Structures, biological activities, and industrial applications of the polysaccharides from Hericium erinaceus (Lion’s Mane) mushroom: A review

Effects of Exidia yadongensis polysaccharide as emulsifier on the stability, aroma, and antioxidant activities of fat-free stirred mango buffalo yogurt

Because of the poor stability and rheological properties of fat-free stirred yogurt fortified with fruit pulp, new functional polysaccharides as a natural emulsifier, which can increase viscosity in the aqueous phase, may be needed. This study aimed to evaluate the effects of Exidia yadongensis polysaccharide (EYP) as emulsifier on the stability, aroma, and antioxidant activities of mango buffalo yogurt at 4 °C for 25 days. The yogurt with 15 g/L EYP gave a higher content of 215 g/L total solids, 11.3 g/L exopolysaccharides, 0.10 g/L total polyphenols, 630.5 g/L water-holding capacity, and 11.43 g/kg total free amino acids, and maintained better texture, DPPH scavenging activity of 54.05 % and OH scavenging rates of 67.16 %. Moreover, the EYP exhibited the expected ability to weaken postacidification, syneresis, and growth of microorganism, and greatly promote the textural, rheological properties, suspension stability, microstructure, and aroma profiles of stirred mango-flavored buffalo yogurt (p < 0.05). In addition, the addition of 15 g/L EYP can inhibit protein degradation and improve the stability of secondary structure of the protein complex in mango yogurt during 25 days of storage. Therefore, EYP (15 g/L) could be used as natural positive functional factors and emulsifiers in such fat-free stirred yogurt industry.

Polysaccharide from Hericium erinaceus improved laying performance of aged hens by promoting yolk precursor synthesis and follicle development via liver-blood-ovary axis

Little information is available on the effect of Hericium erinaceus polysaccharides (HEP) on laying hens, especially on improving liver and ovarian health and function. Therefore, this study was conducted to investigate the impacts of HEP on liver and ovarian function to delay the decline in the laying performance of aged hens. A total of 360 fifty-eight-wk-old laying hens were randomly allocated to 4 treatments, with 6 replicates of 15 birds each. After 2 wk of adaptation, the birds were fed basal diet (CON) or basal diets supplemented with 250, 500, and 750 mg/kg of HEP (HEP250, HEP500, and HEP 750, respectively) for 12 wk. The results showed that, compared with CON, hens fed HEP had significantly increased laying performance (P < 0.05) and promoted follicle development, as evidenced by the increased numbers of hierarchical follicles, small follicles, and total follicles (P < 0.05). Birds fed 500 mg/kg of HEP improved the liver function by increasing T-AOC activity (P < 0.05) and decreasing hepatic oxidative stress and inflammatory responses (inflammatory cell infiltration) caused by aging. The lipid metabolism was improved, and yolk precursor synthesis was promoted in the liver of HEP-treated laying hens by upregulating the mRNA expression of FAS, MTTP, PPAR-α, APOVLDL-Ⅱ, and VTG-Ⅱ (P < 0.05). In addition, HEP significantly decreased ovarian inflammation by regulating the mRNA levels of NF-κB, IL-1β, IL-6, and TNF-α (P < 0.05). As a result, the contents of E2, LH, and FSH in serum and the gene expression of ERα of the liver and FSHR of the ovary increased in HEP-treated hens (P < 0.05). In conclusion, dietary HEP supplementation exhibited potential hepatic and ovarian protective effects, thereby increasing the laying performance of aged hens by enhancing reproductive hormone secretion hormone secretion and promoting yolk precursor synthesis and follicle development via the liver-blood-ovary axis. The optimal supplementation level of HEP in aged hens was 500 mg/kg.

β(1,3) β(1,6) glucogalactan from Rhizopus microsporus var. oligosporus: extraction, characterization, antioxidant and α-amylase inhibitory activities

In this study, the Box-Behnken experimental planning was used to optimize the extraction of polysaccharides from the cell wall of Rhizopus microspore var. oligosporus, with analysis of the quantitative effects of parameters pH, temperature and extraction time for polysaccharide yield. The optimal conditions for extraction were determined by the regression equation and evaluation of the response surface graphs, which indicated: pH 13, temperature of 120ºC and time of 60 min, with maximum yield around 18.5%. Fourier transform infrared spectroscopy analysis indicated typical polysaccharide signals. Nuclear magnetic resonance spectroscopy and monosaccharide analysis indicated a β(1,3) β(1,6) glucogalactan. The polysaccharide exhibited an average molecular weight of 120 kDa and a polymerization degree of 741. Antioxidant assays in vitro revealed the potential of polysaccharide in elimination of ABTS+ radical and hydroxyl radicals. EC50 values for free radical elimination were 7.69 and 17.8 mg/mL, for ABTS+ and hydroxyls, respectively. The polysaccharides showed potential for α-amylase inhibition with an EC50 of 1.66 mg/mL. The results suggest that β(1,3) β(1,6) glucogalactan from Rhizopus microsporus var. oligosporus can be used in biotechnological applications.

Isolation and Evaluation of Erinacine A Contents in Mycelia of Hericium erinaceus Strains

Hericium erinaceus has long been favored for its remarkable nutritional and health-promoting benefits, and erinacine A is the key component responsible for the neuroprotective properties of H. erinaceus. Establishing an efficient method for separating erinacine A from H. erinaceus and screening the erinacine A-enriched strains is crucial to maximizing its benefits. Herein, we first reported that high-speed counter current chromatography (HSCCC) is an effective method for separating high-purity erinacine A. Using a two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (4.5:5:4.5:5, v/v/v/v), erinacine A with a purity of over 95% was separated. Then, we evaluated the content and yield of erinacine A in the liquid-fermented mycelia of Hericium germplasms. Both the content and yield of erinacine A varied greatly among the surveyed strains. The significant effect of the strain on the erinacine A content and yield was revealed by an analysis of variance. The highest erinacine A content and yield were observed in the mycelia of a wild strain HeG, reaching 42.16 mg/g and 358.78 mg/L, which is superior to the current highest outcomes achieved using submerged cultivation. The isolation method established and the strains screened in this study can be beneficial for the scaling up of erinacine A extraction and nutraceutical development to industrial levels.

Review on active components and mechanism of natural product polysaccharides against gastric carcinoma

One of the malignant tumors with a high occurrence rate worldwide is gastric carcinoma, which is an epithelial malignant tumor emerging from the stomach. Natural product polysaccharides are a kind of natural macromolecular polymers, which have the functions of regulating immunity, anti-oxidation, anti-fatigue, hypoglycemia, etc. Natural polysaccharides have remarkable effectiveness in preventing the onset, according to studies, and development of gastric cancer at both cellular and animal levels. This paper summarizes the inhibitory mechanisms and therapeutic significance of plant polysaccharides, fungi polysaccharides, and algal polysaccharides in natural product polysaccharides on the occurrence and development of gastric cancer in recent years, providing a theoretical basis for the research, development, and medicinal value of polysaccharides.

