Physico-chemical characterization and pharmacological activities of sulfated polysaccharide from sea urchin, Paracentrotus lividus

•Sulfated polysaccharide (SP) from the eggs of sea urchin was extracted by papain digestion.•Physico-chemical characterization of polysaccharides was performed.•Extracted polysaccharides exhibit significant anti-inflammatory, gastroprotective and analgesic activities. Sulfated polysaccharide (SP) from the eggs of sea urchin Paracentrotus lividus, extracted by papain digestion, was characterized by size exclusion chromatography coupling on-line with light scattering and viscosity detectors (SEC/MALS/VD/DRI), gas chromatography coupled to mass spectrometer (GC–MS), and Fourier transform infrared spectroscopy (FTIR) analysis. The native molecular mass of the extracted polysaccharide is high (≥22 000 KDa) and it is composed mainly of arabinose, accompanied by other monosaccharides (mostly galactose, glucose and fucose), significant amounts of uronic acids (18.4%) and relatively high proportions of sulfate (22.4%). The pharmacological evaluation of SP showed a significant in vivo anti-inflammatory activity (p