Agaricus brasiliensis-derived β-glucans exert immunoenhancing effects via a dectin-1-dependent pathway

Effects of Outdoor-Grown Royal Sun Medicinal Mushroom Agaricus brasiliensis KA21 (Agaricomycetes) Fruiting Body on Canine Malassezia Dermatitis

Brazil-grown outdoor-cultivated Agaricus brasiliensis KA21 fruiting body (KA21) significantly increases the production of serum anti-beta-glucan antibody. Therefore, KA21 ingestion may be useful for the prevention and alleviation of fungal infections. This study aimed to determine the effects of KA21 in fungal infections in animals. KA21 was administered to nine dogs infected with Malassezia. Notably, the anti-beta-glucan antibody titer remained unchanged or tended to decrease in the oral steroid arm, whereas in the non-steroid arm, antibody titer increased in almost all animals after KA21 ingestion. Dogs showing improved clinical symptoms exhibited increased anti-beta-glucan antibody titers. The results of this study suggest that KA21 ingestion may alleviate the symptoms of Malassezia and other fungal infections and that continuous ingestion may help prolong recurrence-free intervals. Additionally, the ingestion of KA21 during oral steroid dosage reduction or discontinuation may enable smoother steroid withdrawal.

Hot Water Extract of the Caterpillar Medicinal Mushroom Cordyceps militaris (Ascomycetes) Fruiting Body Activates Myeloid Dendritic Cells through A Dectin-1-Mediated Pathway

The traditional use of Cordyceps militaris, an entomopathogenic fungus, in East Asian medicine has been well documented. Our previous study revealed that the fruiting body powder of C. militaris, referred to as Ryukyu-kaso, contains 1,3-β-glucan and stimulates bone marrow-derived dendritic cells via a dectin-1-dependent pathway. However, the immunomodulatory effects of soluble 1,3-β-glucan in Ryukyu-kaso and the underlying mechanisms remain unclear. In the present study, we aimed to investigate the immunostimulatory effects of the hot water extract of C. militaris fruiting body (RK-HWE) on bone marrow-derived dendritic cells and the involvement of the β-glucan receptor dectin-1. Our findings revealed that the hot water extract of C. militaris fruiting body contains soluble 1,3-β-glucan and potently induces bone marrow-derived dendritic cells to secrete both pro-inflammatory and immunoregulatory cytokines. Compared with the control, RK-HWE significantly increased the secretion of tumor necrosis factor (TNF)-α, interleukin (IL)-6, interfer-on-в, IL-12p70, and granulocyte-macrophage colony-stimulating factor (all ,i>p < 0.05), with TNF-α secretion increasing from 7.82 ± 1.57 (control) to 403.7 ± 59.7 pg/mL with (RK-HWE; p < 0.001). Notably, these immunostimulatory effects of RK-HWE were completely abolished in bone marrow-derived dendritic cells derived from dectin-1-knockout mice (p < 0.001, all cytokines), suggesting that dectin-1 is essential for immunomodulation induced by RK-HWE. These findings provide novel insights into the mechanisms underlying the immunostimulatory effects of RK-HWE and highlight its potential as a natural immunomodulatory agent for various therapeutic applications.

Refinement and complete solution NMR analysis of the structure of a 6-branched 1,3-β-D-glucan (OL-2) isolate from Omphalialapidescens

OL-2 is a water-soluble β-glucan produced by Omphalia lapidescens. This versatile glucan has potential applications in various industries, including food, cosmetics, and pharmaceuticals. In addition, OL-2 is known for its promising applications as a biomaterial and drug, owing to its reported antitumor and antiseptic properties. Although the biological activities of β-glucans vary depending on their primary structure, holistic clarification of OL-2 via solution NMR spectroscopy to ascertain its complete and unambiguous structure has not yet been achieved. In this study, a chain of solution NMR techniques, such as correlation spectroscopy, total correlation spectroscopy (TOCSY), nuclear Overhauser effect and exchange spectroscopy, ¹³C-edited heteronuclear single quantum coherence (HSQC), HSQC-TOCSY, heteronuclear multiple bond correlation, and heteronuclear 2-bond correlation pulse sequences were used to unambiguously assign all ¹H and ¹³C atoms in OL-2. Based on our investigation, OL-2 consists of a 1,3-β-glucan backbone chain decorated with a single 6-branched β-glucosyl side unit on every fourth residue.

