A β-d-glucan isolated from the fruiting bodies of Hericium erinaceus and its aqueous conformation

Methods of study on conformation of polysaccharides from natural products: A review

Polysaccharides from natural products play multiple roles and have extensive bioactivities in life process. Bioactivities of polysaccharides (e.g., Lentinan, Schizophyllan, Scleroglucan, Curdlan, Cinerean) have a close relation to their chain conformation. Compared to other types of polysaccharides, the conformation of β-glucan has been studied more. The major research methods of conformation of polysaccharides from natural products (Congo red experiment, circular dichroism spectrum, viscosity method, light scattering method, size exclusion chromatography, atomic force microscope), corresponding experimental schemes, and the external factors affecting polysaccharide conformation were reviewed in this paper. These research methods of conformation have been widely used, among which Congo red experiment and viscosity method are the most convenient ones to study the morphological changes of polysaccharide chains.

Antioxidant Activities and Prebiotic Activities of Water-Soluble, Alkali-Soluble Polysaccharides Extracted from the Fruiting Bodies of the Fungus Hericium erinaceus

In this study, the digestion and fermentation properties of the bioactive water-soluble polysaccharide (HEP-W), and alkali-soluble polysaccharide (HEP-A) from Hericium erinaceus and the impact on the human colonic microbiota were determined using simulated saliva-gastrointestinal digestion and human fecal fermentation models in vitro. The basic physicochemical properties of HEP-W and HEP-A were determined at the same time. The results showed that the in vitro simulated digestion had almost no effect on the physicochemical properties of HEP-W and HEP-A, indicating that HEP-W and HEP-A were partially degraded. During fermentation, HEP-W and HEP-A increased the relative abundance of the dominant butyric acid-producing genera, the microbial community structure was significantly regulated, the gas production and short-chain fatty acid production in the fermentation broth were significantly increased, and the pH of the fermentation broth was reduced. There were structural and other differences in HEP-W and HEP-A due to different extraction methods, which resulted in different results. These results suggest that HEP-W and HEP-A may be potential gut microbial manipulators to promote gut health by promoting the production of beneficial metabolites by intestinal microorganisms using different butyric acid production pathways.

A Review on the Structure and Anti-Diabetic (Type 2) Functions of β-Glucans

Type 2 diabetes, a long-term chronic metabolic disease, causes severe and increasing economic and health problems globally. There is growing evidence that β-glucans can function as bioactive macromolecules that help control type 2 diabetes with minimal side effects. However, conflicting conclusions about the antidiabetic activities of β-glucans have been published, potentially resulting from incomplete understanding of their precise structural characteristics. This review aims to increase clarity on the structure-function relationships of β-glucans in treating type 2 diabetes by examining detailed structural and conformational features of naturally derived β-glucans, as well as both chemical and instrumental methods used in their characterization, and their underlying anti-diabetic mechanisms. This may help to uncover additional structure and function relationships and to expand applications of β-glucans.

A novel polysaccharide from Hericium erinaceus: Preparation, structural characteristics, thermal stabilities, and antioxidant activities in vitro

A novel polysaccharide fraction (HEP) from Hericium erinaceus was successively isolated and purified in the present study. We researched its structure and thermal stabilities, and further studied its antioxidant activities in vitro. The results showed that HEP was an acid heteropolysaccharide, with an average molecular weight of approximately 19.7 kDa by high-performance gel permeation chromatography. Ion chromatography indicated that HEP was mainly composed of fucose:galactose:glucose:mannose:gluconic acid (Fuc:Gal:Glu:Man:GlcA) in a molar ratio of 1:2.87:0.09:0.12:0.01. Additionally, Fourier-transformed infrared and NMR spectroscopy further demonstrated that HEP was a pyranose containing α-configuration, mainly consisting of α-1-4-Fuc and α-1-6-Gal as the main chain, with →3,6)-α-D-Man-(1→and→1,6)-Glc was branched, with α-D-GlcpA-(1 as T-terminal. The specific rotation of HEP was +55°; by the differential scanning calorimetry and the thermal stability measurement of thermogravimetric analysis for HEP showed that the pyrolysis process of HEP was mainly divided into two processes, and its melting point was 75.93℃. In vitro anti-oxidation experiments showed that HEP had a certain ability to scavenge DPPH, hydroxyl, superoxide anion, and ABTS radicals. It was found that HEP had a strong ability to scavenge DPPH-free radicals, and the highest scavenging rate could reach 91.72% ± 0.17%, which was basically equivalent to the scavenging ability of Vitamin C (Vc). Therefore, it was revealed that HEP might be used as a natural antioxidant component. PRACTICAL APPLICATIONS: A novel polysaccharide (HEP) had a potent activity possibly due to its monosaccharide composition, sugar residues, and physicochemical properties. This research proved the potential of HEP in anti-oxidation and provided the possibility of developing new natural anti-oxidation products.

