Longitudinal Consumption of Ergothioneine Reduces Oxidative Stress and Amyloid Plaques and Restores Glucose Metabolism in the 5XFAD Mouse Model of Alzheimer's Disease.

Background: Ergothioneine (ERGO) is a unique antioxidant and a rare amino acid available in fungi and various bacteria but not in higher plants or animals. Substantial research data indicate that ERGO is a physiological antioxidant cytoprotectant. Different from other antioxidants that need to breach the blood-brain barrier to enter the brain parenchyma, a specialized transporter called OCTN1 has been identified for transporting ERGO to the brain. Purpose: To assess whether consumption of ERGO can prevent the progress of Alzheimer's disease (AD) on young (4-month-old) 5XFAD mice. Methods and materials: Three cohorts of mice were tested in this study, including ERGO-treated 5XFAD, non-treated 5XFAD, and WT mice. After the therapy, the animals went through various behavioral experiments to assess cognition. Then, mice were scanned with PET imaging to evaluate the biomarkers associated with AD using [11C]PIB, [11C]ERGO, and [18F]FDG radioligands. At the end of imaging, the animals went through cardiac perfusion, and the brains were isolated for immunohistology. Results: Young (4-month-old) 5XFAD mice did not show a cognitive deficit, and thus, we observed modest improvement in the treated counterparts. In contrast, the response to therapy was clearly detected at the molecular level. Treating 5XFAD mice with ERGO resulted in reduced amyloid plaques, oxidative stress, and rescued glucose metabolism. Conclusions: Consumption of high amounts of ERGO benefits the brain. ERGO has the potential to prevent AD. This work also demonstrates the power of imaging technology to assess response during therapy.

Aqueous Extracts of Pleurotus ostreatus and Hericium erinaceus Protect against Ultraviolet A-Induced Damage in Human Dermal Fibroblasts.

Pleurotus ostreatus (PO) and Hericium erinaceus (HE) have been traditionally used to treat various diseases, owing to their antioxidant, antimicrobial, neuroprotective, and antitumor effects. However, few studies have been reported on their antiaging effects. In this study, the antioxidant and antiaging activities of PO and HE aqueous extracts were investigated in ultraviolet A (UVA)-induced human dermal fibroblast cells (HDFs). The antioxidant properties of PO and HE aqueous extracts were measured by total polyphenol and ergothioneine content, and their antioxidant activity was analyzed with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging assays. To demonstrate the antiaging effect of PO and HE aqueous extracts in UVA-induced HDFs, the secretion and mRNA expression of matrix metalloproteinase-1 (MMP-1), procollagen type I (PC1), and elastase were assessed by enzyme-linked immunosorbent assay (ELISA) and real-time PCR, respectively. The total polyphenol content in each extract was 13.6 and 11.7 mg gallic acid equivalents/g dry weight (DW), respectively, and the total ergothioneine content in each extract was 3.43 and 2.18 mg/g DW, respectively. The PO and HE extracts increased DPPH and ABTS radical-scavenging activity in a dose-dependent manner. In UVA-damaged HDFs, the extracts increased PC1 production but decreased MMP-1 production and elastase-1 activity. Furthermore, the mRNA levels of PC1, MMP-1, and elastase were recovered in the PO- and HE-treated UVA-irradiated HDFs compared to those in the irradiated control group. PO and HE aqueous extracts may be potentially used as a promising antiphotoaging agent.

Mushroom intake and cognitive performance among US older adults: the National Health and Nutrition Examination Survey, 2011-2014.