β-1,6-Glucan From Pleurotus eryngii Modulates the Immunity and Gut Microbiota

Polysaccharides from Pleurotus eryngii exhibit a variety of biological activities. Here, we obtained a homogeneous branched β-1,6-glucan (APEP-A-b) from the fruiting bodies of P. eryngii and investigated its effect on immunity and gut microbiota. Our results showed that APEP-A-b significantly increases splenic lymphocyte proliferation, NK cell activity and phagocytic capacity of peritoneal cavity phagocytes. Furthermore, we found that the proportion of CD4⁺ and CD8⁺ T cells in lamina propria are significantly increased upon APEP-A-b treatment. Additionally, APEP-A-b supplementation demonstrated pronounced changes in microbiota reflected in promotion of relative abundances of species in the Lachnospiraceae and Rikenellaceae families. Consistently, APEP-A-b significantly increased the concentration of acetic and butyric acid in cecum contents. Overall, our results suggest that β-1,6-glucan from P. eryngii might enhance immunity by modulating microbiota. These results are important for the processing and product development of P. eryngii derived polysaccharides.

Role of interleukin-6 in antigen-specific mucosal immunoglobulin A induction by cationic liposomes

The COVID-19 pandemic, caused by a highly virulent and transmissible pathogen, has proven to be devastating to society. Mucosal vaccines that can induce antigen-specific immune responses in both the systemic and mucosal compartments are considered an effective measure to overcome infectious diseases caused by pathogenic microbes. We have recently developed a nasal vaccine system using cationic liposomes composed of 1,2-dioleoyl-3-trimethylammonium-propane and cholesteryl 3β-N-(dimethylaminoethyl)carbamate in mice. However, the comprehensive molecular mechanism(s), especially the host soluble mediator involved in this process, by which cationic liposomes promote antigen-specific mucosal immune responses, remain to be elucidated. Herein, we show that intranasal administration of cationic liposomes elicited interleukin-6 (IL-6) expression at the site of administration. Additionally, both nasal passages and splenocytes from mice nasally immunized with cationic liposomes plus ovalbumin (OVA) were polarized to produce IL-6 when re-stimulated with OVA in vitro. Furthermore, pretreatment with anti-IL-6R antibody, which blocks the biological activities of IL-6, attenuated the production of OVA-specific nasal immunoglobulin A (IgA) but not OVA-specific serum immunoglobulin G (IgG) responses. In this study, we demonstrated that IL-6, exerted by nasally administered cationic liposomes, plays a crucial role in antigen-specific IgA induction.

Insights on the Functional Role of Beta-Glucans in Fungal Immunity Using Receptor-Deficient Mouse Models

Understanding the host anti-fungal immunity induced by beta-glucan has been one of the most challenging conundrums in the field of biomedical research. During the last couple of decades, insights on the role of beta-glucan in fungal disease progression, susceptibility, and resistance have been greatly augmented through the utility of various beta-glucan cognate receptor-deficient mouse models. Analysis of dectin-1 knockout mice has clarified the downstream signaling pathways and adaptive effector responses triggered by beta-glucan in anti-fungal immunity. On the other hand, assessment of CR3-deficient mice has elucidated the compelling action of beta-glucans in neutrophil-mediated fungal clearance, and the investigation of EphA2-deficient mice has highlighted its novel involvement in host sensing and defense to oral mucosal fungal infection. Based on these accounts, this review focuses on the recent discoveries made by these gene-targeted mice in beta-glucan research with particular emphasis on the multifaceted aspects of fungal immunity.