Extraction, purification, structural characteristics and biological properties of the polysaccharides from Armillaria mellea (Vahl) P. Kumm.: A review

Armillaria mellea (Vahl) P. Kumm. is a well-known homoeopathic plant with medicinal and culinary uses. Modern phytochemical researchers have successfully extracted and purified over 40 types of A. mellea polysaccharides (AMPs) from the fruiting bodies, hyphae and fermentation broth of A. mellea, and some of them have been analyzed and identified by their chemical structures. The impressive biological activity of these polysaccharides has been recognized by scientists worldwide. Many studies show that AMPs have remarkable antioxidant, anti-diabetic, anti-tumor, anti-inflammatory, immunoregulatory, hypolipidemic, thrombectomy, anti-aging, pulmonary protective, hepatic protective, anti-Alzheimer's properties, etc. However, the current understanding of the relationships between their chemical structure and biological activity, toxicological effects and pharmacokinetics remains limited. This article provides a systematic review of the research conducted over the past decades on the extraction and purification methods, structural characteristics, biological activity and mechanism of action of AMPs. The aim is to provide a research base that will benefit the future application of AMPs as therapeutic drugs and functional foods, and also provide insights for the further development of AMPs.

The ethnopharmacology, phytochemistry and pharmacology of the genus Hericium

ETHNOPHARMACOLOGICAL RELEVANCE

Mushrooms in the genus Hericium are used as functional food and traditional medicines for a long history in East Asian countries such as China, India, Japan, and Korea. Some species of Hericium are called as monkey head mushroom (Houtougu) in China and Yamabushitake in Japan, which are traditionally considered as rare and precious health promoting food and medicinal materials for the treatment of dyspepsia, insomnia, chronic gastritis, and digestive tract tumors.

THE AIM OF THE REVIEW

This review aims to summarize the ethnopharmacology and structural diversity of secondary metabolites from Hericium species, as well as the pharmacological activities of the crude extracts and pure compounds from Hericium species in recent years.

MATERIALS AND METHODS

All the information was gathered by searching Scifinder, PubMed, Web of Science, ScienceDirect, Springer, Wiley, ACS, CNKI, Baidu Scholar, Google Scholar databases and other published materials (books and Ph.D. and M. Sc. Dissertations) using the keywords "Hericium", "Traditional uses", "Chemical composition", "Quality control" and "Pharmacological activity" (1971-May 2023). The species name was checked with https://www.mycobank.org/.

RESULTS

The traditional uses of Hericium species were summarized, and 230 secondary metabolites from Hericium species were summarized and classified into six classes, mainly focusing on their chemical diversity, biosynthesis, biological activities. The modern pharmacological experiments in vivo or in vitro on their crude and fractionated extracts showed that the chemical components from Hericium species have a broad range of bioactivities, including neuroprotective, antimicrobial, anticancer, α-glucosidase inhibitory, antioxidant, and anti-inflammatory activities.

CONCLUSIONS

The secondary metabolites discovered from Hericium species are highly structurally diverse, and they have the potential to be rich resources of bioactive fungal natural products. Moreover, the unveiled bioactivities of their crude extracts and pure compounds are closely related to critical human health concerns, and in-depth studies on the potential lead compounds, mechanism of pharmacological effects and pharmaceutical properties are clearly warranted.

Auricularia auricula Anionic Polysaccharide Nanoparticles for Gastrointestinal Delivery of Pinus koraiensis Polyphenol Used in Bone Protection under Weightlessness

Auricularia auricula polysaccharides used in Pinus koraiensis polyphenol encapsulation and delivery under weightlessness are rarely reported. In this study, an anionic polysaccharide fragment named AAP Iα with a molecular weight of 133.304 kDa was isolated and purified to construct a polyphenol encapsulation system. Nanoparticles named NPs-PP loaded with a rough surface for Pinus koraiensis polyphenol (PP) delivery were fabricated by AAP Iα and ε-poly-L-lysine (ε-PL). SEM and the DLS tracking method were used to observe continuous changes in AAP Iα, ε-PL and PP on the nanoparticles' rough surface assembly, as well as the dispersion and stability. Hydrophilic, monodisperse and highly negative charged nanoparticles can be formed at AAP Iα 0.8 mg/mL, ε-PL 20 μg/mL and PP 80 μg/mL. FT-IR was used to determine their electrostatic interactions. Release kinetic studies showed that nanoparticles had an ideal gastrointestinal delivery effect. NPs-PP loaded were assembled through electrostatic interactions between polyelectrolytes after hydrogen bonding formation in PP-AAP Iα and PP-ε-PL, respectively. Colon adhesion properties and PP delivery in vivo of nanoparticles showed that NPs-PP loaded had high adhesion efficiency to the colonic mucosa under simulated microgravity and could enhance PP bioavailability. These results suggest that AAP Iα can be used in PP encapsulation and delivery under microgravity in astronaut food additives.

Ultrasound assisted wall-breaking extraction and primary structures, bioactivities, rheological properties of novel Exidia yadongensis polysaccharide

New natural multifunctional polysaccharide and its innovatory extraction technology may be urgently needed for food industries. Our aims were to establish new extraction method and investigate the primary structures, bioactivities and rheological properties of novel E. yadongensis polysaccharide (EYP). Ultrasound assisted mechanical wall-breaking extraction (MAUE) was successfully established for the EYP extraction from a new E. yadongensis. Based on the MAUE with RSM, the polysaccharide yield of 17.92 ± 0.56 % with the optimal parameters of five extraction factors were obtained, and current MAUE was characterized by its high yield, low extraction temperature and short ultrasound time. After the isolation and purification, the EYP as a protein-bound polysaccharide was obtained. FT-IR and NMR analysis showed that the main backbone of the EYP comprised of (1 → 4)-β-D-glucopyranosyl and (1 → 6)-ɑ-D-mannopyranosyl groups; EYP exhibited significant antioxidant, antibacterial, antitumor, antidiabetic activities, and good viscoelastic properties in low pH solutions (P < 0.05). The EYP may be used as a natural functional and cohesive agent in food industries.

Structural characterization, anti-tumor and immunomodulatory activity of intracellular polysaccharide from Armillaria luteo-virens

Armillaria luteo-virens (A. luteo-virens) is a kind of edible fungus mainly exists in Qinghai-Tibet of China, but at present only very few studies focus on the bioactivities of its polysaccharides. This study aimed to purify and characterize the structure features of a novel intracellular polysaccharide (ALP-A) derived from A. luteo-virens and explore its potential anti-tumor and immunomodulatory activities. Through systematic separation and purification, we obtained a homogeneous ALP-A with an average molecular weight of 23693Da. Structural analysis indicated that ALP-A was mainly composed of glucose and mannose with a molar ratio of 6.02:1. The repeating unit of ALP-A was →4) -α-D-Glcp-(1→ backbone with α-Glcp-(1→ and α-Manp-(6→ side chains which branched at O-2 position. The anti-tumor assays in vivo suggested that ALP-A could effectively restrain S180 solid tumor growth, protect immune organs and promote the secretion of cytokines (IL2, IL6 and TNF-α) in serum. Besides, in vitro immunomodulatory assays indicated that ALP-A could improve proliferation, phagocytic capacity and raise the level of NO and cytokines in Raw264.7 cells. These results demonstrate that ALP-A which possess potential antitumor and immunomodulatory abilities can be developed as a new functional food.

