Structure elucidation and antioxidant properties of a soluble β-d-glucan from mushroom Entoloma lividoalbum

Mushroom-derived bioactive compounds pharmacological properties and cancer targeting: a holistic assessment

Worldwide, cancer is a great cause of death and a public health issue. Cancer has been the leading cause of death in developing nations for many years. Cancers are typically treated with surgery, immunotherapy, chemotherapy, and radiation therapies. However, these techniques have some undesirable side effects, including neurological illness, high toxicity levels, discomfort, and mental stress. Biologically active compounds discovered in mushrooms may be utilized to reduce ill effects and increase the efficacy of the current therapies. Mushrooms have efficient therapeutic activities such as antimicrobial, antitumor, antidiabetic, anticancer, and antioxidant activity. Bioactive compounds like polysaccharides, terpenoids, β-glucan, steroids, polyphenols, flavonoids, proteins, and peptides have precisely well-recognized anticancer activity. In this review paper, we described the biomedical activities of the mushroom against various cancers. The immune-modulating components in mushrooms activate NK cells and macrophages to target cancer cells. Due to immunomodulatory properties of mushroom-derived bioactive compounds in cancer therapy to highlight the need for further research in this area further studies needs to validate in clinical samples.

Selenium Enrichment of the Edible Medicinal Mushroom Antrodia camphorata by Submerged Fermentation

Selenium (Se) is an essential nutrient element in human physiological metabolism and immune function. Supplementation of bioavailable Se will confer benefit on human life, especially when intake of this nutrient is inadequate. The edible and medicinal mushroom Antrodia camphorata is a unique fungus endemic to Taiwan, which has shown high therapeutic and nutritive value. This study is the first to demonstrate that A. camphorata can assimilate and transform sodium selenite into organic selenium. With an initial concentration of Se (IV) at 10 mg/L in 100 mL of the medium at 25 °C, the total selenium content in Se-enriched A. camphorata mycelia was 1281.3 ± 79.2 µg/g, in which the organic selenium content accounted for 88.1%. Further analysis demonstrated that selenium-enriched polysaccharide was the main form of Se present in A. camphorata (61.5% of the organic selenium). Four water-soluble Se-polysaccharide fractions were separated from A. camphorata, and ACP II was the major fraction of Se-polysaccharide. The scavenging efficiency of Se-polysaccharides on DPPH and ABTS radicals was determined, proving that selenium enrichment dramatically improved the in vitro antioxidant capacity of A. camphorata polysaccharide. Therefore, the selenium accumulation and transformation ability of A. camphorata provides an opportunity for developing this beneficent fungus into a novel selenium-enriched dietary or medicinal supplement.

Corrigendum: Compounds purified from edible fungi fight against chronic inflammation through oxidative stress regulation

[This corrects the article DOI: 10.3389/fphar.2022.974794.].

Compounds purified from edible fungi fight against chronic inflammation through oxidative stress regulation

Chronic inflammation is associated with various chronic diseases, including cardiovascular disease, neurodegenerative disease, and cancer, which severely affect the health and quality of life of people. Oxidative stress induced by unbalanced production and elimination of reactive oxygen species (ROS) is one of the essential risk factors for chronic inflammation. Recent studies, including the studies of mushrooms, which have received considerable attention, report that the antioxidant effects of natural compounds have more advantages than synthetic antioxidants. Mushrooms have been consumed by humans as precious nourishment for 3,000 years, and so far, more than 350 types have been identified in China. Mushrooms are rich in polysaccharides, peptides, polyphenols, alkaloids, and terpenoids and are associated with several healthy biological functions, especially antioxidant properties. As such, the extracts purified from mushrooms could activate the expression of antioxidant enzymes through the Keap1/Nrf2/ARE pathway to neutralize excessive ROS and inhibit ROS-induced chronic inflammation through the NF-κB pathway. Recently, the antioxidant properties of mushrooms have been successfully applied to treating cardiovascular disease (CAD), neurodegenerative diseases, diabetes mellitus, and cancer. The present review summarizes the antioxidant properties and the mechanism of compounds purified from mushrooms, emphasizing the oxidative stress regulation of mushrooms to fight against chronic inflammation.

