Structural characterization and anti-weightless bone loss activity of an anionic polysaccharide from Dictyophora indusiata

This study explores the extraction and purification of polysaccharides from Dictyophora indusiata (D. indusiata) with its antioxidant and anti-weightlessness bone loss properties. An anionic polysaccharide (SADIP) with a molecular weight of 13.42 kDa was isolated and purified from D. indusiata. SADIP consists of a glucose-based sugar chain backbone. Its backbone consists of glycosidic linkages of →4)-α-D-Glcp-(1 → and →4)-β-D-Glcp-(1→, with sulfate groups attached at the O-6 position of →4)-β-D-Glcp-(1 → residues. Side chains were α-D-Glcp-(1 → 6)-α-D-Glcp-(1 → linked at C-6 position of →4,6)-α-D-Glcp-(1 → through O-6 bonds. In vitro, SADIP scavenged up to 99.32 ± 0.24 % of 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radicals and 76.72 ± 0.34 % of hydroxyl radicals. In vivo, SADIP reduced malondialdehyde (MDA) levels induced by weightlessness and increased low levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) caused by weightlessness. Additionally, three-point mechanical bending tests and Micro-CT analysis demonstrated that SADIP has ability to alleviate bone loss induced by weightlessness. This study provides a theoretical foundation for the rational developmation of D. indusiata resources.