Dietary supplementation with white button mushroom enhances natural killer cell activity in C57BL/6 mice

Increased Fruit and Vegetable Consumption Prevents Dysregulated Immune and Inflammatory Responses in High-Fat Diet-Induced Obese Mice

BACKGROUND

Obesity is often associated with impaired immune responses, including enlarged spleen, increased inflammation, and impaired T-cell-mediated function, which may lead to increased susceptibility to infections. Bioactive compounds found in various fruits and vegetables (F&V) have been shown to have strong anti-inflammatory effects. However, few prospective studies have examined the effects of F&V on preventing obesity-associated dysregulation of immune and inflammatory responses.

OBJECTIVE

The objective of this was to determine the impact of different levels of a mixture of F&V incorporated in a high-fat diet (HFD) on immune function changes in a diet-induced obesity animal model.

METHODS

Six-wk-old male C57BL/6J mice were randomly assigned to 1 of 5 groups (n = 12/group): matched low-fat control (LF, 10% kcal fat) or HFD (45% kcal fat) supplemented with 0%, 5%, 10%, or 15% (wt/wt) freeze-dried powder of the most consumed F&V (human equivalent of 0, 3, 5-7, 8-9 servings/d, respectively) for 20 wk. Spleen weight was recorded, and the immunophenotype of splenocytes was evaluated by flow cytometry. Ex vivo splenic lymphocyte proliferation was assessed by thymidine incorporation and serum cytokines concentrations were measured by Meso Scale Discovery.

RESULTS

Mice fed the HFD exhibited significantly higher spleen weight, decreased splenic CD8+ lymphocytes, suppressed T lymphocyte proliferation, and reduced serum IL-1ß and IFN-γ concentrations compared with those fed the LF diet. Feeding mice with the HFD supplemented with 10% or 15% F&V restored HFD-associated changes of these affected biomarkers compared with those fed HFD only. Furthermore, a significant correlation was found between immunologic markers and F&V level.

CONCLUSIONS

These results suggest that increased consumption of F&V has beneficial effects in preventing HFD-associated dysregulation of immune function.

Reduction of myeloid-derived suppressor cells in prostate cancer murine models and patients following white button mushroom treatment

BACKGROUND

In a previously reported Phase I trial, we observed therapy-associated declines in circulating myeloid-derived suppressor cells (MDSCs) with the administration of white button mushroom (WBM) tablets in prostate cancer (PCa) patients. These observations led us to hypothesise that WBM could mitigate PCa progression by suppressing MDSCs.

METHODS

We performed bidirectional translational research to examine the immunomodulatory effects of WBM consumption in both syngeneic murine PCa models and patients with PCa participating in an ongoing randomised Phase II trial (NCT04519879).

RESULTS

In murine models, WBM treatment significantly suppressed tumour growth with a reduction in both the number and function of MDSCs, which in turn promoted antitumour immune responses mediated by T cells and natural killer (NK) cells. In patients, after consumption of WBM tablets for 3 months, we observed a decline in circulating polymorphonuclear MDSCs (PMN-MDSCs), along with an increase in cytotoxic CD8+ T and NK cells. Furthermore, single immune cell profiling of peripheral blood from WBM-treated patients showed suppressed STAT3/IRF1 and TGFβ signalling in circulating PMN-MDSCs. Subclusters of PMN-MDSCs presented transcriptional profiles associated with responsiveness to fungi, neutrophil chemotaxis, leukocyte aggregation, and regulation of inflammatory response. Finally, in mouse models of PCa, we found that WBM consumption enhanced the anticancer activity of anti-PD-1 antibodies, indicating that WBM may be used as an adjuvant therapy with immune checkpoint inhibitors.

CONCLUSION

Our results from PCa murine models and patients provide mechanistic insights into the immunomodulatory effects of WBM and provide a scientific foundation for WBM as a nutraceutical intervention to delay or prevent PCa progression.

HIGHLIGHTS

White button mushroom (WBM) treatment resulted in a reduction in pro-tumoural MDSCs, notably polymorphonuclear MDSCs (PMN-MDSCs), along with activation of anti-tumoural T and NK cells. Human single immune cell gene expression profiling shed light on the molecular alterations induced by WBM, specifically on PMN-MDSCs. A proof-of-concept study combining WBM with PD-1 blockade in murine models revealed an additive effect on tumour regression and survival outcomes, highlighting the clinical relevance of WBM in cancer management.

Alginate/κ-carrageenan oral microcapsules loaded with Agaricus bisporus polysaccharides MH751906 for natural killer cells mediated colon cancer immunotherapy

The current study explores the effect of the extracted novel Mushroom polysaccharides and its formulation onto Alginate (Alg.)/kappa carrageenan microcapsules to exert immunotherapeutic effect upon activating gut resident natural killer cells (NK) against colon cancer. The extracted polysaccharides of Agaricus bisporus MH751906 was microcapsulated in Alg/κ-carrageenan microcapsules as an oral delivery system for colon cancer. The microcapsule is characterized by SEM, FTIR, Raman and TGA; and showed a superior acidic stability, controlled release, and thermal stability at high temperature with higher hydrogel swelling rate in colon-mimicking pH. Upon activation of human NK cells with microcapsules (^ANK cells), a significant increase in CD16⁺CD56⁺ NK cell populations were recorded. These activated NK cells showed 74.09% cytotoxic effects against human colon cancer Caco-2 cells where majority of cancer cell populations arrested at G0/G1 phase leading to apoptosis. The apoptotic molecular mechanism induced by ^ANK cells on Caco-2 treated cells is through down regulations of both BCL2 and TGF surviving genes and up regulation in IkappaB-α gene expression. Therefore, this novel polysaccharides-alginate/κ-carrageenan microcapsules can be used as an oral targeted delivery system for colon cancer immunotherapy.

Edible Mushrooms: A Comprehensive Review on Bioactive Compounds with Health Benefits and Processing Aspects

Mushrooms are well-known functional foods due to the presence of a huge quantity of nutraceutical components. These are well recognized for their nutritional importance such as high protein, low fat, and low energy contents. These are rich in minerals such as iron, phosphorus, as well as in vitamins like riboflavin, thiamine, ergosterol, niacin, and ascorbic acid. They also contain bioactive constituents like secondary metabolites (terpenoids, acids, alkaloids, sesquiterpenes, polyphenolic compounds, lactones, sterols, nucleotide analogues, vitamins, and metal chelating agents) and polysaccharides chiefly β-glucans and glycoproteins. Due to the occurrence of biologically active substances, mushrooms can serve as hepatoprotective, immune-potentiating, anti-cancer, anti-viral, and hypocholesterolemic agents. They have great potential to prevent cardiovascular diseases due to their low fat and high fiber contents, as well as being foremost sources of natural antioxidants useful in reducing oxidative damages. However, mushrooms remained underutilized, despite their wide nutritional and bioactive potential. Novel green techniques are being explored for the extraction of bioactive components from edible mushrooms. The current review is intended to deliberate the nutraceutical potential of mushrooms, therapeutic properties, bioactive compounds, health benefits, and processing aspects of edible mushrooms for maintenance, and promotion of a healthy lifestyle.

