A gel-forming β-glucan isolated from the fruit bodies of the edible mushroom Pleurotus florida

Glucans from Armillaria luteo-virens: Structural Characterization and In Vivo Immunomodulatory Investigation under Different Administration Routes

Polysaccharides fromArmillaria luteo-virens (ALP) were investigated for structural characterization and immunomodulatory activities. Three fractions (ALP-1, ALP-2, and ALP-3) were obtained with the yield of 2.4, 3.7, and 3.0 wt %, respectively. ALP-1 was proposed as a β-(1 → 3)(1 → 6)-glucan with a triple-helix conformation; ALP-2 and ALP-3 were both identified as α-(1 → 4)(1 → 6)-glucan differing in their Mw and branching degree with a spherical conformation. The in vitro digestibility experiment and in vivo experiments using cyclophosphamide (CY)-treated mice demonstrated that intraperitoneal injection of α-glucan (1 mg·kg-1·day-1) and intragastric gavage of β-glucan (10 mg·kg-1·day-1) both effectively restored the decrease in body weight, immune organ indexes, immune cell activities, serum immune marker levels, colonic short-chain fatty acids (SCFA) levels, and Bacteroidetes/Firmicutes ratio in immunosuppression mice. This study provides novel insights into the immunomodulatory activity of α- and β-glucans under different administration routes, thereby promoting their application in both food and pharmaceutical areas.

Probiotic growth-stimulating capacity and antimicrobial activities of aqueous extracts of Lentinus crinitus (L.) Fr (polyporales, basidiomycota)

Lentinus crinitus (L.) Fr is a wild macrofungus that is popular as antimicrobial and various biological activities. This study aims to determine the capacity growth stimulation of Lactobacillus paracasei and antimicrobial activity of aqueous extracts of L. crinitus obtained from wild basidiomata, mycelial biomass by liquid fermentation and spent mushroom substrate obtained by solid-state fermentation. The antimicrobial activity was investigated against bacterial and fungal pathogens and growth stimulation L. paracasei probiotic bacterium. The total carbohydrate and β-glucan contents of the extracts were determined using colorimetric analysis. The aqueous extracts obtained showed inhibition against Fusarium oxysporum., Penicillium sp., Rhizopus oryzae, Aspergillus niger, Escherichia coli and Salmonella typhimurium. The aqueous extract obtained from wild basidiomata, and mycelial biomass showed the highest percentage of stimulation of L. paracasei growth in 48 h. The extracts obtained from L. crinitus have antimicrobial potential and stimulating capacity of the probiotic Lactobacillus paracasei. Additionally, different biotechnological techniques such as liquid and solid-state fermentation can be used to obtain aqueous extracts.

Structural analysis and antidiabetic activity study of three acidic-type polysaccharides from Crepis crocea (Lam.) Babc

In this article, we analyzed the structures of three acidic hetero-chain polysaccharides (CTP3-B, CTP3-C, and CTP3-D) fractionated from the herb Crepis crocea (Lam.) Babc. by a combination of ethanol precipitation, dialysis and gel permeation chromatography. Three polysaccharides were all highly branched polysaccharide. KK-Ay mice were chosen to determine the hypoglycemic effect of CTP3. The anti-diabetic activity of CTP3 was explored in detail from the aspects of body weight, daily dietary intake, blood glucose level and oral glucose tolerance test (OGTT). It was found that the body weight and daily food intake of the high dose group were significantly decreased compared with the diabetic control group. In addition, there was significant decrease in the levels of blood glucose in the middle and high dose group. These results suggest that CTP3 had a regulative role in blood glucose level. CTP3 may be useful in the treatment of type 2 diabetes mellitus.

Structural characterization of a safflower polysaccharide and its promotion effect on steroid-induced osteonecrosis in vivo

A water-soluble polysaccharide (SPAW) was purified from Safflower and it was identified to be (1→3)-linked β-d-Glucan. The therapeutic effect and underlying mechanism of SPAW on steroid-induced avascular necrosis of the femoral head (SANFH) in a rabbit model was performed here. The abnormal histopathologic changes and apoptosis of femoral head in model group were significantly reverted after SPAW (25, 100 and 200 mg/kg) administration for 60 days, as evidenced by the a decline of empty lacunae rate, the average bone marrow fat cell size and the proportion of apoptotic cells. Furthermore, administration of SPAW significantly decreased the Bax and caspase-3 protein expression, but increased the protein expression of Bcl-2 when compared these in model rabbits. Meanwhile, increased hydroxyproline (HOP) and decreased serum hexosamine (HOM) concentration in rabbit serum were turned to the opposite way. The present study suggested that SPAW may provide an alternative treatment for the treatment of SANFH.