Nature's Own Pharmacy: Mushroom-Based Chemical Scaffolds and Their Therapeutic Implications

Mushrooms are new potential sources of valuable medicines, long neglected because of difficulties experienced in their cultivation. There is a large variety of medicinal mushrooms which possess significant therapeutic properties and are used as medications for various diseases because they contain several novel highly bioactive components. Medicinal mushrooms can be identified based on their morphology, size, mass, and the color of the stalk, cap and spore, and attachment to the stalk. Medicinal mushrooms possess a variety of important biological activities and are used as antioxidants, hepatoprotectors, anticancer, antidiabetic, anti-inflammatory, antiaging, antiviral, antiparasitic, and antimicrobial agents, among others. This review provides a basic overview of the chemical scaffolds present in mushrooms and their therapeutic implications in the human body.

Insights into the Chemical Compositions and Health Promoting Effects of Wild Edible Mushroom Chroogomphus rutilus

Chroogomphus rutilus is an edible mushroom that has been an important food source since ancient times. It is increasingly sought after for its unique flavor and medicinal value. It is one of the most important wild mushrooms for its medicinal and economic value. C. rutilus contains a variety of active ingredients such as vitamins, proteins, minerals, polysaccharides, and phenolics. C. rutilus and its active compounds have significant anti-oxidant, anti-tumor, immunomodulatory, anti-fatigue, hypoglycemic, gastroprotective, hypolipemic, and neuronal protective properties. This paper summarizes the fungal chemical compositions and health-promoting effects of C. rutilus by collecting the literature on the role of C. rutilus through its active ingredients from websites such as Google Scholar, Scopus, PubMed, and Web of Science. Current research on C. rutilus is limited to the cellular and animal levels, and further clinical trials are needed to conduct and provide theoretical support for further development.

Over the Counter Supplements for Memory: A Review of Available Evidence

In 2021, the Global Brain Health Supplement Industry Market size was valued at US$7.6 billion. It is predicted to increase to US$15.59 billion by 2030. Memory and its enhancement are a segment of the market that comprised the highest global revenue share in 2021. In the USA alone, dietary supplement sales reached US$18 billion in 2018. The US Food and Drug Administration (FDA) does not have the authority to approve dietary supplements' safety, effectiveness, or labeling before products go on the market. The FDA often does not even review supplements before they go to market. Supplement manufacturers are thus responsible for ensuring their products are safe and that their claims are truthful. An extensive review of current supplements on the market was performed by surveying memory products for sale at local and national pharmacies and grocery stores. A list of 103 supplements was compiled and the ingredients in these memory supplements were reviewed. The 18 most common ingredients in these supplements were identified. Each of the supplements included at least one of the 18 most common ingredients. Scientific data relative to these ingredients and their effect on memory was searched using PubMed and Cochrane library databases. Currently, there is no compelling evidence for use of apoaequorin, coenzyme Q10, coffee extracts, L-theanine, omega-3 fatty acids, vitamin B6, vitamin B9, or vitamin B12 supplementation for memory. On the other hand, there is some current evidence for memory benefit from supplementation with ashwagandha, choline, curcumin, ginger, Lion's Mane, polyphenols, phosphatidylserine, and turmeric. There are current studies with mixed results regarding the benefit of carnitine, gingko biloba, Huperzine A, vitamin D, and vitamin E supplementation for memory. Dietary supplements geared toward improving cognition are a billion-dollar industry that continues to grow despite lacking a solid scientific foundation for their marketing claims. More rigorous studies are needed relative to the long-term use of these supplements in homogenous populations with standardized measurements of cognition. Health care providers need to be aware of any and all supplements their older adult patients may be consuming and be educated about their side effects and interactions with prescription medications. Lastly, the FDA needs to take an active position relative to monitoring marketed supplements regarding safety, purity and claims of efficacy.

Hericium coralloides Ameliorates Alzheimer's Disease Pathologies and Cognitive Disorders by Activating Nrf2 Signaling and Regulating Gut Microbiota

Alzheimer's disease (AD) is prone to onset and progression under oxidative stress conditions. Hericium coralloides (HC) is an edible medicinal fungus that contains various nutrients and possesses antioxidant properties. In the present study, the nutritional composition and neuroprotective effects of HC on APP/PS1 mice were examined. Behavioral experiments showed that HC improved cognitive dysfunction in APP/PS1 mice. Immunohistochemical and Western blotting results showed that HC reduced the levels of p-tau and amyloid-β deposition in the brain. By altering the composition of the gut microbiota, HC promoted the growth of short-chain fatty acid-producing bacteria and suppressed the growth of Helicobacter. Metabolomic results showed that HC decreased D-glutamic acid and oxidized glutathione levels. In addition, HC reduced the levels of reactive oxygen species, enhanced the secretion of superoxide dismutase, catalase, and glutathione peroxidase, inhibited the production of malondialdehyde and 4-hydroxynonenal, and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. Collectively, HC demonstrated antioxidant activity by activating Nrf2 signaling and regulating gut microbiota, further exerting neuroprotective effects. This study confirms that HC has the potential to be a clinically effective AD therapeutic agent and offers a theoretical justification for both the development and use of this fungus.

Natural products of pentacyclic triterpenoids: from discovery to heterologous biosynthesis

Covering: up to 2022Pentacyclic triterpenoids are important natural bioactive substances that are widely present in plants and fungi. They have significant medicinal efficacy, play an important role in reducing blood glucose and protecting the liver, and have anti-inflammatory, anti-oxidation, anti-fatigue, anti-viral, and anti-cancer activities. Pentacyclic triterpenoids are derived from the isoprenoid biosynthetic pathway, which generates common precursors of triterpenes and steroids, followed by cyclization with oxidosqualene cyclases (OSCs) and decoration via cytochrome P450 monooxygenases (CYP450s) and glycosyltransferases (GTs). Many biosynthetic pathways of triterpenoid saponins have been elucidated by studying their metabolic regulation network through the use of multiomics and identifying their functional genes. Unfortunately, natural resources of pentacyclic triterpenoids are limited due to their low content in plant tissues and the long growth cycle of plants. Based on the understanding of their biosynthetic pathway and transcriptional regulation, plant bioreactors and microbial cell factories are emerging as alternative means for the synthesis of desired triterpenoid saponins. The rapid development of synthetic biology, metabolic engineering, and fermentation technology has broadened channels for the accumulation of pentacyclic triterpenoid saponins. In this review, we summarize the classification, distribution, structural characteristics, and bioactivity of pentacyclic triterpenoids. We further discuss the biosynthetic pathways of pentacyclic triterpenoids and involved transcriptional regulation. Moreover, the recent progress and characteristics of heterologous biosynthesis in plants and microbial cell factories are discussed comparatively. Finally, we propose potential strategies to improve the accumulation of triterpenoid saponins, thereby providing a guide for their future biomanufacturing.

