Anti-Inflammatory activity and structural analysis of fucoidan extracted from Sargassum fusiforme via ESI-TOF MS spectrometry

This study used Celluclast-assisted hydrolysis and DEAE-cellulose anion-exchange chromatography to extract, purify, and assess the anti-inflammatory activity of fucoidan derived from Sargassum fusiforme. The Celluclast-assisted hydrolysate was used for obtaining ethanol-precipitated S. fusiforme fucoidans (SFF) which were rich in polysaccharides and sulfates. Five fractions obtained through DEAE-cellulose chromatography, notably SFF-F5, displayed high sulfate content (29.16 ± 0.15%). The anti-inflammatory potential of these fractions was tested in lipopolysaccharide-induced RAW 264.7 macrophages. SFF-F5 was found to significantly reduce NO production at non-toxic concentrations of 12.5, 25, and 50 μg/mL. Structural analysis using Matrix assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF MS) revealed repetitive patterns in the fucoidan fractions. And Electrospray ionization mass spectrometry (ESI-TOF MS) spectrum of SFF fractions identified various structures of glycans bound with fucose and sulfate (Fuc1(SO3)1, Fuc2(SO3)1, Hex5Fuc1(SO3)1). In-silico evaluation based on the detected glycan structures indicated that fucoidan fractions could inhibit the dimerization of the TLR4-MD2 complex, demonstrating their potential as anti-inflammatory agents. This result confirm that the anti-inflammatory activity varies depending on the glycan composition of fucoidan. This study provides a foundation for further exploration into the relationship between the structure and anti-inflammatory activity of S. fusiforme-derived fucoidan, facilitating its effective industrial application.