Structural characteristics of a hyperbranched acidic polysaccharide from the stems of Ephedra sinica and its effect on T-cell subsets and their cytokines in DTH mice

► An immunosuppressive acidic hetero-polysaccharide (ESP-B4) was enriched from the stems of Ephedra sinica. ► It contained a repeating unit of [→4)-GalpA-(1→2)-Rhap-(1→] as hairy region, substituted by arabinose, xylose, galactose, glucose, mannose and glucuronic acid. ► The immunosuppressive mechanism may be attributed to its inhibition of IL-2, IL-4 and ratio of CD4+/CD8+ in DTH mice serum.