ABSTRACT
The polysaccharides (DIP) extracted from Dictyophora indusiate has been found featuring great anti-cancer activity through enhancing organism immunity ability, and the DIP-induced macrophages activation might be mediated via TLR4/NF-κB signaling pathway. In this work, we make further investigation of the effect of DIP on macrophages and whether there was another pathway to regulate the immunoenhancement effect of DIP. The results showed that DIP could activate macrophages, causing the enhancement of its phagocyte activity, and then increase the secretion of IL-1ß and TNF-α. It could also activate the MAPK pathway and promoted the phosphorylation and nuclear translocation of NF-κB p65. However, these effects of DIP on macrophage was inhibited by anti-Dectin-1, indicating that besides TLR-4, Dectin-1 act as another receptor on macrophage surface which was responsible for the activation effect of DIP. In conclusion, we further illuminate the molecular mechanism involving in the immune enhancement activities on macrophages.
Subject(s)
Basidiomycota/chemistry , Fungal Polysaccharides/pharmacology , Immunologic Factors/pharmacology , Lectins, C-Type/metabolism , Animals , Cytokines/metabolism , Fungal Polysaccharides/chemistry , Immunologic Factors/chemistry , MAP Kinase Signaling System/drug effects , Macrophage Activation/drug effects , Macrophage Activation/immunology , Macrophages/drug effects , Macrophages/immunology , Macrophages/metabolism , Mice , NF-kappa B/metabolism , Phagocytosis/drug effects , Phagocytosis/immunology , Phosphorylation , Protein Binding , Protein Transport , RAW 264.7 CellsABSTRACT
Dictyophora indusiata, an edible mushroom, is widely used not only as health foods but also as traditional Chinese medicine. This study aimed to investigate the molecular mechanism involved in the immunostimulatory activity of a polysaccharide from Dictyophora indusiata (DIP) in RAW264.7 cells. Results indicated that DIP induced the up-regulation of nitric oxide (NO), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumour necrosis factor (TNF-α) production as well as the mRNA expression levels of iNOS, IL-1ß, IL-6 and TNF-α in macrophages. Furthermore, the functional blocking antibodies against TLR4 could markedly suppress DIP-mediated NO, IL-1ß, IL-6 and TNF-α production. Flow cytometry and confocal laser-scanning microscopy analyses confirmed that DIP could bind specifically to target cells, and the binding could be inhibited by anti-TLR4 monoclonal antibodies. The expression of nuclear factor kappa B (NF-κB) p65 was significantly induced by DIP. Therefore, the DIP-induced macrophage activation may be mediated via the TLR4/NF-κB signalling pathway.
Subject(s)
Adjuvants, Immunologic/pharmacology , Agaricales/chemistry , Fungal Polysaccharides/pharmacology , Macrophages/metabolism , Signal Transduction/drug effects , Adjuvants, Immunologic/chemistry , Animals , Cell Line , Fungal Polysaccharides/chemistry , Mice , Monokines/metabolism , NF-kappa B/metabolism , Nitric Oxide/metabolism , Toll-Like Receptor 4/metabolismABSTRACT
In this study, we aim to investigate the physiochemical and biological properties of water-soluble phosphorylated polysaccharides (P-DIP) obtained from a water-insoluble polysaccharide (DIP) extracted from Dictyophora indusiata. A series of physiochemical properties were determined, including morphology, water-solubility, molecular weight, and degree of substitution (DS). To investigate the antioxidant activity of P-DIP, we determined the scavenging activity of hydroxyl radicals and DPPH, as well as the reducing power. MTT assay was performed to determine the cytotoxic effects of DIP and P-DIP on the cellular proliferation of MCF-7 and B16 cells. Compared with DIP, P-DIP showed a satisfactory water-solubility and significant increase in the antioxidant properties. Moreover, P-DIP also showed more significant inhibitory effects on the growth of MCF-7 and B16 tumor cells than the water-insoluble DIP. These results indicated that phosphorylation might contribute to the improvement of water solubility, as well as antioxidant and anti-tumor activities of natural DIP.
