Nameko Mushroom (Pholiota microspore), Hiratake Mushroom (Pleurotus ostreatus) and Shimeji Mushrooms (Lyophyllum shimeji): Bioactive Compounds as a Source of Various Biological Activities: A Review

Mushrooms are substantial source of nutritional, medicinal compounds, and other benefits compounds still need to be worked out for their important applications. Mushrooms as higher Basidiomycetes and Ascomycetes contain secondary metabolites in their fruit bodies, cultured mycelium, and cultured broth. These secondary metabolites have been used in many sides of human activity for many years for maintaining long and healthy life. The genera Pholiota, Pleurotus and Lyophyllum are a group of edible mushrooms that are distributed all over the world. The studies on different species of these edible mushrooms have revealed their nutritional medicinal potentials. This review aims to present the importance of Pholiota microspore, Pleurotus ostreatus and Lyophyllum shimeji, as both food and medicine, and they offer new visions to researchers to develop new drugs and nutraceuticals.

The rapid growth of human civilizations has led to escalating pressures to develop new functional food products with nutritional characteristics having therapeuticall potentials. Mushrooms, have been utilized in a wide variety of foods for thousands of years and have gained extensive attention in research communities and commercial ventures seeking to explore new and innovative applications in a diverse array of food products of therapeuticall potentials. Technological advances in the cultivation and processing of mushrooms have created new frontiers in the control of textures, flavours, and nutritional properties of fungi-based foods. Mushrooms create a wide range of secondary metabolites, including physiologically active chemicals, in addition to having a high quantity of micro and macronutrients. About 700 of the 14,000 or so species of known mushrooms are thought to be pharmacologically active. Some of these mushroom species are used as functional foods and food supplements as well as for direct consumption. Many researchers are interested in the use of secondary metabolites produced by microbes normally, and mushroom metabolites especially in different biotechnology fields, due to the bioactive properties of these metabolites, which have led to their use in pharmaceutical, industrial, and agricultural fields [1-5].

Mushrooms in general and edible mushrooms especially are an excellent source of proteins, minerals, polysaccharides, unsaturated fatty acids, and secondary metabolites. Numerous studies have provided evidence for the protective effects of edible mushrooms against various chronic diseases. Mushrooms have provided food for millennia and production methods and species diversity have recently expanded. Beside mushrooms, cultured fungal mycelia are now harvested as a primary product for food. Mushrooms and mycelia provide dietary protein, lipids and fatty acids, vitamins, fibre, and flavour, and can improve the organoleptic properties of processed foods (including meat analogues). Further, they are often key ingredients in nutritional or therapeutic supplements because of diverse specialised metabolites. Mycelia can also improve feed conversion efficiency, gut health, and wellbeing in livestock [6-10].

The fungal kingdom is full of members that have significant roles in different aspects, and improved life of humanity starting from penicillin that saved the life of millions, besides their applications in food, industry, and pharmaceutical fields. Mushrooms as higher Basidiomycetes and Ascomycetes contain secondary metabolites in their fruit bodies, cultured mycelium, and cultured broth. Mushrooms are those macrofungi known from centuries as food and in traditional medicine. Science has proven the contribution of mushrooms as nutritional foods and as efficient component in medical and pharmaceutical fields. This is due to their richness in biologically active compounds that belong to different chemical classes such as peptides, terpenes, phenols, fatty acids, glucans, flavonoids, and others. There is an elevated scientific interest in mushrooms due to the high number of identified mushroom species (over 14.000 species and counting) [11-15]. Also, due to the achieved advances in analyses techniques and instruments that allow accurate analysis and estimation of components originated from each mushroom species. Especially that even within the same species, a considerable difference in metabolic profile and chemical composition is noticed. Many researches have described the biological activities of components and extracts originated from mushrooms [16-19]. Mushrooms have been used in many sides of human activity for many years. Some of these mushrooms have been called medicinal mushrooms due to their various morphological, physiological, and ecological characteristics that are also responsible for their diversity [20-29]. Some mushrooms and other fruiting bodies of filamentous fungi are edible and provide a good source of protein, whereas others have narcotic effects and used as medicine. Mushrooms contain many valuable secondary metabolites such as fatty acids, polysaccharides, phenolic compounds, and terpenoids. Mushroom secondary metabolites have different biological activities including, anti-oxidant, anti-viral, anti-inflammatory, anti-coagulate, anti-cholesterol, anti-cancer, antimicrobial activities and other different activities. Mushroom-associated compounds, applied as therapeutic agents such as anti-aging and skin whitening agents. Thanks to the richness of mushrooms in bioactive compounds that belong to different chemical classes such as phenols, terpenes, proteins, fatty acids, flavonoids, polysaccharides, polyketides, alkaloids, steroids, and other compounds. Mushrooms are reported among the two fungal phyla, Ascomycota and Basidiomycota, and each group ate characterized by having edible members, as well as non-edible (poisonous) members. Majority of mushrooms are saprophytes, but some are insect parasites, which extend the environmental application of mushrooms as agents that clean environment and recycle essential elements among food chain [1].