Emerging evidence has suggested that mushrooms, which are a rich source of the potent antioxidants ergothioneine and glutathione as well as vitamin D, may have neuroprotective properties. This study investigated the association between mushroom consumption and cognitive performance in a nationally representative sample of US older adults. We analysed data from older adults aged ≥ 60 years from the 2011-2014 National Health and Nutrition Examination Survey. Mushroom intake was measured using up to two 24-h dietary recalls and was categorised into three groups (lowest, middle and highest). Cognitive function tests included the Animal Fluency (AF) Test; Consortium to Establish a Registry for Alzheimer's Disease Delayed Recall (CERAD-DR) and Word Learning (CERAD-WL); and Digit Symbol Substitution Test (DSST). Multivariable linear regression models were developed, adjusting for socio-demographics, major lifestyle factors, self-reported chronic diseases and dietary factors, including the Healthy Eating Index-2015 score and total energy. The study included 2840 participants. Compared with the lowest category of mushroom intake, participants in the highest category (median intake = 13·4 g /4184 KJ (1000 kcal)/d) had higher scores for DSST (ß = 3·87; 95 % CI 0·30, 7·45; P for trend = 0·03) and CERAD-WL (ß = 1·05; 95 % CI 0·0003, 2·10; P for trend = 0·04). Similar non-significant trends were observed for AF (ß = 0·24; 95 % CI -2·26, 2·73; P for trend = 0·92) but not for the CERAD-DR. Greater mushroom intake was associated with certain cognitive performance tests, suggesting regular mushroom consumption may reduce the risk of cognitive decline.

Improved synthesis of an ergothioneine PET radioligand for imaging oxidative stress in Alzheimer's disease.

L-ergothioneine (ERGO) is a potent antioxidant with cytoprotective effects. To study ERGO biodistribution and detect oxidative stress in vivo, we report an efficient and reproducible preparation of [11 C]-labeled ERGO PET radioligand based on protecting the histidine carboxylic group with a methyl ester. Overall, this new protection approach using methyl ester improved the chemical yield of a 4-step reaction from 14% to 24% compared to the previous report using t-butyl ester. The [11 C]CH3 methylation of the precursor provided the desired product with 55 ± 10% radiochemical purity and a molar activity of 450 ± 200 TBq·mmol-1 . The [11 C]ERGO radioligand was able to detect threshold levels of oxidative stress in a preclinical animal model of Alzheimer's disease.

Health consequences of improving the content of ergothioneine in the food supply.

Ergothioneine (ERGO) is a potent antioxidant and anti-inflammatory amino acid that is highly bioavailable to humans from the diet. ERGO is now regarded by some as a 'longevity vitamin' that has the potential to mitigate some chronic diseases of ageing and thereby increase life expectancy when present in adequate amounts. However, only limited knowledge exists regarding ERGO content in the human diet. Since ERGO is produced primarily by fungi, mushrooms are known to be the leading dietary source, but ERGO is found in relatively low amounts throughout the food chain as a result of soil-borne fungi or bacteria passing it on to plants through their roots. Some conventional agricultural practices that negatively impact soil fungi, such as excessive soil disturbance (ploughing), can significantly reduce ERGO content of food crops when compared to regenerative practices such as eliminating tillage of the soil (no-till). This has led us to the concept that ERGO may be a definitive connection between soil health and human health.

Prospective study of dietary mushroom intake and risk of mortality: results from continuous National Health and Nutrition Examination Survey (NHANES) 2003-2014 and a meta-analysis.

BACKGROUND: Whether mushroom consumption, which is a rich source of potent antioxidants ergothioneine and glutathione, vitamins, and minerals (e.g., selenium & copper), is associated with a lower mortality risk is not well understood. This study aimed to examine the association between mushroom consumption and risk of mortality in a prospective cohort study and a meta-analysis of prospective cohort studies. METHODS: We followed 30,378 participants from the continuous National Health and Nutrition Examination Survey (NHANES) extant data (2003-2014). Dietary mushroom intake was assessed using up to two 24-h recalls. Mortality was evaluated in all participants linked to the National Death Index mortality data through December 31, 2015. We used Cox proportional hazards regression models to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs). We also conducted a meta-analysis, including results from our present study and 4 other cohort studies. RESULTS: During a mean (SD) of 6.7 (3.4) years of follow-up, a total of 2855 death cases were documented among NHANES participants. In our analysis of continuous NHANES, we found a non-significant association between mushroom consumption and all-cause mortality (adjusted hazard ratio (HR) = 0.84; 95% CI: 0.67-1.06) after adjusting for demographic, major lifestyle factors, overall diet quality, and other dietary factors, including total energy. The meta-analysis of prospective cohort studies, including 601,893 individuals, showed that mushroom consumption was associated with a lower risk of all-cause mortality (pooled risk ratio: 0.94; 95% CI: 0.91, 0.98). CONCLUSION: In a meta-analysis of prospective cohort studies, mushroom consumption was associated with a lower risk of all-cause mortality.

A novel antioxidant ergothioneine PET radioligand for in vivo imaging applications.