The Antioxidant Properties of Mushroom Polysaccharides can Potentially Mitigate Oxidative Stress, Beta-Cell Dysfunction and Insulin Resistance

Diabetes mellitus is a prevalent metabolic and endocrine illness affecting people all over the world and is of serious health and financial concern. Antidiabetic medicine delivered through pharmacotherapy, including synthetic antidiabetic drugs, are known to have several negative effects. Fortunately, several natural polysaccharides have antidiabetic properties, and the use of these polysaccharides as adjuncts to conventional therapy is becoming more common, particularly in underdeveloped nations. Oxidative stress has a critical role in the development of diabetes mellitus (DM). The review of current literature presented here focusses, therefore, on the antioxidant properties of mushroom polysaccharides used in the management of diabetic complications, and discusses whether these antioxidant properties contribute to the deactivation of the oxidative stress-related signalling pathways, and to the amelioration of β-cell dysfunction and insulin resistance. In this study, we conducted a systematic review of the relevant information concerning the antioxidant and antidiabetic effects of mushrooms from electronic databases, such as PubMed, Scopus or Google Scholar, for the period 1994 to 2021. In total, 104 different polysaccharides from mushrooms have been found to have antidiabetic effects. Most of the literature on mushroom polysaccharides has demonstrated the beneficial effects of these polysaccharides on reactive oxygen and nitrogen species (RONS) levels. This review discuss the effects of these polysaccharides on hyperglycemia and other alternative antioxidant therapies for diabetic complications through their applications and limits, in order to gain a better understanding of how they can be used to treat DM. Preclinical and phytochemical investigations have found that most of the active polysaccharides extracted from mushrooms have antioxidant activity, reducing oxidative stress and preventing the development of DM. Further research is necessary to confirm whether mushroom polysaccharides can effectively alleviate hyperglycemia, and the mechanisms by which they do this, and to investigate whether these polysaccharides might be utilized as a complementary therapy for the prevention and management of DM in the future.

Prebiotic potential of mushroom d-glucans: implications of physicochemical properties and structural features

Mushroom d-glucans are recognized as dietary fibers and as biologically active natural polysaccharides, with the advantages of being quite inexpensive for production, tolerable, and having a range of possible structures and physicochemical properties. The prebiotic potential of mushroom d-glucans has been explored in recent years, but the relationship between their various structural features and activity is poorly understood. This review focuses on comprehensively evaluating the prebiotic potential of mushroom d-glucans in face of their structural variations. Overall, mushroom d-glucans provide a unique set of different structures and physicochemical properties with prebiotic potential, where linkage type and solubility degree seem to be associated with prebiotic activity outcomes. The understanding of the effects of distinct structures and physicochemical properties in mushroom d-glucans on the gut microbiota contributes to the design and selection of new prebiotics in a more predictable way.

Biologically active polysaccharide from edible mushrooms: A review

Mushrooms are renewable natural gift for humankind, furnished with unique taste, flavor and medicinal properties. For the last few decades study of mushroom polysaccharides has become a matter of great interest to the researchers for their immunomodulating, antimicrobial, antioxidant, anticancer, and antitumor properties. Molecular mass, branching configuration, conformation of polysaccharides and chemical modification are the major factors influencing their biological activities. The mechanism of action of mushroom polysaccharides is to stimulate T-cells, B-cells, natural killer cells, and macrophage dependent immune responses via binding to receptors like the toll-like receptor-2, dectin-1. The present review offers summarized and significant information about the structural and biological properties of mushroom polysaccharides, and their potential for development of therapeutic materials.

Gallic Acid-Laminarin Conjugate Is a Better Antioxidant than Sulfated or Carboxylated Laminarin

A 12.4 kDa laminarin (LM) composed of β(1→3)-glucan with β(1→6)-branches was extracted from brown seaweed Lobophora variegata and modified via carboxylation using dielectric barrier discharge (LMC), conjugation with gallic acid (LMG), and sulfation (LMS). Analyses of the chemical composition of LMC, LMG, and LMS yielded 11.7% carboxyl groups, 1.5% gallic acid, and 1.4% sulfate content, respectively. Antioxidant activities of native and modified laminarins were assessed using six different in vitro methods. Sulfation stopped the antioxidant activities of LM. On the other hand, carboxylation improved cooper chelation (1.2 times). LMG was found to be a more efficient antioxidant agent than LM in terms of copper chelation (1.3 times), reducing power (1.3 times), and total antioxidant capacity (80 times). Gallic acid conjugation was further confirmed using Fourier transform infrared spectroscopy (FT-IR) and one- and two-dimensional NMR spectroscopy analyses. LMG also did not induce cell death or affect the cell cycle of Madin–Darby canine kidney (MDCK) cells. On the contrary, LMG protected MDCK cells from H₂O₂-induced oxidative damage. Taken together, these results show that LMG has the potent antioxidant capacity, and, therefore, potential applications in pharmacological and functional food products.