Preparation, structural characterization, and bioactivities of polysaccharides from Psidium guajava: A review

Psidium guajava L. is one of the most pivotal members belong to the Myrtaceae family, and it is an important tropical fruit with highly nutritional, healthy, and pharmacological values prevailing in worldwide for decades. The polysaccharides of P. guajava (PGPs) are served as one of the most active constituents, which possess a variety of biofunctionalities including anti-inflammatory, antidiarrheic, antihypertension, and antidiabetic properties. Hence, a systematic review aimed to comprehensively summarize the recent research advances of PGPs is necessary for facilitating their better understanding. The present review discussed current research progress on the PGPs, including extraction and purification methods, structural features, biological activities, and potential pharmacological mechanism. In addition, this review may also provide some valuable insights for further development and potential value in affording functionally useful agents in food industry or therapeutically effective medicine in the fields of P. guajava polysaccharides.

Comparison and the lipid-lowering ability evaluation method discussion of Dendrobium officinale polysaccharides from different origins based on principal component analysis

As typical acetylated glucomannans, Dendrobium officinale polysaccharides (DOPs) from different origins differ in their structural characteristics and some of their physicochemical properties. To rapidly select D. officinale plants, we systematically investigate the differences among DOPs from different origins and analyzed the structural characteristics, such as the degree of acetylation and monosaccharide composition; the physicochemical properties, such as solubility, water absorption and apparent viscosity; and the lipid-lowering activity of the obtained DOPs. Principal component analysis (PCA), a method for analyzing multiple variables, was used to analyze the relationship between the physicochemical and structural properties, and lipid-lowering activity. It was found that the structural and physicochemical characteristics had significant effects on lipid-lowering activity, and DOPs with a high degree of acetylation, high apparent viscosity and large D-mannose-to-d-glucose ratio were associated with greater lipid-lowering activity. Therefore, this study provides a reference for the selection and application of D. officinale.

Ameliorating effects of Hericium erinaceus polysaccharides on intestinal barrier injury in immunocompromised mice induced by cyclophosphamide

Hericium erinaceus is a kind of large fungus with rich nutrition and its polysaccharides exhibit various biological activities. In recent years, widespread interest has been focused on maintaining or improving intestinal health through the consumption of edible fungi. Studies have shown that hypoimmunity can damage the intestinal barrier, which in turn seriously affects human health. The aim of this work was to investigate the ameliorative effects of Hericium erinaceus polysaccharides (HEPs) on intestinal barrier damage in cyclophosphamide (CTX)-induced immunocompromised mice. The results showed that the HEP effectively increased the levels of total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-PX), and total superoxide dismutase (T-SOD), and decreased malondialdehyde (MDA) content in the liver tissues of mice. In addition, the HEP restored the immune organ index, increased the serum levels of IL-2 and IgA, augmented the mRNA expression levels of intestinal Muc2, Reg3γ, occludin and ZO-1, and reduced intestinal permeability in mice. It was further confirmed by an immunofluorescence assay that the HEP enhanced the expression level of intestinal tight junction proteins to protect the intestinal mucosal barrier. These results suggested that the HEP could reduce intestinal permeability and enhance intestinal immune functions by increasing antioxidant capacity, tight junction proteins and immune-related factors in CTX-induced mice. In conclusion, the HEP effectively ameliorated CTX-induced intestinal barrier damage in immunocompromised mice, which provides a new application direction for the HEP as a natural immunopotentiator with antioxidant function.

Hericium erinaceus polysaccharide improves the microstructure, immune function, proliferation and reduces apoptosis of thymus and spleen tissue cells of immunosuppressed mice

In order to study the effect of Hericium erinaceus polysaccharide (HEP) on the immune and antioxidation functions of immunosuppressed mice. The control group received distilled water orally and the model and experimental groups I, II, and III received 0, 80, 160, and 320 mg/kg HEP respectively for a fortnight after re-molding with cyoclphosphnalide (CTX). Compared with the control group, the secretion of IL-2, IL-4, and IFN-γ, the activity or content of T-AOC, T-SOD, and GSH-PX, and the expression of PCNA mRNA in the thymus and spleen were reduced in immunosuppressed mice (P < .05 or P < .01). Compared with immunosuppressed mice, the levels of IL-2, IFN-γ, and GSH-PX and the PCNA mRNA expression of spleen and thymus were increased (P < .05 or P < .01), and the microstructure were also obviously improved in the experimental group III. Overall, 320 mg/kg of HEP significantly improved the immune and antioxidant functions.

Quantitative estimation of enzymatic released specific oligosaccharides from Hericium erinaceus polysaccharides using CE-LIF

Polysaccharides exhibit multiple pharmacological activities which are closely related to their structural features. Therefore, quantitatively quality control of polysaccharides based on their chemical characteristics is important for their application in biomedical and functional food sciences. However, polysaccharides are mixed macromolecular compounds that are difficult to isolate and lack standards, making them challenging to quantify directly. In this study, we proposed an improved saccharide mapping method based on the release of specific oligosaccharides for the assessment of Hericium erinaceus polysaccharides from laboratory cultured and different regions of China. Briefly, a polysaccharide from H. erinaceus was digested by β-(1-3)-glucanase, and the released specific oligosaccharides were labeled with 8-aminopyrene-1,3,6-trisulfonic-acid (APTS) and separated by using micellar electrokinetic chromatography (MEKC) coupled with laser induced fluorescence (LIF), and quantitatively estimated. MEKC presented higher resolution compared to polysaccharide analysis using carbohydrate gel electrophoresis (PACE), and provided great peak capacity between oligosaccharides with polymerization degree of 2 (DP2) and polymerization degree of 6 (DP6) in a dextran ladder separation. The results of high performance size exclusion chromatography coupled with multi-angle laser light scattering and refractive index detector (HPSEC-MALLS-RI) showed that 12 h was sufficient for complete digestion of polysaccharides from H. erinaceus. Laminaritriose (DP3) was used as an internal standard for quantification of all the oligosaccharides. The calibration curve for DP3 showed a good linear regression (R ² > 0.9988). The limit of detection (LOD) and limit of quantification (LOQ) values were 0.05 μg/mL and 0.2 μg/mL, respectively. The recovery for DP3 was 87.32 (±0.03)% in the three independent injections. To sum up, this proposed method is helpful for improving the quality control of polysaccharides from H. erinaceus as well as other materials.

Neuroprotective Effects of Erinacine A on an Experimental Model of Traumatic Optic Neuropathy

