Effects and mechanisms of crude astragalosides fraction on liver fibrosis in rats

Astragalosides is the major active constituent of Radix Astragali. The present study was carried out to investigate the effect of crude astragalosides fraction (CAF) on rats liver fibrosis and its possible mechanisms. Hepatic fibrosis was induced by subcutaneous injection with 50% CCl4 in Sprague-Dawley rats. The amount of CCl4 administered was 1 mg kg(-1). The alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels in plasma and hydroxyproline (Hyp), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) contents in liver tissue were assayed by spectrophotometry. The hyaluronic acid (HA) and procollagen III (PC III) were assessed by radioimmunoassay. Tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta 1) levels in culture supernatants of Kupffer cells (KCs) were determined with ELISA. Liver, samples collected after 8 weeks Of CCl4 treatment were stained with hematoxylin-eosin (HE) and massion, and scored. Intragastric administration of CAF (10, 20 and 40 mg kg(-1)) significantly decreased indices of liver and spleen, the serum transaminase activities, HA and PC III levels, and Hyp and MDA contents in liver tissue in rats of hepatic fibrosis. Decreased SOD and GSH-px levels were reversed after administration of CAR Histopathological scores showed CAF had inhibitory effect on the progression of hepatic fibrosis. In the in vitro experiments, CAF significantly reduced TNF-alpha and TGF-beta 1 levels in culture supernatants of KCs. The results showed CAF significantly inhibited the progression of hepatic fibrosis induced by CCl4, and the inhibitory effect of CAF on hepatic fibrosis might be associated with its ability to scavenge free radical and inhibit the production of TNF-a and TGF-beta 1 from activated KCs. (c) 2005 Elsevier Ireland Ltd. All rights reserved.