Isolation, Purification, Antioxidant and Immunological Activities in Vitro of Polysaccharide from Acanthopanacis Senticosi

This study is designed to isolate and purify water-soluble polysaccharide from Acanthopanacis Senticosi, investigate its structure, antioxidant and immunological activities. A water-soluble polysaccharide fraction, coded as ASP-2-1, was obtained by hot water extraction, ethanol precipitation, and fractionated by EDAE-Sepharose Fast Flow Ion-exchange column and Sephadex G-75 gelpermeation column. Total sugar content of ASP-2-1 was determined by the phenol-sulfuric acid method. Protein content was determined by Bradford method. Total uronic acid content was determined by photometry with m-hydroxybiphenyl. Monosaccharide composition was determined by capillary zone electrophoresis (CZE), molecular weight and purity was determined by high-performance gel-permeation chromatography (HPGPC). Furthermore, the immunobilological and antioxidant activities of ASP-2-1 were evaluated by MTT assay, ferric-reducing antioxidant power (FRAP) assay, superoxide radical (center dot O-2(-)), hydroxyl (OH) and 2,2-diphenyl-1-picrylhydrazyl (DPPH center dot) free radical-scavenging assay, respectively. The ASP-2-1 contained 89.47% carbohydrate, 7.45% uronic acid, 2.16% protein and six kinds of monosaccharides including glucose (Glu), arabinose (Ara), galactose (Gal), fructose (Fr u), rhamnose (Rha), xylose (Xyl) in a molar ratio of 27.33: 8.92: 3.03: 1: 7.59: 20.51, with an average molecular weight of about 14573 Da. The ASP-2-1 could significantly promote the Spleen lymphocyte proliferation, pronounced higher reductive power, strong center dot OH radical scavenging activity, moderate center dot O-2(-) and DPPH center dot radicals scavenging activities. It should be explored as a novel and potential natural antioxidant and immunostimulating agent for use in functional foods or medicine.