Structural characterization of a sulfated polysaccharide from Ishige okamurae and its effect on recovery from immunosuppression

A sulfated polysaccharide from the brown alga Ishige okamurae Yendo, designated IOY, was successfully isolated by anion-exchange and size-exclusion chromatography. Chemical and spectroscopic analyses demonstrated that IOY was a fucoidan, that consisted of -> 3)-alpha-L-Fucp-(1 ->, -> 4)-alpha-L-Fucp-(1 ->, -> 6)-beta-D-Galp-(1 -> and -> 3)-beta-D- Galp-(1 -> residues with sulfate groups at C-2/C-4 the of (1 -> 3)-alpha-L-Fucp and C-6 the of (1 -> 3)-beta-D-Galp res-idues. IOY possessed a potent immunomodulatory effect in vitro as measured by lymphocyte proliferation assay. The immunomodulatory effect of IOY was further investigated in vivo using immunosuppressed mice induced by cyclophosphamide (CTX). The results showed that IOY significantly increased the spleen and thymus indexes and alleviated CTX-induced spleen and thymus damage. Furthermore, IOY had a significant effect on hematopoietic function recovery and promoted the secretion of interleukin-2 (IL-2) and tumor necrosis factor (TNF-alpha). Notably, IOY reversed CD4+ and CD8+ T cell reduction and improved immune response. These data indicated that IOY had vital in immunomodulatory function and could be used as drug or functional food to lessen chemotherapy-induced immunosuppression.

Automated summary

A sulfated polysaccharide (IOY) from the brown alga Ishige okamurae Yendo, identified as a fucoidan, was isolated and characterized. IOY showed potent immunomodulatory effects in vitro and in vivo, including increasing spleen and thymus indexes, alleviating chemotherapeutic-induced damage, promoting hematopoietic function recovery, and enhancing immune response. IOY could be a promising candidate for drug development or application in functional foods to counteract chemotherapy-induced immunosuppression.