Mushrooms are highly valued for their pharmacological significance as sources of significant bioactive compounds, such as anti-inflammatory. Since ancient times, people have employed mushrooms as a food source and for their medical (mostly anticancer) effects. The secondary metabolites found in the fruit bodies, cultured mycelium, and cultured broth of basidiomycetes and ascomycetes are what make mushrooms more advanced. For many years, people have used mushrooms in a variety of human endeavors [10]. Mushrooms engage in a variety of potent biological processes that may help humans fight off sickness. Due to the diverse morphological, physiological, and ecological traits that also contribute to their diversity, several of these mushrooms have been dubbed medicinal mushrooms. Researchers have recently focused more on the uses of mushrooms for food and medicine. Certain mushrooms and other filamentous fungi's fruiting bodies are edible or non-edible in the wild, and they are a good source of many secondary metabolites with therapeutic benefits [10]. With a high level of proteins, vitamins, minerals, fibers, and trace elements as well as minimal or no calories and cholesterol, mushrooms have a rich nutritional value. They enhance the diet and give individuals access to additional high-quality vegetables, both of which are directly beneficial to human health and fitness. The bioactive substances that may be extracted from medicinal mushrooms will strengthen the immune systems of people and raise their quality of life. Among the most frequent substances discovered in mushrooms are phenolics, flavonoids, glycosides, polysaccharides, tocopherols, ergothioneine, carotenoids, and vitamins [30-37].

Mushrooms were valued as palatable foods and as medicinal substances. In addition, because of their bioactive components, which have a variety of positive impacts on human health, mushrooms are regarded as functional foods [6]. A metabolic disorder called diabetes mellitus disorder is shown by high blood glucose levels. It is indicated by insulin insufficiency, receptor, or dysfunction that causes increased blood glucose levels and metabolic problems. Proteins, polysaccharides, fibers, and many other biomolecules isolated from mushrooms have been exhibited to help in the management of diabetes as biological anti-hyperglycaemic drugs [7]. Studies have shown that mushrooms display anti-diabetic properties [35], including antioxidants, blood glucose level reduction, and insulin secretion through glucose stimulation, digestive enzymes, and inhibitory effects on tyrosine kinase [8-16]. Mushrooms in the phyla Ascomycota and Basidiomycota are much admired for pharmacological properties and their nutritional value. In traditional medicine, they have long been used to maintain health and prevent and treat various human diseases. Many studies have documented the advantages of medicinal mushrooms for the management of diabetes [35].

Nameko mushroom (Pholiota nameko) description and ecology

Nameko mushroom (Pholiota nameko) belonging to; Kingdom: Fungi; Division: Basidiomycota; Class: Agaricomycetes; Order: Agaricales; Family: Strophariaceae Genus: Pholiota Species: Pholiota microspora. Nameko mushroom identification and description, Cap: Smallish, yellow, orangish, or yellow-brown, with whitish flesh. The upper surface has a thin, clear, often shiny, gelatinous layer. Gills: Whitish at first, becoming yellow, then brown. Stem: Thin, about twice as long as the cap is wide, whitish to yellowish and covered with orange-brown scales. Spores: Oval, smooth. Edibility: Edible, popular. Habitat: Eats dead wood. Nameko is an Asian member of a large group of mushroom species, many of which can only be correctly identified with the use of a microscope [38]. The definitions of some of these species may be in change. These are classic-looking mushrooms with round caps, long, centrally-attached stems, and closely-spaced gills that do not run down the stem (Figure 1).

