Sulfated fucan polysaccharide from Holothuria scabra attenuates LPS-induced inflammation in RAW264.7 macrophages via modulation of NF-κB and MAPK signalling pathways

Crude aqueous polysaccharides were extracted using a 1% NaOH solution and purified using DEAE cellulose ion exchange chromatography, yielding two fractions: F1 and F2. The crude polysaccharides and fractions primarily comprised carbohydrates, proteins, and sulfates, ranging from 51.5 – 62.2%, 11.3 – 22.2%, and 18.9 – 30.7%, respectively. Both the crude and the fractions had molecular weights ranging from 315.3 to 429.6 kDa. The study utilized RAW264.7 cells to investigate the effects of crude polysaccharides and their fractions on LPS-induced inflammatory responses, revealing that the F2 polysaccharide demonstrated significant anti-inflammatory properties by reducing NO generation. Consequently, we aimed to modify the structure of F2 polysaccharides through desulfation and partial hydrolysis. We found that all derivatives enhanced cell proliferation after testing the desulfated and partially hydrolyzed derivatives on RAW264.7 macrophage cells. Additionally, both chemically modified derivatives increased NO production, except for the partially hydrolyzed F2 polysaccharide derivative from H. scabra (HSP2). Notably, HSP2 significantly reduced NO production in LPS-induced RAW264.7 cells, indicating remarkable anti-inflammatory activity. This effect was further confirmed by the downregulation of inflammatory mediators and surface receptor expression through NF-κB and MAPK signaling pathways. Overall, the findings suggest that H. scabra polysaccharides, particularly HSP2, hold promise as anti-inflammatory agents for the management of immunological and inflammatory diseases. • Fucan sulfate from Holothuria scabra was extracted and characterized. • Purification of crude polysaccharides yielded two fractions, F1 and F2. • F2 significantly enhanced anti-inflammatory activity by reducing NO production. • The structure of F2 was modified through desulfation and partial hydrolysis. • Among these, partially hydrolyzed HSP2 exhibited the greatest anti-inflammatory activity.