Ergothioneine (ERGO) is a rare amino acid mostly found in fungi, including mushrooms, with recognized antioxidant activity to protect tissues from damage by reactive oxygen species (ROS) components. Prior to this publication, the biodistribution of ERGO has been performed solely in vitro using extracted tissues. The aim of this study was to develop a feasible chemistry for the synthesis of an ERGO PET radioligand, [11C]ERGO, to facilitate in vivo study. The radioligand probe was synthesized with identical structure to ERGO by employing an orthogonal protection/deprotection approach. [11C]methylation of the precursor was performed via [11C]CH3OTf to provide [11C]ERGO radioligand. The [11C]ERGO was isolated by RP-HPLC with a molar activity of 690 TBq/mmol. To demonstrate the biodistribution of the radioligand, we administered approximately 37 MBq/0.1 mL in 5XFAD mice, a mouse model of Alzheimer's disease via the tail vein. The distribution of ERGO in the brain was monitored using 90-min dynamic PET scans. The delivery and specific retention of [11C]ERGO in an LPS-mediated neuroinflammation mouse model was also demonstrated. For the pharmacokinetic study, the concentration of the compound in the serum started to decrease 10 min after injection while starting to distribute in other peripheral tissues. In particular, a significant amount of the compound was found in the eyes and small intestine. The radioligand was also distributed in several regions of the brain of 5XFAD mice, and the signal remained strong 30 min post-injection. This is the first time the biodistribution of this antioxidant and rare amino acid has been demonstrated in a preclinical mouse model in a highly sensitive and non-invasive manner.

Mushroom intake and depression: A population-based study using data from the US National Health and Nutrition Examination Survey (NHANES), 2005-2016.

BACKGROUND: Mushrooms contain numerous bioactive compounds that may be associated with reduced anxiety including vitamin B12, nerve growth factor, antioxidants, and anti-inflammatory agents. We hypothesized that mushroom consumption is associated with a lower risk of depression in American adults. METHODS: Data from the National Health and Nutrition Examination Survey 2005-2016 was used. Up to two days of 24 h dietary recall were analyzed to assess mushroom intake frequency. Depression was measured using the Patient Health Questionnaire (PHQ-9, score ≥ 10). We used multivariable logistic regression models, adjusting for potential confounding factors. RESULTS: Among 24,699 participants (mean (SE) age: 45.5 (0.3) years), the weighted prevalence of depression was 5.9%. Mushrooms were consumed by 5.2% of participants. Compared with the lowest tertile of mushroom intake, participants in the middle tertile (median intake = 4.9 g/d, number of cases = 16) had lower odds of depression (adjusted OR = 0.31; 95% confidence interval [CI] 0.16, 0.60) while those in the highest tertile did not differ (median intake = 19.6 g/d, adjusted OR = 0.91; 95% CI: 0.47, 1.78, number of cases = 22) (P-trend = 0.42). LIMITATIONS: Cross-sectional data and lack of information on specific types of mushrooms consumed. CONCLUSION: Mushroom consumers had a lower odd of depression. However, we did not observe a dose-response relationship.

Association of mushroom consumption with all-cause and cause-specific mortality among American adults: prospective cohort study findings from NHANES III.

BACKGROUND: Whether mushroom consumption, which is rich in several bioactive compounds, including the crucial antioxidants ergothioneine and glutathione, is inversely associated with low all-cause and cause-specific mortality remains uncertain. This study aimed to prospectively investigate the association between mushroom consumption and all-cause and cause-specific mortality risk. METHODS: Longitudinal analyses of participants from the Third National Health and Nutrition Examination Survey (NHANES III) extant data (1988-1994). Mushroom intake was assessed by a single 24-h dietary recall using the US Department of Agriculture food codes for recipe foods. All-cause and cause-specific mortality were assessed in all participants linked to the National Death Index mortality data (1988-2015). We used Cox proportional hazards regression models to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for all-cause and cause-specific mortality. RESULTS: Among 15,546 participants included in the current analysis, the mean (SE) age was  44.3 (0.5) years. During a mean (SD) follow-up duration of 19.5 (7.4) years , a total of 5826 deaths were documented. Participants who reported consuming mushrooms had lower risk of all-cause mortality compared with those without mushroom intake (adjusted hazard ratio (HR) = 0.84; 95% CI: 0.73-0.98) after adjusting for demographic, major lifestyle factors, overall diet quality, and other dietary factors including total energy. When cause-specific mortality was examined, we did not observe any statistically significant associations with mushroom consumption. Consuming 1-serving of mushrooms per day instead of 1-serving of processed or red meats was associated with lower risk of all-cause mortality (adjusted HR = 0.65; 95% CI: 0.50-0.84). We also observed a dose-response relationship between higher mushroom consumption and lower risk of all-cause mortality (P-trend = 0.03). CONCLUSION: Mushroom consumption was associated with a lower risk of total mortality in this nationally representative sample of US adults.

