Oyster mushroom reduced blood glucose and cholesterol in diabetic subjects

Edible mushrooms as potential functional foods in amelioration of hypertension

Edible mushrooms are popular functional foods attributed to their rich nutritional bioactive constituent profile influencing cardiovascular function. Edible mushrooms are omnipresent in various prescribed Dietary Approaches to Stop Hypertension, Mediterranean diet, and fortified meal plans as they are rich in amino acids, dietary fiber, proteins, sterols, vitamins, and minerals. However, without an understanding of the influence of mushroom bioactive constituents, mechanism of action on heart and allergenicity, it is difficult to fully comprehend the role of mushrooms as dietary interventions in alleviating hypertension and other cardiovascular malfunctions. To accomplish this endeavor, we chose to review edible mushrooms and their bioactive constituents in ameliorating hypertension. Hypertension and cardiovascular diseases are interrelated and if the former is managed by dietary changes, it is postulated that overall heart health could also be improved. With a concise note on different edible varieties of mushrooms, a particular focus is presented on the antihypertensive potential of mushroom bioactive constituents, mode of action, absorption kinetics and bioavailability. Ergosterol, lovastatin, cordycepin, tocopherols, chitosan, ergothioneine, γ-aminobutyric acid, quercetin, and eritadenine are described as essential bioactives with hypotensive effects. Finally, safety concerns on allergens and limitations of consuming edible mushrooms with special reference to chemical toxins and their postulated metabolites are highlighted. It is opined that the present review will redirect toxicologists to further investigate mushroom bioactives and allergens, thereby influencing dietary interventions for heart health.

Nutritional Value, Medicinal Importance, and Health-Promoting Effects of Dietary Mushroom (Pleurotus ostreatus)

Pleurotus ostreatus is the second cultivated and most popular edible mushroom after Agaricus bisporus worldwide. As dietary supplements, nutraceuticals like Pleurotus ostreatus that go beyond the usual health benefits of mushrooms are becoming more popular. The objective of this study is to put together a summary of the nutrition information and link it to the possible health benefits and health-improving effects of eating oyster mushrooms. This review is based on secondary data from 102 published articles about P. ostreatus. All papers were examined following predetermined criteria for inclusion and exclusion, and this study contained 83 publications. The high nutritional content and beneficial health effects make P. ostreatus a high-quality food. It makes up for the lack of protein by switching between a diet based on wheat, rice, and maize. Nowadays, P. ostreatus is famous precious functional food ingredients due to the fact they may be cholesterol-free and low in calories, carbohydrates, fat, and sodium. Side by side, they offer crucial nutrients including riboflavin, selenium, potassium, niacin, proteins, and fiber.

Accumulation of Selected Metal Elements in Fruiting Bodies of Oyster Mushroom

The species Pleurotus ostreatus is a commercially, gastronomically, and biotechnologically important fungus. Its strain variability has been little researched. The study provides an evaluation of 59 oyster mushroom production strains in terms of the ability to accumulate selected metals in the cap and stipe. The fruiting bodies were grown under identical model conditions on straw substrate. Metal concentrations (ET-AAS) in dry fruiting bodies ranged in values 1.7-22.4 mg kg-1 for Al, 2.6-9.7 mg kg-1 Ba, 199-4560 mg kg-1 Ca, 1.7-12.0 mg kg-1 Cu, 12-120 mg kg-1 Fe, 16,000-49,500 mg kg-1 K, 876-2400 mg kg-1 Mg, 0.39-11.0 mg kg-1 Mn, 46-920 mg kg-1 Na and 11-920 mg kg-1 for Zn. More Cu, Fe, K, Mg, Mn, Zn accumulated in the cap, while in the stipe Ba was amassed. No significant difference was found between Al, Ca and Na between the accumulation in the cap and the stipe. Furthermore, the dependence of metal uptake from the substrate depending on the fortification of the substrate was confirmed. Statistically significant (p < 0.05) synergistic relationships were shown in pairs Al and Ba, Al and Fe, Ba and Na, Ba and Ca, Ca and Na, Cu and Fe, Fe and Mn, Fe and Zn, K and Mg, K and Mn, K and Zn, Mg and Mn, Mg and Na, Mg and Zn and Mn and Zn in the substrate without the addition of sodium selenate to the substrate. Altered relationships were observed after the application of sodium selenate to the substrate, synergism of Se and Ni, Se and Co and Se and Hg, Cu and Mn, Cu and Fe, Zn and Co, Zn and Ni, Zn and Hg, Mn and Fe, Mn and Cr, Co and Ni, Co and Hg, Ni and Hg, Pb and Cd. The findings of the study may help in the selection of production strains with hypercumulative properties for a particular metal and subsequent use in the addition of fortified fruiting bodies (e.g., with Zn). Based on the study the strains less sensitive to the accumulation of hazardous metals is possible to select for large-scale production, which is important from the perspective of food safety.