Enzymatic-fingerprinting workflow of polysaccharides in Hericium erinaceus fruiting bodies: From HILIC-ESI--MS screening to targeted MIM profiling

In this study, an uncommon enzymatic-fingerprinting workflow, was proposed for characterization and discrimination of mushroom polysaccharides (MPs) by hydrophilic interaction liquid chromatography-negative electrospray mass spectrometry (HILIC-ESI^--MS). Firstly, the HILIC-ESI^--MS was used to screen and identify the enzymatic digestion products of MPs using HILIC-Orbitrap based on full scan and MS/MS modes. Secondly, a targeted structural-fingerprinting of polysaccharides (SFP) was built in a multiple-ion monitoring (MIM) mode using the same HILIC separation with a triple quadrupole MS. Thirdly, a case study of polysaccharides in Hericium erinaceus fruiting bodies (HEP) was performed to obtain the expected SFP based on dextranase digestion that allows for visual discrimination of polysaccharides from other five edible mushrooms attributed to Agrocybe cylindracea, Arimillaria mellea, Flammulina velutipes, Pleurotus eryngii, and Lentinula edodes. Furthermore, a major structural backbone of HEP was unveiled by occurrence of → ⁶(Hex)¹ → along with multiple possible substitutions including of terminal GalA, Fuc, acetyl, → ⁴Hex¹ →, and → ³Hex¹ →. Finally, the similarity analysis, hierarchical cluster analysis (HCA), and partial least squares discriminant analysis (PLS-DA) were performed to visualize various MPs. As a result, the enzymatic-fingerprinting workflow presents an effective example for quality evaluation of fungi polysaccharides using a SFP strategy.

Structural characterization and immunostimulatory activity of a novel polysaccharide isolated with subcritical water from Sagittaria sagittifolia L

In the present study, we obtained polysaccharides from Sagittaria sagittifolia L. (SSP) with subcritical water extraction (SWE). Two water-soluble polysaccharides (SSP-W1 and SSP-S1) from the acquired SSP were isolated with DEAE-52 and Sephadex G-100. Besides, the structural characteristics and immunostimulatory activity were also investigated. The results showed that both SSP-W1 and SSP-S1 were homogeneous polysaccharides and the molecular weight was 62.03 KDa and 15.2 KDa, respectively. In addition, both SSP-W1 and SSP-S1 are heteropolysaccharides. Moreover, FT-IR analysis showed that SSP-W1 was α-pyranose polysaccharide, while SSP-S1 was a typical β-pyranose polysaccharide. Congo red staining showed that there was no triple helix structure in both SSP-W1 and SSP-S1. Furthermore, both SSP-W1 and SSP-S1 could promote the proliferation, production of NO, and secretion of TNF-α and IL-10 of macrophages RAW 264.7, significantly. Therefore, the polysaccharides extracted from Sagittaria sagittifolia L. with SWE have the potential to be used as immunoreactive agent in medicine and functional foods.