White button mushroom interrupts tissue AR-mediated TMPRSS2 expression and attenuates pro-inflammatory cytokines in C57BL/6 mice

White button mushroom (WBM) is a common edible mushroom consumed in the United States and many European and Asia-Pacific countries. We previously reported that dietary WBM antagonized dihydrotestosterone (DHT)-induced androgen receptor (AR) activation and reduced myeloid-derived suppressor cells (MDSCs) in prostate cancer animal models and patients. Transmembrane protease serine 2 (TMPRSS2), an androgen-induced protease in prostate cancer, has been implicated in influenza and coronavirus entry into the host cell, triggering host immune response. The present study on C57BL/6 mice revealed that WBM is a unique functional food that (A) interrupts AR-mediated TMPRSS2 expression in prostate, lungs, small intestine, and kidneys through its AR antagonistic activity and (B) attenuates serum pro-inflammatory cytokines and reduces MDSC counts through its immunoregulatory activity. These findings provide a scientific basis for translational studies toward clinical applications of WBM in diseases related to TMPRSS2 expression and immune dysregulation.

White Button Mushroom (Agaricus bisporus) Interrupts Tissue AR-TMPRSS2 Expression and Attenuates Pro-inflammatory Cytokines in C57BL/6 Mice: Implication for COVID-19 Dietary Intervention

Transmembrane protease serine 2 (TMPRSS2), an androgen-induced protease associated with prostate cancer, is one putative receptor for coronavirus entry into host cells, where triggering aggressive inflammatory cytokine storm and possibly death in COVID-19 patients. We previously reported that dietary white button mushroom (WBM) antagonized dihydrotestosterone (DHT)-induced androgen receptor (AR) activation and reduced myeloid-derived suppressor cells (MDSCs) in prostate cancer animal models and patients. The present study on C57BL/6 mice revealed that WBM is a unique food that A ) interrupts DHT induced AR-TMPRSS2 expression in putative COVID-19 targeted organs through its AR antagonistic activity and B ) attenuates serum pro-inflammatory cytokines which have been implicated in COVID-19 pathogenesis. We hereby propose WBM intake as a potentially low-cost, efficient, and safe dietary intervention to mitigate COVID-19.

Immunomodulation of Chinese Herbal Medicines on NK cell populations for cancer therapy: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Immunomodulation has become a crucial modality for cancer treatment. Chinese Herbal Medicines (CHMs) are expected as adjuvant therapy for immunomodulation against cancer, but face the key challenge of poor scientific evidence. Changes of natural killer (NK) cells on numbers and/or cytotoxicity are a novel respect to evaluate the immunomodulation of CHMs.

AIM OF THE STUDY

The purpose of this review is to investigate the immunomodulation of Chinese Herbal Medicines (CHMs) on NK cell populations for cancer therapy.

MATERIALS AND METHODS

A systematic review was conducted and outside mainstream electronic databases were screened for potential reference articles. This review tried to report and critically analyzed all the correlative studies, especially these clinical trials (3 CHM extracts and 11 CHM formulas).

RESULTS

Evidence-based functions of CHMs against cancer could be summarized as: (1) enhancement of NK cells activity or relative percentage; (2) prevention of tumor growth and metastasis; (3) relief on side-effects or complications of therapeutic strategies (i.e. chemotherapy, radiotherapy and resection). Briefly, most of cellular studies and two thirds animal studies were based on the extract or components of single herbs, whilst most of clinical trials were keen on formula or prescription of CHMs. The main components of CHMs were demonstrated active on promoting the cytotoxicity of NK cells, including Angelica sinensis, Ganoderma lucidum, Panax ginseng, Radix Astragali, Lentinus edodes, etc. CONCLUSIONS: This comprehensive review demonstrated NK cells activity was positively associated with quality of life but not survival benefit of cancer patients. Thus exploring the roles of NK cells in adjuvant therapy against cancer is confirmed to be beneficial to explore the underlying relationship between immunomodulation and quality of life.

Mushroom Bulgaria inquinans Modulates Host Immunological Response and Gut Microbiota in Mice

We aimed to determine the prebiotic impact of Mushroom Bulgaria inquinans (BI) on the host immune response and gut microbiota. Male C57BL/6 mice were fed a diet supplemented with 0, 1, or 2% BI for 4 wks. Compared to mice fed with a control diet (0% BI), mice fed with 1 or 2% BI had an increase of T cell proliferation from the spleen, but such change was not found between 1 and 2% BI treated mice. Also, BI at 2% increased the production of IL-2 of splenocytes stimulated with T-cell mitogens, but BI at 1 and 2% did not affect productions of other splenic-T cell cytokines including IL-4, IL-10, and IFN-γ. Interestingly, BI at 1 or 2% inhibited T cell proliferation of mesenteric lymph node (mLN) but this effect was not found between 1 and 2% BI treated mice. Furthermore, BI inhibited the production of IL-2 in anti-CD3/CD28-stimulated T cells from mLN in a dose-dependent manner. Meanwhile, BI at 2%, not 1% inhibited the production of IL-4, IL-10, and IFN-γ of mLN. Since BI at 2% produced a more significant effect on the immune response, we further used BI at 2% to evaluate the effect of BI on gut microbiota. Of note, BI reduced the diversity of gut microbiota and resulted in an increase of Faecalibaculum and Parabacteroides abundance and the decrease of Allobaculum, Candidatus_Saccharimonas, and Rikenella abundance at the genus level. Finally, the correlation was observed between specific bacteria genera and the productions of T-cell cytokines from mesenteric lymphocytes: Rikenella and Candidatus_Saccharimonas correlated positively with IL-2, IL-4, IL-10, and IFN-γ; Bacteroides and Parabacteroides correlated negatively with IL-2 and IL-4; Faecalibaculum correlated negatively with IFN-γ and IL-4 and Bacteroides and Bifidobacterium correlated negatively with IFN-γ. The specific role of each intestinal microbiota observed is still unclear, but BI might exert a prebiotic effect on gut microbiota by increasing the abundance of potentially beneficial bacteria (Faecalibaculum). This is helpful for further demonstrating the healthy-promotion mechanism of B. inquinans.