Erinacine A (EA), a natural neuroprotectant, is isolated from a Chinese herbal medicine, Hericium erinaceus. The aim of this study was to investigate the neuroprotective effects of EA in a rat model of traumatic optic neuropathy. The optic nerves (ONs) of adult male Wistar rats were crushed using a standardized method and divided into three experimental groups: phosphate-buffered saline (PBS control)-treated group, standard EA dose-treated group (2.64 mg/kg in 0.5 mL of PBS), and double EA dose-treated group (5.28 mg/kg in 0.5 mL of PBS). After ON crush, each group was fed orally every day for 14 days before being euthanized. The visual function, retinal ganglion cell (RGC) density, and RGC apoptosis were determined using flash visual-evoked potentials (fVEP) analysis, retrograde Fluoro-Gold labelling, and TdT-dUTP nick end-labelling (TUNEL) assay, respectively. Macrophage infiltration of ON was detected by immunostaining (immunohistochemistry) for ED1. The protein levels of phosphor-receptor-interacting serine/threonine-protein kinase1 (pRIP1), caspase 8 (Cas8), cleaved caspase 3 (cCas3), tumour necrosis factor (TNF)-α, tumour necrosis factor receptor1 (TNFR1), interleukin (IL)-1β, inducible nitric oxide synthase (iNOS), nuclear factor erythroid 2-related factor 2 (Nrf2), haem oxygenase-1 (HO-1), and superoxide dismutase 1 (SOD1) were evaluated by Western blotting. When comparing the standard EA dose-treated group and the double EA dose-treated group with the PBS-treated group, fVEP analysis showed that the amplitudes of P1−N2 in the standard EA dose group and the double EA dose-treated group were 1.8 and 2.4-fold, respectively, higher than that in the PBS-treated group (p < 0.05). The density of RGC in the standard EA dose-treated group and the double EA dose-treated group were 2.3 and 3.7-fold, respectively, higher than that in the PBS-treated group (p < 0.05). The TUNEL assay showed that the standard EA dose-treated group and the double EA dose-treated group had significantly reduced numbers of apoptotic RGC by 10.0 and 15.6-fold, respectively, compared with the PBS-treated group (p < 0.05). The numbers of macrophages on ON were reduced by 1.8 and 2.2-fold in the standard EA dose-treated group and the double EA dose-treated group, respectively (p < 0.01). On the retinal samples, the levels of pRIP, Cas8, cCas3, TNF-α, TNFR1, IL-1β, and iNOS were decreased, whereas those of Nrf2, HO-1, and SOD1 were increased in both EA-treated groups compared to those in the PBS-treated group (p < 0.05). EA treatment has neuroprotective effects on an experimental model of traumatic optic neuropathy by suppressing apoptosis, neuroinflammation, and oxidative stress to protect the RGCs from death as well as preserving the visual function.

Total Synthesis of Isohericerinol A and Its Analogues to Access Their Potential Neurotrophic Effects

The secondary metabolites from Hericium erinaceus are well-known to have neurotrophic and neuroprotective effects. Isohericerinol A (1), isolated by our colleagues from its fruiting parts has a strong ability to increase the nerve growth factor secretion in C6 glioma cells. The current work describes the total synthesis of 1 and its regioisomer 5 in a few steps. We present two different approaches to 1 and a regiodivergent approach for both 1 and 5 by utilizing easily accessible feedstocks. Interestingly, the natural product 1, regioisomer 5, and their intermediates exhibited potent neurotrophic activity in in vitro experimental systems. Thus, these synthetic strategies provide access to a systematic structure-activity relationship study of natural product 1.

Immunomodulatory activity of extracts from five edible basidiomycetes mushrooms in Wistar albino rats

Mushrooms are nutritious foods that are widely cultivated all over the world. They are rich in a range of compounds linked to improving functions of the immune system including carotenoids, alkaloids, lectins, enzymes, folates, fats, organic acids, minerals, polysaccharides, phenolics, proteins, tocopherols, terpenoids, and volatile compounds. In this study we investigated, the immunomodulatory activity in rats of the aqueous extracts of five of the most common edible mushrooms belonging to Family Basidiomycota-white-rot fungi including, Lentinula edodes, Agaricus bisporus, Pleurotus ostreatus, Pleurotus columbinus, and Pleurotus sajor-caju. Male Wistar albino rats were assigned to thirteen groups and Immunosuppression was induced by oral administration of dexamethasone (0.1 mg/kg), followed by oral administration of the mushroom extracts at low (200 mg/kg) and high (400 mg/kg) doses. A positive control group received the immune stimulant Echinacea extract Immulant® at (30 mg/kg), while the negative control group received only saline. From each animal, in each group, blood samples were collected after 15 days for complete blood counts and for measurement of immunologic parameters, including lysozyme activity, nitric oxide (NO) production and serum cytokines including tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ) and interleukin 1 beta (IL-1β) levels. Results have shown that white blood cells (WBCs) and lymphocytic counts were significantly boosted by high doses of each of the five mushroom extracts (207-289% increase for WBC and 153-175% for lymphocytes) with a significant increase in lysozyme activity (110-136% increase), NO concentration (159-232% increase) and cytokines as compared to the negative control group. Histopathological examination of the rats' spleen and thymus tissues has shown marked lymphocytic proliferation that was more obvious at the higher doses. In conclusion, our results showed that the five edible mushroom extracts revealed significant immunostimulatory effects preclinically particularly, at the higher doses (400 mg/kg) which can be considered the effective dose.

Fungal Mushrooms: A Natural Compound With Therapeutic Applications

Fungi are extremely diverse in terms of morphology, ecology, metabolism, and phylogeny. Approximately, 130 medicinal activities like antitumor, immunomodulation, antioxidant, radical scavenging, cardioprotective and antiviral actions are assumed to be produced by the various varieties of medicinal mushrooms. The polysaccharides, present in mushrooms like β-glucans, micronutrients, antioxidants like glycoproteins, triterpenoids, flavonoids, and ergosterols can help establish natural resistance against infections and toxins.. Clinical trials have been performed on mushrooms like Agaricus blazei Murrill Kyowa for their anticancer effect, A. blazei Murrill for its antihypertensive and cardioprotective effects, and some other mushrooms had also been evaluated for their neurological effects. The human evaluation dose studies had been also performed and the toxicity dose was evaluated from the literature for number of mushrooms. All the mushrooms were found to be safe at a dose of 2000 mg/kg but some with mild side effects. The safety and therapeutic effectiveness of the fungal mushrooms had shifted the interest of biotechnologists toward fungal nanobiotechnology as the drug delivery system due to the vast advantages of nanotechnology systems. In complement to the vital nutritional significance of medicinal mushrooms, numerous species have been identified as sources of bioactive chemicals. Moreover, there are unanswered queries regarding its safety, efficacy, critical issues that affect the future mushroom medicine development, that could jeopardize its usage in the twenty-first century.

A Novel Polysaccharide From Heimioporus retisporus Displays Hypoglycemic Activity in a Diabetic Mouse Model

A novel polysaccharide, Heimioporus retisporus Polysaccharide (HRP) was extracted from the edible mushroom Heimioporus retisporus. HRP had weight-average molecular weight 1,949 kDa and number-average molecular weight 873 kDa, and its major components were arabinose (0.71%), galactose (12.93%), glucose (49.00%), xylose (8.59%), mannose (17.78%), and glucuronic acid (10.99%). Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy revealed that HRP was composed of 1,3-linked β-D-glucose, 1,6-linked β-D-mannose, 1,6-linked β-D-galactose, 1,4-linked β-D-galactose, 1,4-linked β-D-xylose, and 1,5-linked α-L-arabinose. Thermogravimetric analysis indicated that degradation temperature (T₀) of HRP was 200°C. In an STZ-induced diabetic mouse model, oral administration of HRP (40 mg/kg/d) for 28 days significantly reduced blood glucose levels, and reduced heart organ index by decreasing expression of IL-6 and TNF-α. Our findings indicate hypoglycemic effect of HRP, and its potential application as a hypoglycemic agent.

