Chemical structure and inhibition on α-glucosidase of a novel polysaccharide from Hypsizygus marmoreus

Characterization of Polysaccharide Extracts of Four Edible Mushrooms and Determination of In Vitro Antioxidant, Enzyme Inhibition and Anticancer Activities

Mushroom polysaccharides are important bioactive compounds derived from mushrooms with various beneficial properties. In this study, the chemical characterization and bioactivities of polysaccharide extracts from four different edible mushrooms, Clavariadelphus truncatus Donk, Craterellus tubaeformis (Fr.) Quél., Hygrophorus pudorinus (Fr.) Fr., and Macrolepiota procera (Scop.) Singer were studied. Glucose (13.24-56.02%), galactose (14.18-64.05%), mannose (2.18-18.13%), fucose (1.21-5.78%), and arabinose (0.04-5.43%) were identified in all polysaccharide extracts by GC-MS (gas chromatography-mass spectrometry). FT-IR (Fourier transform infrared spectroscopy) confirmed the presence of characteristic carbohydrate patterns. 1H NMR suggested that all polysaccharide extracts had α- and β-d-mannopyranose, d-glucopyranose, d-galactopyranose, α-l-arabinofuranose, and α-l-fucopyranose residues. Approximate molecular weights of polysaccharide extracts were determined by HPLC (high-performance liquid chromatography). The best antioxidant activity was found in M. procera polysaccharide extract in DPPH• (1,1-diphenyl-2-picrylhydrazyl) scavenging (39.03% at 800 μg/mL), CUPRAC (cupric reducing antioxidant capacity) (A0.50: 387.50 μg/mL), and PRAP (phosphomolybdenum reducing antioxidant power) (A0.50: 384.08 μg/mL) assays. C. truncatus polysaccharide extract showed the highest antioxidant activity in ABTS•+ scavenging (IC50: 734.09 μg/mL), β-carotene-linoleic acid (IC50: 472.16 μg/mL), and iron chelating (IC50: 180.35 μg/mL) assays. Significant anticancer activity was found in C. truncatus polysaccharide extract on HT-29 (IC50: 46.49 μg/mL) and HepG2 (IC50: 48.50 μg/mL) cell lines and H. pudorinus polysaccharide extract on the HeLa cell line (IC50: 51.64 μg/mL). Also, H. pudorinus polysaccharide extract possessed prominent AChE (acetylcholinesterase) inhibition activity (49.14% at 200 μg/mL).

Beech Mushroom (Hypsizygus marmoreus, Agaricomycetes) Cultivation and Outstanding Health-Promoting Properties: A Review

Currently, in many Asian and European countries, a group of mushrooms has been distinguished, which, due to their medicinal and/or dietary properties, are referred to as medicinal mushrooms. Hypsizygus marmoreus is a species valued for its proven nutritional and healing properties. In the scientific literature available so far, mainly from Asian countries, it is possible to find research on the therapeutic effect of H. marmoreus. Biologically active substances, their presence, and in particular, their level in this species have not been the subject of extensive research. The aim of the present review is to describe and summarize the dietary and therapeutic potential of this increasingly popular species among consumers in European countries. Because H. marmoreus is a species with known dietary and health-promoting properties, this species of wood fungi could be commonly obtained from cultivation in European countries.

Shiitake polysaccharides acted as a non-competitive inhibitor to α-glucosidase and inhibited glucose transport of digested starch from Caco-2 cells monolayer

The inhibition mechanism of shitake mushroom polysaccharides (Lentinula edodes polysaccharides, LEP) against α-glucosidase was studied by enzyme kinetic assay, fluorescence quenching and molecular docking. The effect of LEP on glucose transport of digested starch was investigated via an in vitro digestion/Caco-2 transwell model. LEP exhibited a stronger inhibiting effect (IC50 = 0.66 mg/mL) than acarbose and presented a non-competitive inhibition mechanism. The interaction between LEP and α-glucosidase primarily involved electrostatic interaction and hydrogen bonding. Molecular docking modelling showed that the four structures of LEP were bound to the allosteric tunnel or adjacent pocket of α-glucosidase via electrostatic force and hydrogen bonds. The (1 → 6)-linkages in LEP structures favoured its binding affinity to the α-glucosidase. The α-glucosidase inhibiting activity of LEP was also found to emanate from the reduction in glucose transport of digested starch as deducted from the in vitro digestion/Caco-2 transwell data. The release of glucose from digested starch cooked with LEP was significantly reduced (33.7%) compared to the digested starch without LEP. The findings from the current study suggest that LEP could be a promising ingredient to inhibit α-glucosidase activity as well as control the level of postprandial blood glucose when incorporated into starchy foods.