Figure 1: Medicinally important mushrooms. Pholiota nameko. (Photographs were taken by Dr. Waill Elkhateeb. Location: Kuwabara, Nishi-Ku, Fukuoka City, Japan).

Pholiota microspora, commonly known as Pholiota nameko or simply nameko (“nameko” in Japanese), is a small, amber-brown mushroom with a slightly gelatinous coating that is used as an ingredient in miso soup and nabemono. In some countries this mushroom is available in kit form and can be grown at home. Pholiota microspora is one of the most common edible mushrooms, especially in Japan, where sawdust-based cultivation is the most dominant method accounting for 99% of the production. It is one of Japan's most popular cultivated mushrooms, tastes slightly nutty and is often used in stir-fries [39]. 

Pholiota nameko biological activities

Pholiota nameko, a type of edible and medicinal fungus, is currently grown extensively for food and traditional medicine in China and Japan. It possesses various biological activities, such as anti-inflammatory, anti-hyperlipidemia and antitumor activities. Pholiota nameko provides a potentially antioxidant and anti-inflammatory health food and drug [40]. Pholiota nameko, rich in carbohydrates, cellulose, and minerals. Pharmacological studies have shown that P. nameko polysaccharides have many medicinal effects on the human body. However, P. nameko has rarely been discussed in the field of dermatology; identifying its biological activities could be beneficial in development of a new natural ingredient used in wound care.

Sung TJ, et al. [41], studied antioxidant and anti-collagenase activities of Pholiota nameko Polysaccharides (PNPs) prepared through fractional precipitation (40%, 60% and 80% (v/v)); the assessments were conducted using reducing power, hydroxyl radical scavenging activity, dichloro-dihydro-fluorescein diacetate and collagenase activity assays. The ability of PNPs to facilitate L929 fibroblast cell proliferation and migration was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and scratch assays. The results indicated that, among all fractions, PNP-80 showed the best antioxidant and anti-collagenase activity, as measured by their reducing power (IC50 of PNP-80 was 2.43 ± 0.17 mg/mL), the hydroxyl radical scavenging (IC50 of PNP-80 was 2.74 ± 0.11 mg/mL) and collagenase activity assay, and significantly reduced cellular ROS content, compared with that of H2O2-induced L929 cells. Sung TJ, et al. [41], suggested that PNP-80 could be a promising candidate for further evaluation of its potential application on wound healing.

Pholiota nameko has received increasing attention in recent years because of its nutritive value and unique taste. An increasing number of studies on the bioactivities of Pholiota nameko, such as antitumor, antioxidant, and antihyperlipidemic activities, have generated further interest in nameko mushrooms. Today, there are a lot of studies paying attention to Pholiota nameko extract and polysaccharides for their inflammatory and antioxidant activity [42,43]. Pholiota nameko , also known as pearl mushroom, is a kind of edible and medicinal fungus that is currently widely grown for food and traditional medicine in China and Japan [44], and is rich in protein, carbohydrates, fiber, vitamins, and unsaturated fatty acids. There is a variety of biological activities from polysaccharides, such as immunomodulating, anti-inflammatory, anti-hyperlipidemia, antibacterial, and antioxidant activities [45]. Many research have pointed out that Pholiota nameko Polysaccharides (PNPs) can promote the secretion of macrophages, enhance phagocytic ability, and have anti-cancer and anti-inflammatory activities and immunomodulatory effects [46,47] 

Three strains of Pholiota nameko were collected by Toshiyuki T, et al. [48], from Fukushima N1, Fukushima N2, and KX008, were cultivated in three types of sawdust media and flushed. The fruiting bodies were then harvested in the button-cap and flat stages. The 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) radical-scavenging activity of 80% ethanol extract from these fruiting bodies was measured. DPPH radical-scavenging activity of the flat-stage fruiting bodies was higher than that of the button-cap stage in every case. In addition, the Fukushima N1 strain had higher activity than the Fukushima N2 and KX008 strains, especially in the first flush and when rice bran was used as a nutrient Toshiyuki T, et al. [48].

