosis-related genes provides useful insight into the molecular mechanisms underlying liver damage and provides potential targets for the rational development of therapeutic drugs such as GP.
    Evidence-based Complementary and Alternative Medicine 07/2012; 2012(4):256561. DOI:10.1155/2012/256561 · 1.88 Impact Factor
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    • "The primary active constituent of milk thistle is silymarin that is composed of four isomers: silybin, isosilybin, silychristin, and silydianin (El-Kamary et al. 2009). Silymarin medical properties are associated with antioxidant, anti-inflammatory, anti-carcinogenic (Kaur and Agarwal 2007; Ramasamy and Agarwal 2008), and anti-fibrotic properties (Jia et al. 2001) as well as with increased cellular-reduced glutathione (GSH) content, cellular protein biosynthesis potency, stimulation of regeneration ability, and increased stability of the cellular membrane in liver (Flora et al. 1998; Basiglio et al. 2009). However, there is a lack of reports on the side effect of silymarin in laboratory models (S ˇ eršeň et al. 2006) such as mice, rat, rabbit, and dog, and there is no information about oral administration of silymarin in fishes. "
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    ABSTRACT: Silymarin, an extract from "milk thistle" (Silybum marianum) plant is traditionally used as herbal medicine. The present study was conducted to investigate the clinical effects and possible side effects of silymarin on biochemical blood parameters of rainbow trout (Oncorhynchus mykiss). Fishes were treated with 0 (control), 100, 400, and 800 mg of silymarin per kg of food during 4 weeks. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), creatine kinase (CK), glucose, total protein, creatinine, triglyceride, cholesterol, urea, uric acid and liver cellular total antioxidant, and protein content were measured after 7, 14, and 28 days of silymarin treatment. The results showed that oral administration of silymarin in fish significantly reduced plasma glucose and cholesterol levels and relatively increased plasma total protein and globulin concentrations (P < 0.05). Increasing plasma albumin levels indicate the important role of albumin in drug transportation in circulatory system of fish. Silymarin also stabilized cellular membrane structure and regulated the levels of AST, ALT, ALP, CK, and LDH activity. In conclusion, on the basis of these results, oral administration of silymarin up to 400 mg per 1 kg of food has no side effect on blood biochemical and clinical parameters of fishes. However, oral administration of 800 mg/kg- of silymarin caused cytotoxicity and modifications in blood biochemical parameters of fish.
    Fish Physiology and Biochemistry 04/2011; 37(4):885-96. DOI:10.1007/s10695-011-9486-z · 1.62 Impact Factor
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