Higher Mushroom Consumption Is Associated with Lower Risk of Cancer: A Systematic Review and Meta-Analysis of Observational Studies.

Mushrooms are rich in bioactive compounds. The potential health benefits associated with mushroom intake have gained recent research attention. We thus conducted a systematic review and meta-analysis to assess the association between mushroom intake and risk of cancer at any site. We searched MEDLINE, Web of Science, and Cochrane Library to identify relevant studies on mushroom intake and cancer published from 1 January, 1966, up to 31 October, 2020. Observational studies (n = 17) with RRs, HRs, or ORs and 95% CIs of cancer risk for ≥2 categories of mushroom intake were eligible for the present study. Random-effects meta-analyses were conducted. Higher mushroom consumption was associated with lower risk of total cancer (pooled RR for the highest compared with the lowest consumption groups: 0.66; 95% CI: 0.55, 0.78; n = 17). Higher mushroom consumption was also associated with lower risk of breast cancer (pooled RR for the highest compared with the lowest consumption groups: 0.65; 95% CI: 0.52, 0.81; n = 10) and nonbreast cancer (pooled RR for the highest compared with the lowest consumption groups: 0.80; 95% CI: 0.66, 0.97; n = 13). When site-specific cancers were examined, a significant association with mushroom consumption was only observed with breast cancer; this could be due to the small number of studies that were conducted with other cancers. There was evidence of a significant nonlinear dose-response association between mushroom consumption and the risk of total cancer (P-nonlinearity = 0.001; n = 7). Limitations included the potential for recall and selection bias in case-control designs, which comprised 11 out of the 17 studies included in this meta-analysis, and the large variation in the adjustment factors used in the final models from each study. The association between higher mushroom consumption and lower risk of cancer, particularly breast cancer, may indicate a potential protective role for mushrooms in the diet.

Is ergothioneine a 'longevity vitamin' limited in the American diet?

There is mounting evidence for the potential for the natural dietary antioxidant and anti-inflammatory amino acid l-Ergothioneine (ERGO) to prevent or mitigate chronic diseases of aging. This has led to the suggestion that it could be considered a 'longevity vitamin.' ERGO is produced in nature only by certain fungi and a few other microbes. Mushrooms are, by far, the leading dietary source of ERGO, but it is found in small amounts throughout the food chain, most likely due to soil-borne fungi passing it on to plants. Because some common agricultural practices can disrupt beneficial fungus-plant root relationships, ERGO levels in foods grown under those conditions could be compromised. Thus, research is needed to further analyse the role agricultural practices play in the availability of ERGO in the human diet and its potential to improve our long-term health.

Are Ergothioneine Levels in Blood Associated with Chronic Peripheral Neuropathy in Colorectal Cancer Patients Who Underwent Chemotherapy?

Objective: Chronic Chemotherapy-Induced Peripheral Neuropathy (CIPN) is highly prevalent among colorectal cancer (CRC) patients. Ergothioneine (ET) - a dietary antioxidant -protected against CIPN in experimental models, but human studies are lacking. We explored whether whole blood ET levels were associated with chronic peripheral neuropathy among CRC patients who had completed chemotherapy.Methods: At diagnosis, median ET-concentration in whole blood of 159 CRC patients was 10.2 µg/ml (7.2-15.8). Patients completed questionnaires on peripheral neuropathy 6 months after completion of chemotherapy. We calculated prevalence ratios (PR) to assess associations of ET-concentrations and prevalence of peripheral neuropathy and used linear regression to assess associations with severity of peripheral neuropathy.Results: Prevalence of total and sensory peripheral neuropathy were both 81%. Higher ET-concentrations tended to be associated with lower prevalence of total and sensory peripheral neuropathy, but not statistically significant (highest versus lowest tertile of ET: PR = 0.93(0.78, 1.11) for total neuropathy, and PR = 0.84(0.70, 1.02) for sensory neuropathy). ET-concentrations were not associated with severity of neuropathy.Conclusion: Statistically significant associations were not observed, possibly because of limited sample size. Although data may putatively suggest higher levels of ET to be associated with a lower prevalence of neuropathy, analyses should be repeated in larger populations with larger variability in ET-concentrations.