Structural Properties and Macrophage Activation of Cell Wall Polysaccharides from the Fruiting Bodies of Hericium erinaceus

In this study, water-soluble and alkali-soluble cell wall polysaccharides were obtained from fruiting body extracted residual micropowders of Hericium erinaceus, harvested at seven different growing stages. The structural properties and in vitro immunity activities of cell wall polysaccharides extracted successively by hot water and sodium hydroxide solution were studied, and the results indicated that the yield and content of polysaccharides increased during the reproductive growth stage and decreased with the maturity of the fruiting body. Water-soluble cell wall polysaccharides mainly composed of glucose and galactose at a molar ratio of 3.4⁻14:1.0, and also contained a small ratio of glucuronic acid. The alkali-soluble cell wall polysaccharides were glucans with lower molecular weight and higher macrophage activation activity in vitro than water-soluble ones. Our findings suggest that the growth stages (H4 and H5) are suitable for harvesting H. erinaceus fruiting bodies with higher cell wall polysaccharide yield and functional benefits.

Proteome analysis provides insight into the regulation of bioactive metabolites in Hericium erinaceus

BACKGROUND

Hericium erinaceus, a famous edible mushroom, is also a well-known traditional medicinal fungus. To date, a large number of bioactive metabolites with antitumor, antibacterial, and immune-boosting effects were isolated from the free-living mycelium and fruiting body of H. erinaceus.

OBJECTIVE

Here we used the proteomic approach to explore proteins involved in the regulation of bioactive metabolites, including terpenoid, polyketide, sterol and etc. RESULTS: Using mass spectrometry, a total of 2543 unique proteins were identified using H. erinaceus genome, of which 2449, 1855, 1533 and 690 proteins were successfully annotated in Nr, KOG, KEGG and GO databases. Among them, 722 proteins were differentially expressed (528 up- and 194 down-regulated) in fruiting body compared with mycelium. Most of differentially expressed proteins were putatively involved in energy metabolism, molecular signaling, and secondary metabolism. Additionally, numerous proteins involved in terpenoid, polyketide, and sterol biosynthesis were identified. Our data revealed that proteins involved in polyketide biosynthesis were up-regulated in the fruiting body, while some proteins in mevalonate (MEP) pathway from terpenoid biosynthesis were generally up-regulated in mycelium.

CONCLUSIONS

The present study suggested that the differential regulation of biosynthesis genes could produce various bioactive metabolites with pharmacological effects in H. erinaceus.

Immunomodulatory effects of Hericium erinaceus derived polysaccharides are mediated by intestinal immunology

This study was aimed at investigating the immunomodulating activity of Hericium erinaceus polysaccharide (HEP) in mice, by assessing splenic lymphocyte proliferation (cell-mediated immunity), serum hemolysin levels (humoral immunity), phagocytic capacity of peritoneal cavity phagocytes (macrophage phagocytosis), and NK cell activity. ELISA of immunoglobulin A (SIgA) in the lamina propria, and western blotting of small intestinal proteins were also performed to gain insight into the mechanism by which HEP affects the intestinal immune system. Here, we report that HEP improves immune function by functionally enhancing cell-mediated and humoral immunity, macrophage phagocytosis, and NK cell activity. In addition, HEP was found to upregulate the secretion of SIgA and activate the MAPK and AKT cellular signaling pathways in the intestine. In conclusion, all these results allow us to postulate that the immunomodulatory effects of HEP are most likely attributed to the effective regulation of intestinal mucosal immune activity.

The structure of mushroom polysaccharides and their beneficial role in health

Mushroom is a kind of fungus that has been popular for its special flavour and renowned biological values. The polysaccharide contained in mushroom is regarded as one of the primary bioactive constituents and is beneficial for health. The structural features and bioactivities of mushroom polysaccharides have been studied extensively. It is believed that the diverse biological bioactivities of polysaccharides are closely related to their structure or conformation properties. In this review, the structural characteristics, conformational features and bioactivities of several mushroom polysaccharides are summarized, and their beneficial mechanisms and the relationships between their structure and bioactivities are also discussed.

Isolation and identification of phytochemicals and biological activities of Hericium ernaceus and their contents in Hericium strains using HPLC/UV analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Hericium ernaceus has been traditionally used for the treatment of dyspepsia, gastric ulcer and enervation in traditional Chinese medicine for a long time.