Split Enzyme-Based Biosensors for Structural Characterization of Soluble and Insoluble β-Glucans

β-Glucan is widely distributed in various plants and microorganisms and is composed of β-1,3-linked d-glucose units. It may have a branched short or long side chain of glucose units with β-1,6- or β-1,4-linkage. Numerous studies have investigated different β-glucans and revealed their bioactivities. To understand the structure-function relationship of β-glucan, we constructed a split-luciferase complementation assay for the structural analysis of long-chain β-1,6-branched β-1,3-glucan. The N- and C-terminal fragments of luciferase from deep-sea shrimp were fused to insect-derived β-1,3-glucan recognition protein and fungal endo-β-1,6-glucanase (Neg1)-derived β-1,6-glucan recognition protein, respectively. In this approach, two β-glucan recognition proteins bound to β-glucan molecules come into close proximity, resulting in the assembly of the full-length reporter enzyme and induction of transient luciferase activity, indicative of the structure of β-glucan. To test the applicability of this assay, β-glucan and two β-glucan recognition proteins were mixed, resulting in an increase in the luminescence intensity in a β-1,3-glucan with a long polymer of β-1,6-glucan in a dose-dependent manner. This simple test also allows the monitoring of real-time changes in the side chain structure and serves as a convenient method to distinguish between β-1,3-glucan and long-chain β-1,6-branched β-1,3-glucan in various soluble and insoluble β-glucans.

Latent 1,3-β-D-glucan acts as an adjuvant for allergen-specific IgE production induced by Japanese cedar pollen exposure

BACKGROUND

The pollen grains of several plant species contain 1,3-β-D-glucan (BG). BG activates dendritic cells (DCs) and subsequently regulates the innate immune responses. Within Japan, the most common disease associated with type-I hypersensitivity is Japanese cedar pollinosis. However, the role of BG in Japanese cedar pollen (JCP) remains unclear. This study examined the localization and immunological effects of BG in JCP.

METHODS

The localization of BG in JCP grain was determined by immunohistochemical staining using a soluble dectin-1 protein probe and a BG recognition protein (BGRP). The content of BG extracted from JCP was measured by a BGRP-based ELISA-like assay. The cytokine production by bone marrow-derived DCs (BMDCs) obtained from wild-type and BG receptor (dectin-1) knock-out mice was examined in vitro. The mice were intranasally administered JCP grains and the specific serum Ig levels were then quantified.

RESULTS

BG was detected in the exine and cell wall of the generative cell and tube cell of the JCP grain. Moreover, BG in the exine stimulated production of TNF-α and IL-6 in the BMDCs via a dectin-1-dependent mechanism. Meanwhile, JCP-specific IgE and IgG were detected in the serum of wild-type mice that had been intranasally administered with JCP grains. These mice also exhibited significantly enhanced sneezing behavior. However, dectin-1 knock-out mice exhibited significantly lower JCP-specific IgE and IgG levels compared to wild-type mice.

CONCLUSIONS

Latent BG in JCP can act as an adjuvant to induce JCP-specific antibody production via dectin-1.

Mushrooms and immunity

In the wide field of nutraceuticals, the effects of mushrooms on immunity, cancer and including autoimmunity have been proposed for centuries but in recent years a growing interest has led scientists to elucidate which specific compounds have bioactive properties and through which mechanisms. Glucans and specific proteins are responsible for most of the biological effects of mushrooms, particularly in terms of immunomodulatory and anti-tumor results. Proteins with bioactive effects include lectins, fungal immunomodulatory proteins (FIPs), ribosome inactivating proteins (RIPs), ribonucleases, laccases, among others. At the present status of knowledge, numerous studies have been performed on cell lines and murine models while only a few clinical trials have been conducted. As in most cases of dietary components, the multitude of variables implicated in the final effect and an inadequate standardization are expected to affect the observed differences, thus making the available evidence insufficient to justify the treatment of human diseases with mushrooms extracts. We will herein provide a comprehensive review and critically discussion the biochemical changes induced by different mushroom compounds as observed in in vitro studies, particularly on macrophages, dendritic cells, T cells, and NK cells, compared to in vivo and human studies. Additional effects are represented by lipids which constitute a minor part of mushrooms but may have a role in reducing serum cholesterol levels or phenols acting as antioxidant and reducing agents. Human studies provide a minority of available data, as well illustrated by a placebo-controlled study of athletes treated with β-glucan from Pleurotus ostreatus. Variables influencing study outcomes include different mushrooms strains, growing conditions, developmental stage, part of mushroom used, extraction method, and storage conditions. We foresee that future rigorous research will be needed to determine the potential of mushroom compounds for human health to reproduce the effects of some compounds such as lentinan which a metaanalysis demonstrated to increase the efficacy of chemotherapy in the treatment of lung cancer and in the improvement of the patients quality of life.