Examining the health effects and bioactive components in Agaricus bisporus mushrooms: a scoping review

There is evidence from both in vitro and animal models that the consumption of edible mushrooms has beneficial effects on health. It is unclear whether similar effects exist in humans and which bioactive compounds are present. This review synthesises the evidence on the world's most commonly consumed mushroom, Agaricus bisporus to (i) examine its effect on human health outcomes; and (ii) determine the nutrient density of its bioactive compounds, which may explain their health effects. A systematic literature search was conducted on the consumption of A. bisporus, without date and study design limits. Bioactive compounds included ergosterol, ergothioneine, flavonoids, glucans and chitin. Two authors independently identified studies for inclusion and assessed methodological quality. Beneficial effects of A. bisporus on metabolic syndrome, immune function, gastrointestinal health and cancer, with the strongest evidence for the improvement in Vitamin D status in humans, were found. Ultraviolet B (UVB) exposed mushrooms may increase and maintain serum 25(OH)D levels to a similar degree as vitamin D supplements. A. bisporus contain beta-glucans, ergosterol, ergothioneine, vitamin D and an antioxidant compound usually reported as flavonoids; with varying concentrations depending on the type of mushroom, cooking method and duration, and UVB exposure. Further research is required to fully elucidate the bioactive compounds in mushrooms using vigorous analytical methods and expand the immunological markers being tested. To enable findings to be adopted into clinical practice and public health initiatives, replication of existing studies in different population groups is required to confirm the impact of A. bisporus on human health.

Macrophage activation by edible mushrooms is due to the collaborative interaction of toll-like receptor agonists and dectin-1b activating beta glucans derived from colonizing microorganisms

Research supports the theory that the microbiome of plants and mushrooms produce potent activators of pathogen recognition receptors which are principal contributors to the stimulation of macrophages. We have previously reported that the in vitro macrophage stimulatory activity of water-soluble extracts from 13 different types of edible mushrooms is predominantly due to bacterial components originating from the naturally occurring bacterial communities within these materials. The purpose of the current study was to further investigate the bacterial-dependent activity of the water-soluble extracts and assess whether these 13 types of mushrooms contain water-insoluble beta glucans that activate the dectin-1b signaling pathway. Activity of the water-soluble extracts was predominantly due to Toll-like receptor 2 (TLR2) and TLR4 agonists. For dectin-1b-dependent activity (indicative of water-insoluble beta glucans), culinary mushrooms (Agaricus bisporus varieties) were essentially inactive, whereas most of the medicinal mushrooms (Lentinula edodes, Grifola frondosa, Hypsizygus marmoreus varieties, Flammulina velutipes) exhibited potent activation. A. bisporus samples with no detectable dectin-1b-dependent activity had yeast colony forming units that were 687 times lower than L. edodes exhibiting high activity, indicating that the active insoluble beta glucans are derived from colonizing yeast. In addition, co-stimulation of macrophages with the TLR agonists and insoluble beta glucan was found to result in a synergistic enhancement of in vitro cytokine production. Taken together, these findings indicate that the in vitro macrophage activating potential of edible mushrooms is due to the collaborative interaction of water-soluble TLR agonists (derived from colonizing bacteria) and water-insoluble beta glucans (derived from colonizing yeast).

Edible Mushrooms Reduce Atherosclerosis in Ldlr-/- Mice Fed a High-Fat Diet

BACKGROUND

Commonly consumed mushrooms, portobello (PBM) and shiitake (SHM), are abundant in nutrients, soluble dietary fibers, and bioactive compounds that have been implicated as beneficial in reducing inflammation, improving lipid profiles, and ameliorating heart disease and atherosclerosis, an inflammatory disease of the arteries.

OBJECTIVE

The aim of this study was to determine effects of PBM and SHM in preventing atherosclerosis and associated inflammation in an animal model.

METHODS

Four-week-old Ldlr-/- male mice were divided into 5 dietary groups for 16 wk: a low-fat control (LF-C, 11 kcal% fat), high-fat control (HF-C, 18.9 kcal% fat), HF + 10% (wt:wt) PBM (HF-PBM, 19.5 kcal% fat) or SHM (HF-SHM, 19.7 kcal% fat) powder, and HF + mushroom control mix (MIX-C, 19.6 kcal% fat), a diet best matched to the average macronutrient content of both mushrooms. Body composition was measured using MRI. Aortic tricuspid valves and aortas were collected and stained to quantify plaque formation. Adhesion molecule expression was quantified by immunohistochemistry. Plasma lipid and cytokine concentrations were measured.

RESULTS

We found that mice fed a HF-SHM diet had ∼86% smaller aortic lesion area than mice in both HF-C (P < 0.01) and MIX-C (P < 0.01) groups and also expressed 31-48% lower vascular cell adhesion molecule-1 levels (P < 0.05) than all other groups. Similarly, HF-PBM-fed mice displayed a 70% reduction in aortic lesion area in the tricuspid valve only (P < 0.05). Both mushroom-fed groups had lower weight gain and fat mass (P < 0.05) than the control groups.

CONCLUSION

These results suggest that consumption of PBMs and particularly SHMs is effective in preventing development of high-fat diet-induced atherosclerosis in Ldlr-/- mice. Future studies will determine active components in mushrooms responsible for this beneficial effect.

B-glucans from Grifola frondosa and Ganoderma lucidum in breast cancer: an example of complementary and integrative medicine

Culinary and medicinal mushrooms are widely used in Asian countries, both as dietary supplements and as nutraceutical foods. They have recently become popular in Europe, as well, for their nutritional and health benefits. In particular, epidemiological studies conducted in Asia suggest that mushroom intake, together with other phytotherapy substances, protects against cancer, specifically gastrointestinal (GI) and breast cancers. Most of the data come from in vitro studies and in vivo experimental animal models. Therefore, in order to translate the updated knowledge to clinical research (i.e., from bench to bedside) a systematic translational research program should be initiated. Future randomized controlled trials comparing the effects of G. frondosa and G. lucidum on conventional treatment outcomes are warranted. The purpose of this review was to describe the emerging mechanisms of action of the mushrooms' anticancer functions which makes their use in clinical practice so promising. Clinical effects of mycotherapy (specifically, the use of Ganoderma lucidum and Grifola frondosa) on long-term survival, tumor response, host immune functions, inflammation, and QoL in cancer patients were also addressed. Adverse events associated with mycotherapy were also investigated. Emerging data point to a potential role of G. lucidum for modulating the carcinogenic potential of GI microbiota, which suggests a new complementary and integrated approach to breast cancer treatment.