AIM OF THE STUDY

To examine the effect of Hericium strains on their ability to inhibit LPS and interferon-γ induced NO production in cell culture and the bioassay correlation of hericenone C, D, F, isolated from H. ernaceus.

MATERIALS AND METHODS

Hericenone C, D, F were isolated from H. ernaceus by open column chromatography and identified on the basis of spectroscopic analyses including (1)H NMR, (13)C NMR and MS. The amounts of hericenone C, D, and F in Hericium strains were determined by HPLC/UV analysis. In order to investigate the anti-inflammatory effect of Hericium strains extracts, RAW 264.7 cells were treated with 200μg/mL of Hericium strains extracts for 48h. Cell growth was assessed by MTT assay.

RESULTS

Phytochemical constituents were isolated from H. ernaceus by open column chromatography. Their structures were elucidated as hericenones C, D, and F on the basis of spectroscopic analyses including (1)H NMR, (13)C NMR and MS. The amounts of hericenones C, D, and F in Hericium strains were determined by HPLC/UV analysis. Hericenones C, D, and F contents were highest in Norugungdenglee-2 (8.289±0.593mg/g), KFRI-1453 (4.657±0.462mg/g), and KFRI-1093 (5.408±0.420mg/g) strains, respectively. All Hericium strains extracts tested inhibited the lipopolysaccharide- and interferon-γ-induced inflammatory activity of RAW264.7 cells. The strain KFRI-1093 about 39.6% reduced NO generation with compared to control.

CONCLUSION

We believe that the anti-inflammatory effect of KFRI-1093 was due to hericenone F content. Our results contribute towards validation of the traditional use, natural drugs and health supplements. And also, the developed simple, accurate and rapid LC method can be used determinate the content of hericenones from other Hericium strains.

Detoxification of Olive Mill Wastewater and Bioconversion of Olive Crop Residues into High-Value-Added Biomass by the Choice Edible Mushroom Hericium erinaceus

Environmentally acceptable disposal of olive cultivation residues (e.g., olive prunings; olive pruning residues (OLPR)) and olive mill wastes is of paramount importance since they are generated in huge quantities within a short time. Moreover, olive mill wastewater (OMW) or sludge-like effluents ("alperujo"; two-phase olive mill waste (TPOMW)) are highly biotoxic. Hericium erinaceus is a white-rot fungus which produces choice edible mushrooms on substrates rich in lignocellulosics, and its suitability for the treatment of olive by-products was examined for the first time. Fungal growth resulted in a notable reduction of OMW's pollution parameters (i.e., 65 % decolorization, 47 % total phenolic reduction, and 52 % phytotoxicity decrease) and correlated with laccase and manganese peroxidase activities. Solid-state fermentation of various mixtures of OLPR, TPOMW, and beech sawdust (control) by H. erinaceus qualified OLPR in subsequent cultivation experiments, where it exhibited high mushroom yields and biological efficiency (31 %). Analyses of proximate composition and bioactive compound content revealed that mushrooms deriving from OLPR substrates showed significantly higher crude fat, total glucan, β-glucan, total phenolics, and ferric-reducing antioxidant potential values than the control. H. erinaceus demonstrated the potential to detoxify OMW and bioconvert OLPR into high-quality biomass, and hence, this fungus could be successfully exploited for the treatment of such by-products.

Structure elucidation of a bioactive polysaccharide from fruiting bodies of Hericium erinaceus in different maturation stages

HPB-3, a heteropolysaccharide, with a mean molecular weight of 1.5×10(4)Da, was obtained from the maturating-stage IV, V and VI fruiting body of Hericium erinaceus, exhibited higher macrophages stimulation activities, was able to upregulate the functional events mediated by activated macrophages, such as production of nitric oxide (NO). Monosaccharide composition analysis showed that HPB-3 comprised l-fucose, d-galactose and d-glucose in the ratio of 5.2:23.9:1. Its chemical structure was characterized by sugar and methylation analysis, along with (1)H and (13)C NMR spectroscopy, including (1)H-(1)H COSY, TOCSY, NOESY, HMQC and HMBC experiments. The results indicated that HPB-3 contained a-(1/6)-linked galactopyranosyl backbone, partially with a side chain composed of α-l-fucopyranose at the O-2 position. The predicted primary structure of the polysaccharide was established as below.

