The immunobiology of mushrooms

Antifatigue Activity of Liquid Cultured Tricholoma matsutake Mycelium Partially via Regulation of Antioxidant Pathway in Mouse

Tricholoma matsutake has been popular as food and biopharmaceutical materials in Asian countries for its various pharmacological activities. The present study aims to analyze the antifatigue effects on enhancing exercise performance of Tricholoma matsutake fruit body (ABM) and liquid cultured mycelia (TM) in mouse model. Two-week Tricholoma matsutake treatment significantly enhances the exercise performance in weight-loaded swimming, rotating rod, and forced running test. In TM- and ABM-treated mice, some factors were observed at 60 min after swimming compared with nontreated mice, such as the increased levels of adenosine triphosphate (ATP), antioxidative enzymes, and glycogen and the reduced levels of malondialdehyde and reactive oxygen species in muscle, liver, and/or serum. Further data obtained from western blot show that CM and ABM have strongly enhanced the activation of 5'-AMP-activated protein kinase (AMPK), and the expressions of peroxisome proliferator have activated receptor γ coactivator-1α (PGC-1α) and phosphofructokinase-1 (PFK-1) in liver. Our data suggest that both Tricholoma matsutake fruit body and liquid cultured mycelia possess antifatigue effects related to AMPK-linked antioxidative pathway. The information uncovered in our study may serve as a valuable resource for further identification and provide experimental evidence for clinical trials of Tricholoma matsutake as an effective agent against fatigue related diseases.

Apoptosis of Hepatocellular Carcinoma Cells Induced by Nanoencapsulated Polysaccharides Extracted from Antrodia Camphorata

Antrodia camphorata is a well-known medicinal mushroom in Taiwan and has been studied for decades, especially with focus on anti-cancer activity. Polysaccharides are the major bioactive compounds reported with anti-cancer activity, but the debates on how they target cells still remain. Research addressing the encapsulation of polysaccharides from A. camphorata extract (ACE) to enhance anti-cancer activity is rare. In this study, ACE polysaccharides were nano-encapsulated in chitosan-silica and silica (expressed as ACE/CS and ACE/S, respectively) to evaluate the apoptosis effect on a hepatoma cell line (Hep G2). The results showed that ACE polysaccharides, ACE/CS and ACE/S all could damage the Hep G2 cell membrane and cause cell death, especially in the ACE/CS group. In apoptosis assays, DNA fragmentation and sub-G₁ phase populations were increased, and the mitochondrial membrane potential decreased significantly after treatments. ACE/CS and ACE/S could also increase reactive oxygen species (ROS) generation, induce Fas/APO-1 (apoptosis antigen 1) expression and elevate the proteolytic activities of caspase-3, caspase-8 and caspase-9 in Hep G2 cells. Unsurprisingly, ACE/CS induced a similar apoptosis mechanism at a lower dosage (ACE polysaccharides = 13.2 μg/mL) than those of ACE/S (ACE polysaccharides = 21.2 μg/mL) and ACE polysaccharides (25 μg/mL). Therefore, the encapsulation of ACE polysaccharides by chitosan-silica nanoparticles may provide a viable approach for enhancing anti-tumor efficacy in liver cancer cells.

A phase I trial of mushroom powder in patients with biochemically recurrent prostate cancer: Roles of cytokines and myeloid-derived suppressor cells for Agaricus bisporus-induced prostate-specific antigen responses

BACKGROUND

Each year in the United States, nearly 50,000 prostate cancer patients exhibit a rise in prostate-specific antigen (PSA) levels, which can indicate disease recurrence. For patients with biochemically recurrent prostate cancer, we evaluated the effects of white button mushroom (WBM) powder on serum PSA levels and determined the tolerability and biological activity of WBM.

METHODS

Patients with continuously rising PSA levels were enrolled in the study. Dose escalation was conducted in cohorts of 6; this ensured that no more than 1 patient per cohort experienced dose-limiting toxicity (DLT). The primary objective was to evaluate treatment feasibility and associated toxicity. The secondary objectives were to determine WBM's effect on serum PSA/androgen levels; myeloid-derived suppressor cells (MDSCs); and cytokine levels.

RESULTS

Thirty-six patients were treated; no DLTs were encountered. The overall PSA response rate was 11%. Two patients receiving 8 and 14 g/d demonstrated complete response (CR): their PSA declined to undetectable levels that continued for 49 and 30 months. Two patients who received 8 and 12 g/d experienced partial response (PR). After 3 months of therapy, 13 (36%) patients experienced some PSA decrease below baseline. Patients with CR and PR demonstrated higher levels of baseline interleukin-15 than nonresponders; for this group, we observed therapy-associated declines in MDSCs.

CONCLUSIONS

Therapy with WBM appears to both impact PSA levels and modulate the biology of biochemically recurrent prostate cancer by decreasing immunosuppressive factors.

Immunomodulatory and immunorestorative activities of β-D-glucan-rich extract and polysaccharide fraction of mushroom, Pleurutus tuberregium

CONTEXT

Some edible mushrooms are reputed to possess useful medicinal properties which are related to their ability to modulate the protective responses of the immune system.

OBJECTIVE

This study explored the immunomodulatory and immunorestorative properties of a hot aqueous extract (APTR) and of a β-d-glucan-enriched polysaccharide fraction (BGP) of a local oyster mushroom Pleurutus tuberregium (Fr.) Singer (Pleurotaceae).