Structural features and antioxidant activity of a new galactoglucan from edible mushroom Pleurotus djamor

A new water soluble galactoglucan with apparent molecular weight ~1.61 × 10⁵ Da, was isolated from the edible mushroom Pleurotus djamor by hot water extraction followed by purification through dialysis tubing cellulose membrane and sepharose 6B column chromatography. The sugar analysis showed the presence of glucose and galactose in a molar ratio of nearly 3:1 respectively. The structure of the repeating unit in the polysaccharide was determined through chemical and NMR experiments as: In vitro antioxidant studies showed that the PDPS exhibited hydroxyl radical scavenging activity (EC₅₀ = 1.681 ± 0.034 mg/mL), DPPH radical scavenging activity (EC₅₀ = 3.83 ± 0.427 mg/mL), reducing power (EC₅₀ = 4.258 ± 0.095 mg/mL), and ABTS radical quenching activity (EC₅₀ = 0.816 ± 0.077 mg/mL). So, PDPS should be explored as a natural antioxidant.

Structural studies of immunomodulatory (1 → 3)-, (1 → 4)-α glucan from an edible mushroom Polyporus grammocephalus

A water soluble polysaccharide (PGPS) with molecular weight ~ 1.4 × 10⁵ Da was isolated by alkali treatment from an edible mushroom Polyporus grammocephalus and purified by gel chromatography using sepharose-6B column. Monosaccharide analysis revealed that PGPS was made up of glucose only. PGPS contained (1 → 3)-α-D-Glcp and (1 → 4)-α-D-Glcp moieties in a molar ratio of nearly 1:2. Through a series of chemical and spectroscopic (1D/2D NMR) investigations, the repeating unit of the glucan was established as: →3)-α-D-Glcp(1 → [4)-α-D-Glcp(1]₂→ This α-glucan was observed to stimulate some prime components of immune system, namely, macrophages, splenocytes, and thymocytes.

The purification, structural characterization and antidiabetic activity of a polysaccharide from Anoectochilus roxburghii

Anoectochilus roxburghii, a traditional Chinese medicinal herb, has been widely used for treating numerous chronic diseases.

Notes, outline and divergence times of Basidiomycota

The Basidiomycota constitutes a major phylum of the kingdom Fungi and is second in species numbers to the Ascomycota. The present work provides an overview of all validly published, currently used basidiomycete genera to date in a single document. An outline of all genera of Basidiomycota is provided, which includes 1928 currently used genera names, with 1263 synonyms, which are distributed in 241 families, 68 orders, 18 classes and four subphyla. We provide brief notes for each accepted genus including information on classification, number of accepted species, type species, life mode, habitat, distribution, and sequence information. Furthermore, three phylogenetic analyses with combined LSU, SSU, 5.8s, rpb1, rpb2, and ef1 datasets for the subphyla Agaricomycotina, Pucciniomycotina and Ustilaginomycotina are conducted, respectively. Divergence time estimates are provided to the family level with 632 species from 62 orders, 168 families and 605 genera. Our study indicates that the divergence times of the subphyla in Basidiomycota are 406–430 Mya, classes are 211–383 Mya, and orders are 99–323 Mya, which are largely consistent with previous studies. In this study, all phylogenetically supported families were dated, with the families of Agaricomycotina diverging from 27–178 Mya, Pucciniomycotina from 85–222 Mya, and Ustilaginomycotina from 79–177 Mya. Divergence times as additional criterion in ranking provide additional evidence to resolve taxonomic problems in the Basidiomycota taxonomic system, and also provide a better understanding of their phylogeny and evolution.