Nutraceutical potential of mushroom bioactive metabolites and their food functionality

Numerous mushroom bioactive metabolites, including polysaccharides, eritadenine, lignin, chitosan, mevinolin, and astrakurkurone have been studied in life-threatening conditions and diseases such as diabetes, cardiovascular, hypertension, cancer, DNA damage, hypercholesterolemia, and obesity attempting to identify natural therapies. These bioactive metabolites have shown potential as antiviral and immune system strengthener natural agents through diverse cellular and physiological pathways modulation with no toxicity evidence, widely available, and inexpensive. In light of the emerging literature, this paper compiles the most recent information describing the molecular mechanisms that underlie the nutraceutical potentials of these mushroom metabolites suggesting their effectiveness if combined with existing drug therapies while discussing the food functionality of mushrooms. The findings raise hope that these mushroom bioactive metabolites may be utilized as natural therapies considering their therapeutic potential while anticipating further research designing clinical trials and developing new drug therapies while encouraging their consumption as a natural adjuvant in preventing and controlling life-threatening conditions and diseases. PRACTICAL APPLICATIONS: Diabetes, cardiovascular, hypertension, cancer, DNA damage, hypercholesterolemia, and obesity are among the world's largest life-threatening conditions and diseases. Several mushroom bioactive compounds, including polysaccharides, eritadenine, lignin, chitosan, mevinolin, and astrakurkurone have been found potential in tackling these diseases through diverse cellular and physiological pathways modulation with no toxicity evidence, suggesting their use as nutraceutical foods in preventing and controlling these life-threatening conditions and diseases.

Report: The effects of topical pleurotus tuberregium (PT) aqueous extract on intraocular pressure in monkeys

PURPOSE

In earlier experiments in Nigeria, aqueous extract of Pleurotus tuber-regium (PT) had been shown to lower intra ocular pressure (IOP) in a feline model. The aim of the current study was to determine whether PT had the same or a similar IOP-lowering effect in ocularly normal non-human primates.

METHODS

Four monkeys were treated twice daily for 4 days with 2 x 20 μl drops of 50 mg/ml PT (pH = 4.3). The monkeys were sedated with 5-10 mg/kg ketamine HCl IM. PT was administered to the right eye and BSS to the left eye. Baseline IOP was measured just prior to beginning treatment, and on day 5 before treatment and then hourly for 3 hours, beginning 1 hour after treatment. SLEs were performed at baseline and on day 5 pre- and 3 hours post-treatment.

RESULTS

There was no significant difference between IOP in treated vs control eyes in the protocol. There were no adverse effects or toxicity as seen by SLE.

CONCLUSIONS

The inability of the extract to lower IOP in monkeys, in contrast to ocular hypertensive cats in an earlier study, could be due to species differences or duration of treatment. Since no adverse effects were observed in the monkeys, further studies with varying durations and dosages are recommended.

Mushroom Consumption and Cardiovascular Health: A Systematic Review

INTRODUCTION

Edible mushrooms have a great nutritional value including high protein, essential amino acids, fiber, vitamins (B₁, B₂, B₁₂, C, and D), minerals (calcium [Ca], potassium [K], magnesium [Mg], sodium [Na], phosphorus [P], copper [Cu], iron [Fe], manganese [Mn], and selenium [Se]), low fatty foods, and sodium. The objective of this systematic review was to determine the relationship between edible mushroom consumption and overall cardiovascular risk.

