Abstract:Enzymatic hydrolysis of Sipunculus nudus was performed using Protamex to obtain SNPH. Subsequently, the amino acid composition of SNPH was analyzed, and the distribution of relative molecular mass was determined using a high performance gel chromatography method. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, hydroxyl radical scavenging activity, superoxide anion scavenging activity, and reducing power of SNPH were evaluated using ultraviolet (UV) spectrophotometry. The effects of SNPG treatment on the splenic lymphocyte proliferation induced by concanavalin (Con) A and lipopolysaccharide (LPS) in mice were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results indicated that SNPH had high contents of essential amino acids and hydrophobic amino acids. The molecular weight distribution showed that SNPH had a high content of oligopeptides, and the substances with a relative molecular mass of 120~1800 accounted for 85.11%. The antioxidant activity experiment revealed that SNPH possessed potent scavenging activities on DPPH free radical, hydroxyl free radical, and superoxide anion in a good dose-effect relationship. The experiment on immunomodulatory activity indicated that SNPH could have a synergistic effect on the splenic lymphocyte proliferation induced by Con A and LPS. SNPH had good antioxidant and immunomodulatory activities.
