Immunomodulatory and anti-metastatic activities of polysaccharide isolated from red cabbage

摘要

In this study, we examined the immunostimulating characteristics of a hot water extract (RCW) and crude polysaccharides (RCP) of red cabbage. RCW and RCP did not show any cytotoxicity in B16BL6 cells and macrophages. Although the sugar compositions ofRCW and RCP were similar, the uronic acid content of RCP was higher than that of RCW RCP significantly increased the production of various cytokines and NO, whereas RCW did not affect the production of cytokines and NO. In an ex vivo assay of natural killer (NK) cell activity, intravenous (i.v.) administration of RCP significantly augmented NK cytotoxicity against Yac-1 tumor cells at 3 days after RCP treatment. In an experimental lung metastasis model using B16BL6 melanoma cells, i.v. administration of RCP at a dose of 1,000 ug per mouse significantly inhibited 47.3% of lung metastasis. These results suggest that crude polysaccharide isolated from red cabbage is a promising food ingredient for the prevention of tumor metastasis.