Hericium erinaceus Mycelium Ameliorates In Vivo Progression of Osteoarthritis

Osteoarthritis (OA) is an age-related disorder that affects the joints and causes functional disability. Hericium erinaceus is a large edible mushroom with several known medicinal functions. However, the therapeutic effects of H. erinaceus in OA are unknown. In this study, data from Sprague-Dawley rats with knee OA induced by anterior cruciate ligament transection (ACLT) indicated that H. erinaceus mycelium improves ACLT-induced weight-bearing asymmetry and minimizes pain. ACLT-induced increases in articular cartilage degradation and bone erosion were significantly reduced by treatment with H. erinaceus mycelium. In addition, H. erinaceus mycelium reduced the synthesis of proinflammatory cytokines interleukin-1β and tumor necrosis factor-α in OA cartilage and synovium. H. erinaceus mycelium shows promise as a functional food in the treatment of OA.

Digestive Characteristics of Hericium erinaceus Polysaccharides and Their Positive Effects on Fecal Microbiota of Male and Female Volunteers During in vitro Fermentation

Hericium erinaceus polysaccharides (HEPs) have attracted widespread attention in regulating gut microbiota (GM). To investigate digestibility and fermentation of HEPs and their effects on GM composition, three polysaccharide fractions, namely, HEP-30, HEP-50, and HEP-70, were fractionally precipitated with 30%, 50%, and 70% ethanol concentrations (v/v) from hot water-soluble extracts of Hericium erinaceus, respectively. Three kinds of prepared HEPs were structurally characterized and simulated gastrointestinal digestion, and their effects on human fecal microbiota fermentations of male and female and short-chain fatty acid (SCFA) production in vitro were clarified. Under digestive conditions simulating saliva, stomach, and small intestine, HEPs were not significantly influenced and safely reached the distal intestine. After 24 h of in vitro fermentation, the content of SCFAs was significantly enhanced (p < 0.05), and the retention rates of total and reducing sugars and pH value were significantly decreased (p < 0.05). Thus, HEPs could be utilized by GM, especially HEP-50, and enhanced the relative abundance of SCFA-producing bacteria, e.g., Bifidobacterium, Faecalibacterium, Blautia, Butyricicoccus, and Lactobacillus. Furthermore, HEPs reduced the relative abundances of opportunistic pathogenic bacteria, e.g., Escherichia-Shigella, Klebsiella, and Enterobacter. This study suggests that gradual ethanol precipitation is available for the preparation of polysaccharides from Hericium erinaceus, and the extracted polysaccharide could be developed as functional foods with great development value.

Subchronic toxicity and genotoxicity studies of Hericium erinaceus β-glucan extract preparation

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β-Glucan from Hericium erinaceus was investigated for subchronic toxicity and mutagenicity.

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In the subchronic study, The No-Observed-Adverse-Effect Level (NOAEL) for Hericium erinaceus β-glucan was 2000 mg/kg bw/day.

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In mutagenicity studies, Hericium erinaceus β-glucan did not reveal genotoxic effects.

The medicinal effects of Hericium erinaceus have been long documented in scientific studies of Eastern traditional medicine. It is widely consumed, because of its nutritional qualities and perceived health benefits. Also, it is rich in β-glucans, which has been shown to have immunomodulating and antitumor effects. The objective of the present study was to investigate adverse effects, if any, of β-glucan extract preparation from H. erinaceus in subchronic toxicity and genotoxicity studies. The conduct of these studies was in compliance with Good Laboratory Practice (GLP) and test guidelines established by the Organization for Economic Cooperation and Development (OECD). In the subchronic toxicity study, Sprague Dawley rats (12/sex/group) were administered (gavage) H. erinaceus β-glucan extract preparation at dose levels of 0, 500, 1000 and 2000 mg/kg body weight (bw)/day for 90 days. Treatment with H. erinaceus β-glucan extract preparation did not result in any toxicologically significant treatment-related changes in clinical observations, ophthalmic examinations, body weights, body weight gains, feed consumption, and organ weights. Clinical pathology including hematology, serum chemistry, urinalysisand terminal necropsy (gross or histopathology findings) did not reveal any treatment-related adverse effects. The results of genotoxicity studies as evaluated by gene mutations in Salmonella typhimurium, in vitro chromosome aberrations and in vivo micronucleus test in mice did not reveal any genotoxicity of H. erinaceus β-glucan extract preparation. Based on the subchronic study, the no observed-adverse-effect level (NOAEL) for H. erinaceus β-glucan extract preparation was determined as 2000 mg/kg bw/day, the highest dose tested.

Isolation, structures and bioactivities of the polysaccharides from Radix Hedysari: A review

Radix Hedysari, a well-known traditional Chinese herbal medicine, has a long history as a medicinal plant in China based on its wide spectrum of biological and pharmacological activities. Until now, many chemical constituents have been isolated and identified from Radix Hedysari, such as polysaccharides, flavonoids, phenylpropanoids, trace elements and so on. Of these, Radix Hedysari polysaccharides are one of the most important active compounds of the Radix Hedysari and have various biological activities, including anti-tumor activity, antioxidant activity, anti-diabetic activity, immunity enhancement effect and regulation of intestinal flora. These beneficial biological activities are related to the chemical structure of the Radix Hedysari polysaccharides. The chemical structure of HPS is the basis of its biological activity, which is affected by many factors, such as the composition of monosaccharide, the size of relative molecular weight, the way of glycoside bond connection, the three-dimensional structure of polysaccharide, and so on. Different extraction and separation methods lead to different configurations of polysaccharides and different biological activities of polysaccharides. In general, the bioactivity of polysaccharides showed a certain dose-response or structure-activity relationship. At present, few studies of regarding the structure-function relationships of these polysaccharides have been reported, and it is not easy to relate the structures of HPS to their biological activities. Nevertheless, some relationships can be inferred as follows. This article is aimed to provide a systematic and up-to-date review on the extraction, purification, structural characterization, and biological activities of the Radix Hedysari polysaccharides to support its further therapeutic potentials and sanitarian functions. Furthermore, the possible development and a perspective for future research of Radix Hedysari polysaccharides are also discussed.

Optimisation of enzyme-assisted extraction of Erythronium sibiricum bulb polysaccharide and its effects on immunomodulation

In this study, polysaccharides of Erythronium sibiricum bulb were extracted using enzyme-assisted extraction technology and then optimised by response surface methodology. The characteristics and immunomodulatory activities of the polysaccharide (E1P) were investigated. Setting the yield of polysaccharides as the index, the effects of amylase content, zymolytic time, extraction pH and zymolytic temperature were investigated. The optimal extraction conditions for polysaccharides were as follows: amylase content, 1% weight of pre-treated powder; zymolytic time, 2 h; extraction pH, 7.5; and zymolytic temperature, 55 °C. The yield was predicted to be 61.10%, which agreed with the value obtained in confirmatory experiments (59.71% ± 2.72%). Further research indicated that the primary component of E1P is glucose; however, it also contains a small quantity of galactose and arabinose. In vitro assays showed that E1P and ESBP (another kind of E. sibiricum bulb polysaccharide extracted by water decoction in our previous study) could significantly promote the cellular viability and phagocytosis of RAW264.7 cells without cytotoxicity. Moreover, they could enhance the ability to secrete nitric oxide and cytokines such as TNF-α and IL-1β. However, the immunomodulatory activities of E1P were better than those of ESBP. According to the results of this study, enzyme-assisted extraction represents a new strategy for extracting E. sibiricum bulb polysaccharides with higher yield and better immune activity.