Mushroom consumption and incident risk of prostate cancer in Japan: A pooled analysis of the Miyagi Cohort Study and the Ohsaki Cohort Study.

In vivo and in vitro evidence has shown that mushrooms have the potential to prevent prostate cancer. However, the relationship between mushroom consumption and incident prostate cancer in humans has never been investigated. In the present study, a total of 36,499 men, aged 40-79 years, who participated in the Miyagi Cohort Study in 1990 and in the Ohsaki Cohort Study in 1994 were followed for a median of 13.2 years. Data on mushroom consumption (categorized as <1, 1-2 and ≥3 times/week) was collected using a validated food frequency questionnaire. Cox proportional hazards regression analysis was used to estimate multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for prostate cancer incidence. During 574,397 person-years of follow-up, 1,204 (3.3%) cases of prostate cancer were identified. Compared to participants with mushroom consumption <1 time/week, frequent mushroom intake was associated with a decreased risk of prostate cancer (1-2 times/week: HRs [95% CIs] = 0.92 [0.81, 1.05]; ≥3 times/week: HRs [95% CIs] = 0.83 [0.70, 0.98]; p-trend = 0.023). This inverse relationship was especially obvious among participants aged ≥50 years and did not differ by clinical stage of cancer and intake of vegetables, fruit, meat and dairy products. The present study showed an inverse relationship between mushroom consumption and incident prostate cancer among middle-aged and elderly Japanese men, suggesting that habitual mushroom intake might help to prevent prostate cancer.

Mushrooms: A rich source of the antioxidants ergothioneine and glutathione.

While mushrooms are the highest dietary source for the unique sulfur-containing antioxidant ergothioneine, little is known regarding levels of the major biological antioxidant glutathione. Thus, our objectives were to determine and compare levels of glutathione, as well as ergothioneine, in different species of mushrooms. Glutathione levels varied >20-fold (0.11-2.41mg/gdw) with some varieties having higher levels than reported for other foods. Ergothioneine levels also varied widely (0.15-7.27mg/gdw) and were highly correlated with those of glutathione (r=0.62, P<0.001). Both antioxidants were more concentrated in pileus than stipe tissues in selected mushrooms species. Agaricus bisporus harvested during the third cropping flush contained higher levels of ergothioneine and glutathione compared to the first flush, possibly as a response to increased oxidative stress. This study demonstrated that certain mushroom species are high in glutathione and ergothioneine and should be considered an excellent dietary source of these important antioxidants.

A Retrospective Study in Adults with Metabolic Syndrome: Diabetic Risk Factor Response to Daily Consumption of Agaricus bisporus (White Button Mushrooms).

Adults with metabolic syndrome from different race/ethnicities are often predisposed to developing type 2 diabetes (T2D); however, growing evidence suggests that healthy diets and lifestyle choices can significantly slow or prevent progression to T2D. This poorly understood relationship to healthy dietary patterns and prevention of T2D motivated us to conduct a retrospective analysis to determine the potential impact of a minor dietary lifestyle change (daily mushroom consumption) on known T2D risk factors in racially diverse adults with confirmed features of the metabolic syndrome. Retrospectively, we studied 37 subjects who had participated in a dietary intervention focused on vitamin D bioavailability from white button mushrooms (WBM). All 37 had previously completed a 16-week study where they consumed 100 g of WBM daily and were then followed-up for one month during which no mushrooms were consumed. We analyzed differences in serum risk factors from baseline to 16-week, and from baseline to one-month follow-up. Measurement of serum diabetic risk factors included inflammatory and oxidative stress markers and the antioxidant component naturally rich in mushrooms, ergothioneine. Significant beneficial health effects were observed at 16-week with the doubling of ergothioneine from baseline, increases in the antioxidant marker ORAC (oxygen radical absorption capacity) and anti-inflammatory hormone, adiponectin and significant decreases in serum oxidative stress inducing factors, carboxymethyllysine (CML) and methylglyoxal (MG), but no change in the lipid oxidative stress marker 8-isoprostane, leptin or measures of insulin resistance or glucose metabolism. We conclude that WBM contain a variety of compounds with potential anti-inflammatory and antioxidant health benefits that can occur with frequent consumption over time in adults predisposed to T2D. Well-controlled studies are needed to confirm these findings and identify the specific mushroom components beneficial to health.