MATERIALS AND METHODS

Immunomodulatory activities were investigated by assessing specific and none-specific immune responses in immunocompetent and immunosuppressed mice; as well as in vitro in culture of RAW264.7 macrophages stimulated with BGP.

RESULTS

In a homologous prime-boost immunization schedule, oral supplementation with APTR (100, 200, or 400 mg/kg) and BGP (100 or 200 mg/kg) resulted in significantly higher titers of total IgG, IgG1, and IgG2a by as much as 2-4-folds compared with the levels in untreated control mice. The mean hemagglutination (HA) titer in immunized mice that were treated with dexamethasone (DEX; 5 mg/kg) was significantly (p < 0.05) lower than the titer in groups that did not receive dexamethasone; however, short-term alternate day administration of APTR (200 mg/kg) to mice that had been immunosuppressed with 5 mg DEX/kg produced significant increases in secondary anti-SRBC antibody compared with the mean titer of mice immunized and treated with DEX alone. In in vitro studies, stimulation of RAW264.7 macrophages with BGP caused significant increases in iNO and TNF-α expression, and phagocytic functions of the cell.

CONCLUSION

Taken together, the results of these studies showed that P. tuberregium imparts immunostimulatory and immunorestorative effects that could be explained, in part, by the actions of its β-d-glucan constituent(s) on macrophages.

Screening of antimicrobial, antioxidant properties and bioactive compounds of some edible mushrooms cultivated in Bangladesh

BACKGROUND

For a long time mushrooms have been playing an important role in several aspects of the human activity. Recently edible mushrooms are used extensively in cooking and make part of new food in Bangladesh for their beneficial properties. The aim of this study is to screen some values of mushrooms used in Bangladesh.

METHODS

Methanolic extracts of 3 edible mushrooms (Pleurotus ostreatus, Lentinula edodes, Hypsizigus tessulatus) isolated from Chittagong, Bangladesh were used in this study. Phenolic compounds in the mushroom methanolic extracts were estimated by a colorimetric assay. The antioxidant activity was determined by radical 1, 1-diphenyl;-2-picrylhydrazyl (DPPH) radical scavenging assay. Eight microbial isolates were used for antimicrobial activity of methanolic extract of mushrooms by the agar well diffusion method with slight modification.

RESULTS

Determination of antimicrobial activity indicated considerable activity against all bacteria and fungi reveling zone of inhibition ranged from 7 ± 0.2 to 20 ± 0.1 mm. Minimum inhibitory concentration values of the extracts showed that they are also active even in least concentrations ranged from 1 mg/ml to 9 mg/ml. Lentinula edodes showed the best antimicrobial activity than others. Pseudomonas aeruginosa was quite resistant and Saccharomyces cerevisiae was more sensitive than others microbial isolates. Antioxidant efficiency by inhibitory concentration on 1,1-Diphenly-2-picrylhydrazyl (DPPH) was found significant when compared to standard antioxidant like ascorbic Acid . The concentration (IC50) ranged from 100 ± 1.20 to 110 ± 1.24 μg/ml. Total phenols are the major bioactive component found in extracts of isolates expressed as mg of GAE per gram of fruit body, which ranged from 3.20 ± 0.05 to 10.66 ± 0.52 mg/ml. Average concentration of flavonoid ranged from 2.50 ± 0.008 mg/ml to 4.76 ± 0.11 mg/ml; followed by very small concentration of ascorbic acid (range, 0.06 ± 0.00 mg/ml to 0.21 ± 0.01 mg/ml) in all the isolates. All the isolates showed high phenol and flavonoid content (except Pleurotus ostreatus), but ascorbic acid content was found in traces.

CONCLUSION

This study has revealed that selected edible mushrooms have not only nutritional values but also some therapeutic values. Proper and more investigations can lead us to use these as strong medicine in future.

Assessing the immunomodulatory potential of high-molecular-weight extracts from mushrooms; an assay based on THP-1 macrophages

BACKGROUND

Food is a potential source of immunomodulating compounds that may be used to steer immune responses towards a desired status such as reducing inflammatory disorders. However, to identify and characterize such bioactive compounds, biologically relevant and standardized assays are required. Macrophages play an important role in immunomodulation and are suited for developing cell-based assays. An assay was developed based on macrophages, in a homogeneous differentiation state, using the human monocytic cell line THP-1 previously used to assess immunomodulatory properties of low-molecular-weight allergens, hormones, dietary supplements and therapeutic drugs.

RESULTS

Zymosan and mushroom polysaccharide extracts lead to a heterogeneous differentiation state of THP-1 monocytes, and these cells secrete low levels of cytokines upon stimulation. Differentiation into macrophages using a low concentration of phorbol 12-myristate 13-acetate improved responsiveness. Elevated levels of cytokines were secreted by cells in a homogenous differentiation state. In addition, it was determined that the assay performs best when using cells at a concentration of (2.5-5) × 10(5) cells mL(-1).

CONCLUSION

An assay was developed suitable to distinguish the immunomodulatory properties of food compounds in a reproducible manner. It was evaluated using eight mushroom species by measuring the secretion of relevant cytokines TNF-α, IL-1β, IL-6 and IL-10.

