A Polysaccharide from Amusium Pleuronectes Combined with Praziquantel Treatment Ameliorates Hepatic Fibrosis in Schistosoma Japonicum-Infected Mice

BACKGROUND Polysaccharides from bivalves have multiple bioactivities in various aspects of biology. However, the role of a polysaccharide derived from Amusium pleuronectes on potential hepatoprotective effects remains unclear. MATERIAL AND METHODS A water-soluble polysaccharide was isolated from Amusium pleuronectes (APS-1) using ultrasound-assisted hot-water extraction. The molecular weight of APS-1 was approximately 11.7 kDa and was determined by calibration with dextran. APS-1 was analyzed by high-performance liquid chromatography (HPLC), and mainly consisted of a uniform glucose polymer. The protective effect of APS-1 on Schistosoma japonicum-induced liver fibrosis was investigated in a mouse model. RESULTS Treatment with APS-1 increased serum levels of interleukin (IL)-12 and interferon (IFN)-γ, increased superoxide dismutase (SOD) activity, and decreased levels of IL-13 and IL-5, and hyaluronidase activity. Moreover, immunohistochemical analysis revealed that the collagen content of hepatic tissue of APS-1-treated mice, including that of collagen I, II, and IV, was dramatically decreased. Furthermore, our data showed that combined treatment of APS-1 with praziquantel had more pronounced effects than treatment with either APS-1 or praziquantel alone. CONCLUSIONS Our findings suggest that the treatment using APS-1 in combination with praziquantel attenuated S. japonicum egg-induced hepatic fibrosis, and possessed potent hepatoprotective activity.