The Structure Characterization of Polysaccharides from Codonopsis pilosula and the Structure-activity Relationship with Immune-regulation on THP-1 Cells.

In recent years, polysaccharides from Codonopsis pilosula (CPs) have received increasing attention for their excellent behaviors in immune-regulation. However, the relationship between the structure and immunomodulatory activity has rarely been reported. In this work, four fractions purified from crude CPs (CPW, CPS0.2, CPS0.5, CPS1) by chromatographic column separation were explored with both structure and immunomodulatory effects by THP-1 cells. The results showed that the monosaccharide composition, chain conformation, molecular weight (Mw) and aggregated state of CPs were different. At the same time, the immunomodulatory effects of CPs were also varied depend on structure differences, as indicated by the released cytokines of TNF-α and IL-1β by LPS-induced THP-1 cells. Finally, we summarized and concluded that the spherical structure and smaller particle size of CPs were the key factors attributed to better immune-enhancing effects. The results showed that the monosaccharide combination differences of polysaccharides might lead to anti-inflammatory or pro-inflammatory activity. Moreover, the higher percentage of glucose, the relatively large particle size, as well as the extended chain conformation of CPs might be the key factors attributed to better immune-enhancing effects. This study aims to provide a theoretical basis for establishing the structure-activity relationship of CPs.