Structural Characterization and Chain Conformation of Water-Soluble β-Glucan from Wild Cordyceps sinensis

Water-soluble β-d-glucan was obtained from wild Cordyceps sinensis by alkali solution and ethanol precipitation. The structure characteristics were determined using high-performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD), methylation combined with gas chromatography-mass spectrometry, and one-/two-dimensional nuclear magnetic resonance spectroscopy. Results showed that β-d-glucan had a structure of every seven (1→3)-β-d-Glcp backbone residues with two (1→6)-β-d-Glcp branches. Additionally, conformation properties in different solvents were investigated by static light scattering, dynamic light scattering, and HPSEC with multiple detectors. It was found that β-d-glucan in 0.5 M NaOH had a narrow unimodal distribution of hydrodynamic radius displaying a spherical coil conformation, whereas it formed severe aggregation in dimethyl sulfoxide. In 0.1 M NaNO₃, β-d-glucan mainly existed as a rod-like conformation corresponding to a helical structure together with small aggregates (10%). This work added more information to the understanding of C. sinensis polysaccharides.

A β-glucan from Durvillaea Antarctica has immunomodulatory effects on RAW264.7 macrophages via toll-like receptor 4

We studied the mechanisms underlying the immunostimulatory effects of aβ-1,3/1,6-glucan (BG136) from Durvillaea Antarctica. Our data showed that BG136 promoted the activation of MAPKs and NF-κB signaling pathways and cytokines production. BG136 did not increase MCP-1 or NO production or phosphorylation of NF-κB and MAPK in TLR4 siRNA knockdown cells, indicating that BG136 activates macrophages through TLR4. Flow cytometry analysis and confocal experiment showed that BG136 bound to TLR4 expressed on RAW264.7 macrophage cells surface. The affinity of BG136 for TLR4 was determined using Surface Plasmon Resonance (SPR) (KD: 4.51 × 10-6M). Altogether, our results showed that BG136 activates RAW264.7 cells by binding to TLR4 and then triggering TLR4-mediated signaling pathways to promote cytokines secretion.

Structural characterization and anti-inflammatory activity of a linear β-D-glucan isolated from Pleurotus sajor-caju

Glucans comprise an important class of polysaccharides present in basidiomycetes with potential biological activities. A (1 → 3)-β-D-glucan was isolated from Pleurotus sajor-caju via extraction with hot water followed by fractionation by freeze-thawing and finally by dimethyl sulfoxide extraction. The purified polysaccharide showed a (13)C-NMR spectrum with six signals consisting of a linear glucan with a β-anomeric signal at 102.8 ppm and a signal at 86.1 ppm relative to O-3 substitution. The other signals at 76.2, 72.9, 68.3, and 60.8 ppm were attributed to C5, C2, C4, and C6, respectively. This structure was confirmed by methylation analysis, and HSQC studies. The β-d-glucan from P. sajor-caju presented an immunomodulatory activity on THP-1 macrophages, inhibited the inflammatory phase of nociception induced by formalin in mice, and reduced the number of total leukocytes and myeloperoxidase levels induced by LPS. Taken together, these results demonstrate that this β-d-glucan exhibits a significant anti-inflammatory activity.

Water-soluble polysaccharides from Pleurotus ostreatus var. florida mycelial biomass

Pleurotus ostreatus var. florida known as Hiratake has a high nutritional value, presents medicinal and nutraceutical properties and it is one of the consumed mushrooms in Brazil. Thus, the aim of this study was to characterize the chemical structure of polysaccharides found in mycelial biomass produced by submerged culture of P. ostreatus var. florida in order to compare with those found in P. ostreatus var. florida fruit bodies. Aqueous and alkali extracts obtained from mycelial biomass were purified, 13C NMR, GC-MS and chemical techniques were used to characterize three polysaccharide structures: a mannogalactan (MG-PfM) with α-D-Galp and 3-O-Me-α-D-Galp units, both (1→6)-linked, highly substituted at O-2 by D-Manp, a glycogen-like polymer (GLY-PfM) with α-D-Glp (1→4)-linked main chain, partially substituted at O-6 by α-D-Glcp side chains and a (1→3), (1→6) β-D-glucan (βGLC-PfM) with a main chain of β-D-Glcp (1→3)-linked units, partially substituted at O-6 by side chains of 6-O-substituted β-D-glucopyranosyl units, on an average of one to every two residues of the backbone. These results show the possibility to obtain similar and also different molecules from those found in the fruiting body of the same mushroom species, therefore the submerged culture of mushroom is a promising way to give raise molecules of interest.

Lactarius rufus (1→3),(1→6)-β-D-glucans: structure, antinociceptive and anti-inflammatory effects

Medicinal health benefits uses of edible as well as non-edible mushrooms have been long recognized. The pharmacological potential of mushrooms, especially antitumor, immunostimulatory and anti-inflammatory activities has been documented. Wild ectomycorrhizal mushroom, Lactarius rufus had the anti-inflammatory and antinociceptive potential of their polysaccharides evaluated using the formalin model. Two structurally different (1→3),(1→6)-linked β-D-glucans were isolated from fruiting bodies. Soluble (FSHW) β-D-glucan 1-30 mg kg(-1) produced potent inhibition of inflammatory pain caused by formalin when compared with the insoluble one (IHW), suggesting that solubility and/or branching degree could alter the activity of β-glucans. Their structures were determined using mono- and bi-dimensional NMR spectroscopy, methylation analysis, and controlled Smith degradation. They were β-D-glucans, with a main chain of (1→3)-linked Glcp residues, substituted at O-6 by single-unit Glcp side chains (IHW), on average to every fourth residue of the backbone, or by mono- and few oligosaccharide side chains for soluble β-glucan.

