Bioactive mushroom polysaccharides as antitumor: an overview

Effect of sodium and calcium on polysaccharide production and the activities of enzymes involved in the polysaccharide synthesis of Lentinus edodes

Lentinan is a Lentinus edodes secondary metabolite that can regulate human immune function, but yields are low. Here, the effects of Ca²⁺ and Na⁺ on L. edodes lentinan content were investigated. Metal ion concentrations and induction times were optimized according to mycelial biomass, and intracellular polysaccharide (IPS), extracellular polysaccharide (EPS), and total polysaccharide (TPS) content. The activities and gene expression of phospho-glucose isomerase (PGI), phosphoglucomutase (PGM), and UDP-glcpyrophosphorylase (UGP) were also measured. Ca²⁺ and Na⁺ concentration and induction time affected biomass, IPS, and EPS concentrations. Na⁺ increased EPS, IPS and TPS, while Ca²⁺ increased biomass, IPS, and TPS. During fermentation, mycelial biomass varied greatly under Ca²⁺ induction, while IPS, EPS and TPS varied greatly under Na⁺ induction. PGM and UGP activities increased in the presence of Na⁺, while PGI increased with Ca²⁺. Compared to control samples, pgi and pgm expression under Na⁺ was greater at days 45 and 60, respectively, while under Ca²⁺, ugp expression was greater at day 45. IPS content correlated significantly with enzyme activity, while EPS correlated with PGM activity. Our data contributes to better understanding how Na⁺ and Ca²⁺ affect mycelial growth and secondary metabolite production, and of polysaccharide biosynthesis mechanisms of L. edodes.

Adjuvant Therapy With Mushroom Polysaccharides for Diabetic Complications

Background

Diabetic complications seriously endanger the health of most diabetic patients around the world. Most chemical hypoglycemic agents have adverse effects and are unable to improve the progression of diabetic complications. In recent years, a number of medicinal herbs have become increasingly popular for the treatment of diabetic complications due to their relative safety. Polysaccharides extracted from medicinal herbs with multiple pharmacological activities and low toxicity have been reported to be useful in the treatment of diabetic complications.

Methods

Primary studies with keywords including polysaccharide and diabetic complications were retrieved from the Web of Science and NCBI databases and were read and analyzed.

Results

Mushroom polysaccharides were proven to have positive effects on diabetic complications.

Conclusions

We studied the effects of mushroom polysaccharides on hyperglycemia and as adjuvant therapies for diabetic complications and summarized the applications and limitations of mushroom polysaccharides to better understand their application for the treatment of diabetic complications.

Recent Advances in Chain Conformation and Bioactivities of Triple-Helix Polysaccharides

Natural polysaccharides derived from renewable biomass sources are regarded as environmentally friendly and sustainable polymers. As the third most abundant biomacromolecule in nature, after proteins and nucleic acids, polysaccharides are also closely related with many different life activities. In particular, β-glucans are one of the most widely reported bioactive polysaccharides and are usually considered as biological response modifiers. Among them, β-glucans with triple-helix conformation have been the hottest and most well-researched polysaccharides at present, especially lentinan and schizophyllan, which are clinically used as cancer therapies in some Asian countries. Thus, creation of these active triple-helix polysaccharides is beneficial to the research and development of sustainable "green" biopolymers in the fields of food and life sciences. Therefore, full fundamental research of triple-helix polysaccharides is essential to discover more applications for polysaccharides. In this Review, the recent research progress of chain conformations, bioactivities, and structure-function relationships of triple-helix β-glucans is summarized. The main contents include the characterization methods of the macromolecular conformation, proof of triple helices, bioactivities, and structure-function relationships. We believe that the governments, enterprises, universities, and institutes dealing with the survival and health of human beings can expect the development of natural bioproducts in the future. Hence, a deep understanding of β-glucans with triple-helix chain conformation is necessary for application of natural medicines and biologics for a sustainable world.

