Characterization of an Immune-Enhancing Polysaccharide Fraction Isolated from Heat-Processed Ginseng Derived from Panax ginseng C.A. Meyer

Panax ginseng C.A. Meyer (ginseng) has shown immune-enhancing activity in many studies. The purpose of the present study was to analyze the chemical properties of a polysaccharide fraction (SGP) purified from heat- processed ginseng and to evaluate its immune-enhancing activity using RAW264.7 macrophages. The results showed that SGP increased inducible nitric oxide synthase expression and nitric oxide production in RAW264.7 macrophages. In addition, SGP increased mRNA expression and secretion of interleukin 6 and tumor necrosis factor alpha. Immunoblotting results showed that SGP increased the phosphorylation of mitogen-activated protein kinases (MAPKs) and NF-κB subunit p65 at 500 μg/mL and 1000 μg/mL. Taken together, SGP can activate macrophages through the MAPK and NF-κB signaling pathways, and it may help maintain homeostasis during viral and bacterial infections.

Crosstalk Between Polygonatum kingianum, the miRNA, and Gut Microbiota in the Regulation of Lipid Metabolism

Objectives:Polygonatum kingianum is a medicinal herb used in various traditional Chinese medicine formulations. The polysaccharide fraction of P. kingianum can reduce insulin resistance and restore the gut microbiota in a rat model of aberrant lipid metabolism by down regulating miR-122. The aim of this study was to further elucidate the effect of P. kingianum on lipid metabolism, and the roles of specific miRNAs and the gut microbiota.Key findings:P. kingianum administration significantly altered the abundance of 29 gut microbes and 27 differentially expressed miRNAs (DEMs). Several aberrantly expressed miRNAs closely related to lipid metabolism were identified, of which some were associated with specific gut microbiota. MiR-484 in particular was identified as the core factor involved in the therapeutic effects of P. kingianum. We hypothesize that the miR-484-Bacteroides/Roseburia axis acts as an important bridge hub that connects the entire miRNA-gut microbiota network. In addition, we observed that Parabacteroides and Bacillus correlated significantly with several miRNAs, including miR-484, miR-122-5p, miR-184 and miR-378b.Summary:P. kingianum alleviates lipid metabolism disorder by targeting the network of key miRNAs and the gut microbiota.

Identification of the Primary Structure of Selenium-Containing Polysaccharides Selectively Inhibiting T-Cell Proliferation

We previously described the biosynthesis, isolation, and immunosuppressive activity of the selenium-containing polysaccharide fraction isolated from the mycelial culture of Lentinula edodes. Structural studies have shown that the fraction was a protein-containing mixture of high molar mass polysaccharides α- and β-glucans. However, which of the components of the complex fraction is responsible for the immunosuppressive activity non-typical for polysaccharides of fungal origin has not been explained. In the current study, we defined four-polysaccharide components of the Se-containing polysaccharide fraction determined their primary structure and examined the effect on T- and B-cell proliferation. The isolated Se-polysaccharides, α-1,4-glucan (Mw 2.25 × 106 g/mol), unbranched β-1,6-d-glucan, unbranched β-1,3-d-glucan and β-1,3-branched β-1,6-d-glucan (Mw 1.10 × 105 g/mol), are not typical as components of the cell wall of L. edodes. All are biologically active, but the inhibitory effect of the isolated polysaccharides on lymphocyte proliferation was weaker, though more selective than that of the crude fraction.