Protective Effect and Mechanism of Polysaccharides from Cordyceps cicadae on Acute Liver Injury Induced by D-GlaN in Mice

[Objectives]To observe the protective effect of Cordyceps cicadae polysaccharides on acute liver injury induced by D-galactosamine( D-GlaN) in mice,and to explore its mechanism. [Methods] Seventy-five male Kunming mice were randomly and evenly divided into 5 groups according to the digital table method: normal group( CK)( injected intraperitoneally with saline solution),model group( injected intraperitoneally with D-GlaN),low-dose C. cicadae polysaccharides group( administered with 0. 5 g/kg of C. cicadae polysaccharides solution by gavage),middle-dose C. cicadae polysaccharides group( administered with 1. 0 g/kg of C. cicadae polysaccharides solution by gavage) and high-dose C. cicadae polysaccharides group( administered with 2. 0 g/kg of C. cicadae polysaccharides solution by gavage). After 12 d of administration,the liver histopathological score,liver homogenate indexes( superoxide dismutase,SOD; malondialdehyde,MDA; glutathione peroxidase,GSH-Px; nitric oxide,NO) and serum markers( aspartate transaminase,AST; alanine transaminase,ALT; alkaline phosphatase,ALP; cholinesterase,CHE) of mice in each group were detected. The expression levels of nuclear factor-κB( NF-κB) and tumor necrosis factor-α( TNF-α) in liver tissues were detected by immunohistochemistry. [Results]The liver histopathological score and the MDA,NO,AST,ALT,ALP,NF-κB and TNF-α levels were significantly higher( P < 0. 05) and the SOD,GSH-Px and CHE levels were significantly lower( P <0. 05) in the model group compared with the normal group. Compared with those in the model group,the liver tissue histopathological scores in the low-,middle-and high-dose C. cicadae polysaccharides groups were all significantly reduced( P < 0. 05). With the increase of treatment dose,the liver tissue histopathological scores showed a significant decrease( P < 0. 05). Compared with the model group,the levels of MDA,NO,AST,ALT,ALP,NF-κB and TNF-α were significantly lower( P < 0. 05),and the levels of SOD,GSH-Px and CHE were significantly higher( P < 0. 05) in the low-,middle-and high-dose C. cicadae polysaccharides groups. With the increase of treatment dose,the levels of MDA,NO,AST,ALT,ALP,NF-κB and TNF-α declined significantly( P < 0. 05),while the levels of SOD,GSH-Px and CHE rose significantly( P < 0. 05). [Conclusions] C. cicadae polysaccharides have a significant protective effect on D-GlaN-induced acute liver injury in mice in a dose-dependent manner,and the mechanism may be related to the inhibition of NF-κB inflammatory signaling pathway.