Alkaline Extraction, Structural Characterization, and Bioactivities of (1→6)-β-d-Glucan from Lentinus edodes

The purpose of this study is to develop a robust approach to obtain β glucans from Lentinus edodes and to characterize their structural and biological properties for sustainable utilization. The alkali extraction was optimized with an orthogonal experimental design, and a concise process for obtaining specific targeting polysaccharides from Lentinus edodes was developed in this study. After purification with a Q-Sepharose Fast Flow strong anion-exchange column, the monosaccharide composition, a methylation analysis, and NMR spectroscopy were employed for their structural characterizations. LeP-N2 was found to be composed of (1→6)-β-d-glucans with minor β-(1→3) glucosidic side chains. Atomic force microscopy (AFM) and high-performance gel permeation chromatography–refractive index–multi-angle laser light scattering (HPGPC-RI-MALLS) also revealed LeP-N2 exhibiting a compact unit in aqueous solution. This (1→6)-β-d-glucan was tested for antioxidant activities with IC₅₀ at 157 μg/mL. Moreover, RAW 264.7 macrophage activation indicated that the release of nitric oxide (NO) and reactive oxygen species (ROS) were markedly increased with no cytotoxicity at a dose of 100 μg/mL. These findings suggest that the (1→6)-β-d-glucans obtained from Lentinus edodes could serve as potential agents in the fields of functional foods or medicine.

Agaricus bisporus and its by-products as a source of valuable extracts and bioactive compounds

Edible mushrooms constitute an appreciated nutritional source for humans due to their low caloric intake and their high content in carbohydrates, proteins, dietary fibre, phenolic compounds, polyunsaturated fatty acids, vitamins and minerals. It has been also demonstrated that mushrooms have health-promoting benefits. Cultivation of mushrooms, especially of the most common species Agaricus bisporus, represents an increasingly important food industry in Europe, but with a direct consequence in the increasing amount of by-products from their industrial production. This review focuses on collecting and critically investigating the current data on the bioactive properties of Agaricus bisporus as well as the recent research for the extraction of valuable functional molecules from this species and its by-products obtained after industrial processing. The state of the art regarding the antimicrobial, antioxidant, anti-allergenic and dietary compounds will be discussed for novel applications such as nutraceuticals, additives for food or cleaning products.

Studies on structure and antioxidant properties of a heteroglycan isolated from wild edible mushroom Lentinus sajor-caju

A water-soluble heteroglycan (PS-I) isolated from the aqueous extract of a wild edible mushroom Lentinus sajor-caju showed average molecular weight ∼1.79×10⁵Da. The structure of the polysaccharide was determined using chemical and 1D/2D NMR experiments. Acid hydrolysis indicated the presence of d-glucose, d-galactose, d-mannose, and l-fucose in a molar ratio of nearly 4:4:1:1 respectively. The presence of terminal Fucp, terminal Galp, (1→3)-Glcp, (1→6)-Galp, (1→6)-Glcp, (1→4,6)-Galp, and (1→2,4)-Manp moieties were established from methylation analysis. The chemical and NMR analyses indicated that the PS-I was a heteroglycan composed of a repeating unit with backbone chain of three (1→6)-α-d-galactopyranosyl residues, two (1→6)-β-d-glucopyranosyl residues, one (1→4)-α-d-mannopyranosyl residue, and two (1→3)-β-d-glucopyranosyl residues where one (1→6)-α-d-galactopyranosyl residue was branched at O-4 position with terminal α-l-fucopyranosyl residue and (1→4)-α-d-mannopyranosyl residue was branched at O-2 position with terminal α-d-galactopyranosyl residue and the structure was proposed as; The PS-I is a moderate antioxidant compound which showed DPPH radical scavenging activity, hydroxyl radical scavenging activity, ABTS radical scavenging property, reducing power, and ferrous ion chelating ability.

Antimelanogenic, Antioxidant and Antiproliferative Effects of Antrodia camphorata Fruiting Bodies on B16-F0 Melanoma Cells

Antrodia camphorata is a fungus that is endemic to Taiwan, and its fruiting body has been used as a folk medicine for the prevention or treatment of diverse diseases. The present study is aimed at investigating the antimelanogenesis and antioxidation effect of the ethanolic extract of Antrodia camphorata fruiting body (EE-AC), as well as its antiproliferation effects in B16-F0 melanoma cells. Regarding antimelanogenic effects, EE-AC had effective cupric ions reducing capacity and expressed more potent inhibitory effect than kojic acid on mushroom tyrosinase activity. Moreover, EE-AC significantly inhibited cellular tyrosinase activity and the melanin content in B16-F0 cells at 12.5 μg/mL concentration without cell toxicities. Regarding antioxidant effects, EE-AC exhibited potent DPPH radical- and SOD-like-scavenging activities. Regarding antiproliferative effects, EE-AC exhibited a selective cytotoxic effect and markedly inhibited the migration ability of B16-F0 cells. EE-AC increased the population of B16-F0 cells at sub-G1 phase of the cell cycle. EE-AC also caused the increase of early apoptotic cells and chromatin condensation, which indicated the apoptotic effects in B16-F0 cells. We demonstrated that EE-AC possessed antimelanogenic, antioxidant and anti-skin cancer actions. The results would contribute to the development and application of cosmetics, healthy food and pharmaceuticals.

