Chemical Characterization and Immunomodulatory Activity of Fucoidan from Sargassum hemiphyllum .

Fucoidan is a sulfated algal polyanionic polysaccharide that possesses many biological activities. In this paper, a fucoidan (SHF) polysaccharide was extracted from Sargassum hemiphyllum collected in the South China Sea. The SHF, with a molecular weight of 1166.48 kDa (44.06%, w / w ), consisted of glucose (32.68%, w / w ), galactose (24.81%, w / w ), fucose (20.75%, w / w ), xylose (6.98%, w / w ), mannose (2.76%, w / w ), other neutral monosaccharides, and three uronic acids, including glucuronic acid (5.39%, w / w ), mannuronic acid (1.76%, w / w ), and guronuronic acid (1.76%, w / w ). The SHF exhibited excellent immunostimulatory activity. An immunostimulating assay showed that SHF could significantly increase NO secretion in macrophage RAW 264.7 cells via upregulation of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) levels based on both gene expression and protein abundance. These results suggest that SHF isolated from Sargassum hemiphyllum has great potential to act as a health-boosting ingredient in the pharmaceutical and functional-food fields.