Extraction, purification, structure characterization of polysaccharides from Cistanche deserticola and their biological effects

The polysaccharide fraction (CDP-D2-N1) from the stem of Cristanche deseticola was obtained after extraction and purification. The structural characteristics and in vitro antioxidant and anti-inflammatory activities of CDP-D2-N1 were investigated by physical, chemical and instrumental analyses. The results showed that CDP-D2-N1 (127.784 kDa) is a heterogeneous polysaccharide with an irregular non-crystalline structure, containing mainly Rha:Ara:Xyl:Gal:Gal:GlcA:Glc:GalA, and a molar ratio of 6.75 : 26.68 : 1.56 : 37.87 : 3.94 : 2.17 : 21.02. Combined with the results of NMR spectroscopy and methylation analyses, the main chain of CDP-D2-N1 was determined to be →4)-α-d-GalpA-(1→,→3,6)-β-d-Galp-(1→, →5)-α-l-Araf-(1→, containing a small amount of fragment →3,4)-β-d-Galp-(1→ and →3)-β-d-Galp-(1→, and the CDP-D2-N1 structure was inferred. In vitro assays demonstrated that CDP-D2-N1 possessed significant antioxidant capacity and attenuated inflammation induced by lipopolysaccharide (LPS) from Escherichia coli O55:B5 in bovine endothelial cells (bEEcs) by inhibiting the expression levels of TNF-α, IL-6, TLR 4 and IL-1.