546 THE USE OF CONTRAST-ENHANCED SONOGRAPHY IN THE DIFFERENTIAL DIAGNOSIS BETWEEN BENIGN AND MALIGNANT PORTAL VEIN THROMBOSIS

Background and Aims: Amomum xanthoides (AX) is a traditional herbal medicine that frequently used for especially digestive disorders in Asia. In this study, methanol fraction of AX (MFAX) was investigated for the hepatoprotective and antihepatofibrotic effects and its related mechanisms in thioacetamide (TAA)-induced animal model and in vitro experiment. Methods: Fifty four Sprague-Dawley rats were divided into six groups of nine rats each, and induced chronic liver fibrosis by TAA (200mg kg, ip) on twice per week for 14 weeks. MFAX (25, 50 or 100mg kg, po) was administered once a day for 14 weeks, and DDB was used (Dimethyl Dimethoxy Biphenyl Dicarboxylate, 5mg kg, po) as a positive control. Associated mechanisms were confirmed in vitro using HepG2, Raw 264.7, Lx-2 and HSC-T6 cell lines. Results: MFAX significantly attenuated the TAA-induced excessive level of bilirubin (p < 0.01) in serum, and hydroxyproline and malondialdehyde contents in liver tissue (p< 0.01). MFAX significantly lowered the ROS level and restored the GSH content and GSH-peroxidase activity (p < 0.01). Histophathological and immunohistochemical results revealed that MFAX markedly ameliorated the inflammation, collagen acumination and hepatic satellite cells activation. In gene expression analysis, MFAX downregulated fibrosis-related genes including iNOS, TNF-a TGF-b, PDGF-b and CTGF in liver tissue, and also down-regulated a-SMA, procollagen type I and III genes in MFAX-treated HSC-T6 cells. In protein level, MFAX significantly decreased the profibrosis cytokines including TGF-b, PDGF-b and CTGF in liver tissue (p < 0.01). Additionally, MFAX showed free radical scavenging capacity, protected hepatocyte against CCl4-induced cytotoxicity. MFAX also showed suppressive effect of LPS induced-NO production in Raw 264.7 and rat peritoneal macrophage. Conclusions: These result demonstrated that MFAX has hepatoprotective and antihepatofibrotic effects against TAAinduced liver fibrosis. Its possible mechanisms are associated with the prevention of oxidative stress through amelioration of the GSH antioxidant system, protection of hepatocytes and down-regulation of the profibrogenic cytokines, especially TGF-b, PDGF-b and CTGF.