Metabolic Response of Pleurotus ostreatus to Continuous Heat Stress

Heat stress seriously threatens the growth of Pleurotus ostreatus. Various studies have been performed to study the resistance of P. ostreatus to heat stress. Here, the metabolome was evaluated to determine the response of P. ostreatus mycelia to heat stress at different times (6, 12, 24, 48 h). More than 70 differential metabolites were detected and enriched in their metabolic pathways. Dynamic metabolites changes in enrichment pathways under heat stress showed that heat stress enhanced the degradation of unsaturated fatty acids and nucleotides, increased the content of amino acids and vitamins, and accelerated glycolysis and the tricarboxylic acid cycle in P. ostreatus. The time course changes of P. ostreatus metabolites under continuous heat stress demonstrated that amino acids continuously changed with heat stress, nucleotides clearly changed with heat stress at 12 and 48 h, and lipids exhibited an increasing trend with prolonged heat stress, while few types saccharides and vitamins changed under heat stress. Additionally, heat-treated P. ostreatus produced salicylic acid and other stress-resistant substances that were reported in plants. This study first reported the metabolites changes in P. ostreatus mycelia during 48 h of heat stress. The metabolic pathways and substances that changed with heat stress in this research will aid future studies on the resistance of P. ostreatus and other edible fungi to heat stress.

Purification, characterization, and bioactivity of two new polysaccharide fractions from Thelephora ganbajun mushroom

Two new polysaccharide fractions (TZP1-1 and TZP2-1) were obtained from the fruiting bodies of Thelephora ganbajun using DEAE-52 cellulose and Superdex 200 columns chromatography. The physiochemical characterization and biological activities of TZP1-1 and TZP2-1 were investigated. The relative molecular weight of TZP1-1 and TZP2-1 were 2.07 × 10⁶ and 4,886 Da, respectively. TZP1-1 included mannose, rhamnose, galactose, and xylose (4:1:83.9:7.5), while TZP2-1 included mannose, glucose, galactose, and xylose (5.4:1:79.0:8.1). The Congo red experiment results confirmed that TZP2-1 had triple helix conformation. Furthermore, both TZP1-1 and TZP2-1 showed a certain cytotoxicity on HeLa and SH-SY5Y cells, while they exhibited a stronger inhibitory effect on HeLa than SH-SY5Y. Besides, the cytotoxicity of TZP1-1 was better than that of TZP2-1. Moreover, both of them exhibited a moderate inhibitory effect on α-amylase and α-glucosidase. These findings could promote the application of polysaccharides from T. ganbajun. PRACTICAL APPLICATIONS: Thelephora ganbajun is an edible fungus widely distributed in Southwestern China. T. ganbajun polysaccharides as important active ingredients have not been reported. In this current study, two polysaccharides fractions (TZP1-1 and TZP2-1) were characterized, and their cytotoxicities and antidiabetic effect were also assayed. These findings could promote polysaccharides from T. ganbajun to be better application.

Aromatic compounds from the sclerotia of Inonotus obliquus

Three new aromatic compounds (1a/1b, 2) including a pair of enantiomers (1a/1b), were isolated from Inonotus obliquus. The structures of the new compounds were elucidated by extensive spectroscopic analyses, and the absolute configurations of 1a and 1b were determined by electronic circular dichroism (ECD) calculated. All isolates were evaluated for their cytotoxic activities against Hep3B and HepG2 cell lines. Compounds 1b and 2 showed weak cytotoxicity toward the Hep3B cells at 25 μM.

Study on antidepressant-like effect of protoilludane sesquiterpenoid aromatic esters from Armillaria Mellea

Armillaria mellea, also known as Hazel mushroom, is a delicious food material and traditional herbal medicine in East Asia. Protoilludane sesquiterpenoid aromatic esters from A. mellea (PSAM) are the main active components with antibacterial and anticancer activities. This study explored the antidepressant-like activities of PSAM and its possible mechanisms of action using the open field test (OFT), tail suspension test (TST) and forced swimming test (FST) in mice for the first time. The results revealed that PSAM (1 mg/kg, i.p.) exhibited markedly antidepressant-like activity, which could be reversed by pretreatment with haloperidol (a non-selective D₂ receptor antagonist), bicuculline (a competitive GABA antagonist), NMDA (an agonist at the glutamate site). Meanwhile, PSAM also effectively increased the hippocampus dopamine (DA) and γ-aminobutyric acid (GABA) and decreased the hippocampus glutamate (Glu) levels of mice, indicating that the antidepressant-like effect of PSAM might be mediated by the DAergic, GABAergic and Gluergic systems.