Enhancement of natural killer activity and IFN-γ production in an IL-12-dependent manner by a Brassica rapa L

Certain food components possess immunomodulatory effects. The aim of this study was to elucidate the mechanism of the immunostimulatory activity of Brassica rapa L. We demonstrated an enhancement of natural killer (NK) activity and interferon (IFN)-γ production in mice that were orally administered an insoluble fraction of B. rapa L. The insoluble fraction of B. rapa L. significantly induced IFN-γ production in mouse spleen cells in an interleukin (IL)-12-dependent manner, and NK1.1+ cells were the main cells responsible for producing IFN-γ. Additionally, the results suggested that the active compounds in the insoluble fraction were recognized by Toll-like receptor (TLR) 2, TLR4, and C-type lectin receptors on dendritic cells, and they activated signaling cascades such as MAPK, NF-κB, and Syk. These findings suggest that B. rapa L. is a potentially promising immuno-improving material, and it might be useful for preventing immunological disorders such as infections and cancers by activating innate immunity.

Peptides from Colochirus robustus Enhance Immune Function via Activating CD3ζ- and ZAP-70-Mediated Signaling in C57BL/6 Mice

Colochirus robustus, a species of sea cucumber, has long been used in East and Southeast Asia as nutritious food as well as for certain medicinal purpose. Studies have shown a number of biological functions associated with consumption of sea cucumber, many of which are attributed to its major component, sea cucumber peptides (SCP). However, how SCP impacts immune system, which is critical for host defense, has not been defined. To address this issue, in the present study, we conducted comprehensive analysis of immune function after oral administration of SCP (0, 25, 50 and 75 mg/kg body weigh) for eight weeks in C57BL/6 mice. We found that SCP treatment significantly enhanced lymphocyte proliferation, serum albumin (ALB) levels, and the natural killer (NK) cell activity. Moreover, SCP promoted functions of helper T cells (Th) as indicated by increased production of Th1 type cytokines of Interleukin (IL)-1β, IL-2, Interferon (IFN)-γ and TNF-α and Th2 type cytokines (IL-4, IL-6 and IL-10). To determine the effective components, SCP was hydrolyzed into 16 types of constituent amino acids in simulated gastrointestinal digestion and these hydrolytic amino acids (HAA) were used for the mechanistic studies in the in vitro models. Results showed that HAA enhanced lymphocyte proliferation and production of IL-2, IL-10 and IFN-γ. Furthermore, CD3ζ (CD3ζ) and ζ-chain-associated protein kinase 70 (ZAP-70), the signaling molecules essential for activating T lymphocytes, were significantly up-regulated after HAA treatment. In summary, our results suggest that SCP is effective in enhancing immune function by activating T cells via impacting CD3ζ- and ZAP-70-mediated signaling pathway.

Antifatigue Functions and Mechanisms of Edible and Medicinal Mushrooms

Fatigue is the symptom of tiredness caused by physical and/or psychological stresses. As fatigue is becoming a serious problem in the modern society affecting human health, work efficiency, and quality of life, effective antifatigue remedies other than pharmacological drugs or therapies are highly needed. Mushrooms have been widely used as health foods, because of their various bioactive constituents such as polysaccharides, proteins, vitamins, minerals, and dietary fiber. This paper reviews the major findings from previous studies on the antifatigue effects, the active components of mushrooms, and the possible mechanisms. Many studies have demonstrated the antifatigue effects of edible and medicinal mushrooms. These mushrooms probably mitigate human fatigue through effects on the functional systems, including the muscular, cardiovascular, hormone, and immune system. The bioactive constituents that contribute to the antifatigue effects of mushrooms may include polysaccharides, peptides, nucleosides, phenolic compounds, and triterpenoids. Further research is still needed to identify the active ingredients and to investigate their mechanism of action on the antifatigue effects. Since most previous studies have been carried out in animal models, more human trials should be performed to verify the antifatigue function of edible and medicinal mushrooms.

Immunomodulatory effect of a formula developed from American ginseng and Chinese jujube extracts in mice

BACKGROUND

American ginseng (Panax quinquefolius L.) and Chinese jujube (Zizyphus jujuba Mill.) are commonly used in traditional Chinese medicine to enhance immune function.

OBJECTIVE

The present study aimed to develop one Chinese prescription, Shenzao Cha (SZC), consisting of American ginseng and Chinese jujube, and systematically investigate its immunomodulation in healthy ICR mice.

METHODS

Normal ICR mice received intragastric administration of SZC (1.3, 2.6, and 5.2 g raw material/kg body weight) once daily for four weeks, while a control group received the same amount of sterile water.

RESULTS

SZC significantly increased the spleen and thymus indices and T-lymphocyte proliferation, while the T-lymphocyte proliferation in the 5.2 g/kg group was 1.4-fold higher than that in the control. Further, 1.3 g/kg SZC could markedly improve hemolytic activity by 25.2%, and 2.6 g/kg SZC increased the NK cell activity by 78.6% relative to the control. In addition, the activities of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase), that participated in modulating oxidative stress, were significantly increased in the liver, spleen, thymus, and serum, while the contents of malondialdehyde were dramatically decreased.

CONCLUSIONS

SZC exhibited potent immunomodulatory effects on innate and adaptive immunity in healthy ICR mice, as well as potential antioxidant activity for prevention of oxidative stress, which was suggested to partly contribute to the immune enhancement.

Bacterial components are the major contributors to the macrophage stimulating activity exhibited by extracts of common edible mushrooms

Recent studies have indicated that a major contributor to the innate immune enhancing properties of some medicinal plants is derived from the cell wall components of bacteria colonizing these plants. The purpose of the current study was to assess if the bacteria present within edible and medicinal mushrooms substantially contribute to the innate immune stimulating potential of these mushrooms. Whole mushrooms from thirteen types of edible fungi and individual parts from Agaricus bisporus were analyzed for in vitro macrophage activation as well as bacterial lipopolysaccharides (LPS) content, cell load, and community composition. Substantial variation between samples was observed in macrophage activation (over 500-fold), total bacterial load (over 200-fold), and LPS content (over 10 million-fold). Both LPS content (ρ = 0.832, p < 0.0001) and total bacterial load (ρ = 0.701, p < 0.0001) correlated significantly with macrophage activation in the whole mushroom extracts. Extract activity was negated by treatment with NaOH, conditions that inactivate LPS and other bacterial components. Significant correlations between macrophage activation and total bacterial load (ρ = 0.723, p = 0.0001) and LPS content (ρ = 0.951, p < 0.0001) were also observed between different tissues of Agaricus bisporus. Pseudomonas and Flavobacterium were the most prevalent genera identified in the different tissue parts and these taxa were significantly correlated with in vitro macrophage activation (ρ = 0.697, p < 0.0001 and ρ = 0.659, p = 0.0001, respectively). These results indicate that components derived from mushroom associated bacteria contribute substantially to the innate immune enhancing activity exhibited by mushrooms and may result in similar therapeutic actions as reported for ingestion of bacterial preparations such as probiotics.

