Immunomodulatory Activity of Polysaccharide–Protein Complex from the Mushroom Sclerotia of Polyporus rhinocerus in Murine Macrophages

Abstract

A novel water-soluble polysaccharide-protein complex (PRW1) isolated from the sclerotia of an edible mushroom Polyporus rhinocerus which was purified by membrane ultrafiltration could significantly activate murine macrophages RAW264.7 in vitro. PRW1 had a molecular weight of less than 50 kDa and was found to be a highly branched heteropolysaccharide-protein complex composed of 45.7 ± 0.97% polysaccharide and 44.2 ± 0.41% protein. Based on the results of total acid hydrolysis, methylation analysis, and Fourier transform infrared spectroscopy, the carbohydrate moiety of PRW1 was found to be a β-d-mannoglucan with its backbone containing →1)-d-Glcp-(4→, →1)-d-Glcp-(6→, and →1)-d-Manp-(2→ residues (molar ratio of 5:4:6) and having terminal d-Glcp as side chain (degree of branching of 0.62). In vitro studies showed that PRW1 significantly induced NO production and enhanced the release of a variety of cytokines including G-CSF, GM-CSF, IL-6, IL12p40/70, MCP-1, MCP-5, MIP-1-α, MIP-2, RANTES, sTNFRI, and TNF-α. Mechanistically, PRW1 treatment triggered ERK phosphorylation to activate macrophages within 15 min and significantly increased the expression level of inducible NOS after 6 h. In summary, this study indicates that PRW1 derived from the sclerotia of P. rhinocerus is a potential immunomodulatory agent for cancer immunotherapy.

Airway Relaxation Effects of Water-Soluble Sclerotial Extract From Lignosus rhinocerotis

“…The slight variations in the sugar composition between our study and the previous report might be attributed to the differences in extraction method, cultivar and geographical origins. In addition, in contrary with the previous findings by Liu et al (2016) , our preliminary experiments with the hot water extract of L. rhinocerotis have showed no bronchorelaxation effect (unpublished data), suggesting that the manno-glycoprotein linkages in the polysaccharide–protein complex are not likely to contribute to the bronchorelaxation effect.…”

“…We postulate that the glucose and galactose consistently found in the HMW fraction, the MMW fraction, and the CWE appeared to be the important residues in the glycosidic linkages of the polysaccharide–protein complex contributing to the bronchorelaxation activities. Recently, a novel polysaccharide–protein complex was isolated from the hot-water-soluble polysaccharide fraction of P. rhinocerus and chemically characterised, indicating that glucose and mannose are the predominant carbohydrate moieties in the polysaccharide–protein complex with antitumor activity ( Liu et al, 2016 ). The slight variations in the sugar composition between our study and the previous report might be attributed to the differences in extraction method, cultivar and geographical origins.…”

In Vitro Infant Faecal Fermentation of Low Viscosity Barley β-Glucan and Its Acid Hydrolyzed Derivatives: Evaluation of Their Potential as Novel Prebiotics

“…The infrared spectra of the five BBG samples were recorded with a Fourier transform infrared spectrometer (FT-IR, Nicolet 670, Thermo Scientific, Waltham, MA, USA) in the range 4000–400/cm using the KBr-disk method [29]. One-dimensional proton NMR measurements of the samples were analyzed on a 700 MHz NMR spectrometer (Bruker Advanced III HD, Bruker, Billerica, MA, USA) at 60 °C using DMSO-d 6 as the solvent [30].…”

A Status Review of the Bioactive Activities of Tiger Milk Mushroom Lignosus rhinocerotis (Cooke) Ryvarden

“…In another study, a water-soluble polysaccharide-protein complex (PRW1) was isolated from the sclerotium of Polyporus rhinocerus Cooke (synonym of L. rhinocerotis ) and further purified by membrane ultrafiltration (Liu et al, 2016 ). It showed a significant increase of NO production and enhanced the release of a variety of cytokines, for example, granulocyte colony stimulating factor (GCSF) and granulocyte-macrophage colony-stimulating factor (GMCSF).…”