Mushrooms-Biologically Distinct and Nutritionally Unique: Exploring a "Third Food Kingdom"

Mushrooms are fungi, biologically distinct from plant- and animal-derived foods (fruits, vegetables, grains, dairy, protein [meat, fish, poultry, legumes, nuts, and seeds]) that comprise the US Department of Agriculture food patterns operationalized by consumer-focused MyPlate messages. Although mushrooms provide nutrients found in these food groups, they also have a unique nutrient profile. Classified into food grouping systems by their use as a vegetable, mushrooms’ increasing use in main entrées in plant-based diets is growing, supporting consumers’ efforts to follow dietary guidance recommendations. Mushrooms’ nutrient and culinary characteristics suggest it may be time to reevaluate food groupings and health benefits in the context of 3 separate food kingdoms: plants/botany, animals/zoology, and fungi/mycology.

Polysaccharides from Inonotus obliquus sclerotia and cultured mycelia stimulate cytokine production of human peripheral blood mononuclear cells in vitro and their chemical characterization

Inonotus obliquus is an edible and medicinal mushroom to treat many diseases. In the present study, polysaccharides and fractions were isolated and purified by DEAE-52 and Sephadex G-200 chromatography from I. obliquus wild sclerotia, culture broth and cultured mycelia under submerged fermentation. The extracts and fractions could significantly induce the secretion of TNF-α, IFN-γ, IL-1β, and IL-2 in human peripheral blood mononuclear cells (PBMCs) and showed no toxicity to PBMCs. The stimulation effect of the six extracts and eight fractions on the four-cytokine production was dose-dependent. Sclerotial polysaccharides were more effective in the four-cytokine production at 150 μg/ml while exopolysaccharides and endopolysacchrides showed a much better effect on IL-1β production at 30 μg/ml. Purified fractions from exopolysaccharides and endopolysaccharides were more effective than the fraction from sclerotia in most cytokine production. These heteropolysaccharide-protein conjugates mainly contained glucose, galactose, and mannose. Protein content, molecular weight, monosaccharide molar ratio, and anomeric carbon configuration differed from each other and had effects on the cytokine induction activity of the polysaccharides to some extent.

Immunoregulatory activities of Dendrobium huoshanense polysaccharides in mouse intestine, spleen and liver

To evaluate the immunomodulating responses in intestine, spleen and liver, 50-200mg/kg of DHP was orally administrated to mice without or with methotrexate. The proliferation of marrow cells, which was performed with the addition of the supernatant of small intestinal lymphocytes isolated from the mice administrated orally with DHP, showed that the intestinal immune response was significantly enhanced in all DHP-treated groups. For the immune response in spleen, all tested doses of DHP remarkably promoted the proliferation of splenic cells and increased the secretion of interferon-γ (IFN-γ). For the immune responses in liver, DHP not only significantly stimulated the proliferation of hepatic cells and the secretion of IFN-γ at all tested doses of DHP, but also significantly elevated the secretion interleukin-4 (IL-4) at the doses of 100 and 200mg/kg. Moreover, DHP could recover methotrexate-injured small intestinal immune function (100 and 200mg/kg) and promoted cell proliferation and IFN-γ production (200mg/kg) in spleen and liver of methotrexate-treated mice. These results suggested that DHP after oral administration possessed immunomodulating effects both in small intestine immune system and in systemic immune system, which were further proved by the mRNA expression of IFN-γ and IL-4.

In vivo and in vitro anti-tumor effects of fungal extracts

Fungal extracts are extensively used as nutritional supplements in Far-Eastern Asia. In this study, we aimed to evaluate the anti-cancer activities of some different fungal species against different cancer cell lines. The water or ethanol extracts of Fomitopsis pinicola (F. pinicola), Ganoderma sinense, Fomitopsis officinalis, Polyporus melanopus, and Taiwanofungus camphorates were used to evaluate the anti-cancer activities in various cancer cells. We found that all of the fungi ethanol extracts used in this study exert anti-cancer activities in vitro, whereas water extracts show lower inhibitory activities as determined by 3-(4,5-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Among the tested fungi species, F. pinicola ethanol extract exerts the most significant anti-cancer activity (growth inhibitory ratio 82.8%, p < 0.001) by increasing cell apoptosis. Moreover, F. pinicola ethanol extract significantly decreased tumor size (tumor growth inhibitory ratio 54%, p < 0.05) and increased the lifespan in mice bearing sarcoma-180 tumors. Taken together, this is the first study indicating the anti-tumor effect of F. pinicola in vivo and in vitro. F. pinicola ethanol extract induces cell apoptosis to exert a significant anti-tumor activity, with potential to be a new alternative anti-tumor medicine.

Mushroom immunomodulators: unique molecules with unlimited applications

For centuries, mushrooms have been used as food and medicine in different cultures. More recently, many bioactive compounds have been isolated from different types of mushrooms. Among these, immunomodulators have gained much interest based on the increasing growth of the immunotherapy sector. Mushroom immunomodulators are classified under four categories based on their chemical nature as: lectins, terpenoids, proteins, and polysaccharides. These compounds are produced naturally in mushrooms cultivated in greenhouses. For effective industrial production, cultivation is carried out in submerged culture to increase the bioactive compound yield, decrease the production time, and reduce the cost of downstream processing. This review provides a comprehensive overview on mushroom immunomodulators in terms of chemistry, industrial production, and applications in medical and nonmedical sectors.

In vitro and in vivo immunostimulatory effects of hot water extracts from the leaves of Artemisia princeps Pampanini cv. Sajabal

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia princeps Pampanini (Asteraceae) is used as a traditional medicine to immune function-related diseases, such as dysmenorrhea, inflammation, cancer, and ulcers.