Agaricus brasiliensis Mushroom Protects Against Sepsis by Alleviating Oxidative and Inflammatory Response

Sepsis is characterized by the host's dysregulated immune response to an infection followed by a potentially fatal organ dysfunction. Although there have been some advances in the treatment of sepsis, mainly focused on broad-spectrum antibiotics, mortality rates remain high, urging for the search of new therapies. Oxidative stress is one of the main features of septic patients, so antioxidants can be a good alternative treatment. Agaricus brasiliensis is a nutraceutical rich in bioactive compounds such as polyphenols and polysaccharides, exhibiting antioxidant, antitumor, and immunomodulatory activities. Here, we investigated the immunomodulatory and antioxidant effects of A. brasilensis aqueous extract in the cecal ligation and puncture (CLP) sepsis model. Our data showed that aqueous extract of A. brasiliensis reduced systemic inflammatory response and improved bacteria clearance and mice survival. In addition, A brasiliensis decreased the oxidative stress markers in serum, peritoneal cavity, heart and liver of septic animals, as well as ROS production (in vitro and in vivo) and tert-Butyl hydroperoxide-induced DNA damage in peripheral blood mononuclear cells from healthy donors in vitro. In conclusion, the aqueous extract of A. brasiliensis was able to increase the survival of septic animals by a mechanism involving immunomodulatory and antioxidant protective effects.

Development of a novel β-1,6-glucan-specific detection system using functionally-modified recombinant endo-β-1,6-glucanase

β-1,3-d-Glucan is a ubiquitous glucose polymer produced by plants, bacteria, and most fungi. It has been used as a diagnostic tool in patients with invasive mycoses via a highly-sensitive reagent consisting of the blood coagulation system of horseshoe crab. However, no method is currently available for measuring β-1,6-glucan, another primary β-glucan structure of fungal polysaccharides. Herein, we describe the development of an economical and highly-sensitive and specific assay for β-1,6-glucan using a modified recombinant endo-β-1,6-glucanase having diminished glucan hydrolase activity. The purified β-1,6-glucanase derivative bound to the β-1,6-glucan pustulan with a KD of 16.4 nm We validated the specificity of this β-1,6-glucan probe by demonstrating its ability to detect cell wall β-1,6-glucan from both yeast and hyphal forms of the opportunistic fungal pathogen Candida albicans, without any detectable binding to glucan lacking the long β-1,6-glucan branch. We developed a sandwich ELISA-like assay with a low limit of quantification for pustulan (1.5 pg/ml), and we successfully employed this assay in the quantification of extracellular β-1,6-glucan released by >250 patient-derived strains of different Candida species (including Candida auris) in culture supernatant in vitro We also used this assay to measure β-1,6-glucan in vivo in the serum and in several organs in a mouse model of systemic candidiasis. Our work describes a reliable method for β-1,6-glucan detection, which may prove useful for the diagnosis of invasive fungal infections.