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.

Inactivation of human pathogens during phase II composting of manure-based mushroom growth substrate.

Commercial production of white button mushrooms (Agaricus bisporus) requires a specialized growth substrate prepared from composted agricultural by-products. Because horse and poultry manures are widely used in substrate formulations, there is a need to determine the extent to which the composting process is capable of eliminating human pathogens. In this study, partially composted substrate was inoculated with a pathogen cocktail (log 106 to 108 CFU/g) containing Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella. Pathogen and indicator-organism reductions were followed at temperatures that typically occurred during a standard 6-day phase II pasteurization and conditioning procedure. Controlled-temperature water bath studies at 48.8, 54.4, and 60°C demonstrated complete destruction of the three pathogens after 36.0, 8.0, and 0.5 h, respectively. Destruction of L. monocytogenes and E. coli O157:H7 at 54.4°C occurred more slowly than E. coli, total coliforms, Enterobacteriaceae, and Salmonella. Microbial reductions that occurred during a standard 6-day phase II pasteurization and conditioning treatment were studied in a small-scale mushroom production research facility. After phase II composting, E. coli, coliforms, and Enterobacteriaceae were below detectable levels, and inoculated pathogens were not detected by direct plating or by enrichment. The results of this study show that a phase II composting process can be an effective control measure for eliminating risks associated with the use of composted animal manures during mushroom production. Growers are encouraged to validate and verify their own composting processes through periodic microbial testing for pathogens and to conduct studies to assure uniform distribution of substrate temperatures during phase II.

Generation of potentially bioactive ergosterol-derived products following pulsed ultraviolet light exposure of mushrooms (Agaricus bisporus).

The production of vitamin D(2) from ergosterol in mushrooms upon exposure to ultraviolet (UV) irradiation has been well established in recent years. However, the effect of this treatment on the generation of non-vitamin D(2) products of ergosterol in mushrooms has not been reported. In this study, the ergosterol-derived photoproducts previtamin D(2), lumisterol(2) and tachysterol(2) were, for the first time, identified and quantified in white button mushrooms (Agaricus bisporus) following treatment with pulsed UV (PUV) light. Mushrooms were treated with up to 60pulses of PUV irradiation and the formation of major photoproducts was observed to increase as a function of dose. Vitamin D(2) was the most abundant product, followed by previtamin D(2), lumisterol(2) and tachysterol(2) in order of decreasing abundance. Untreated mushroom samples were not observed to contain detectable levels of any photoproduct. This study shows for the first time the production of these photoproducts in UV irradiated mushrooms. A complete understanding of the potential biological significance of these products remains to be seen.

The cancer preventive effects of edible mushrooms.

An increasing body of scientific literature suggests that dietary components may exert cancer preventive effects. Tea, soy, cruciferous vegetables and other foods have been investigated for their cancer preventive potential. Some non-edible mushrooms like Reishi (Ganoderma lucidum) have a history use, both alone and in conjunction with standard therapies, for the treatment of various diseases including cancer in some cultures. They have shown efficacy in a number of scientific studies. By comparison, the potential cancer preventive effects of edible mushrooms have been less well-studied. With similar content of putative effective anticancer compounds such as polysaccharides, proteoglycans, steroids, etc., one might predict that edible mushrooms would also demonstrate anticancer and cancer preventive activity. In this review, available data for five commonly-consumed edible mushrooms: button mushrooms (Agaricus bisporus), A. blazei, oyster mushrooms (Pleurotus ostreatus), shiitake mushrooms (Lentinus edodes), and maitake (Grifola frondosa) mushrooms is discussed. The results of animal model and human intervention studies, as well as supporting in vitro mechanistic studies are critically evaluated. Weaknesses in the current data and topics for future work are highlighted.