Preparation, Characterization and Gelation of a Fungal Nano Chitin Derived from Hericium erinaceus Residue

Nano chitin is a promising biocompatible material with wide applications. In this work, a fungal-derived nano chitin was prepared from Hericium erinaceus residue via mineral/protein purification and subsequent TEMPO-mediated oxidation. The structure, dispersity, and gelation ability of the prepared fungal nano chitin were studied. The results showed that the average length and width of the prepared fungal nano chitin were 336.6 nm and 6.4 nm, respectively, and the aspect ratio exceeded 50:1. The nano chitin retained the basic structure of chitin, while the crystallization index was improved. In addition, the dispersity of the nano chitin in aqueous media was evaluated by the effective diameter, and the polydispersion index was mainly affected by pH and ionic strength. Under acetic acid “gas phase coagulation”, the prepared nano chitin dispersions with mass concentrations of 0.2, 0.4, 0.6, and 0.8% were converted into gels by enhanced hydrogen bond crosslinking between nano chitins.

Identification of Common Liver Metabolites of the Natural Bioactive Compound Erinacine A, Purified from Hericium erinaceus Mycelium

Metabolite identification, in the early stage, for compound discovery is necessary to assess the knowledge for the pharmaceutical improvement of drug safety and efficacy. Even if the drug has been released into the market, identification and continuous evaluation of the metabolites are required to avoid the risk of post-marketing withdrawal. Hericium erinaceus (HE), a medicinal mushroom, has broadly documented nutraceutical benefits, including anti-oxidant, anti-tumor, anti-aging, hypolipidemic, and gastric mucosal protection effects. Recently, erinacine A has been reported as the main natural bioactive compound in the mycelium of HE for functional food development. In neurological studies, the consumption of enrinacine A enriched HE mycelium demonstrates its significant nutraceutical effects in Alzheimer’s disease, Parkinson’s disease, and ischemic stroke. For the first time, we explored the metabolic process of erinacine A molecule and identified its metabolites from the rat and human liver S9 fraction. Using a liquid chromatography/triple quadrupole mass spectrometer for quantitative analysis, we observed that 75.44% of erinacine A was metabolized within 60 min in rat, and 32.34% of erinacine A was metabolized within 120 min in human S9. Using an ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) to identify the metabolites of erinacine A, five common metabolites were identified, and their possible structures were evaluated. Understanding the metabolic process of erinacine A and establishing its metabolite profile database will help promote the nutraceutical application and discovery of related biomarkers in the future.

Structural characterization of two Hericium erinaceus polysaccharides and their protective effects on the alcohol-induced gastric mucosal injury

Hericium erinaceus, a traditional edible mushroom, is known as a medicine food homology to ameliorate gastrointestinal diseases. However, the relationship between the structural characteristics of Hericium erinaceus and its stomach-protecting activity remains unclear. Here, the structural properties of two polysaccharides from Hericium erinaceus, mycelium polysaccharide (HMP) and fruiting body polysaccharide (HFP) were investigated by spectral approaches. The results showed that the distribution of HMP was more uniform compared to HFP. Both HMP and HFP have triple helix structures, but the HMP conformation showed greater stability. Subsequently, the preventive effect of HMP and HFP on ethanol-induced gastric mucosal injury was also evaluated in rats and GES-1 cells, and it showed that both HMP and HFP had significant protective activity against gastric mucosal injury, but HMP showed better activity than HFP. These results suggested that conformational stability polysaccharide in Hericium erinaceus is more related to its gastric-protecting activity.

Structural characterization of polysaccharide purified from Hericium erinaceus fermented mycelium and its pharmacological basis for application in Alzheimer's disease: Oxidative stress related calcium homeostasis

The purified polysaccharides from Hericium erinaceus fermented mycelium entitled with PHEB was analyzed and it was mainly composed of six glycosidic bonds. It has been confirmed to show the relieving activity against Alzheimer's Disease (AD)- just as behaviors of B6C3-Tg (APPswePSEN1d E9)/Nju double transgenic [Genotype: (Appswe)T, (Psen1) T] (APP/PS1) mice. Six-week PHEB administration significantly improved the cognitive behavior of mice. Brain injury, amyloid beta deposition and tau hyperphosphorylation were alleviated in PHEB-treated AD mice without changes in other tissues. PHEB alleviated the oxidative stress in brains of AD mice via regulation the Nrf2 and its downstream kinase, which further improved the cholinergic system function. Proteomics and bioinformatics analysis showed that the therapeutic effect of PHEB is achieved by regulating calcium homeostasis mediated by oxidative stress. Furthermore, PHEB regulated the CaMK II/IV to achieve the calcium homeostasis in brains; and ultimately to show the anti-AD property.

Chemical properties and anti-fatigue effect of polysaccharide from Pholiota nameko

The aim of this study was to explore the primary chemical properties and anti-fatigue effect in vivo of Pholiota nameko polysaccharide (PNP). Through UV-visible spectrum, the absorption peaks of proteins, nucleic acids and pigments were not found. The organic functional groups of polysaccharides (3,289.97, 1,584.72, and 1,045.23 cm^-1 so on) were measured by IR spectroscopy. The PNP was a semi-crystalline or non-crystalline substance, possessed a three-dimensional lump structure with a smooth, dense surface and amorphous structure according to the scanning electron microscopy and XRD images. Moreover, the PNP was chain or bright-spot structures formed by the entanglement of multiple polysaccharide fibers on the basis of atomic force microscopy. The results of anti-fatigue suggested the PNP could significantly extend the forced swim time from 121.58 ± 18.48 and 101.91 ± 14.27 min to 154.95 ± 24.26 and 134.13 ± 25.71 min in male and female mice respectively. The LDH activity was up to 31.68 ± 4.60 U/ml in male mice and 29.49 ± 5.12 U/ml in female mice. Meanwhile, the Ca²⁺ -Mg²⁺ -ATPase activity was reached to 2.49 ± 0.41 μmol/(mg·h) in male mice and 2.44 ± 0.29 μmol/(mg·h) in female mice. The SOD activity was increased to 5.92 ± 1.19 U/ml in male mice and 5.89 ± 0.98 U/ml in female mice, while the MDA content was decreased to 2.24 ± 0.34 nmol/mg in male mice and 2.02 ± 0.41 nmol/mg in female mice. These results showed a theoretical basis for application of the PNP in food and pharmacy as a natural physical strengthening substance. PRACTICAL APPLICATIONS: Fatigue affects physical and mental health in vivo, which resulted in negative effects on everyday tasks, leisure activities, cognitive and behavioral performances and is very common in modern life. Therefore, this study was designed to explore the primary chemical properties and research the anti-fatigue effects of Pholiota nameko polysaccharide (PNP) in mice. And then, it would be a reference for the development and utilization of PNP as a kind of healthy food on sub-health.