METHODS

We systematically searched Ovid MEDLINE, Embase, Ovid Cochrane Database of Systematic Reviews, Scopus, and Web of Science from database inception from 1966 through August 2020 for observational studies that reported the association between edible mushroom consumption and cardiovascular risk. Two investigators independently reviewed data. Conflicts were resolved through consensus discussion.

RESULTS

Of 1479 studies, we identified 7 prospective studies. Edible mushroom consumption may have favorable effects on lipid profiles by changing some metabolic markers such as low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, total cholesterol, and triglycerides. Moreover, edible mushroom consumption is probably associated with reduced mean blood pressure. The beneficial overall cardiovascular risk, stroke risk, and coronary artery disease of edible mushroom consumption are not consistent.

CONCLUSIONS

Edible mushroom consumption has not been shown to conclusively affect cardiovascular risk factors to date. However, potential health benefits may exist, including a favorable alteration of lipid profiles and blood pressure reduction.

Modulation of human intestinal microbiota in a clinical trial by consumption of a β-D-glucan-enriched extract obtained from Lentinula edodes

PURPOSE

The aim of this study was to evaluate the hypocholesterolemic, immune- and microbiota-modulatory effect of a mushroom extract in hypercholesterolemic subjects.

METHODS

A randomized, controlled, double-blind, and parallel clinical trial was carried out with subjects from 18 to 65 years old (n = 52) with untreated mild hypercholesterolemia. Volunteers consumed a β-D-glucan-enriched (BGE) mixture (10.4 g/day) obtained from shiitake mushrooms (Lentinula edodes) ensuring a 3.5 g/day of fungal β-D-glucans or a placebo incorporated in three different commercial creams.

RESULTS

This mixture showed hypocholesterolemic activities in vitro and in animal studies. After eight weeks intervention, no significant differences in lipid- or cholesterol-related parameters were found compared to placebo subjects as well as before and after the BGE mixture administration. No inflammatory or immunomodulatory responses were noticed and no changes in IL-1β, IL-6, TNF-α or oxLDL were recorded. However, consumption of the BGE mixture was safe and managed to achieve the dietary fibre intake recommended as cardiovascular protective diet. Moreover, the BGE mixture modulated the colonic microbiota differently compared to placebo. Microbial community composition varied from before to after the intervention with several genera being positively or negatively correlated with some biomarkers related to cholesterol metabolism.

CONCLUSION

These results suggested a relation between cholesterol metabolism, microbiota and BGE administration. Nevertheless, the precise significance of this differential modulation was not fully elucidated and requires further studies.

Medicinal Mushrooms: Bioactive Compounds, Use, and Clinical Trials

Medicinal mushrooms have important health benefits and exhibit a broad spectrum of pharmacological activities, including antiallergic, antibacterial, antifungal, anti-inflammatory, antioxidative, antiviral, cytotoxic, immunomodulating, antidepressive, antihyperlipidemic, antidiabetic, digestive, hepatoprotective, neuroprotective, nephroprotective, osteoprotective, and hypotensive activities. The growing interest in mycotherapy requires a strong commitment from the scientific community to expand clinical trials and to propose supplements of safe origin and genetic purity. Bioactive compounds of selected medicinal mushrooms and their effects and mechanisms in in vitro and in vivo clinical studies are reported in this review. Besides, we analyzed the therapeutic use and pharmacological activities of mushrooms.

The biology of ergothioneine, an antioxidant nutraceutical

Ergothioneine (ERG) is an unusual thio-histidine betaine amino acid that has potent antioxidant activities. It is synthesised by a variety of microbes, especially fungi (including in mushroom fruiting bodies) and actinobacteria, but is not synthesised by plants and animals who acquire it via the soil and their diet, respectively. Animals have evolved a highly selective transporter for it, known as solute carrier family 22, member 4 (SLC22A4) in humans, signifying its importance, and ERG may even have the status of a vitamin. ERG accumulates differentially in various tissues, according to their expression of SLC22A4, favouring those such as erythrocytes that may be subject to oxidative stress. Mushroom or ERG consumption seems to provide significant prevention against oxidative stress in a large variety of systems. ERG seems to have strong cytoprotective status, and its concentration is lowered in a number of chronic inflammatory diseases. It has been passed as safe by regulatory agencies, and may have value as a nutraceutical and antioxidant more generally.

