Surface morphology and action mechanism of macrophage immunostimulating activity of Rosa Setate x Rosa Rugosa polysaccharide WSRP-1b

This is the authors' abstract. We don't add key points for this paper.

• WSRP-1b has a loose and smooth surface and flake-like structure. • WSRP-1b has irregular curls, a spherical chain, and triple-helical conformation. • WSRP-1b promoted phagocytic capacity in macrophages. • WSRP-1b activated macrophages via the MAPKs and NF-κB signaling pathway. • WSRP-1b up-regulated the mRNA expression of iNOS, TNF-α, and IL-6. Our previous research demonstrated that the glucomannan WSRP-1b, which was obtained from waste biomass of Rosa Setate x Rosa Rugosa , had potent immunostimulatory activity. However, the specific mechanisms involved in the activation of RAW264.7 macrophages by WSRP-1b remain unclear. Scanning electron microscopy, atomic force microscopy and Congo red analyses revealed that WSRP-1b exhibited a flake structure with irregular curls and had a triple-helix conformation in solution. The immunostimulation assays showed that WSRP-1b could substantially enhance macrophages phagocytosis and promote the accumulation of iNOS, TNF-α, and IL-6 mRNA. Western blot analysis indicated that the expression of mitogen-activated protein kinases (MAPKs) was upregulated in WSRP-1b-induced RAW264.7 cells. Furthermore, pretreatment of RAW 264.7 cells using specific inhibitors against MAPKs and NF-κB remarkably attenuated nitric oxide production and cytokine secretion. These data suggest that WSRP-1b activates RAW264.7 macrophages via the MAPK and NF-κB signaling pathways and may be a novel immunomodulatory agent for hypoimmunity disease therapy.