Modulation of Toll-like receptor signaling in innate immunity by natural products

For centuries, natural products and their derivatives have provided a rich source of compounds for the development of new immunotherapies in the treatment of human disease. Many of these compounds are currently undergoing clinical trials, particularly as anti-oxidative, anti-microbial, and anti-cancer agents. However, the function and mechanism of natural products in how they interact with our immune system has yet to be extensively explored. Natural immune modulators may provide the key to control and ultimately defeat disorders affecting the immune system. They can either up- or down-regulate the immune response with few undesired adverse effects. In this review, we summarize the recent advancements made in utilizing natural products for immunomodulation and their important molecular targets, members of the Toll-like receptor (TLR) family, in the innate immune system.

Effects of 4-week continuous ingestion of champignon extract on halitosis and body and fecal odor

This was placebo-controlled double-blind parallel-group comparative clinical trial targeting 80 men and women aged 50–79 years with halitosis and body and fecal odor. We investigated whether daily champignon extract ingestion for 4 weeks improved these conditions. Subjects were divided into four groups: a placebo group and 50, 500, and 1000 mg/day ingestion groups. No severe adverse events or side effects were noted during the study period. Compared with the placebo group, all champignon extract ingestion groups showed improvement or tendency toward improvement in halitosis and body and fecal odor. Furthermore, our results suggested that the effectiveness of champignon extract in alleviating odors is dose-dependent, i.e., it increases with the dosage.

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.

Immunomodulator 'mushroom beta glucan' induces Wnt/β catenin signalling and improves wound recovery in tilapia and rat skin: a histopathological study

The present study aims to investigate the effects of mushroom beta glucan (MBG) on wound recovery in partial hepatectomy (PH) in Nile tilapia (Oreochromis niloticus) and in rat skin wound healing examination. Following PH, we focussed on the effects on liver repair ability using in vitro and in vivo tests. In vitro, we examined whether the MBG has an impact on liver cell proliferation, mainly through 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assays and bromodeoxyuridine (BrdU) cell proliferation assay detection method. Results showed that MBG treatment was remarkable in enhancing cell proliferation of hepatocytes and in maintaining the cellular viability. Immunohistochemical staining to analyse Wnt/β-catenin signalling also showed that MBG has the effect of promoting cell proliferation of liver tissues after PH surgery.

Impact of dietary components on NK and Treg cell function for cancer prevention

An important characteristic of cancer is that the disease can overcome the surveillance of the immune system. A possible explanation for this resistance arises from the ability of tumor cells to block the tumoricidal activity of host immune cells such as natural killer (NK) cells by inducing the localized accumulation of regulatory T (Treg) cells. Evidence exists that components in commonly consumed foods including vitamins A, D, and E, water-soluble constituents of mushrooms, polyphenolics in fruits and vegetables, and n-3 fatty acids in fish oil can modulate NK cell activities, Treg cell properties, and the interactions between those two cell types. Thus, it is extremely important for cancer prevention to understand the involvement of dietary components with the early stage dynamics of interactions among these immune cells. This review addresses the potential significance of diet in supporting the function of NK cells, Treg cells, and the balance between those two cell types, which ultimately results in decreased cancer risk.

Ameliorating Effect of Mycoleptodonoides aitchisonii on High-fat Diet-induced Obese Mice

The present study investigated the anti-obesity effects of Mycoleptodonoides aitchisonii (MA) in mice fed a high-fat (HF) diet. Two groups were fed either a normal control diet or an HF (45% kcal fat) diet for 12 weeks and three groups were fed an HF diet supplemented with powdered MA (MAP, 1%, 3%, and 5%) for 12 weeks. The anti-obesity effects of MAP supplementation on body weight, fat mass development, and lipid-related markers were assessed. Consumption of an HF diet resulted in increased body weight, serum lipids, relative adipose tissues weight, and liver fat accumulation. However, administration of MAP significantly decreased body weight gain, food intake, food efficiency ratio, hepatic cholesterol level, and adipose tissue weight in a dose-dependent manner. In addition, treatment with MAP significantly reduced the occurrence of fatty liver deposits and steatosis, and inhibited an HF diet-induced increase in adipocyte size. These results suggest that dietary supplementation with MAP exerts anti-obesity effects and indicate that MAP could be used as a functional food to control obesity.

Mushrooms and Health Summit proceedings

The Mushroom Council convened the Mushrooms and Health Summit in Washington, DC, on 9-10 September 2013. The proceedings are synthesized in this article. Although mushrooms have long been regarded as health-promoting foods, research specific to their role in a healthful diet and in health promotion has advanced in the past decade. The earliest mushroom cultivation was documented in China, which remains among the top global mushroom producers, along with the United States, Italy, The Netherlands, and Poland. Although considered a vegetable in dietary advice, mushrooms are fungi, set apart by vitamin B-12 in very low quantity but in the same form found in meat, ergosterol converted with UV light to vitamin D2, and conjugated linoleic acid. Mushrooms are a rare source of ergothioneine as well as selenium, fiber, and several other vitamins and minerals. Some preclinical and clinical studies suggest impacts of mushrooms on cognition, weight management, oral health, and cancer risk. Preliminary evidence suggests that mushrooms may support healthy immune and inflammatory responses through interaction with the gut microbiota, enhancing development of adaptive immunity, and improved immune cell functionality. In addition to imparting direct nutritional and health benefits, analysis of U.S. food intake survey data reveals that mushrooms are associated with higher dietary quality. Also, early sensory research suggests that mushrooms blended with meats and lower sodium dishes are well liked and may help to reduce intakes of red meat and salt without compromising taste. As research progresses on the specific health effects of mushrooms, there is a need for effective communication efforts to leverage mushrooms to improve overall dietary quality.