Structural characterization of cell-wall polysaccharides purified from chayote (Sechium edule) fruit

Chayote (Sechium edule), an underutilized cucurbit vegetable crop, has gained attention as it exhibits health-promoting properties. However, the primary structure of chayote cell-wall polysaccharides has not been comprehensively studied. In this study, two cell-wall polysaccharides, CP-1 (41.1 KDa) and CP-2 (15.6 KDa), were extracted from chayote, and the structural analysis of CP-1 and CP-2 was carried out by monosaccharide composition analysis, Fourier transform infrared spectroscopy (FTIR), methylation analysis, and nuclear magnetic resonance spectroscopy (NMR). The results demonstrated that CP-1 was a galactan, and CP-2 was an anionic heteropolysaccharide composed of galacturonic acid, galactose, arabinose, rhamnose, glucose, glucuronic acid, mannose, and xylose in the molar ratio of 31.2:26.3:24.9:7.4:6.5:1.9:1.3:0.5. CP-2 has a backbone of → 4)-β-d-Galp-(1 → 3,6)-β-d-Galp-(1 → 3)-β-d-Galp-(1 → 4)-α-d-GalpA-(1→, with branches at O-6 of → 3,6)-β-d-Galp-(1→, consisting of α-l-Araf-(1 → 5)-α-l-Araf-(1 → 4)-β-d-Glcp-(1 →. Analysis of the structural and physicochemical properties confirmed the excellent application characteristics of CP-1 and CP-2. Hence, cell-wall polysaccharides of chayote could be used as new polysaccharides materials.

Preparation, structural characterization and neuroprotective effects to against H2O2-induced oxidative damage in PC12 cells of polysaccharides from Pleurotus ostreatus

Pleurotus ostreatus is one of the most common edible and medicinal fungi in life, and its polysaccharide has been a hot research topic in recent years. In this paper, a new intracellular polysaccharide component named P. ostreatus polysaccharide (POP-W) was obtained from the mycelium of P. ostreatus, and its structure was analyzed. The results showed that its molecular weight was Mw = 3.034 × 10³ kDa, and it did not contain protein and nucleic acid. POP-W was composed of mannose, glucose, galactose and xylose in a molar ratio of 40.34:47.60:7.97:4.09. The backbone of POP-W was α-D-Glcp(1→,→3,4)-α-D-Glcp(1→, →3,4)-α-D-Manp(1→,→3)-α -D-Galp(1→, →4)-α-D-Glcp(1→, →3)-α-D-Glcp(1→, →2)-β-D-Manp(1→, →4) -β-D-Xylp(1 →. SEM and TGA analysis showed the structure of POP-W and good thermal stability. In addition, POP-W showed significant antioxidant activity in vitro. More importantly, POP-W protected PC12 cells induced by H₂O₂ by inhibiting the contents of lactate dehydrogenase (LDH) and malondialdehyde (MDA) and increasing the levels of superoxide dismutase (SOD) and reduced glutathione (GSH). Western blot detection of Caspase-3, BAX, Bcl-2, PI3K/Akt protein expression. The results showed that POP-W inhibited the expression of caspase-3 and BAX, while promoting the expression of Bcl-2. In addition, POP-W can also promote the phosphorylation of Akt. In conclusion, POP-W pretreatment can protect PC12 cells from H₂O₂-induced oxidative damage through PI3K/Akt signaling pathway and regulation of apoptosis-related pathway proteins. It provided a theoretical basis for the practical application of the polysaccharide of P. ostreatus in production.

Isolation, Structural Characterization, and Biological Activity of the Two Acidic Polysaccharides from the Fruits of the Elaeagnus angustifolia Linnaeus