Analysis of Nutritional Composition in 23 Kinds of Edible Fungi

To explore the differences in the main nutritional composition of 23 kinds of common edible fungi in the market, the moisture, ash, protein, fat, dietary fiber, carbohydrates, polysaccharides, and energy were analyzed using national standard methods. The results showed that the 23 kinds of edible fungi varied greatly in nutritional composition. Based on dry weight, the moisture content was 6.9∼15.5 g/100 g, the ash content ranged from 1.3 to 10.1 g/100 g, the protein content ranged from 8.5 to 36.9 g/100 g, the fat content was 0.5∼3.9 g/100 g, the dietary fiber content was between 14.4∼70.2 g/100 g, the carbohydrate content is 0.5∼37.3 g/100 g, the polysaccharide content was 2.1∼8.3 g/100 g, and the energy is about 751∼1322 100 g/kJ. All the 23 kinds of edible fungi can be regarded as high-protein low-fat foods, which have their own advantages in terms of nutritional value. This study provides reference for people to use edible fungi in a more scientific and reasonable way.

Effect of the Intake of Oyster Mushrooms (Pleurotus ostreatus) on Cardiometabolic Parameters-A Systematic Review of Clinical Trials

Cardiometabolic diseases are a leading global health challenge. Their incidence as well as progression is strongly affected by diet. Consumption of Pleurotus ostreatus (P. ostreatus), an edible oyster mushroom rich in functional ingredients (e.g., β-glucans), may improve glucose and lipid metabolism, blood pressure, body weight and appetite sensations. Hence, this systematic review aimed to provide an overview on the effects of P. ostreatus intake on cardiometabolic parameters from clinical trials, taking into account risk of bias (RoB). Relevant studies were investigated for details with consideration of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. The Cochrane Collaboration’s tool was used to assess the RoB. In total, eight trials included observed beneficial effects of P. ostreatus intake on glucose metabolism (reduction in fasting and/or 2 h postprandial glucose) and lipids (decrease in total cholesterol, LDL-cholesterol and/or triglycerides), and some found a reduction in blood pressure. In contrast, body weight did not change. Appetite sensations were not assessed. In most studies, the RoB was high or unclear due to methodological weaknesses and/or inadequate reporting. Thus, P. ostreatus intake may improve cardiometabolic health, but evidence for this is low. Hence, further clinical trials with an adequate study design are warranted to validate these suggestions.

Oyster mushroom functions as an anti-hyperglycaemic through phosphorylation of AMPK and increased expression of GLUT4 in type 2 diabetic model rats

Objectives

Traditionally, mushrooms have been used to reduce hyperglycaemia. However, the mechanism underlying this effect has not yet been explored. AMP-activated protein kinase (AMPK) is known to reduce hyperglycaemia through an insulin-independent pathway. This study aimed to observe the effect of oyster mushroom powder (OMP) on phosphorylation of AMPK (p-AMPK) and expression of GLUT4 mRNA in diabetic model rats.

Methods

Long-Evans rats were used to develop type 2 diabetic model rats through intraperitoneal induction of streptozotocin (STZ). OMP was supplemented at 5% with the usual feed of rats for 8 consecutive weeks. Then, the rats were sacrificed. RNA was extracted by the TRIzol reagent, and proteins were extracted from different tissues with RIPA lysis buffer. Expression of GLUT4 mRNA was measured through cDNA-PCR techniques, and p-AMPK was detected using western blotting. The band intensities of the PCR products and proteins were measured using Image J software.

Results

Supplementation of OMP for 8 weeks resulted in a reduction of the serum glucose level in STZ-induced, type 2 diabetic model rats. The levels of p-AMPK, as a ratio relative to β-actin, increased in the muscle and adipose tissues of mushroom-treated type 2 diabetic model rats, compared to those in control diabetic model rats. Expression of GLUT4, as a ratio relative to GAPDH, increased significantly in both the muscle and adipose tissues of mushroom-treated diabetic rats.