Oral Administration of MBG to Modulate Immune Responses and Suppress OVA-Sensitized Allergy in a Murine Model

Recently studies performed on mushroom isolated polysaccharides demonstrated that β -(1,3)-glucan may affect the balance of Th1/Th2 cell response. Using ovalbumin (OVA) as a hypersensitivity inducer, we evaluated the ability of mushroom beta-glucan (MBG) in modulating Th1/Th2 cell responses in B6 mice. As compared to the control group, administration of MBG resulted in an increase of phagocytic activities, Th1 cytokine productions, immunoglobulins including IgG2A and IgA, and a significant expression of the splenic surface markers including CD3, CD4, CD8, and F4/80. In contrast, administration of MBG has significantly suppressed IgE and IgG1 levels and Th2 cytokines including IL-4, IL-5, and IL-6. Histopathological observation of MBG-treated followed by OVA-treated mice showed less filtration of eosinophil in pulmonary tissue sections. Our data suggested that administration of MBG treatments alters the natural course of the IgE-mediated hypersensitivities. In this investigation, we realize the mushroom beta glucan alter the Th2 response toward the Th1 in the allergic, resulting in a reduction in IgE productions which played a substantive role in reducing the severity of IgE-mediated hypersensitivity.

Dietary supplementation with white button mushrooms augments the protective immune response to Salmonella vaccine in mice

We previously showed that dietary white button mushrooms (WBMs) enhanced natural killer cell activity and that in vitro WBM supplementation promotes maturation and function of dendritic cells (DCs). The current study investigated whether WBM consumption would enhance pathogen-specific immune response using a Salmonella vaccination and infection animal model. C57BL/6 mice were fed diets containing 0%, 2%, or 5% WBM for 4 wk before oral vaccination with live attenuated Salmonella typhimurium SL1479. Four weeks after immunization, mice were orally infected with virulent Salmonella typhimurium SL1344. Immunization increased animal survival and, among immunized mice, the 2% WBM group had a higher survival rate than the other groups. Next, we fed mice 2% WBMs to determine the immunological mechanism underlying the WBM-potentiated protective effect. We found that WBM supplementation increased Salmonella-specific blood immunoglobulin (Ig) G and fecal IgA concentrations. WBM-fed mice also had a higher IgG2a and unchanged IgG1 production, leading to an elevated IgG2a:IgG1 ratio and indicating an enhanced T helper 1 response. Consistent with these results, WBM-fed mice had higher interferon-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-17A production and unchanged IL-4 production in their splenocytes after polyclonal (anti-CD3/CD28) or antigen-specific stimulation. Furthermore, WBM-fed mice had more DCs in the spleen, and these DCs expressed higher levels of activation markers CD40 and major histocompatibility complex-II. These mice also produced more IL-12 and TNF-α postimmunization. Together, these results suggest that WBMs may improve Salmonella vaccine efficacy through an enhanced adaptive immune response.

White button mushrooms increase microbial diversity and accelerate the resolution of Citrobacter rodentium infection in mice

The effect of feeding C57BL/6 mice white button (WB) mushrooms or control (CTRL) diets for 6 wk was determined on the bacterial microflora, urinary metabolome, and resistance to a gastrointestinal (GI) pathogen. Feeding mice a diet containing 1 g WB mushrooms/100 g diet resulted in changes in the microflora that were evident at 2 wk and stabilized after 4 wk of WB feeding. Compared with CTRL-fed mice, WB feeding (1 g/100 g diet) increased the diversity of the microflora and reduced potentially pathogenic (e.g., Clostridia) bacteria in the GI tract. Bacteria from the Bacteroidetes phylum increased and the Firmicutes phylum decreased in mushroom-fed mice compared with CTRL. The changes in the microflora were also reflected in the urinary metabolome that showed a metabolic shift in the WB-fed compared with the CTRL-fed mice. The WB feeding and changes in the microbiome were associated with fewer inflammatory cells and decreased colitis severity in the GI mucosa following Citrobacter rodentium infection compared with CTRL. Paradoxically, the clearance of C. rodentium infection did not differ even though Ifn-γ and Il-17 were higher in the colons of the WB-fed mice compared with CTRL. Adding modest amounts of WB mushrooms (1 g/100 g diet) to the diet changed the composition of the normal flora and the urinary metabolome of mice and these changes resulted in better control of inflammation and resolution of infection with C. rodentium.

Dietary supplementation with lacto-wolfberry enhances the immune response and reduces pathogenesis to influenza infection in mice

Despite the availability of vaccines, influenza is a considerable public health problem, which emphasizes the need for development of additional strategies to enhance host defense against influenza. Wolfberry, or goji berry, long used as a medicinal food in China, has recently been shown to improve immune response in mice. Because immune response plays a key role in the body's defense against pathogens, we hypothesized that wolfberry may increase host resistance to influenza infection by enhancing immune response. To test this hypothesis, we fed adult mice (4 mo old) a milk-based preparation of wolfberry called Lacto-Wolfberry (LWB) for 4 wk and then infected them with influenza A/Puerto Rico/8/34 (H1N1) while continuing the same experimental diets. Viral titer, lung pathology, and immune response were determined at different time points postinfection. LWB supplementation prevented infection-induced weight loss and reduced lung pathology on days 6 and 9 postinfection (P < 0.05). LWB-fed mice showed overall, significantly higher concanavalin A-induced IL-2 production (P < 0.05). Furthermore, we found positive correlations between weight loss and lung viral titer, pathology score, TNFα, and IL-6 production as well as negative correlations with T cell proliferation and IL-2 production (all P ≤ 0.05). These results indicate that LWB supplementation can attenuate symptoms and pathology of influenza infection by decreasing inflammatory cytokines in lungs while enhancing systemic T cell-mediated function as measured by their ability to produce IL-2.

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.

Schizophyllan inhibits the development of mammary and hepatic carcinomas induced by 7,12 dimethylbenz(α)anthracene and decreases cell proliferation: comparison with tamoxifen

BACKGROUND

Breast cancer is one of the leading causes of cancer mortality among women. Some anticancer compounds have been isolated from mushrooms. The aim of the present work was to study the anticancer effects of schizophyllan (SCH), a β-D: -glucan extracted from the mushroom Schizophyllum commune alone or in combination with tamoxifen (TAM) on 7, 12 Dimethylbenz(α)anthracene (DMBA)-induced carcinomas in mice.

METHODS

We isolated SCH from S. commune. Female mice received DMBA, SCH, DMBA+SCH, DMBA+TAM or DMBA+TAM+SCH or vehicles. We studied mice survival, tumour incidence, histopathology, oestrogen receptor (ER) expression, cell proliferation by immunohistochemical detection of proliferating cell nuclear antigen (PCNA), apoptosis by TUNEL assay, as well as caspase-3 expression.