A polysaccharide from cultured mycelium of Hericium erinaceus and its anti-chronic atrophic gastritis activity

A polysaccharide named EP-1 was found by screening cultured mycelium of Hericium erinaceus, which was extracted and subjected to precipitation with ethanol, hollow-fiber ultrafiltration and ion-exchange chromatography. The polysaccharide has a molecular weight of approximately 3100Da and is composed of glucose, mannose and galactose, thus being a heteroglycan. EP-1 has a backbone of α-d-Glc(1→3) and β-d-Glc(1→3). The β-d-Glc(1→3) and α-d-Gal-(1→3) were regarded as branches attached to the C-4 position. The α-d-Man was regarded as a terminal residue. The anti-CAG activity was evaluated in experimental systems using a cell model for identification. The polysaccharide significantly inhibited the growth of MC cells obtained from human gastric mucosa epithelium (GES-1) cells transformed by MNNG, which were used as a chronic atrophic gastritis cell model. It also interfered with the MC cells by inducing cell cycle arrest. Thus, EP-1 shows potential for the development of new functional foods and drugs.

Chemistry, Nutrition, and Health-Promoting Properties of Hericium erinaceus (Lion's Mane) Mushroom Fruiting Bodies and Mycelia and Their Bioactive Compounds

The culinary and medicinal mushroom Hericium erinaceus is widely consumed in Asian countries, but apparently not in the United States, for its nutritional and health benefits. To stimulate broader interest in the reported beneficial properties, this overview surveys and consolidates the widely scattered literature on the chemistry (isolation and structural characterization) of polysaccharides and secondary metabolites such as erinacines, hericerins, hericenones, resorcinols, steroids, mono- and diterpenes, and volatile aroma compounds, nutritional composition, food and industrial uses, and exceptional nutritional and health-promoting aspects of H. erinaceus. The reported health-promoting properties of the mushroom fruit bodies, mycelia, and bioactive pure compounds include antibiotic, anticarcinogenic, antidiabetic, antifatigue, antihypertensive, antihyperlipodemic, antisenescence, cardioprotective, hepatoprotective, nephroprotective, and neuroprotective properties and improvement of anxiety, cognitive function, and depression. The described anti-inflammatory, antioxidative, and immunostimulating properties in cells, animals, and humans seem to be responsible for the multiple health-promoting properties. A wide range of research advances and techniques are described and evaluated. The collated information and suggestion for further research might facilitate and guide further studies to optimize the use of the whole mushrooms and about 70 characterized actual and potential bioactive secondary metabolites to help prevent or treat human chronic, cognitive, and neurological diseases.

Medicinal properties of Hericium erinaceus and its potential to formulate novel mushroom-based pharmaceuticals

Hericium erinaceus is an important mushroom with edible values and medicinal properties. Both the mycelium and the fruiting bodies contain many bioactive compounds with drug efficacy. Recent evidence demonstrates that it is helpful to various diseases, such as Alzheimer's disease, immunoregulatory, and many types of cancer. Furthermore, emerging pieces of evidence have shown that different active molecules in H. erinaceus have different functions on different organs in different diseases via the different mechanisms. Drawing on current research results, this review mainly focuses on the therapeutic effects of H. erinaceus on various diseases of multiple physiological systems, including the nervous system, digestive system, circulatory system, and immune system. This paper also discusses systematically the efficient protection of H. erinaceus against the diseases from the intricate experimental proofs by using the systematic viewpoints, which provides a framework for future research directions.

