title: Characterization and immunomodulatory activities of polysaccharides extracted from green alga Chlorella ellipsoidea.
abstract: Polysaccharides of green alga Chlorella ellipsoidea were extracted using hot water and fractionated using an anion-exchange chromatography to investigate their molecular characteristics and immunomodulatory activities. The crude polysaccharide and two fractions (F1and F2) consisted mainly of carbohydrate (68.1-89.7%) and protein (2.0-11.8%) with small amounts of sulfate (1.9-6.1%) and uronic acid (0.5-6.1%). Glucose (58.8-97.6%) was the major monosaccharide of these polysaccharides, with different levels of rhamnose (0.2-11.6%), mannose (0.4-2.6%), and galactose (1.8-27.0%). The average molecular weights (Mw) of the crude, F1, and F2were 175.8×103, 126.9×103, and 237.0×103g/mol, respectively. The crude, F1, and F2stimulated murine macrophage, RAW264.7 cells, to produce considerable amounts of nitric oxide (NO) and various cytokines via up-regulation of their mRNA expression by the activation of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. The fraction F2with higher Mwand protein content showed stronger immunomodulatory activity. The main backbone of the fraction F2was mainly connected via (1→4)-linked glucose and (1→6)-linked galactose with branches at C-3 and C-4 positions in (1→3,4)-linked glucose and (1→4,6)-linked galactose residues, respectively.
authors.affiliation: Department of Marine Food Science and Technology, Gangneung-Wonju National University, Gangneung 25457, Republic of Korea.
authors.forename: Jia
authors.initials: J
authors.lastname: Qi
authors.affiliation: Department of Marine Food Science and Technology, Gangneung-Wonju National University, Gangneung 25457, Republic of Korea. Electronic address: smkim@gwnu.ac.kr.
authors.forename: Sang Moo
authors.initials: SM
authors.lastname: Kim
mesh_terms: D000818:Animals; D002708:Chlorella / Q000737:chemistry*; D006031:Glycosylation; D007155:Immunologic Factors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D051379:Mice; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D000067996:RAW 264.7 Cells
chemical_list: D007155:Immunologic Factors; D011134:Polysaccharides
keywords: Characterization; Chlorella ellipsoidea; Immunomodulatory activity; Polysaccharide