RESULTS

DMBA treatment resulted in mammary and hepatocellular carcinomas (HCC). Both SCH and TAM reduced the incidence of DMBA-induced mammary tumours by 85 and 75 %, respectively, and equally decreased the PCNA labelling index relative to DMBA. TAM treatment increased the incidence of- and PCNA index in HCCs relative to DMBA, while SCH suppressed these effects. TAM was more effective than SCH in the induction of apoptosis in both mammary and hepatic carcinomas. Caspase-3 levels correlated with the apoptotic index in most experimental groups.

CONCLUSIONS

Only one dose of SCH had similar therapeutic effects against DMBA-induced mammary carcinomas as 4 weeks of TAM treatment. This coupled with the ability of SCH to suppress hepatic lesions associated with TAM treatment provides the rationale for further investigating the combined therapeutic effects of TAM+SCH in preclinical models of ER-positive breast cancer, as well as in liver cancer.

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.

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.

Avenanthramides inhibit proliferation of human colon cancer cell lines in vitro

A high intake of whole grain foods is associated with reduced risk of colon cancer, but the mechanism underlying this protection has yet to be elucidated. Chronic inflammation and associated cyclooxygenase-2 (COX-2) expression in the colon epithelium are causally related to epithelial carcinogenesis, proliferation, and tumor growth. We examined the effect of avenanthramides (Avns), unique polyphenols from oats with anti-inflammatory properties, on COX-2 expression in macrophages, colon cancer cell lines, and on proliferation of human colon cancer cell lines. We found that Avns-enriched extract of oats (AvExO) had no effect on COX-2 expression, but it did inhibit COX enzyme activity and prostaglandin E(2) (PGE(2)) production in lipopolysaccharide-stimulated mouse peritoneal macrophages. Avns (AvExO, Avn-C, and the methylated form of Avn-C (CH3-Avn-C)) significantly inhibited cell proliferation of both COX-2-positive HT29, Caco-2, and LS174T, and COX-2-negative HCT116 human colon cancer cell lines, CH3-Avn-C being the most potent. However, Avns had no effect on COX-2 expression and PGE(2) production in Caco-2 and HT29 colon cancer cells. These results indicate that the inhibitory effect of Avns on colon cancer cell proliferation may be independent of COX-2 expression and PGE(2) production. Thus, Avns might reduce colon cancer risk through inhibition of macrophage PGE(2) production and non-COX-related antiproliferative effects in colon cancer cells. Interestingly, Avns had no effect on cell viability of confluence-induced differentiated Caco-2 cells, which display the characteristics of normal colonic epithelial cells. Our results suggest that the consumption of oats and oat bran may reduce the risk of colon cancer not only because of their high fiber content but also due to Avns, which attenuate proliferation of colonic cancer cells.

White button and shiitake mushrooms reduce the incidence and severity of collagen-induced arthritis in dilute brown non-agouti mice

Exotic mushrooms have been used in ancient Chinese medicine due to their immunomodulatory properties for the treatment and/or prevention of chronic diseases. However, only limited data exist on the health benefits of white button mushrooms (WBM), the most common in the American diet. In the current study, we investigated the effects of WBM and shiitake mushrooms (SM) on collagen-induced arthritis (CIA) using a 2 x 3 factorial design in 8-wk-old female dilute brown non-agouti mice that were fed a control diet (n = 37) or the same diet supplemented with 5% lyophilized WBM or SM (n = 27) for 6 wk. CIA was induced by immunizing mice with 100 µg bovine collagen followed by 50 µg LPS on d 20 post-collagen injection. CIA was assessed by mononuclear cell infiltration, bone erosion, plasma IL-6, TNFα, and intercellular adhesion molecule-1 (sICAM-1) concentrations. Compared with the control diet, WBM and SM tended to reduce the CIA index from 5.11 ± 0.82 to 3.15 ± 0.95 (P = 0.06) (median, 6-9 to 1-2) 31 d post-collagen injection. Whereas 58% of control mice had a CIA index ≥ 7, only 23% of WBM and 29% of SM mice did (P = 0.1). Although both types of mushrooms reduced plasma TNFα (34%, WBM; 64%, SM), only SM increased plasma IL-6 by 1.3-fold (P < 0.05). The CIA index was positively correlated with sICAM1 (r = 0.55; P < 0.05) but negatively correlated with TNFα (r = 0.34; P < 0.05). Whether mushrooms are beneficial for arthritis management remains to be investigated. To our knowledge, this is the first report demonstrating a possible health benefit of WBM in arthritis treatment.

High molecular weight glucan of the culinary medicinal mushroom Agaricus bisporus is an alpha-glucan that forms complexes with low molecular weight galactan

An alpha-glucan was isolated from the culinary medicinal mushroom A. bisporus by hot water extraction, ethanol precipitation and DEAE-cellulose chromatography. The resulting material showed a single HMW peak excluded from a Sephadex G50 column that could completely be degraded by alpha-amylase treatment. After heating in 1% SDS a small additional peak of low MW eluted from the G50 column. The monosaccharide composition of the main peak was evaluated by HPLC, and was found to consist of a majority of glucose (97.6%), and a minor proportion of galactose (2.4%). Methylation analysis and degradation by alpha-amylase indicated the presence of an alpha-glucan with a main chain consisting of (1(R)4)-linked units, substituted at O-6 by alpha-D-glucopyranose single-units in the relation 1:8. Mono- (13C-, 1H-NMR) and bidimensional [1H (obs.),13C-HSQC] spectroscopy analysis confirmed the alpha-configuration of the Glcp residues by low frequency resonances of C-1 at delta 100.6, 100.2, and 98.8 ppm and H-1 high field ones at delta 5.06, 5.11, and 4.74 ppm. The DEPT-13C-NMR allowed assigning the non-substituted and O-substituted -CH(2) signals at delta 60.3/60.8 and 66.2 ppm, respectively. Other assignments were attributed to C-2, C-3, C-4, C-5 and C-6 of the non-reducing ends at delta 71.8; 72.8; 70.0; 71.3 and 60.3/60.8 ppm, respectively. The minor proportion of galactose that was demonstrated was probably derived from a complex between the alpha-glucan and a low molecular weight galactan.

Medicinal mushrooms: Towards a new horizon

The arising awareness about functional food has created a boom in this new millennium. Mushrooms are widely consumed by the people due to their nutritive and medicinal properties. Belonging to taxonomic category of basidiomycetes or ascomycetes, these mushrooms possess antioxidant and antimicrobial properties. They are also one of the richest source of anticancer and immunomodulating agents. Thus these novel myochemicals from these mushrooms are the wave of future.