Enhancement of glucose homeostasis through the PI3K/Akt signaling pathway by dietary with Agaricus blazei Murrill in STZ-induced diabetic rats

Agaricus blazei Murrill (ABM) is an edible fungus. This study investigated the protective role of ABM fruiting body against streptozotocin (STZ)-induced diabetic rats. After 4 weeks of ABM supplement, glucose homeostasis was improved in diabetic rats. Quantitative real-time and Western blot analyses suggested that ABM could promote the gene and protein expression level of insulin receptor, pyruvate dehydrogenase kinase, phospho-kinase B, kinase B, phosphatidylinositol 3-kinase, insulin receptor substrate 1, glucose transporter-4, and glutamine synthetase, while inhibiting the expression of glycogen synthase kinase 3β and c-jun N-terminal kinase 1 and 2. According to multivariate and univariate statistical analysis, liver metabolite profiles of the normal and diabetic rats fed basal and experimental diet were clearly separated. The differential liver metabolites from diabetic rats fed basal and ABM diet-related pathways including the glycolysis pathway, pentose phosphate pathway, tricarboxylic acid cycle, and oxidative phosphorylation were analyzed. A total of 18 potential biomarker metabolites were identified as differential biomarkers associated with ABM supplement diet.

Assessment of antioxidant and antidiabetic properties of Agaricus blazei Murill extracts

Agaricus blazei Murill (ABM), a medicinal mushroom, has beneficial effects on various human metabolic diseases. The objective of this research was to evaluate the antioxidant and antidiabetic properties of ABM extracts (ethanol extract and ethyl acetate extract). The antioxidant activities of ABM ethanol extract (EE) and ethyl acetate extract (EA) were analyzed using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydroxyl radical scavenging assays and the reducing power using K3Fe(CN)6 in vitro. Moreover, the effects of EE and EA on α-glucosidase inhibitory activity and improving glucose uptake by HepG2 cells were investigated in vitro. The EA showed stronger antioxidant activity, as well as inhibition of α-glucosidase, compared to EE. The analysis of glucose uptake by HepG2 cells showed that EA had significant glucose-lowering activity and exhibited no difference compared to metformin. The results suggest that ABM extracts could improve the glucose uptake by HepG2 cells and thereby alleviate postprandial hyperglycemia. This investigation provides a strong rationale for further studies on the application of ABM to control type 2 diabetes.

The cooperative induction of macrophage activation by fucoidan derived from Cladosiphon okamuranus and β-glucan derived from Saccharomyces cerevisiae

The present study investigated immune stimulatory effects of Cladosiphon okamuranus-derived fucoidan to activate murine macrophage-like cell line RAW264, and the functional relationship with zymosan, a Saccharomyces cerevisiae-derived β-glucan. The production of nitric oxide (NO) and tumor necrosis factor-α (TNF-α) in RAW264 cells were remarkably enhanced in the presence of 10 μg/mL fucoidan, and the stimulatory effects of fucoidan were maximally augmented in combinational treatment with 500 ng/mL zymosan, whereas any TLR ligands had no those effects. Confocal microscopic analyses suggested that fucoidan bound on plasma membrane, and it was estimated that some cell surface molecules acted as receptor for fucoidan because cytochalasin D, an inhibitor of phagocytosis, did not affect the immune enhancing activities, whereas methyl-β-cyclodextrin (MβCD), a general agent for disruption of lipid rafts, diminished that. Furthermore, it was revealed that the additive effects of zymosan on the immune activation with fucoidan was thought to be mediated by dectin-1 based on the results with dectin-1-knockdown RAW264 cells. All of results suggested that fucoidan and some kinds of β-glucan would cooperatively reinforce the activity of innate immune cells via interactive receptor crosstalk.

Xinjiang herbal tea exerts immunomodulatory activity via TLR2/4-mediated MAPK signaling pathways in RAW264.7 cells and prevents cyclophosphamide-induced immunosuppression in mice

ETHNOPHARMACOLOGICAL RELEVANCE

A multi-herb Chinese medicinal formula consisting of a variety of medicinal and edible materials has long been consumed as a hot drink and immune enhancer for its efficiency to increase disease resistance in Xinjiang, China. However, no fundamental data has been collected associated with traditional consumption. The present work was designed to evaluate the immunostimulatory role of Xinjiang herbal tea (XMT-WE) in RAW 264.7 macrophages and cyclophosphamide (CTX)-induced immunosuppression mice model.