Conclusion

Oyster mushroom may decrease hyperglycaemia through increased p-AMPK and also expression of GLUT4 in the muscle and adipose tissues.

Factors affecting mushroom Pleurotus spp

Pleurotus genus is one of most extensively studied white-rot fungi due to its exceptional ligninolytic properties. It is an edible mushroom and it also has several biological effects, as it contains important bioactive molecules. In basidiomycete fungi, lignocellulolytic enzymes are affected by many typical fermentation factors, such as medium composition, ratio of carbon to nitrogen, pH, temperature, air composition, etc. The survival and multiplication of mushrooms is related to a number of factors, which may act separately or have interactive effects among them. Out that understanding challenges in handling Pleurotus species mushroom requires a fundamental understanding of their physical, chemical, biological and enzymatic properties. This review presents a practical checklist of available intrinsic and extrinsic factors, providing useful synthetic information that may help different users. An in-depth understanding of the technical features is needed for an appropriate and efficient production of Pleurotus spp.

Enhancement of the Th1-phenotype immune system by the intake of Oyster mushroom (Tamogitake) extract in a double-blind, placebo-controlled study

Pleurotus cornucopiae (Oyster mushroom, Tamogitake) has long been eaten as a functional food for enhancement of the immune system, but its effectiveness has not been well confirmed in humans. To this end, we set up a double-blind placebo-controlled human clinical trial to investigate the potential of Oyster mushrooms with respect to the up-regulation of the immune system. The subjects ingested Oyster mushroom extract for 8 weeks. We measured the serum cytokine levels involved in regulation of the immune system, including interferon (IFN)-γ, interleukin (IL)-4, IL-5, IL-10, IL-12, IL-13, and tumor-necrosis factor (TNF)-α. We found that intake of Oyster mushroom extract elevated IFN-γ (P = 0.013) and IL-12, whereas serum levels of IL-10 and IL-13 and other cytokines were minimally changed. We also measured natural killer (NK) cell activity, the levels of which tended to increase, but not significantly. Taken together, these facts suggest that Oyster mushrooms have the potential to enhance the immune system, through Th1 phenotype potentiation as the macrophage-IL-12 - IFN-γ pathway. This results in activation of the cell-mediated immune system as exemplified by up-regulation of NK cell activity. Oyster mushroom extract may be beneficial for the prevention of various diseases, including infectious diseases and cancer, due to its stimulation of the immune system.

Yield, size, nutritional value, and antioxidant activity of oyster mushrooms grown on perilla stalks

Perilla is an edible medical plant with rapidly increasing acreage in China. In this study, we investigated the potential of perilla stalks (PSs) as an alternative substrate for the cultivation of oyster mushrooms (Pleurotus ostreatus). P. ostreatus was cultivated on cottonseed hulls (CSH) alone or mixed with PSs in different ratios. The production parameters, physical characteristics, nutritional values, and antioxidant activity of mushrooms cultivated on different substrate mixtures were determined. The addition of PSs to CSH significantly improved the growth rate, yield, biological efficiency, and proximate composition and shortened the cultivation cycle. Cultivation on PSs alone increased the amino acid content in P. ostreatus fruiting bodies and the antioxidant activity of mushroom extracts. The PS75 (25% CSH + 75% PS) substrate was deduced to be the most effective substrate on the basis of yield and biological efficiency obtained in a large area where perilla had been planted. The results demonstrate that mixtures of PS with CSHs could be used as novel, practical, and easily accessible alternative substrates for P. ostreatus cultivation.