AIM OF THE STUDY

The purpose of this study is to evaluate the immunostimulatory effects of the hot water extract from the leaves of Artemisia princeps Pampanini (WAPP) in recombinant interferon-γ (rIFN-γ)-primed RAW 264.7 macrophages and in cyclophosphamide (20mg/kg, i.p.)-induced immunosuppressed Sprague-Dawley rats.

MATERIALS AND METHODS

RAW 264.7 macrophages were treated with WAPP and production and expressions of nitric oxide (NO) and tumor necrosis factor-α (TNF-α) via nuclear factor-κB (NF-κB) were detected by immunoassay, western blot, qRT-PCR and reporter gene assay. In addition, in vivo immunomodulatory activity was studied by cyclophosphamide-induced myelosuppression in rats.

RESULTS

In rIFN-γ-primed RAW 264.7 macrophages, pretreatment with WAPP increased the productions of nitric oxide (NO) and tumor necrosis factor-α (TNF-α),and increased the expressions of inducible nitric oxide synthase (iNOS) at the protein level and of iNOS and TNF-α at the mRNA level. Molecular data revealed that WAPP upregulated the transcriptional activity and translocation of nuclear factor-κB (NF-κB) by activating inhibitory kappa B-α (IκB-α) degradation and phosphorylation. Furthermore, WAPP upregulated the phosphorylations of p38 MAP kinase, c-Jun NH2-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK1/2). In cycloheximide-induced immunosuppressed rats, pretreatment with WAPP (100, 200, or 400mg/kg, p.o.) increased the serum levels of albumin and globulin, and reduced immobility times.

CONCLUSION

Our results suggest that upregulations of the expressions of iNOS and TNF-α via the activations of NF-κB and MAPK are responsible for the immunostimulatory effects of WAPP.

Anti-oxidant and anti-inflammatory activities of Inonotus obliquus and germinated brown rice extracts

Inonotus obliquus (IO) is parasitic mushroom that grows on birch and other trees in Russia, Korea, Europe and United States. However, IO is not readily available for consumption due to its high cost and difficult growth. In this regard, IO was inoculated on germinated brown rice (GBR) in the present study and the antioxidant and anti-inflammatory activities of the IO grown on germinated brown rice (IOGBR) extracts were evaluated extensively and compared with those for IO and GBR. IOGBR showed highest antioxidant activities with scavenging total intracellular ROS and MDA levels as well as increasing the antioxidant enzymes activity in the H₂O₂-stimulated mice liver. It also exhibited best inflammatory activities by suppressing the proinflammatory mediators such as NO, PGE₂, iNOS, COX-2, TNF-α, IL-1β, and IL-6 in an LPS-stimulated RAW 264.7 cell line. This study provides a comparative approach to find out an excellent natural source of antioxidants and anti-inflammatory agent as a dietary supplement.

Isolation and characterization of exopolysaccharide with immunomodulatory activity from fermentation broth of Morchella conica

Background and the purpose of this study

Mushroom polysaccharides have traditionally been used for the prevention and treatment of a multitude of disorders like infectious illnesses, cancers and various autoimmune diseases. In vitro and in vivo studies suggest that certain polysaccharides affect immune system function. Morchella conica (M. conica) is a species of rare edible mushroom whose multiple medicinal functions have been proven. Thus, the objective of this study is to isolate and characterize of exopolysaccharide from submerged mycelial culture of M. conica, and to evaluate its immunomodulatory activity.

Methods

A water-soluble Morchella conica Polysaccharides (MCP) were extracted and isolated from the fermentation broth of M. conica through a combination of DEAE-cellulose and Sephacryl S-300 HR chromatograph. NMR and IR spectroscopy has played a developing role in identification of polysaccharide with different structure and composition from fungal and plant sources, as well as complex glycosaminoglycans of animal origin. Thus, NMR and IR spectroscopy were used to analyze the chemical structure and composition of the isolated polysaccharide. Moreover, the polysaccharide was tested for its immunomodulatory activity at different concentrations using in vitro model.

Results

The results showed that MCP may significantly modulate nitric oxide production in macrophages, and promote splenocytes proliferation. Analysis from HPLC, infrared spectra and nuclear magnetic resonance spectroscopy showed that MCP was a homogeneous mannan with an average molecular weight of approximately 81.2 kDa. The glycosidic bond links is →6)-α-D-Man p-(1→.

Conclusion

The results suggested that the extracted MCP may modulate nitric oxide production in macrophages and promote splenocytes proliferation, and it may act as a potent immunomodulatory agent.

Diuretic activity of the ethanol and aqueous extracts of the surface layer of Poria cocos in rat

ETHNOPHARMACOLOGICAL RELEVANCE

Poria cocos Wolf (Polyporaceae) is a well-known traditional East-Asian medicinal fungus. the epidermis ("Fu-Ling-Pi" in Chinese) of the sclerotia is used as a diuretic. This study was conducted to evaluate of ethanol extract (EE) and aqueous extract (AE) of the diuretic activity of Fu-Ling-Pi in saline-loaded rats.

MATERIAL AND METHODS

The EE and AE were orally administered to rats. Urinary excretion rate, pH and electrolyte excretion were measured in the urine of saline-loaded rats.

RESULTS

Urinary excretion rates were significantly increased by the EE. The three doses of AE only produced a slight increase urinary output. The EE had little or no effect on K(+) excretion, but did indeed induce a notable excretion of Na(+), that was in agreement with the urinary excretion. The three doses of AE produced an increase Na(+) and K(+) excretion, but did not arrive at statistical significance.

