Molecular characteristics and biological activities of anionic macromolecules from Codium fragile

Abstract

Water-soluble anionic macromolecules isolated from Codium fragile and fractionated using ion-exchange chromatography were investigated to determine their molecular characteristics and immunostimulating activity. The crude molecules and fractions (F-1, F-2, and F-3) consisted mostly of carbohydrates (44.1-80.5%), sulfates (3.2-22.2%) and proteins (3.0-15.7%) with small amounts of uronic acids (1.1-4.2%), and included different levels of mannose (91.3-18.7%), glucose (62.7-8.6%) and galactose (37.5-59.5%). These molecules contained one or two subfractions with molecular weights (M-w) ranging from 148 x 10(3) to 4879 x 10(3) g/mol. The crude, F-1 and F-2 stimulated RAW264.7 cells to produce considerable amounts of pro-inflammatory mediator nitric oxide (NO) and cytokines. The treatment of sample molecules facilitated the degradation of I kappa-B and phosphorylation of MAPK in RAW264.7 cells, suggesting that they might stimulate RAW264.7 cells through the activation of NF-kappa B and MAPK pathway. Proteins in fraction F-2 were essential to possess its bioactivity and its main backbone was composed of mixed linkages of (1 -> 3)-alpha and beta-D-mannan. (C) 2013 Elsevier B.V. All rights reserved.