The Involvement of Serotonin in the Hypoglycemic Effects Produced by Administration of the Aqueous Extract of Xylaria nigripes with Steroid-Induced Insulin-Resistant Rats

Xylaria nigripes (XN) is a medicinal fungus with a high-economic value. The aim of this study was to explore the hypoglycemic effects and mechanisms of the XN aqueous extract in steroid-induced insulin-resistant (SIIR) rats. Significant hypoglycemic effects were observed 60 min after administration of XN aqueous extract. In normal Wistar, hypoglycemic effects were 21% (the plasma glucose level decreased from 128.6 ± 12.5 to 100.9 ± 10.7 mg/dL). In SIIR, hypoglycemic effects were 26% (the plasma glucose level decreased from 177.6 ± 12.5 to 133.3 ± 29.7 mg/dL) rats refer to their baseline. The signaling proteins for insulin-receptor substrate-1 and glucose transporter-4 increased 0.51-fold and 1.12-fold, respectively, as determined by Western blotting; the increase in the proteins was 13% and 9%, respectively, as determined by immunohistochemistry. The serotonin antagonist, α-p-chlorophenylalanine, effectively blocked the hypoglycemic effects and increased the signaling protein levels. After XN administration, none of the animals showed significant changes in plasma-free fatty acids in 60 min. In summary, the XN extract may have hypoglycemic effects in normal Wistar and SIIR rats that may have a serotonin-related hypoglycemic effect and enhance insulin sensitivity in the SIIR rats.

Hypolipidemic effect of the edible mushroom Agaricus blazei in rats subjected to a hypercholesterolemic diet

The effects of Agaricus blazei intake on the lipid profile of animals fed a hypercholesterolemic diet were evaluated. Thirty-two female Fisher rats were divided into four groups and given the standard AIN-93 M diet (C), this diet + 1 % A. blazei (CAb), a hypercholesterolemic diet with 25 % soybean oil and 1 % cholesterol (H) or this diet + 1 % A. blazei (HAb) for 6 weeks. Food intake, weight gain, liver and serum lipid profiles, activity of aminotransferases [alanine aminotransferase (ALT) and aspartate aminotransferase (AST)], and creatinine and urea levels as well as abdominal fat weight were measured. Histological analysis of kidney and liver tissue was also performed. The HAb group had a higher food intake, but a lower weight gain as compared to group H. This resulted in a significant decrease in abdominal fat weight, to values close to those of groups C and CAb. Supplementing the hypercholesterolemic diet with A. blazei promoted a significant reduction in total and non-HDL cholesterol, as well as in the atherogenic index, as compared to group H, and this effect was more pronounced in the serum. There was no hepatotoxic effect caused by the supplementation of the diets with the mushroom. We conclude that in our experimental model and in the concentration used, A. blazei was effective in improving the lipid profile of the animals.

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.

Particle and naked RNA mycoviruses in industrially cultivated mushroom Pleurotus ostreatus in China

Many cultivated mushroom strains, such as Pleurotus ostreatus TD300, displayed symptoms of degeneration. A spherical virus POSV and four dsRNA segments were extracted from mycelium of P. ostreatus TD300. POSV had a diameter of 23 nm and encapsidated a 2.5kb dsRNA segment with coat proteins whose molecular weights were 39 kDa and 30 kDa. Four dsRNA segments were 8.2 kb, 2.5 kb, 2.0 kb, and 1.1 kb in size, respectively. The 1.1 kb dsRNA segment often escaped detection. The cDNA and the amino acid sequences of the 8.2 kb dsRNA were homologous to those of RNA-dependent RNA polymerases (RDRP) of ssRNA oyster mushroom spherical virus (OMSV), and contained conserved motifs A to D which were almost identical to those in RDRP of OMSV. The cDNA and amino acid sequences of the 2.5 kb and 2.0 kb dsRNA segments were homologous to that of RDRP and capsid protein of dsRNA virus P. ostreatus virus 1 (PoV1), respectively. In particular, the amino acid sequence of 2.5 kb dsRNA segment had high identity with the conserved motifs A to C in RDRP of PoV1, a Partiviridae virus. After eliminating the viruses in P. ostreatus TD300, the symptoms of degeneration completely disappeared. The results reveal that P. ostreatus TD300 was at least infected by a particle virus POSV, and two naked viruses, one was a dsRNA virus with a 2.0 kb dsRNA segment, the other was an ssRNA virus whose replicating form of genome was an 8.2 kb dsRNA segment. Mycoviruses infection is a causative agent of mushroom strain degeneration.