Effects of Hyriopsis cumingii Polysaccharides on Mice Immunologic Receptor, Transcription Factor, and Cytokine

To discuss the molecular mechanism of immunoenhancing activities of Hyriopsis cumingii polysaccharides (HCPS), effects of HCPS on mice immunologic receptors (toll-like receptors-4 [TLR-4] and mannose receptor-1 [MR-1]), transcription factor (nuclear factor kappa-B [NF-κB]), and cytokines (interleukin-6 [IL-6] and tumor necrosis factor-α [TNF-α]) were evaluated by cell model in vitro and cyclophosphamide-induced immunosuppression animal model in vivo. Results showed that HCPS could promote the mRNA synthesis of TLR-4, MR-1, IL-6, and TNF-α in spleen, and the gene expression of TLR-4, MR-1, NF-κB, IL-6, and TNF-α in spleen and serum in a dose-dependent manner. Crude HCPS and its purified fractions (HCPS-1, HCPS-2, and HCPS-3) could strengthen peritoneal macrophage expressing MR-1 and NF-κB in a dose-dependent manner. In addition, HCPS-3 showed stronger promotions on MR-1 and NF-κB than crude HCPS, HCPS-1, and HCPS-2. It suggested that HCPS-stimulated immunostrengthening was mediated, at least in part, by TLR-4/NF-κB/IL-6 and TLR-4/NF-κB/ TNF-α signaling pathways. MR-1, IL-6, and TNF-α might be 3 of the immune regulators mediating immunity and homeostasis when HCPS performed immunoenhancing activities.