CONCLUSIONS

The present study confirmed that the not aqueous but ethanol extracts of the epidermis of Poria cocos presents a remarkable diuretic effect.

β-Glucans are involved in immune-modulation of THP-1 macrophages

SCOPE

We aimed to examine different immunological aspects of β-glucans derived from different food sources (oat, barley and shiitake) on phorbol myristate acetate (PMA)-differentiated THP-1 macrophages. Commercially purified barley β-glucan (commercial BG) and lentinan were included to compare β-glucans from the same origin but different degree of purity and processing.

METHODS AND RESULTS

Chemical composition and molecular weight distribution of β-glucan samples were determined. Inflammation-related gene expression kinetics (IL-1β, IL-8, nuclear factor kappa B [NF-κB] and IL-10) after 3, 6 and 24 h of stimulation with 100 μg/mL β-glucan were investigated. All tested β-glucans mildly upregulated the observed inflammation-related genes with differential gene expression patterns. Similar gene expression kinetics, but different fold induction values, was found for the crude β-glucan extracts and their corresponding commercial forms. Pre-incubation of THP-1 macrophages with β-glucans prior to lipopolysaccharide (LPS) exposure decreased the induction of inflammation-related genes compared to LPS treatment. No production of nitric oxide (NO) and hydrogen peroxide (H₂O₂) was detected in β-glucan stimulated THP-1 macrophages. Phagocytic activity was not different after stimulation by β-glucan samples.

CONCLUSION

Based on these in vitro analyses, it can be concluded that the analysed β-glucans have varying levels of immunomodulating properties, which are likely related to structure, molecular weight and compositional characteristic of β-glucan.

Induction of a T-Helper 1 (Th1) immune response in mice by an extract from the Pleurotus eryngii (Eringi) mushroom

To assess the effect of edible mushroom extracts on the induction of T-helper 1 (Th1) immunity, we examined differences in interferon-gamma (IFN-γ) and interleukin (IL)-4 production in mice induced by hot-water extracts of 15 species of edible mushroom. Extracts from Agaricus bisporus, Flammulina velutipes, Hypsizigus marmoreus, Lentinula edodes, and Lyophyllum decastes induced both IFN-γ and IL-4 production in mice, whereas extracts from Pleurotus ostreatus only induced IL-4. In contrast, extracts from Agaricus blazei, Grifola frondosa, Morchella esculenta, Pholiota nameko, Pleurotus citrinopileatus, and Pleurotus eryngii induced only IFN-γ production. In particular, the extract from P. eryngii induced high levels of IFN-γ and reduced levels of IL-4. We further investigated the use of a trial immunogen using the P. eryngii extract as a Th1 immunostimulator. An oil-in-water emulsion of the hot-water extract from P. eryngii (immunostimulator) and ovalbumin (OVA; antigen) was used as a trial immunogen. This immunogen induced strong OVA-specific IgG2a antibody production in mice compared with the negative controls. In addition, OVA-specific IgG1 antibody levels were lower than those for the negative controls. Marked increases in serum IFN-γ levels and high-level production of IFN-γ in the culture supernatant from the CD4(+) spleen cells in the trial immunogen group mice were observed. Our results suggested that the hot-water extract from P. eryngii induced Th1 immunity by acting as an immunostimulator.

Mushroom Ganoderma lucidum prevents colitis-associated carcinogenesis in mice

BACKGROUND

Epidemiological studies suggest that mushroom intake is inversely correlated with gastric, gastrointestinal and breast cancers. We have recently demonstrated anticancer and anti-inflammatory activity of triterpene extract isolated from mushroom Ganoderma lucidum (GLT). The aim of the present study was to evaluate whether GLT prevents colitis-associated carcinogenesis in mice.

METHODS/PRINCIPAL FINDINGS

Colon carcinogenesis was induced by the food-borne carcinogen (2-Amino-1-methyl-6-phenylimidazol[4,5-b]pyridine [PhIP]) and inflammation (dextran sodium sulfate [DSS]) in mice. Mice were treated with 0, 100, 300 and 500 mg GLT/kg of body weight 3 times per week for 4 months. Cell proliferation, expression of cyclin D1 and COX-2 and macrophage infiltration was assessed by immunohistochemistry. The effect of GLT on XRE/AhR, PXR and rPXR was evaluated by the reporter gene assays. Expression of metabolizing enzymes CYP1A2, CYP3A1 and CYP3A4 in colon tissue was determined by immunohistochemistry. GLT treatment significantly suppressed focal hyperplasia, aberrant crypt foci (ACF) formation and tumor formation in mice exposed to PhIP/DSS. The anti-proliferative effects of GLT were further confirmed by the decreased staining with Ki-67 in colon tissues. PhIP/DSS-induced colon inflammation was demonstrated by the significant shortening of the large intestine and macrophage infiltrations, whereas GLT treatment prevented the shortening of colon lengths, and reduced infiltration of macrophages in colon tissue. GLT treatment also significantly down-regulated PhIP/DSS-dependent expression of cyclin D1, COX-2, CYP1A2 and CYP3A4 in colon tissue.

CONCLUSIONS

Our data suggest that GLT could be considered as an alternative dietary approach for the prevention of colitis-associated cancer.

