In vitro and in vivo anti-inflammatory activities of a fucose-rich fucoidan isolated from Saccharina japonica.

A fucoidan (LJSF4) purified from Saccharina japonica was found to show a strong anti-inflammatory effect via activity assay in lipopolysaccharide (LPS) induced RAW 264.7 macrophage cells and zebrafish. Chemical and structural analysis indicated that LJSF4 with a sulfate content of 30.72% was composed of fucose, galactose, rhamnose, xylose and mannose with molar ratio percentages of 79.49%, 16.76%, 0.82%, 1.08% and 1.84%. NMR spectroscopy showed that LJSF4 is a polysaccharide with a backbone of alternating 1 → 3 linked α- l -fucopyranosyl and →4-α- l -fucopyranosyl with sulfate groups mainly at C–4 and partially at C–2 positions. Moreover, it also contained branches in the form of β- d -Galp-(1 → 4) units. The results of anti-inflammatory effect in vitro demonstrated that LJSF4 decreased the production of nitric oxide (NO) and cytokines, including TNF-α, IL-1β and IL-6. The mechanism revealed to be associated with the down-regulated expression of signal pathways including MAPK and NF-κB. By in vivo assay, LJSF4 showed a significantly protective effect by reducing the cell death rate, and the production of NO and ROS on LPS exposed zebrafish. Our results indicated that LJSF4 has the potential to be developed as an anti-inflammatory agent applied in functional food and cosmetic industries. • A novel fucose-rich fucoidan named as LJSF4 was purified from Saccharina japonica. • The chemical composition and structural characteristics of LJSF4 were investigated. • LJSF4 inhibited production of NO and pro-inflammatory mediators, and levels of iNOS, COX-2 on LPS-induced RAW 264.7 cells. • The mechanism of anti-inflammatory properties was associated with the suppression of NF-κB and MAPK signaling pathways. • LJSF4 showed significantly protective effect by reducing the production of NO and ROS in LPS-induced zebrafish. [ABSTRACT FROM AUTHOR]