Glucomannan and branched (1→3)(1→6) β-glucan from the aposymbiotically grown Physcia kalbii mycobiont

Cultures of the mycobiont Physcia kalbii were obtained from germinated ascospores and cultivated on Sabouraud-Sucrose-agar medium. Alkaline extraction of freeze-dried mycelia provided a branched (1→3),(1→6)-β-glucan and a glucomannan, whose chemical structure was determined by monosaccharide composition, methylation, controlled Smith degradation and NMR spectroscopic analysis. The β-glucan had a (1→3)-linked β-glucopyranosyl backbone, partially substituted (approx. 50% of the units) at O-6. The side chains were formed by 6-O- (∼82%) and 2,6-O-linked-β-Glcp units, while the non-reducing ends were formed by β-glucopyranosyl residues. The glucomannan had (1→6)-linked α-Manp units in the main chain, almost all being substituted at O-2 by α-Manp and α-Glcp units. This glucomannan could be a typical polysaccharide of lichens from the family Physciaceae.

Branching structure and chain conformation of water-soluble glucan extracted from Auricularia auricula-judae

A water-soluble neutral polysaccharide (AF1) was extracted from Auricularia (A.) auricula-judae with 0.15 M aqueous NaCl at 80-100 °C. Its chemical components and structure were analyzed by GC, GC-MS, and NMR. AF1 was identified as a β-(1→3)-D-glucan with two β-(1→6)-D-glucosyl residues for every three main chain glucose residues, showing a comb-branched structure. The M(w) values of AF1 in both aqueous solution and DMSO determined by LLS and SEC-LLS were in the narrow range of 2.07-2.15 × 10(6), indicating AF1 existed as single chains in the two solvents. The high intrinsic viscosity [η] of 1753 mL/g and the structure-sensitive parameter ρ (≡R(g)/R(h)) value of 2.3 in water revealed that AF1 existed as stiff chain conformation. Moreover, we directly observed the extended stiff chain conformation by AFM. The branching structure led to the water solubility of AF1, and the intramolecular hydrogen bonds sustained the stiff chain conformation. The rheological results showed that this polysaccharide aqueous solution had higher viscosity than even xanthan, a pronounced thickening agent. This work provided important information for developing new thickeners in food fields, and how neutral polysaccharides can be used as good candidates.

Antinociception of β-D-glucan from Pleurotus pulmonarius is possibly related to protein kinase C inhibition

β-D-Glucan, a polysaccharide isolated from an edible mushroom Pleurotus pulmonarius (Fr.) Quel., presented antinociceptive activity in mice. This study evaluated the involvement of transient receptor potential (TRP) channels and protein kinase C (PKC) on antinociceptive effect of a (1→3),(1→6)-linked β-D-glucan (GL) in mice. Intraperitoneal administration of GL potently inhibited nociceptive responses induced by intraplantar injections of capsaicin, cinnamaldehyde, menthol, acidified saline and phorbol myristate acetate (PMA). Moreover, Western blot analysis revealed that GL treatment also prevented PMA-induced PKCɛ activation. Collectively, present results demonstrate that GL could constitute an attractive molecule of interest for the development of new analgesic drugs.

(1-3)(1-6)-β-glucan-enriched materials from Lentinus edodes mushroom as a high-fibre and low-calorie flour substitute for baked foods

BACKGROUND

Extensive physiological and biological emphasis has been placed on pharmaceutical and medicinal uses of mushrooms containing β-glucans, but their incorporation into processed functional foods is quite limited. Thus, low-grade Lentinus edodes mushrooms were utilised to produce β-glucan-enriched materials (BGEMs), which were evaluated as a high-fibre and low-calorie substitute for wheat flour.

RESULTS

The fractions obtained from Lentinus edodes mushrooms contained 514 g kg⁻¹ of (1-3)-β-glucans with (1-6)-β-linked side chains and the chemical structure was confirmed by ¹³C NMR and FTIR spectroscopy. Replacement of a portion of the wheat flour with BGEMs resulted in the solutions with lower values of pasting parameters and also caused significant changes in starch gelatinisation. When BGEMs were incorporated into cake formulations, batter viscosity increased with more shear-thinning behaviours and elastic properties improved. Overall, the cakes containing more BGEMs showed decreased volume and increased hardness while no significant differences were observed between the control and BGEM cakes containing 1 g of β-glucan per serving.

CONCLUSION

As a wheat flour substitute, the BGEMs that were prepared from low-grade Lentinus edodes mushrooms, could be successfully used to produce cakes containing 1 g of β-glucan per serving with quality attributes similar to those of the control.