Effect of dietary supplementation with white button mushrooms on host resistance to influenza infection and immune function in mice

Previously, we showed that mice fed white button mushrooms (WBM) had enhanced immune functions known to help the body's antiviral defence. In the present study, we tested whether WBM conferred protection against viral infection. Young (4-month-old) and old (22-month-old) C57BL/6 mice were fed a diet containing 0, 2 or 10 % WBM powder for 8 weeks. Mice were then infected with influenza Puerto Rico/8/34 (H1N1), and killed at day 0 (uninfected), 2, 5 or 7 post-infection. The primary outcomes of the study were viral titre and body weight. Secondary outcomes were natural killer (NK) cell activity, lymphocyte proliferation and cytokine production. The results showed that WBM did not affect viral titre, nor did it prevent infection-induced weight loss. WBM supplementation was found to enhance NK cell activity in old mice and to increase interferon (IFN)-γ production in young and old mice under naive (uninfected) conditions, but it had no such effect after infection. The lack of a mushroom supplementation effect on NK activity and concanavalin A-stimulated IFN-γ production after infection may explain the immune system's failure to reduce viral load and weight loss in mice after influenza infection. WBM supplementation, however, did induce changes in other aspects of the immune response: it significantly increased the production of T-helper type 2 cytokines IL-4 and IL-10 in uninfected mice and pro-inflammatory cytokines IL-1β and TNF-α in infected mice. These mushroom-induced systemic changes, however, were not adequate to confer a protective effect against influenza infection.

Macrophage immunomodulating and antitumor activities of polysaccharides isolated from Agaricus bisporus white button mushrooms

Agaricus bisporus white button mushroom (WBM) is widely consumed in most countries for its culinary properties. Recently, its dietary intake has been shown to protect against breast cancer. Mushroom polysaccharides are known for their immunomodulating and antitumor properties; however, little is known regarding the properties of A. bisporus polysaccharides. Using size-exclusion chromatography to fractionate the crude extract of A. bisporus, two polysaccharide fractions (designated as ABP-1 and ABP-2) were obtained. The estimated molecular masses of ABP-1 and ABP-2 were 2,000 kDa and 40-70 kDa, respectively, and their sugar compositions consisted mainly of glucose, mannose, xylose, and fructose. Analysis of the effects of the polysaccharides on murine macrophages demonstrated that both fractions stimulated the production of nitric oxide, interleukin-6, and tumor necrosis factor-α. Modulation of macrophage function by A. bisporus polysaccharides was mediated in part through activation of nuclear factor-κB with the production p50/105 heterodimers. Both ABP-1 and ABP-2 had the ability to inhibit the growth of human breast cancer MCF-7 cells but had little effect on the growth of human colon, prostate, gastric cancer, and murine Sarcoma 180 cells as assessed by a tetrazolium dye [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]-based assay. However, when murine Sarcoma 180 cells exposed to ABP-1 or ABP-2 were implanted subcutaneously into mice, a reduction in tumor growth was observed compared with that observed in control mice. Taken together, our data provide a molecular basis to explain in part the reported beneficial therapeutic effects of A. bisporus WBM intake and suggest that macrophages likely contribute to the antitumor effects of Agaricus polysaccharides.

Glucans from the edible mushroom Pleurotus pulmonarius inhibit colitis-associated colon carcinogenesis in mice

BACKGROUND

We have recently demonstrated that polysaccharides from fruiting body extract (FBE) or mycelia extract (ME) of the edible mushroom Pleurotus pulmonarius exert antiproliferative effects in intestinal cells and an anti-inflammatory effect in a dextran sulfate sodium (DSS) mouse model of acute colitis. The aim of this study was to assess the role of fungal FBE and ME in colon carcinogenesis.

METHODS

In vitro, human colorectal cancer cells were treated with FBE and ME and analyzed for inflammation response, for markers of apoptosis, and for cell-cycle progression. In vivo, FBE and ME were tested in a mouse model of colitis-associated colorectal carcinogenesis induced by cyclic treatments with DSS and azoxymethane. Treated mice were fed a daily diet containing 2 or 20 mg FBE or ME per mouse for 80 days.

RESULTS

In vitro, FBE and ME induced apoptosis in a dose-responsive manner and modulated the expression of Bcl-2, Bax, and cytochrome c, and blocked tumor necrosis factor (TNF)-α-induced inhibitor of nuclear factor (NF) (Iκ)-Bα degradation and NF-κB nuclear translocation. In vivo, dietary administration of FBE and ME significantly reduced the formation of aberrant crypt foci, which precedes colorectal cancer, and of microadenomas. The treatments significantly lowered the expression of proliferating cell nuclear antigen and increased the number of cells undergoing apoptosis in the colon. Additionally, FBE and ME inhibited the expression of the proinflammatory cytokine TNF-α in colonic tissue.

CONCLUSIONS

We conclude that P. pulmonarius FBE and ME inhibit colitis-associated colon carcinogenesis induced in mice through the modulation of cell proliferation, induction of apoptosis, and inhibition of inflammation.