MATERIALS AND METHODS

RAW 264.7 cells were treated with various concentrations of XMT-WE. Nitric oxide (NO) levels were determined using Griess reagents, and pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α were investigated with a cytometric bead array kit. The effects on mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and TNF-α were investigated. Furthermore, activation of nuclear factor (NF)-κB and AP-1 mitogen-activated protein kinase (MAPK) signaling pathways was investigated.

RESULTS

Pre-treatment with XMT-WE significantly increased secretion of NO, IL-6, and TNF-α. In addition, XMT-WE markedly increased expression of iNOS, COX-2, and TNF-α as well as AP-1 and NF-κB translocation from the cytoplasm into the nucleus, which was associated with an increase of phosphorylated ERK, JNK, and p38 as well as membrane receptors such as toll-like receptor (TLR) 2 and TLR4. Moreover, XMT-WE promoted the secretion of interleukin-2 (IL-2) and interferon-γ (IFN-γ) in cyclophosphamide (CTX)-induced immunosuppressive mice.

CONCLUSION

These results indicated that XMT-WE at 50 µg/ml exerts immunomodulatory activity via TLR2/4-mediated MAPK signaling pathways in RAW 264.7 cells. Furthermore, in vivo experiments revealed that XMT-WE at the dose of 50 and 100 mg/kg strongly stimulated inflammatory cytokines.

Agaricus brasiliensis polysaccharides stimulate human monocytes to capture Candida albicans, express toll-like receptors 2 and 4, and produce pro-inflammatory cytokines

Background

Agaricus brasiliensis is a medicinal mushroom with immunomodulatory and antitumor activities attributed to the β-glucans presented in the polysaccharide fraction of its fruiting body. Since β-glucans enhance cellular immunoresponsiveness, in this study we aimed to evaluate the effect of an acid-treated polysaccharide-rich fraction (ATF) of A. brasiliensis on the ability of human monocytes to adhere/phagocyte C. albicans yeast cells, their expression of pattern recognition receptors and their ability to produce cytokines.

Methods

Adhesion/phagocytosis of FITC-labeled C. albicans was evaluated by flow cytometry. Cells were incubated with specific fluorochrome-labeled antibodies for TLR2 and 4, βGR and MR and also evaluated by flow cytometry. Monocytes were cultured with ATF, and culture supernatants were collected for analysis of in vitro cytokine production by ELISA (TNF-α, IL-1β, IL-12 and IL-10).

Results

ATF significantly increased the adherence/phagocytosis of C. albicans by monocytes and this was associated with enhanced expression of TLR2 and TLR4, while no effect was observed on βGR or MR. Moreover, expression of TLR4 and TLR2 was associated with higher levels of in vitro production of TNF-α and IL-1, respectively. Production of IL-10 was also increased by ATF treatment, but we found no association between its production and the expression of Toll-like receptors.

Conclusion

Our results provided us with evidence that A. brasiliensis polysaccharides affect human monocytes probably through the modulation of Toll-like receptors.

Control of Haemonchus contortus in sheep using basidiocarps of Agaricus blazei Murril

OBJECTIVE

This study evaluated the effects in vitro and in vivo of Agaricus blazei against Haemonchus contortus in sheep.

METHODS

The in vitro efficacy of aqueous extract on egg hatching inhibition (EHI) was investigated and after 72 h incubation with varying concentrations the effects on, blastomeres, embryonated eggs, and first stage larvae (L1) were evaluated. Larval development inhibition (LDI) for dry powder and the aqueous extract were evaluated in fecal cultures of sheep infected with H. contortus. In vivo efficacy was determined by reduction in fecal egg count (FEC). Lambs were treated with powder A. blazei (11.4 g/kg pc) or trichlorfon, or were untreated and the possible toxicity of this fungus was monitored by plasmatic enzyme analysis.

RESULTS

Concentrations equal to and higher than 3.62 mg/mL and of aqueous extract were 100% effective in the EHI test. In the LDI test, LC90 was estimated for 5.66 and 106.0 mg/g fecal culture for aqueous extract and powder, respectively. The mean FEC in lambs 14 days post-treatment with A. blazei powder was significantly lower than observed for the negative control, and the serum levels of aspartate transaminase and alanine transaminase were normal.