Dietary supplementation with chitosan derived from mushrooms changes adipocytokine profile in diet-induced obese mice, a phenomenon linked to its lipid-lowering action

Recent data reported that chitosan reduces high-fat (HF) diet-induced obesity in mice without describing the metabolic consequences of such an effect. The aim of this study was to investigate the capacity of chitosan derived from edible mushrooms to modify adipocytokine levels and to assess the relevance of this effect on the development of fat mass, and on glucose and lipid metabolism in obese mice. Mice were fed a HF diet or a HF diet supplemented with 5% fungal chitosan for ten weeks. HF-induced hypertriglyceridaemia, fasting hyperinsulinaemia and fat accumulation in liver, muscle and white adipose tissue (WAT) were reduced after chitosan treatment. The higher lipid content in the caecum following treatment with chitosan suggested that this dietary fiber reduced lipid absorption. We postulated that the lower triglyceridaemia observed upon chitosan treatment could also be the result of the lower FIAF (fasting-induced adipose factor) expression observed in visceral adipose tissue. IL-6, resistin and leptin levels decreased in the serum after chitosan supplementation. We conclude that fungal chitosan counteracts some inflammatory disorders and metabolic alterations occurring in diet-induced obese mice since it decreases feed efficiency, fat mass, adipocytokine secretion and ectopic fat deposition in the liver and the muscle.

The effects of whole mushrooms during inflammation

BACKGROUND

Consumption of edible mushrooms has been suggested to improve health. A number of isolated mushroom constituents have been shown to modulate immunity. Five commonly consumed edible mushrooms were tested to determine whether whole mushrooms stimulate the immune system in vitro and in vivo.

RESULTS

The white button (WB) extracts readily stimulated macrophage production of TNF-alpha. The crimini, maitake, oyster and shiitake extracts also stimulated TNF-alpha production in macrophage but the levels were lower than from WB stimulation. Primary cultures of murine macrophage and ovalbumin (OVA) specific T cells showed that whole mushroom extracts alone had no effect on cytokine production but co-stimulation with either lipopolysaccharide or OVA (respectively) induced TNF-alpha, IFN-gamma, and IL-1beta while decreasing IL-10. Feeding mice diets that contained 2% WB mushrooms for 4 weeks had no effect on the ex vivo immune responsiveness or associated toxicity (changes in weight or pathology of liver, kidney and gastrointestinal tract). Dextran sodium sulfate (DSS) stimulation of mice that were fed 1% WB mushrooms were protected from DSS induced weight loss. In addition, 2% WB feeding protected the mice from transient DSS induced colonic injury. The TNF-alpha response in the colon and serum of the DSS challenged and 2% WB fed mice was higher than controls.

CONCLUSION

The data support a model whereby edible mushrooms regulate immunity in vitro. The in vivo effects of edible mushrooms required a challenge with DSS to detect small changes in TNF-alpha and transient protection from colonic injury. There are modest effects of in vivo consumption of edible mushrooms on induced inflammatory responses. The result is not surprising since it would certainly be harmful to strongly induce or suppress immune function following ingestion of a commonly consumed food.

Cognitive impairment in folate-deficient rats corresponds to depleted brain phosphatidylcholine and is prevented by dietary methionine without lowering plasma homocysteine

Poor folate status is associated with cognitive decline and dementia in older adults. Although impaired brain methylation activity and homocysteine toxicity are widely thought to account for this association, how folate deficiency impairs cognition is uncertain. To better define the role of folate deficiency in cognitive dysfunction, we fed rats folate-deficient diets (0 mg FA/kg diet) with or without supplemental L-methionine for 10 wk, followed by cognitive testing and tissue collection for hematological and biochemical analysis. Folate deficiency with normal methionine impaired spatial memory and learning; however, this impairment was prevented when the folate-deficient diet was supplemented with methionine. Under conditions of folate deficiency, brain membrane content of the methylated phospholipid phosphatidylcholine was significantly depleted, which was reversed with supplemental methionine. In contrast, neither elevated plasma homocysteine nor brain S-adenosylmethionine and S-adenosylhomocysteine concentrations predicted cognitive impairment and its prevention by methionine. The correspondence of cognitive outcomes to changes in brain membrane phosphatidylcholine content suggests that altered phosphatidylcholine and possibly choline metabolism might contribute to the manifestation of folate deficiency-related cognitive dysfunction.

B-vitamin deficiency causes hyperhomocysteinemia and vascular cognitive impairment in mice

In older adults, mildly elevated plasma total homocysteine (hyperhomocysteinemia) is associated with increased risk of cognitive impairment, cerebrovascular disease, and Alzheimer's disease, but it is uncertain whether this is due to underlying metabolic, neurotoxic, or vascular processes. We report here that feeding male C57BL6/J mice a B-vitamin-deficient diet for 10 weeks induced hyperhomocysteinemia, significantly impaired spatial learning and memory, and caused a significant rarefaction of hippocampal microvasculature without concomitant gliosis and neurodegeneration. Total hippocampal capillary length was inversely correlated with Morris water maze escape latencies (r = -0.757, P < 0.001), and with plasma total homocysteine (r = -0.631, P = 0.007). Feeding mice a methionine-rich diet produced similar but less pronounced effects. Our findings suggest that cerebral microvascular rarefaction can cause cognitive dysfunction in the absence of or preceding neurodegeneration. Similar microvascular changes may mediate the association of hyperhomocysteinemia with human age-related cognitive decline.

The immunobiology of mushrooms

There has been enormous interest in the biologic activity of mushrooms and innumerable claims have been made that mushrooms have beneficial effects on immune function with subsequent implications for inhibition of tumor growth. The majority of these observations are anecdotal and often lack standardization. However, there remains considerable data on both in vitro and in vivo effects that reflect on the potential of mushroom compounds to influence human immunity. A number of these effects are beneficial but, unfortunately, many responses are still characterized based on phenomenology and there is more speculation than substance. With respect to tumor biology, although many neoplastic lesions are immunogenic, tumor antigens frequently are self antigens and induce tolerance and many patients with cancer exhibit suppressed immune responses, including defective antigen presentation. Therefore, if and when mushroom extracts are effective, they more likely function as a result of improved antigen presentation by dendritic cells than by a direct cytopathic effect. In this review we attempt to place these data in perspective, with a particular focus on dendritic cell populations and the ability of mushroom extracts to modulate immunity. There is, at present, no scientific basis for the use of either mushrooms or mushroom extracts in the treatment of human patients but there is significant potential for rigorous research to understand the potential of mushrooms in human disease and thence to focus on appropriate clinical trials to demonstrate effectiveness and/ or potential toxicity.