Immunomodulatory effects exerted by Poria Cocos polysaccharides via TLR4/TRAF6/NF-κB signaling in vitro and in vivo

Biomed Pharmacother. 2019 Apr:112:108709. doi: 10.1016/j.biopha.2019.108709. Epub 2019 Mar 1.

Abstract

Objective: Poria cocos polysaccharide (PCP) is the major active ingredients of P. cocos and possesses various pharmacological effects, including anti-oxidative and anti-apoptosis effects and activity against cancer. This study investigated the immunomodulatory mechanism by which PCP acts on RAW 264.7 macrophages and LLC tumors in mice.

Methods: The concentrations of nitric oxide, and Th1, Th2, and Th17 cytokines were examined by Griess reaction and using a bead-based cytokine assessment kit. qRT-PCR and western blotting were used to investigate relevant signaling molecule expression.

Results: Levels of nitric oxide, IL-2, IL-6, IL-17 A, TNF, and IFN-γ were increased by PCP while levels of IL-4 and IL-10 were unaffected. The addition of TAK-242 (TLR4 inhibitor) or assessment in C57BL/10ScNJ (TLR4-deficient) mice markedly reduced this effect. In C57BL/10 J (TLR4+/+wild-type) mice, the indices of organ immune activity were all elevated, and oral PCP delivery resulted in a significant reduction in tumor volume over a 25 day period. Relative to controls, TLR4, MyD88, TRAF-6, p-NF-κB and p-c-JUN expression significantly increased, while TRAM expression did not change. Nevertheless, there was no PCP-dependent activation of MyD88, TRAF-6, TRAM, p-NF-κB or p-c-JUN in TLR4-deficient mice.

Conclusion: These results support the concept that PCP may exhibit immunomodulatory activity through TLR4/TRAF6/NF-κB signaling both in vitro and in vivo.

Keywords: Immunomodulatory; Lung cancer; Poria Cocos polysaccharide; TLR4.

MeSH terms

  • Animals
  • Antineoplastic Agents / isolation & purification
  • Antineoplastic Agents / therapeutic use*
  • Carcinoma, Lewis Lung / drug therapy*
  • Carcinoma, Lewis Lung / metabolism
  • Cell Line, Tumor
  • Cytokines / metabolism
  • Female
  • Immunologic Factors / isolation & purification
  • Immunologic Factors / therapeutic use*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • NF-kappa B / metabolism*
  • Nitric Oxide / metabolism
  • Polysaccharides / isolation & purification
  • Polysaccharides / therapeutic use*
  • RAW 264.7 Cells
  • Signal Transduction
  • Spleen / drug effects
  • Spleen / immunology
  • TNF Receptor-Associated Factor 6 / metabolism*
  • Thymus Gland / drug effects
  • Thymus Gland / immunology
  • Toll-Like Receptor 4 / metabolism*
  • Wolfiporia / chemistry*

Substances

  • Antineoplastic Agents
  • Cytokines
  • Immunologic Factors
  • NF-kappa B
  • Polysaccharides
  • TNF Receptor-Associated Factor 6
  • TRAF6 protein, mouse
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4
  • Nitric Oxide