Stimulation of Cell Mediated Immune Response by Protein Hydrolysate from Porphyra yezoensis

Aim: To investigate the immunomodulatory effects of the protein hydrolysate from Porphyra yezoensis. Objectives: In this study, the in vitro immunomodulatory effects of protein hydrolysate of Porphyra yezoensis was studied by assay of phagocytosis and Nitric oxide production in RAW 264.7 macrophages and DTH (Delayed type hypersensitivity), NBT (Nitroblue tetrazolium) and Neutrophil adhesion assay in mice. Results: Hydrolysate treatment was found to be non-toxic in both in vitro and in vivo models. In vitro results suggested that hydrolysate could enhance the phagocytic activity and also inhibit the production of nitric oxide. Oral administration of hydrolysate (500 mg/kg) evoked an increase in the percent neutrophil adhesion to nylon fibers as well as potentiated the DTH reaction induced by SRBC (Sheep red blood cells). A phagocytic response was observed with significant changes in formation of formazan crystals. Conclusion: The results indicated that enzymatic hydrolysate from P. yezoensis could enhance the cell mediated immune response. Thus, the Nori protein hydrolysate could be explored as a possible natural immune stimulant to be used as nutraceuticals.