Effects Of Salidroside On TGFβ-Smad Signaling Pathway In Rats Of Experimental Hepatic Fibrosis

Backgrounds and Aims: Hepatic fibrosis is the common stage of most chronic liver diseases regardless of the etiology, and its progression may lead to hepatic cirrhosis or hepatocellular carcinoma (HCC). Although hepatic fibrosis is thought to be a reversible pathological state, there is no established effective therapy for hepatic fibrosis yet. Several traditional Chinese herbs have shown more promising future on anti-fibrotic effects in some studies, such as Chinese cster pillar fungus, dan-shen root, peach seed, compound 861, et al. This study aimed at evaluating the prophylactic anti-fibrobrosis effects of Salidroside, the main active component of Chinese herb Rhodiola sachalinensis A Bor, on carbon tetrachloride (CCl4) -induced experimental hepatic fibrosis in SD rats. By detecting the histopathological damage in liver, HE and Masson staining were observed under light microscope and analyzed with special imaging-analysis software. Serum hepatic fibrosis marker, the concentration of TGFβ1 was assayed with ELISA(enzyme-linked immunoadsordent assay). Gene expression of the essential molecules in TGFβ-Smad signaling pathway, such as TGFβ1, Smad 3, Smad 4, Smad 6, Smad 7, CBP (CREB binding protein), and other two capital molecules in Rho-ROCK signaling pathway, ROCK Ⅰand ROCK Ⅱ, were detected with IH and ISH method, and then analyzed respectively. All these results were compared with the effects of another traditional Chinese anti-fibrotic drug, Oxymatrine. The probable precise effects of Salidroside on rats of experimental hepatic fibrosis and its potential molecular mechanisms would be discussed. Materials and Methods: Healthy male SD rats were randomly divided into four groups: C (normal control), M (model of hepatic fibrosis), S (Salidroside-treated) and O (Oxymatrine-treated) group. Experimental hepatic fibrosis in rats was induced with subcutaneous injection of tetrachloride (300mL/L CCl4 solution in liquid paraffin, at a dosage of 3mL/kg, twice per week for 8 weeks). Sterilized solution of Salidroside was given to rats of S group simultaneously (concentration 100g/L, dosage 5mg/kg, celiac injection, twice per week for 8 weeks). Parenteral solution of Oxymatrine was given to rats of O group (concentration 100g/L,dosage 10mg/kg, celiac injection, twice per week for 8 weeks). Rats in M group obtained celiac injection of tetrachloride and Saline solution. Rats in C group were given Saline solution injection only. At the end of experimental period, rat blood was withdrawn from the heart and the livers were removed. Rat's serum was obtained with centrifugation of blood, and the serum concentration of TGF β 1 was assayed with ELISA. Histopathological changes in rats' liver tissue were detected with HE and Masson collagen staining. The gene expression of TGFβ1, Smad 3, Smad 4, Smad 6, Smad 7, CBP, ROCK Ⅰand ROCK Ⅱ, were detected with immunohistochemistry (IH)and in situ hybridization (ISH) method respectively. All the staining figures were scanned with electronic computer and all the data were analyzed with special software. Results: (1) The survival rate in rats of model group was only 46.67%, and the rate of hepatic fibrosis in survival rats was 100.00%. Chronic subcutaneous injection of carbon tetrachloride (CCl4) could lead severe pathological damages in rats' liver: fatty degeneration or necrosis in hepaticparenchymal cell, mesenchymal inflammation, and excessive collagen deposition in the liver. The semi-quantitative staging score of hepatic fibrosis was raised to 3.29±0.68 in model rats(P<0.01 vs normal group). The average area of collagen fiber was increased to(290.86±89.37)μm2(P<0.01 vs normal rats), showing typical pathological changes of hepatic fibrosis to hepatic cirrhosis. The survival rate was raised to 70.00% after Salidroside treatment. The livers of Salidroside-treated rats showed light inflammation, less necrosis, less collagen deposition and a significantly decreased staging score of 2.29±0.35 (P<0.05 vs model rats). The average area of collagen was decreased to(74.82±21.51)?...