title: Soluble β-1,3/1,6-glucan in seaweed from the southern hemisphere and its immunomodulatory effect.
abstract: Five types of macroalgae from the southern hemisphere were analysed for the presence of β-1,3/1,6-glucan and its immunostimulant properties. We were able to extract soluble β-1,3/1,6-D-glucan from Durvillaea antarctica (Chamisso) Hariot (DA). The morphology of the brown algae influenced extraction, and the highest percentage of β-glucan was found in the fronds. The content of β-glucan in the stipes and holdfast was on average 33% and <5%, respectively, of that in the fronds. A simple laboratory extraction process was developed. A highly pure water-soluble polysaccharide, mainly composed of glucose residues, was obtained with a dominant average molecular weight of 6.9 kDa. NMR spectroscopy confirmed the polysaccharide structure to be of β-1,3/1,6-glucan type, comprising a β-1,3-glucan backbone and 21% degree of branching of β-1,6-glucan side chains. Mouse cells were exposed to four DA extract concentrations in water (50, 100, 250 and 500 μg/mL) and no adverse effects on survival were noted. Remarkably, the β-glucan induced a 16.9% increase in activated CD19+ B lymphocytes compared with the control sample. The optimal concentration for maximum activity was 100 μg DA extract/mL.
authors.affiliation: Facultad Tecnológica, Universidad de Santiago de Chile, Av. Libertador Bernardo, O'Higgins, 3363 Estación Central, Santiago, Chile. francisca.bobadilla@usach.cl
authors.forename: Francisca
authors.initials: F
authors.lastname: Bobadilla
authors.forename: Carolina
authors.initials: C
authors.lastname: Rodriguez-Tirado
authors.forename: Mónica
authors.initials: M
authors.lastname: Imarai
authors.forename: María José
authors.initials: MJ
authors.lastname: Galotto
authors.forename: Roger
authors.initials: R
authors.lastname: Andersson
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D002460:Cell Line / Q000187:drug effects; D007114:Immunization; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D015394:Molecular Structure; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification; D012624:Seaweed / Q000737:chemistry* / Q000276:immunology; D014867:Water / Q000737:chemistry; D047071:beta-Glucans / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000276:Adjuvants, Immunologic; D011134:Polysaccharides; D047071:beta-Glucans; D014867:Water; C064197:beta-1,6-glucan; C033363:beta-1,3-glucan