CNL, a ricin B-like lectin from mushroom Clitocybe nebularis, induces maturation and activation of dendritic cells via the toll-like receptor 4 pathway

A novel lectin, isolated from the basidiomycete mushroom Clitocybe nebularis and termed C. nebularis lectin (CNL), exhibits an immunostimulatory effect on the most potent antigen-presenting cells, the dendritic cells (DCs). Treatment of human monocyte-derived DCs with CNL in doses from 1 to 10 μg/ml resulted in a dose-dependent induction of overall DC maturation characteristics. Exposure of DCs to CNL for 48 hr resulted in extensive up-regulation of co-stimulatory molecules CD80 and CD86, as well as of the maturation marker CD83 and HLA-DR molecules. Such CNL-matured DCs (CNL-DCs) were capable of inducing a T helper type 1-polarized response in naive CD4+  CD45RA+ T cells in 5-day allogeneic co-cultures. The allostimulatory potential of CNL-DCs was significantly increased relative to untreated controls, as was their capacity to produce several pro-inflammatory cytokines such as interleukin-6, interleukin-8 and tumour necrosis factor-α. By using a specific Toll-like receptor 4 (TLR4) signalling inhibitor, CLI-095, as well as Myd88 inhibitory peptide, we have shown that DC activation by CNL is completely dependent on the TLR4 activation pathway. Furthermore, activation of TLR4 by CNL was confirmed via TLR4 reporter assay. Measurement of p65 nuclear factor-κB and p38 mitogen-activated protein kinase (MAPK) phosphorylation levels following CNL stimulation of DCs revealed primarily an increase in nuclear factor-κB activity, with less effect on the induction of p38 MAPK signalling than of lipopolysaccharide-matured DCs. The CNL had the ability to activate human DCs in such a way as to subsequently direct T helper type 1 T-cell responses. Our results encourage the use of mushroom-derived lectins for use in therapeutic strategies with aims such as to strengthen anti-tumour immune responses.

Protective effects of white button mushroom (Agaricus bisporus) against hepatic steatosis in ovariectomized mice as a model of postmenopausal women

Nonalcoholic fatty liver disease (NAFLD) includes various hepatic pathologies ranging from hepatic steatosis to non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. Estrogen provides a protective effect on the development of NAFLD in women. Therefore, postmenopausal women have a higher risk of developing NAFLD. Hepatic steatosis is an early stage of fatty liver disease. Steatosis can develop to the aggressive stages (nonalcoholic steatohepatitis, fibrosis and cirrhosis). Currently, there is no specific drug to prevent/treat these liver diseases. In this study, we found that white button mushroom (WBM), Agaricus Bisporus, has protective effects against liver steatosis in ovariectomized (OVX) mice (a model of postmenopausal women). OVX mice were fed a high fat diet supplemented with WBM powder. We found that dietary WBM intake significantly lowered liver weight and hepatic injury markers in OVX mice. Pathological examination of liver tissue showed less fat accumulation in the livers of mice on WBM diet; moreover, these animals had improved glucose clearance ability. Microarray analysis revealed that genes related to the fatty acid biosynthesis pathway, particularly the genes for fatty acid synthetase (Fas) and fatty acid elongase 6 (Elovl6), were down-regulated in the liver of mushroom-fed mice. In vitro mechanistic studies using the HepG2 cell line showed that down-regulation of the expression of FAS and ELOVL6 by WBM extract was through inhibition of Liver X receptor (LXR) signaling and its downstream transcriptional factor SREBP1c. These results suggest that WBM is protective against hepatic steatosis and NAFLD in OVX mice as a model for postmenopausal women.

Inonotus obliquus extracts suppress antigen-specific IgE production through the modulation of Th1/Th2 cytokines in ovalbumin-sensitized mice

ETHNOPHARMACOLOGICAL RELEVANCE

Chaga mushroom (Inonotus obliquus, IO) has been used as a folk remedy for cancer, digestive system diseases, and other illnesses in Russia and Eastern Europe.

AIM OF THE STUDY

In the present study, we investigated the immunomodulating effects of IO through in vivo and ex vivo studies.

MATERIALS AND METHODS

Serum immunoglobulins (IgE, IgG(1), and IgG(2a)) and cytokines (interleukin (IL)-4, interferon (IFN)-γ, and IL-2) were measured in concanavalin A (ConA)-stimulated splenocytes and CD4(+) T cells. The nitric oxide (NO) secretion of lipopolysaccharide (LPS)-stimulated peritoneal macrophages was also measured after oral administration of 50, 100, or 200 mg kg(-1) d(-1) IO hot water extract (IOE) to ovalbumin (OVA)-sensitized BALB/c mice.

RESULTS

We found that the OVA-induced increase in serum IgE and IgG(2a) was significantly suppressed when IOE was orally administered after the second immunization with OVA. ConA stimulation in spleen cells isolated from OVA-sensitized mice treated with 100 mg kg(-1) IOE resulted in a 25.2% decrease in IL-4 production and a 102.4% increase in IFN-γ, compared to the controls. Moreover, IL-4, IFN-γ, and IL-2 were significantly reduced after ConA stimulation in isolated CD4(+)T cells. We also determined that IOE inhibits the secretion of NO from LPS-stimulated peritoneal macrophages ex vivo.

CONCLUSIONS

We suggest that IO modulates immune responses through secretion of Th1/Th2 cytokines in immune cells and regulates antigen-specific antibody production.

Anti-inflammatory activity of edible oyster mushroom is mediated through the inhibition of NF-κB and AP-1 signaling

Background

Mushrooms are well recognized for their culinary properties as well as for their potency to enhance immune response. In the present study, we evaluated anti-inflammatory properties of an edible oyster mushroom (Pleurotus ostreatus) in vitro and in vivo.

Methods

RAW264.7 murine macrophage cell line and murine splenocytes were incubated with the oyster mushroom concentrate (OMC, 0-100 μg/ml) in the absence or presence of lipopolysacharide (LPS) or concanavalin A (ConA), respectively. Cell proliferation was determined by MTT assay. Expression of cytokines and proteins was measured by ELISA assay and Western blot analysis, respectively. DNA-binding activity was assayed by the gel-shift analysis. Inflammation in mice was induced by intraperitoneal injection of LPS.