Bioactivity-based analysis and chemical characterization of cytotoxic compounds from a poisonous mushroom, Amanita spissacea, in human lung cancer cells in vitro

As part of our systematic study on Korean toxic mushrooms, bioactivity-guided fractionation of the MeOH extract of Amanita spissacea (Amanitaceae) fruiting bodies and chemical investigation of its cytotoxic fractions led to the isolation of (9E)-8-oxo-9-octadecenoic acid (1), (10E)-9-oxo-10-octadecenoic acid (2), (9E)-8-oxo-9-octadecenoate methyl ester (3), (9Z)-9-octadecenoate-(2'S)-2',3'-dihydroxypropyl ester (4), (9Z)-9-octadecenoic acid (5), and palmitic acid (6). The structures of the isolates were elucidated by NMR spectroscopic analysis and LC/MS analysis. Among the isolated compounds, compounds 1 and 2 exhibited the most potent cytotoxic activity in all human lung cancer cell lines examined, with IC₅₀ values ranging from 255.7 to 321.0 μM and 250.2 to 322.5 μM, respectively. The cytotoxicity of these compounds was also found to be mediated by apoptosis associated with caspase-3 activation. These findings provide experimental evidence suggesting the potential of A. spissacea as a promising natural source for the discovery of novel anticancer drug candidates.

Agaricus bisporus-derived β-glucan enter macrophages and adipocytes by CD36 receptor

β-glucans are a heterogeneous group of natural polysaccharides. They are ubiquitously found in bacterial or fungal cell walls, cereals, seaweed, and mushrooms. The beneficial role of β-glucan in tumor, insulin resistance, dyslipidemia, hypertension, and obesity is being continuously documented. Ample evidence showed that β-glucan could act on several receptors, such as Dectin, complement receptor (CR3), TLR-2, 4, 6 and scavenger. Based on the above, we wanted to explore whether agaricus bisporus-derived β-glucan acted on these receptors on Raw 264.7 macrophages and 3T3-L1 adipocytes.

Optimization of polysaccharides extraction from quince peels: partial characterization, antioxidant and antiproliferative properties

In this study, Box-Behnken Design was used to optimize the ultrasonic extraction of polysaccharides from quince peels (QPPs) by ascorbic acid and the effect of extraction temperature, extraction time and pH was evaluated. Under optimized conditions of temperature 90 °C, 60 min sonication time and pH = 3.26, the extraction yield, the galacturonic acid yield and the concentration of sample required to scavenge 50% of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS) values of QPPs were respectively 10.25%, 3.86% and 1.35 mg/mL. The QPPs extracted under optimum conditions was characterized by Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (¹H NMR) and Size exclusion chromatography (SEC/MALS/VD/DRI). The monosaccharide analysis revealed that arabinose was the most abundant, followed by galactose, glucose, mannose and xylose. Moreover, QPPs showed significant antioxidant activities (2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric- reducing antioxidant power (FRAP)) and reduced viability of human Caco-2 and murine B-16 cell lines in a dose-dependent manner. Hence QPPs could be used as antitumor agent in functional foods andpharmaceutical industries.

Artesunate ameliorates high glucose-induced rat glomerular mesangial cell injury by suppressing the TLR4/NF-κB/NLRP3 inflammasome pathway

Inflammatory response is important for the development and progression of diabetic nephropathy (DN). Artesunate (ART), an antimalarial drug, possesses anti-inflammatory effect and exhibits protective effect on chronic kidney diseases. However, the effect of ART on DN is unknown. The aim of the present study was to evaluate the effect and the molecular mechanism of ART on DN in an in vitro model. The rat mesangial cell line, HBZY-1, was induced by high glucose (HG; 30 mM d-glucose) in the presence or absence of ART (15 and 30 μg/ml) and incubated for 24 h. We found that HG induced the proliferation of HBZY-1 cells, while treatment with ART inhibited the cell proliferation. Treatment with ART inhibited HG-induced inflammatory cytokines production and expression of extracellular matrix (ECM). Besides, HG induced reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and inhibited the superoxide dismutase (SOD) activity of HBZY-1 cells, and the effects were attenuated by ART treatment. ART decreased HG-induced the expression levels of toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), nuclear factor κB (NF-κB) p-p65, and nod-like receptor protein 3 (NLRP3). Inhibition of the TLR4/NF-κB pathway suppressed NLRP3 inflammasome in HBZY-1 cells. In conclusion, ART exhibited protective effect on HG-induced HBZY-1 cells by inhibiting the inflammatory response, oxidative stress and ECM accumulation. The TLR4/NF-κB/NLRP3 inflammasome pathway was involved in the protective effect of ART. The results suggested that ART might be a potential therapy agent for the DN treatment.