Immunomodulatory Effects of Extracellular β-Glucan Isolated from the King Oyster Mushroom Pleurotus eryngii (Agaricomycetes) and Its Sulfated Form on Signaling Molecules Involved in Innate Immunity

Abstract

The aim of this study was to determine, using murine RAW 264.7 macrophages, the immunomodulatory effect of extracellular β-glucan isolated from Pleurotus eryngii (PEBG) and its sulfated derivative (PEBG-S) on signaling molecules implicated in host innate immunity. β-Glucan was extracted and purified from the mycelial culture using optimal medium concentrations. It was then chemically converted to its sulfated form. Monosaccharide composition of β-glucan was characterized with p-aminobenzoic acid ethyl ester-derivatized sugars through highperformance liquid chromatography analysis. Fourier transform infrared structural analysis showed an S=O bond at 1250 cm-1 and C-S-O binding at 815 cm-1 in PEBG-S. 13C nuclear magnetic resonance analysis showed 1,3-linked α-D-mannopyranosyl and 1,3-β-D-glucopyranosyl in PEBG-S. A concentration-dependent increase of nitric oxide production was noticed in RAW 264.7 cells treated with PEBG-S or PEBG; those treated with PEBG-S showed less cytotoxicity than those treated with PEBG. Cellular levels of tumor necrosis factor-α, interleukin-1β, and interleukin-6 were increased by PEBG and PEBG-S treatment, suggesting that they have immunomodulatory activity. Real-time polymerase chain reaction array revealed that the expression levels of nuclear factor-κB and Toll-like receptor signaling genes in cells were upregulated by PEBG and PEBG-S. Moreover, the expression of the β-glucan receptor dectin-2 was significantly upregulated by PEBG and PEBG-S treatment, reflecting immune activation through the dectin-2-Syk-(CARD9/Bcl-10/MALT1) pathway. Our results suggest that PEBG-S could be used as an effective adjuvant or immune enhancer that can be sustainably produced by recycling the by-product of mycelial culture.

The preventable efficacy of β-glucan against leptospirosis

“…β-Glucan is a potential immunostimulant. Many studies demonstrate that β-glucan can protect against bacterial and various other infections [35,36] by stimulating immune functions both in vitro and in vivo [37,38]. However, it is not clear whether β-glucan has immunomodulatory effects on leptospirosis.…”

Spatial Distribution of Glucan Type and Content between Caps and Stalks in Pleurotus eryngii: Impact on the Anti-inflammatory Functionality

“…Similarly, Park and associates [ 11 ] have recently demonstrated that the β-glucan contents were also higher in stipes of P. eryngii , claiming that this result is probably associated with the development of the major structural compounds of cell wall in mushrooms allowing for optimal supporting effect of the cap. Since β-glucans were repetitively demonstrated in a myriad of studies [ 2 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ] to induce immunostimulatory events in mammalian cells, we hypothesized that this spatial variation may also impinge on the functionality of the different parts of P. eryngii .…”

“…It was originally consumed in Europe but is now widely distributed and consumed in other parts of the world including America, Asia, and Africa [ 1 ]. The advantageous nutritional and medicinal properties exerted by P. eryngii mushrooms are mediated, at least in part, by potent bioactive constituents such as the polysaccharides fraction (glucans) and other molecules that can confer a variety of health benefits such as strong immunomodulatory effects [ 2 , 3 , 4 ].…”

Preparation of newly identified polysaccharide from Pleurotus eryngii and its anti‐inflammation activities potential

“…Chen et al, 2013), and hepatic structure damage (Zhang et al, 2016).Moreover,P. eryngii polysaccharides (PEPs) have been shown to possess a strong anti-inflammatory activity related to their immunomodulatory effect on macrophages (Kim et al, 2017;S. Li & Shah, 2016;Xu et al, 2016), however, there are no published reports elucidating the molecular mechanism underlying these antiinflammatory effects.…”

“…Polysaccharide fractions have been shown to be the major biological components in P. eryngii and displayed multiple and significant functional properties such as inhibitory effects on renal cancer cells (Yang et al., 2013), hyperlipidemia and hyperglycemia (Chen, Zhang, Sha, Xu, & Wang, 2016), lipid accumulation (J. Chen et al., 2013), and hepatic structure damage (Zhang et al., 2016). Moreover, P. eryngii polysaccharides (PEPs) have been shown to possess a strong anti‐inflammatory activity related to their immunomodulatory effect on macrophages (Kim et al., 2017; S. Li & Shah, 2016; Xu et al., 2016), however, there are no published reports elucidating the molecular mechanism underlying these anti‐inflammatory effects.…”