Protective effect of polysaccharide from Agaricus bisporus in Tibet area of China against tetrachloride-induced acute liver injury in mice

In this study, we systematically investigated the physicochemical properties, hepatoprotective activities and the underlying mechanisms of Agaricus bisporus polysaccharide (FPS). The physicochemical evaluations indicate that FPS is mainly composed of glucose, mannose, galactose, fucose, arabinose and glucuronic acid with the mole percentages of 70.30%, 8.70%, 12.88%, 0.79%, 5.04% and 1.57%, respectively. The results of methylation analysis indicated that FPS mainly included 1-linked-glc, 1,4-linked-glc, 1,6-linked-glc, 1,3-linked-gal and 1,3,6-linked-man glycosidic bonds. The results from hepatoprotective studies showed that FPS significantly decreased the liver index, serum gamma-glutamyltranspeptidase (GGT), alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST) activities and malondialdehyde (MDA) contents in liver tissue, and increased antioxidant capacities of hepatic glutathione (GSH) and superoxide dismutase (SOD). Furthermore, histological examination of liver tissues showed that FPS alleviated CCl4-induced liver injury. Finally, the Western blot results showed that FPS could significantly decrease the expression levels of TGF-β1 and Smad3 in the liver. These results together suggest that FPS possesses hepatoprotective effect against CCl4-induced liver damage, in part through the downregulation of TGF-β1/Smad signaling pathway, therefore FPS could be considered as a hepatoprotective medicine or functional food.