Dextran: Influence of Molecular Weight in Antioxidant Properties and Immunomodulatory Potential

Dextrans (α-d-glucans) extracted from Leuconostoc mesenteroides, with molecular weights (MW) of 10 (D10), 40 (D40) and 147 (D147) kDa, were evaluated as antioxidant, anticoagulant and immunomodulatory drugs for the first time. None presented anticoagulant activity. As for the antioxidant and immunomodulatory tests, a specific test showed an increase in the dextran activity that was proportional to the increase in molecular weight. In a different assay, however, activity decreased or showed no correlation to the MW. As an example, the reducing power assay showed that D147 was twice as potent as other dextrans. On the other hand, all three samples showed similar activity (50%) when it came to scavenging the OH radical, whereas only the D10 sample showed sharp activity (50%) when it came to scavenging the superoxide ion. D40 was the single dextran that presented with immunomodulatory features since it stimulated the proliferation (~50%) of murine macrophages (RAW 264.7) and decreased the release of nitric oxide (~40%) by the cells, both in the absence and presence of lipopolysaccharides (LPS). In addition, D40 showed a greater scavenging activity (50%) for the hydrogen peroxide, which caused it to also be the more potent dextran when it came to inhibiting lipid peroxidation (70%). These points toward dextrans with a 40 kDa weight as being ideal for antioxidant and immunomodulatory use. However, future studies with the D40 and other similarly 40 kDa dextrans are underway to confirm this hypothesis.

Extraction, isolation and MALDI-QTOF MS/MS analysis of β-d-Glucan from the fruiting bodies of Daedalea quercina

We report for the first time the extraction, isolation, and the proposed structure of a polysaccharide from the fruiting bodies of Daedalea quercina. The monosaccharide composition of D. quercina isolate (DQW1Pa1) was mainly glucose as identified using GC-MS. FTIR-ATR spectroscopy and absolute configuration studies showed that this polysaccharide is a β-d-glucan. Its average molecular weight obtained using size exclusion chromatography was 1.6×10⁴Da, consistent with glucans derived from the order Polyporaceae. MALDI-QTOF MS/MS was carried out to identify the linkage and connectivity of the glucose units. Collision Induced Dissociation (CID) of selected parent ions of different oligosaccharide lengths showed the presence of characteristic glycosidic bond cleavages B_n/C_n, the linear backbone by 1-6 linkage, and the cross-ring fragment, ^0,3A_n. Presence of branching unit was identified from high intensity ^0,3A₄ fragment and verified from diagnostic ion of [D] and [D-H₂O] types. To confirm the linkage assignment obtained using MALDI-QTOF MS/MS, DQW1Pa1 was subjected to methylation analysis. Results showed the presence of 1-3, 1-6, 1- and 1-3-6 linked glucose in the order of decreasing abundance, respectively. The repeating unit of isolate DQW1Pa1 was deduced as 1-3 linked linear glucose backbone with branches composed of three 1-3 linked glucose units connected to backbone by 1-6 linkage.

Studies on antioxidative and immunostimulating fucogalactan of the edible mushroom Macrolepiota dolichaula

A water soluble fucogalactan (PS-II) of an average molecular weight ∼1.2×10(5) Da was isolated from the aqueous extract of an edible mushroom Macrolepiota dolichaula. It was composed of fucose, galactose and 3-O-methyl galactose in a molar ratio of nearly 1:4:1. Structural characterization of PS-II was carried out using total hydrolysis, methylation analysis, Smith degradation, and 1D/2D NMR experiments. These results indicated that the proposed repeating unit of the PS-II had a backbone chain consisting of four (1→6)- linked α-d-Galp residues, one residue methylated at O-3, and another one substituted at O-2 by (1→2)-α-d-Galp residue, which is terminated with a α-l-Fucp moiety. The PS-II exhibited the antioxidant properties in different in vitro test systems, and also showed in vitro macrophage activation in RAW 264.7 cell line as well as splenocyte and thymocyte activation in mouse cell culture medium.