Anti-inflammatory activity and structural identification of a sulfated polysaccharide CLGP4 from Caulerpa...

In the present study, the in vitro anti-inflammatory activity of four purified polysaccharides (CLGP1, CLGP2, CLGP3 and CLGP4) extracted from edible green algae Caulerpa lentillifera was evaluated. As a result, CLGP4 exhibited more effectively inhibitory effect on LPS-induced HT29 cells, including reducing the production of IL-1β, TNF-α, SIgA and mucin2, and decreasing the expression of IL-1β and TNF-α. According to the results, CLGP4 showed a better anti-inflammatory effect, might highly related to the presence of sulfate groups. Furthermore, the structure of CLGP4 was analyzed by methylation analysis, GC-MS and NMR spectroscopy. It was found that CLGP4 was a novel xylogalactomanan consisting of β-(1 → 4)-Man_p, →2,4)Man_p(1→, β-(1 → 2)-Man_p, β-(1 → 3)-Gal_p, β-(1 → 4)-Xyl_p, terminal β-Gal_p and terminal β-Xyl_p residues. Additionally, the sulfate groups were located on C-3 of →4)Xyl_p(1→, C-6 of →3)Gal_p(1→ and C-3 of →2)Man_p(1→. These results could enlarge the potential application of CLGP4 as functional ingredient to attenuate inflammation.