CONCLUSION

The fungi supplementation promotes, respectively, high and moderate anthelmintic efficacy with in vitro and in vivo tests, respectively, suggesting it as an alternative or complementary treatment for haemonchosis in sheep.

Species difference in reactivity to lignin-like enzymatically polymerized polyphenols on interferon-γ synthesis and involvement of interleukin-2 production in mice

Recent studies have revealed that lignin-like polymerized polyphenols can activate innate immune systems. In this study, we aimed to evaluate whether these polymerized polyphenols could activate leukocytes from different murine strains. Splenocytes from 12 mouse strains were investigated. Our results revealed species differences in reactivity to phenolic polymers on interferon-γ (IFN-γ) release. Mice that possessed the H2(a) or H2(k) haplotype antigens were the highly responsive strains. To clarify these different points in soluble factors, multiplex cytokine profiling analysis was carried out and we identified interleukin (IL)-2 as a key molecule for IFN-γ induction by polymerized polyphenols. Furthermore, inhibition of IL-2 and IL-2Rα by neutralizing antibodies significantly decreased cytokine production in the highly responsive mice strains. Our results indicate that species difference in reactivity to phenolic polymers is mediated by adequate release of IL-2 and its receptor, IL-2Rα.

Toll-like receptor 4-related immunostimulatory polysaccharides: Primary structure, activity relationships, and possible interaction models

Toll-like receptor (TLR) 4 is an important polysaccharide receptor; however, the relationships between the structures and biological activities of TLR4 and polysaccharides remain unknown. Many recent findings have revealed the primary structure of TLR4/MD-2-related polysaccharides, and several three-dimensional structure models of polysaccharide-binding proteins have been reported; and these models provide insights into the mechanisms through which polysaccharides interact with TLR4. In this review, we first discuss the origins of polysaccharides related to TLR4, including polysaccharides from higher plants, fungi, bacteria, algae, and animals. We then briefly describe the glucosidic bond types of TLR4-related heteroglycans and homoglycans and describe the typical molecular weights of TLR4-related polysaccharides. The primary structures and activity relationships of polysaccharides with TLR4/MD-2 are also discussed. Finally, based on the existing interaction models of LPS with TLR4/MD-2 and linear polysaccharides with proteins, we provide insights into the possible interaction models of polysaccharide ligands with TLR4/MD-2. To our knowledge, this review is the first to summarize the primary structures and activity relationships of TLR4-related polysaccharides and the possible mechanisms of interaction for TLR4 and TLR4-related polysaccharides.

Effects of different extracts of the mushroom Agaricus blazei Murill on the hematologic profile of mice with Ehrlich tumor

The aim of this study was to investigate the effect of the mushroom Agaricus blazeii Murril (ABM) extracts on the hematological profile of Swiss mice bearing an Ehrlich solid tumor. Three fractions (total extract, polysaccharides, and supernatant) of ABM extracts obtained by four methods (ultrasonic or water bath, at pH 4 or pH 7) were administered to mice over 21 days. Polysaccharide solutions were analyzed by gas and liquid chromatography that showed both mannose and glucose concentrations. The method of extraction influenced the degree of glucose polymerization and the mannose/glucose relationship. The treatment with ABM supernatant at pH 7 and water bath was associated with reduced concentrations of leukocytes and lymphocytes and altered the percentage of CD4+ and CD8+ lymphocytes in Ehrlich tumor-bearing mice. The treatment with the ABM extract in water bath and ultrasound at pH 4 resulted in lower lymphocyte counts, regardless of tumor presence, and greater granulocyte values in mice with Ehrlich tumor than in controls. We concluded that different fractions and methods of extraction of A. blazei produced differing blood profiles in mice inoculated with the Ehrlich tumor.