A RG-II type polysaccharide purified from Aconitum coreanum alleviates lipopolysaccharide-induced inflammation by inhibiting the NF-κB signal pathway

Korean mondshood root polysaccharides (KMPS) isolated from the root of Aconitum coreanum (Lévl.) Rapaics have shown anti-inflammatory activity, which is strongly influenced by their chemical structures and chain conformations. However, the mechanisms of the anti-inflammatory effect by these polysaccharides have yet to be elucidated. A RG-II polysaccharide (KMPS-2E, Mw 84.8 kDa) was isolated from KMPS and its chemical structure was characterized by FT-IR and NMR spectroscopy, gas chromatography-mass spectrometry and high-performance liquid chromatography. The backbone of KMPS-2E consisted of units of [→6) -β-D-Galp (1→3)-β-L-Rhap-(1→4)-β-D-GalpA-(1→3)-β-D-Galp-(1→] with the side chain →5)-β-D-Arap (1→3, 5)-β-D-Arap (1→ attached to the backbone through O-4 of (1→3,4)-L-Rhap. T-β-D-Galp is attached to the backbone through O-6 of (1→3,6)-β-D-Galp residues and T-β-D-Ara is connected to the end group of each chain. The anti-inflammatory effects of KMPS-2E and the underlying mechanisms using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and carrageenan-induced hind paw edema were investigated. KMPS-2E (50, 100 and 200 µg/mL) inhibits iNOS, TLR4, phospho-NF-κB-p65 expression, phosphor-IKK, phosphor-IκB-α expression as well as the degradation of IκB-α and the gene expression of inflammatory cytokines (TNF-α, IL-1β, iNOS and IL-6) mediated by the NF-κB signal pathways in macrophages. KMPS-2E also inhibited LPS-induced activation of NF-κB as assayed by electrophorectic mobility shift assay (EMSA) in a dose-dependent manner and it reduced NF-κB DNA binding affinity by 62.1% at 200 µg/mL. In rats, KMPS-2E (200 mg/kg) can significantly inhibit carrageenan-induced paw edema as ibuprofen (200 mg/kg) within 3 h after a single oral dose. The results indicate that KMPS-2E is a promising herb-derived drug against acute inflammation.

Hericium erinaceus (Yamabushitake): a unique resource for developing functional foods and medicines

This article provides valuable scientific information for Hericium erinaceus and shows its potential for the development of new functional foods and drugs.

Src kinase-targeted anti-inflammatory activity of davallialactone from Inonotus xeranticus in lipopolysaccharide-activated RAW264.7 cells

BACKGROUND AND PURPOSE

Mushrooms are popular both as food and as a source of natural compounds of biopharmaceutical interest. Some mushroom-derived compounds such as beta-glucan have been shown to be immunostimulatory; this study explores the anti-inflammatory properties of hispidin analogues derived from the mushroom, Inonotus xeranticus. We sought to identify the molecular mechanism of action of these hispidin analogues by determining their effects on lipopolysaccharide (LPS)-mediated inflammatory responses in a macrophage cell line.

EXPERIMENTAL APPROACH

The production of inflammatory mediators was determined by Griess assay, reverse transcription-PCR and ELISA. The inhibitory effect of davalliactone on LPS-induced activation of signalling cascades was assessed by western blotting, immunoprecipitation and direct kinase assay.

KEY RESULTS

In activated RAW264.7 cells, davallialactone strongly downregulated LPS-mediated inflammatory responses, including NO production, prostaglandin E2 release, expression of proinflammatory cytokine genes and cell surface expression of co-stimulatory molecules. Davallialactone treatment did not alter cell viability or morphology. Davallialactone was found to exert its anti-inflammatory effects by inhibiting a signalling cascade that activates nuclear factor kappa B via PI3K, Akt and IKK, but not mitogen-activated protein kinases. Treatment with davallialactone affected the phosphorylation of these signalling proteins, but not their level of expression. These inhibitory effects were not due to the interruption of toll-like receptor 4 binding to CD14. In particular, davallialactone strongly inhibited the LPS-induced phosphorylation and kinase activity of Src, implying that Src may be a potential pharmacological target of davallialactone.

CONCLUSIONS AND IMPLICATIONS

Our data suggest that davallialactone, a small molecule found in edible mushrooms, has anti-inflammatory activity. Davallialactone can be developed as a pharmaceutically valuable anti-Src kinase agent.