Elaeagnus angustifolia Linnaeus is a medicinal plant and its fruit has pharmacological activity such as antiinflammatory, antiedema, antinociceptive, and muscle relaxant functions, etc. Two acidic homogeneous polysaccharides (EAP-H-a1 and EAP-H-a2) were isolated from the fruits of Elaeagnus angustifolia L. through DEAE-52 and Sephadex G-75 column chromatography, and the physicochemical, structural properties, and biological activities of the polysaccharides were investigated. Both EAP-H-a1 and EAP-H-a2 were composed of Rha, Ara, Xyl, Glc, and Gal with the molar ratios of 13.7:20.5:23.3:8.8:33.4 and 24.8:19.7:8.2:8.4:38.6, respectively, and with the molecular weights of 705.796 kDa and 439.852 kDa, respectively. The results obtained from Fourier transform infrared spectroscopy (FTIR) confirmed the polysaccharide nature of the isolated substances. Congo red assay confirmed the existence of a triple-helix structure. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis revealed that EAP-H-a1 and EAP-H-a2 had irregular fibrous, filament-like surfaces; and both had crystalline and amorphous structures. Bioactivity analysis showed that the crude polysaccharide, EAP-H-a1, and EAP-H-a2 had clear DPPH and ABTS free radical scavenging activity, and could promote the secretion of NO and the phagocytic activities of RAW 264.7 and THP cells, which showed clear antioxidant and immuno-regulatory activity. These results indicated that Elaeagnus angustifolia L fruit acidic polysaccharides may have potential value in the pharmaceutical and functional food industries.

Structure and antioxidant activity of six mushroom-derived heterogalactans

Heterogalactans with weight-average molecular weights ~20 kDa were purified from several species of mushroom: Hypsizygus marmoreus, Pleurotus ostreatus, Pholiota nameko, Agrocybe cylindracea, Hygrophorus lucorum and Hericium erinaceus, and structurally characterized and assessed for antioxidant activity in vitro. Methylation analysis, combined with NMR spectral analysis, indicates that these glycans have a common backbone composed of (1 → 6)-linked-α-D-galactopyranosyl residues that are substituted at O-2. The (1 → 6)-α-D-galactans, branched primarily with β-D-mannopyranosyl (Manp) or α-L-fucopyranosyl (Fucp) residues, have been assigned to mannogalactans or fucogalactans, respectively, as well as to β-D-Manp and α-L-Fucp residues attached in tandem to the main chain as fucomannogalactans. In addition, 3-O-methylated-α-D-galactopyranosyl (3-O-Me-Galp) residues within the mannogalactan chains, exhibit strong reducing power and radical scavenging activity suggesting that this sugar moiety functions as an antioxidant. Our results provide important structural information on mushroom heterogalactans and prompt further investigations into their structure-activity relationships.

Structural characterization of a novel polysaccharide from sweet corncob that inhibits glycosylase in STZ-induced diabetic rats : Structural characterization of a novel polysaccharide

In the current study, we extracted a polysaccharide from sweet corncob and evaluated its hypoglycemic function. After collection in water, alcohol precipitation, and purification by DEAE-52 and Sephadex G-100 columns, we obtained a polysaccharide (SCP50) that was composed primarily of mannose and glucose (9.73:190.27), with a molecular weight of 9280.33 Da. We demonstrated that SCP50 exhibited significant inhibition of α-glucosidase activity, with an IC50 of 4.866 mg/mL, K_m of 1.297 × 10^-3, and V_max of 0.076 mol/L·min^-1 in vitro. We also observed that SCP50 markedly attenuated disaccharidase (maltase, sucrase, and lactase) activity in a rat model of T2DM. We conclude that SCP50 exerts a hypoglycemic effect via inhibition of intestinal glycosylase. These results thus provide new insight into the hypoglycemic action underlying sweet corncob polysaccharide's effects.

Medicinal Components in Edible Mushrooms on Diabetes Mellitus Treatment

Mushrooms belong to the family “Fungi” and became famous for their medicinal properties and easy accessibility all over the world. Because of its pharmaceutical properties, including anti-diabetic, anti-inflammatory, anti-cancer, and antioxidant properties, it became a hot topic among scientists. However, depending on species and varieties, most of the medicinal properties became indistinct. With this interest, an attempt has been made to scrutinize the role of edible mushrooms (EM) in diabetes mellitus treatment. A systematic contemporary literature review has been carried out from all records such as Science Direct, PubMed, Embase, and Google Scholar with an aim to represents the work has performed on mushrooms focuses on diabetes, insulin resistance (IR), and preventive mechanism of IR, using different kinds of mushroom extracts. The final review represents that EM plays an important role in anticipation of insulin resistance with the help of active compounds, i.e., polysaccharide, vitamin D, and signifies α-glucosidase or α-amylase preventive activities. Although most of the mechanism is not clear yet, many varieties of mushrooms’ medicinal properties have not been studied properly. So, in the future, further investigation is needed on edible medicinal mushrooms to overcome the research gap to use its clinical potential to prevent non-communicable diseases.