Beta-Glucans from Fungi: Biological and Health-Promoting Potential in the COVID-19 Pandemic Era

Beta-glucans comprise a group of polysaccharides of natural origin found in bacteria, algae, and plants, e.g., cereal seeds, as well as microfungi and macrofungi (mushrooms), which are characterized by diverse structures and functions. They are known for their metabolic and immunomodulatory properties, including anticancer, antibacterial, and antiviral. Recent reports suggest a potential of beta-glucans in the prevention and treatment of COVID-19. In contrast to β-glucans from other sources, β-glucans from mushrooms are characterized by β-1,3-glucans with short β-1,6-side chains. This structure is recognized by receptors located on the surface of immune cells; thus, mushroom β-glucans have specific immunomodulatory properties and gained BRM (biological response modifier) status. Moreover, mushroom beta-glucans also owe their properties to the formation of triple helix conformation, which is one of the key factors influencing the bioactivity of mushroom beta-glucans. This review summarizes the latest findings on biological and health-promoting potential of mushroom beta-glucans for the treatment of civilization and viral diseases, with particular emphasis on COVID-19.

A review of the therapeutic and biological effects of edible and wild mushrooms

Throughout history, mushrooms have occupied an inseparable part of the diet in many countries. Mushrooms are considered a rich source of phytonutrients such as polysaccharides, dietary fibers, and other micronutrients, in addition to various essential amino acids, which are building blocks of vital proteins. In general, mushrooms offer a wide range of health benefits with a large spectrum of pharmacological properties, including antidiabetic, antioxidative, antiviral, antibacterial, osteoprotective, nephroprotective, hepatoprotective, etc. Both wild edible and medicinal mushrooms possess strong therapeutic and biological activities, which are evident from their in vivo and in vitro assays. The multifunctional activities of the mushroom extracts and the targeted potential of each of the compounds in the extracts have a broad range of applications, especially in the healing and repair of various organs and cells in humans. Owing to the presence of the aforementioned properties and rich phytocomposition, mushrooms are being used in the production of nutraceuticals and pharmaceuticals. This review aims to provide a clear insight on the commercially cultivated, wild edible, and medicinal mushrooms with comprehensive information on their phytochemical constituents and properties as part of food and medicine for futuristic exploitation. Future outlook and prospective challenges associated with the cultivation and processing of these medicinal mushrooms as functional foods are also discussed.

Structural characterization of polysaccharide purified from Amanita caesarea and its pharmacological basis for application in Alzheimer's disease: endoplasmic reticulum stress

Alzheimer's disease (AD) leads to progressive declines in memory and learning. This disease may arise from endoplasmic reticulum stress due to protein misfolding, which promotes inflammatory pathway activation and induces neuronal cell apoptosis. Polysaccharide is one of the main active components of the mushroom Amanita caesarea (A. caesarea) and has been proven to act as an antioxidant, immune regulatory and anti-inflammatory agent with neurodevelopmental effects. In this study, polysaccharide isolated from A. caesarea (ACPS2) was subjected to analysis to determine the main components, homogeneity and molecular weight and characterize the structure. Furthermore, APP/PS1 mice were orally treated with ACPS2 for 6 weeks. Structural characterization of ACPS2 revealed a mass average molar mass of 16.6 kDa and a structure containing a main chain and branching. In vivo, treatment with ACPS2 for 6 weeks significantly improved cognition and anxious behavior in APP/PS1 mice using Morris water maze and open-field test. Alleviation of brain injury, amyloid-β deposition and tau hyperphosphorylation were observed in ACPS2-treated AD mice. No changes in other tissues were observed. ACPS2 appeared to alleviate inflammation in vivo, as determined by decreases in the serum concentrations of tumor necrosis factor-α and interleukin-1β relative to those in non-treated mice. ACPS2 improved cholinergic system function and stabilized oxidative stress in APP/PS1 mice. Proteomics and bioinformatics analyses showed that the therapeutic effect of ACPS2 is achieved through regulation of oxidative stress-mediated endoplasmic reticulum stress. Furthermore, ACPS2 exerted anti-AD effects by regulating nuclear factor-E2-related factor 2 (Nrf2) signaling, thereby inhibiting endoplasmic reticulum stress and nuclear factor-kappa B (NF-κB) activation.

Immunomodulatory Activity of Carboxymethyl Pachymaran on Immunosuppressed Mice Induced by Cyclophosphamide

The effects of immunomodulatory activity of two types of carboxymethyl pachymaran (CMP-1 and CMP-2) on cyclophosphamide (CTX)-induced mice were investigated. Both CMP-1 and CMP-2 were found to restore the splenomegaly and alleviate the spleen lesions and the mRNA expressions of TLR4, MyD88, p65 and NF-κB in spleen were also increased. CMP-1 and CMP-2 could enhance the immunity by increasing the levels of TNF-α, IL-2, IL-6, IFN-γ, Ig-A and Ig-G in serum. In addition, CMP-1 could increase the relative abundance of Bacteroidetes and reduce the relative richness of Firmicutes at the phylum level. CMP-1 and CMP-2 could reduce the relative abundance Erysipelatoclostridum at the genus level. CMP-1 and CMP-2 might enhance the immune function of immunosuppression mice by regulating the gene expression in the TLR4/NF-κB signaling pathway and changing the composition and abundance of the intestinal microbiota. The results suggested that CMP-1 and CMP-2 would be as potential immunomodulatory agents in functional foods.

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.

Structural characterization and immunomodulatory activities of two polysaccharides from Rehmanniae Radix Praeparata

The structures and immunomodulatory activities of two polysaccharides (SDH-WA and SDH-0.2A) from Rehmanniae Radix Praeparata (RRP) were investigated. RRP crude polysaccharide was obtained by water extraction and purified. Ion chromatography, high-performance gel permeation chromatography, Fourier-transform infrared spectroscopy, methylation analysis, gas chromatography-mass spectrometry, and nuclear magnetic resonance were used to characterize the polysaccharides. The main chain of SDH-WA was →6)-α-D-Galp-(1→6)-α-D-Galp-(1→5)-α-L-Araf-(1→3,5)-α-L-Araf-(1→, terminal sugar residue α-L-Araf-(1→ linked to residue →3,5)-α-L-Araf-(1→ on the main chain by an O-3 bond. The other two terminal sugar residues α-D-Galp-(1→ and →6)-β-D-Galp were linked to the end of the main chain. The main chain of SDH-0.2A was →2,4)-α-L-Rhap-(1→4)-α-D-GalpA-(1→. Three branched chains α-D-Galp-(1→6)-α-D-Galp-(1→5)-α-L-Araf-(1→3,5)-α-L-Araf-(1→, →3,6)-β-D-Galp-(1→5)-α-L-Araf-(1→, and →4)-β-D-Galp-(1→5)-α-L-Araf-(1→ were linked to the main chain residue →2,4)-α-L-Rhap-(1→ by an O-2 bond. Three terminal sugar residues α-D-Galp-(1→, α-L-Araf-(1→, and →6)-β-D-Galp were linked to the end of the chain. Both polysaccharides showed no cytotoxic effects on and significantly promoted the phagocytic activity of RAW264.7 cells. They dose-dependently improved lysozyme activity and stimulated the production of TNF-α and IL-6 by RAW264.7 cells, but attenuated the secretion of lysozymes, TNF-α, IL-6, IL-1β, and nitric oxide by lipopolysaccharide-induced RAW264.7 cells. The present studies suggest that PRR polysaccharide is a valuable source with immunomodulating.