Purification and characterization of a novel peptide with inhibitory effects on colitis induced mice by dextran sulfate sodium from enzymatic hydrolysates of Crassostrea gigas.

The anti-inflammatory activity of purified peptides from Crassostrea gigas (C. gigas) hydrolysates was studied. To prepare hydrolysates from C. gigas, we used eight different proteinases and the anti-inflammatory activities were determined using a nitric oxide (NO) assay in RAW264.7 cells. Among the hydrolysates, Protamex hydrolysates showed the highest anti-inflammatory activity. We separated and purified the total hydrolysate using an ultrafiltration membrane system and consecutive chromatographic methods. Finally, we obtained a peptide with the following sequence: Gln-Cys-Gln-Cys-Ala-Val-Glu-Gly-Gly-Leu at N-terminal position. The anti-inflammatory peptide purified from C. gigas inhibited NO production by 72.2% compared to the lipopolysaccharide (LPS) treated group. In addition, the Protamex hydrolysates from C. gigas showed decreased serum IgE levels and increased spleen CD4(+)/CD8(+) levels on dextran sulfate sodium (DSS) induced colitis in mice. These results suggest the peptide and hydrolysate from C. gigas possess potent anti-inflammatory effect.