Differences in antioxidant activities of outdoor- and indoor-cultivated Agaricus brasiliensis, and protective effects against carbon tetrachloride-induced acute hepatic injury in mice

Background

Agaricus brasiliensis (A. brasiliensis) is a medicinal mushroom that exerts various pharmacological actions. We previously demonstrated that different cultivation conditions altered the activity of the polyphenol-related enzymes from this mushroom. However, the influence of cultivation conditions on the antioxidant activity of the fruiting bodies remains unclear. Therefore, in this study we compared the antioxidative effects of fruiting bodies of A. brasiliensis cultivated outdoors and indoors. In addition, we assessed whether different cultivation methods affected the hepatoprotective effects against CCl₄-induced liver injury.

Methods

We assessed the antioxidative effects of mushrooms cultivated in open-air or indoors using the DPPH radical-scavenging assay. Furthermore, we prepared experimental feeds containing outdoor- or indoor-cultivated A. brasiliensis. Acute liver injury was induced by CCl₄ injection in mice that consumed feed containing outdoor- or indoor-cultivated A. brasiliensis. The hepatoprotective effects of these mushrooms were then evaluated by monitoring the reduction in the circulating levels of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase. The significance of the differences between the means was assessed using Student’s t-test. Finally, histopathological analysis of liver was performed.

Results

In the DPPH assay, the antioxidant activity of outdoor-cultivated A. brasiliensis was higher than that of indoor-cultivated mushroom. Moreover, in the mouse model of CCl₄-induced hepatitis, the oral administration of outdoor-cultivated A. brasiliensis reduced liver damage significantly, but indoor-cultivated mushrooms failed to inhibit hepatitis. The hepatoprotective effects of outdoor-cultivated A. brasiliensis were observed even when ingestion commenced only 1 day before CCl₄ injection, and these effects were not affected by excessive heat treatment.

Conclusions

Outdoor cultivation significantly enhanced the antioxidative activity of A. brasiliensis fruiting bodies. In addition, outdoor-cultivated A. brasiliensis was more effective at protecting against CCl₄-induced liver injury in mice than mushrooms grown in a greenhouse.

Mushrooms: a potential natural source of anti-inflammatory compounds for medical applications

For centuries, macrofungi have been used as food and medicine in different parts of the world. This is mainly attributed to their nutritional value as a potential source of carbohydrates, proteins, amino acids, and minerals. In addition, they also include many bioactive metabolites which make mushrooms and truffles common components in folk medicine, especially in Africa, the Middle East, China, and Japan. The reported medicinal effects of mushrooms include anti-inflammatory effects, with anti-inflammatory compounds of mushrooms comprising a highly diversified group in terms of their chemical structure. They include polysaccharides, terpenoids, phenolic compounds, and many other low molecular weight molecules. The aims of this review are to report the different types of bioactive metabolites and their relevant producers, as well as the different mechanisms of action of mushroom compounds as potent anti-inflammatory agents.

Modulation of interferon-γ synthesis by the effects of lignin-like enzymatically polymerized polyphenols on antigen-presenting cell activation and the subsequent cell-to-cell interactions

Lignin-like polymerized polyphenols strongly activate lymphocytes and induce cytokine synthesis. We aimed to characterise the mechanisms of action of polymerized polyphenols on immunomodulating functions. We compared the reactivity of leukocytes from various organs to that of polymerized polyphenols. Splenocytes and resident peritoneal cavity cells (PCCs) responded to polymerized polyphenols and released several cytokines, whereas thymocytes and bone-marrow cells showed no response. Next, we eliminated antigen-presenting cells (APCs) from splenocytes to study their involvement in cytokine synthesis. We found that APC-negative splenocytes showed significantly reduced cytokine production induced by polymerized polyphenols. Additionally, adequate interferon-γ (IFN-γ) induction by polymerized polyphenols was mediated by the coexistence of APCs and T cells because the addition of T cells to PCCs increased IFN-γ production. Furthermore, inhibition of the T cell-APC interaction using neutralising antibodies significantly decreased cytokine production. Thus, cytokine induction by polymerized polyphenols was mediated by the interaction between APCs and T cells.