Structural characterization and anti-inflammatory activity of a neutral polysaccharide from Dendrobium huoshanense C. Z. Tang et S. J. Cheng.

A neutral polysaccharide (NDHP-2-1) was isolated from Dendrobium huoshanense C. Z. Tang et S. J. Cheng (D. huoshanense). Structure characterization revealed that the weight-average molecular weight of NDHP-2-1 was 20.42 kDa, mainly composed of glucose (95.46 %) and mannose (4.54 %). The backbone of NDHP-2-1 consisted of →6)-α-D-Glcp-(1→, →4)-α-D-Glcp-(1→, and →3,4)-α-D-Glcp-(1→. The T-α-D-Glcp was regarded as the branches attached to the O-4 position of →3,4)-α-D-Glcp-(1 → in the backbone. In vitro experiments indicated that NDHP-2-1 exhibited excellent anti-inflammatory activity. The RAW264.7 cell assay results showed that NDHP-2-1 effectively inhibited the release of pro-inflammatory cytokines, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) from LPS-stimulated macrophages. In general, the newly isolated polysaccharide of NDHP-2-1 exhibited significant anti-inflammatory and immunomodulatory properties, suggesting its potential as an effective natural therapeutic agent for managing inflammatory diseases.