Results

OMC suppressed LPS-induced secretion of tumor necrosis factor-α (TNF-α, interleukin-6 (IL-6), and IL-12p40 from RAW264.7 macrophages. OMC inhibited LPS-induced production of prostaglandin E2 (PGE₂) and nitric oxide (NO) through the down-regulation of expression of COX-2 and iNOS, respectively. OMC also inhibited LPS-dependent DNA-binding activity of AP-1 and NF-κB in RAW264.7 cells. Oral administration of OMC markedly suppressed secretion of TNF-α and IL-6 in mice challenged with LPS in vivo. Anti-inflammatory activity of OMC was confirmed by the inhibition of proliferation and secretion of interferon-γ (IFN-γ), IL-2, and IL-6 from concanavalin A (ConA)-stimulated mouse splenocytes.

Conclusions

Our study suggests that oyster mushroom possesses anti-inflammatory activities and could be considered a dietary agent against inflammation. The health benefits of the oyster mushroom warrant further clinical studies.

Immunostimulating activity by polysaccharides isolated from fruiting body of Inonotus obliquus

In this study, we investigated the immunostimulating activity of polysaccharides isolated from fruiting body of Inonotus obliquus (PFIO). Additionally, the signaling pathway of PFIO-mediated macrophage activation was investigated in RAW264.7 macrophage cells. We found that PFIO was capable of promoting NO/ROS production, TNF-α secretion and phagocytic uptake in macrophages, as well as cell proliferation, comitogenic effect and IFN-γ/IL-4 secretion in mouse splenocytes. PFIO was able to induce the phosphorylation of three MAPKs as well as the nuclear translocation of NF-κB, resulting in activation of RAW264.7 macrophages. PFIO also induced the inhibition of TNF-α secretion by anti-TLR2 mAb, consequently, PFIO might be involved in TNF-α secretion via the TLR2 receptor. In addition, our results showed that oral administration of PFIO suppressed in vivo growth of melanoma tumor in tumorbearing mice. In conclusion, our experiments presented that PFIO effectively promotes macrophage activation through the MAPK and NF-κB signaling pathways, suggesting that PFIO may potentially regulate the immune response.

Commonly consumed and specialty dietary mushrooms reduce cellular proliferation in MCF-7 human breast cancer cells

Worldwide, over one million women will be newly diagnosed with breast cancer in the next year. Moreover, breast cancer is the second leading cause of cancer death in the USA. An accumulating body of evidence suggests that consumption of dietary mushrooms can protect against breast cancer. In this study, we tested and compared the ability of five commonly consumed or specialty mushrooms to modulate cell number balance in the cancer process using MCF-7 human breast cancer cells. Hot water extracts (80°C for 2 h) of maitake (MT, Grifola frondosa), crimini (CRIM, Agaricus bisporus), portabella (PORT, Agaricus bisporus), oyster (OYS, Pleurotus ostreatus) and white button (WB, Agaricus bisporus) mushrooms or water alone (5% v/v) were incubated for 24 h with MCF-7 cells. Cellular proliferation determined by bromodeoxyuridine incorporation was significantly ( P < 0.05) reduced up to 33% by all mushrooms, with MT and OYS being the most effective. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) reduction, an often used mitochondrion-dependent marker of proliferation, was unchanged although decreased ( P > 0.05) by 15% with OYS extract. Lactate dehydrogenase release, as a marker of necrosis, was significantly increased after incubation with MT but not with other test mushrooms. Furthermore, MT extract significantly increased apoptosis, or programmed cell death, as determined by terminal deoxynucleotidyl end labeling method, whereas other test mushrooms displayed trends of ∼15%. The total numbers of cells per flask, determined by hemacytometry, were not different from control cultures. Overall, all test mushrooms significantly suppressed cellular proliferation, with MT further significantly inducing apoptosis and cytotoxicity in human breast cancer cells. This suggests that both common and specialty mushrooms may be chemoprotective against breast cancer.

Immunostimulatory properties of a polysaccharide isolated from Astraeus hygrometricus

Mushrooms have been used as food and for therapeutic purpose for decades, and various compounds derived from these have potential biological activities. Application of such agents of natural origin is vital with relevance to an increase in diseases involving immune dysfunction, cancer, and autoimmune conditions in recent years. These compounds belong mainly to polysaccharides, especially beta-D-glucan, glycopeptide/protein complexes, proteoglycans, proteins, and triterpenoids. Among these compounds, polysaccharides and their peptide/protein derivates have extremely important roles in immunomodulating activities. The present study aims to explore the immunomodulatory properties of polysaccharide isolated from the mushroom Astraeus hygrometricus. The polysaccharide isolated by hot alkaline extraction and chromatography was designated as AE2 and studied for its immunostimulatory potential in vivo in a murine model. Macrophages from treated mice showed higher production of nitric oxide and interleukin-1 and also exhibited an increased phagocytic potential. It also enhanced natural killer cell activation and proliferation of splenocytes with an increase in the T-helper (Th) 1 cytokine level of splenocyte culture supernatant. The cytokine level in serum also indicated a Th1 skew. The observed activities were associated with no general toxicity to the organism. The findings will be helpful in considering A. hygrometricus as a potential source of an immunomodulator and in designing further studies to understand its mode of action on immune system.