Edible fungi polysaccharides generally exhibit antioxidant activity, and zinc has been shown to have antioxidant properties. Zheng L, et al. [49], represented that Pholiota nameko SW-03 was used as a vector of zinc biotransformation in order to obtain Mycelia Zinc Polysaccharide (MZPS), and the structural characterization and anti-ageing activity of MZPS were investigated. Pholiota nameko SW-03 could accumulate zinc in the form of zinc-enriched polysaccharide, and the zinc content in MZPS was 16.39 ± 0.72 mg g (-1). Three fractions (MZPS-1, MZPS-2 and MZPS-3) were successfully isolated. The main fraction (MZPS-2) with the highest antioxidant activity in vitro was composed of glucose, mannose, glucuronic acid, galactose, galacturonic acid and arabinose. Also the anti-ageing capability was measured in d-galactose-induced ageing mice, and the results showed that MZPS could improve antioxidant status (superoxide dismutase, total antioxidant capability, malondialdehyde and lipid peroxide), indicating that MZPS had strong anti-ageing capability in vivo.

Edible mushrooms including Pholiota nameko are excellent sources of extractable bioactive compounds with much to explore. Enzymatic extractions with Cellulase and Viscozyme were responsible for highest extraction yields (67-77%) [45]. Potential prebiotic activity was observed in all extracts, some increasing 1.4-2 Log cycles of Lactobacillus acidophilus La-5 and Bifidobacterium animalis BB12. 30-50% α-glucosidase inhibition was observed in ultrasound, Flavourzyme and Cellulase extracts. Flavourzyme and Cellulase extracts are richer in macro (Mg, K and P) and micro elements (Zn, Mn and Fe) in comparison to mushroom. Monosaccharides content and profile varied slightly among both extracts with predominance of glucose, galactose and mannose with no uronic acids detection; Flavourzyme extract reported higher free amino acids content. Presence of α and β-glycosidic structures such as glucans and glucan-protein complexes are among the polysaccharides found in both extracts [45].

A β-D-glucan was obtained from the edible mushroom Pholiota nameko collected by Abreu H, et al. [50], by hot aqueous extraction and purification. NMR and methylation analyses of the purified fraction (GHW-PN, 1.46% yield) indicated the presence of a (1 → 3)-linked β-D-glucan, highly substituted (~ 27%) at O-6 by single units of β-D-Glcp or by (1 → 6)-β-D-Glcp fragments. The β-glucan (at 0.5, 1, and 2%) showed shear thinning behavior and when the concentration of the solution increased, there was an increase in apparent viscosity. The β-D-glucan presented gel-like behavior and thermal stability under a simulated pasteurization process, suggesting its potential as a thickening and gelling agent in products submitted to temperature variations. Abreu H, et al. [50], resulted that β-D-glucan at 0.3, 1.0 and 3.0 mg kg-1 significantly inhibited the inflammatory pain in 24.8, 56.9 and 82.3%, respectively, in the formalin-induced nociception in mice. The results pointed out that the β-D-glucan (GHW-PN) isolated from P. nameko presents potential application for the food industry or for medical purposes [50].

Hiratake mushroom (Pleurotus ostreatus) description and ecology

Pleurotus ostreatus, the oyster mushroom, oyster fungus, also known by hiratake in Asian some country like Japan, or pearl oyster mushroom is a common edible mushroom. It is one of the more commonly sought wild mushrooms, though it can also be cultivated on straw and other media. Pleurotus ostreatus belonging to; Kingdom: Fungi; Division: Basidiomycota; Class: Agaricomycetes; Order: Agaricales; Family: Pleurotaceae; Genus: Pleurotus Species: Pleurotus ostreatus. Hiratake mushroom is often seen growing on dying hardwood trees, it only appears to be acting saprophytically, rather than parasitically. As the tree dies of other causes, P. ostreatus grows on the rapidly increasing mass of dead and dying wood. They actually benefit the forest by decomposing the dead wood, returning vital elements and minerals to the ecosystem in a form usable to other plants and organisms. Description; Cap: 3-15 cm across; broadly convex, becoming flat or shallowly depressed; kidney-shaped to fan-shaped in outline, or nearly round if growing on the tops of logs; somewhat greasy when young and fresh; bald; pale to dark brown; fading to buff; sometimes fading slowly and becoming two-toned; the margin somewhat inrolled when young. Gills: Running down the stem (or pseudostem); close; short-gills frequent; whitish or with a gray tinge, becoming yellowish in age and sometimes developing brownish edges; often filled with black beetles, in my collecting areas. Stem: Usually rudimentary and lateral (or nearly absent) when mushrooms are growing from the sides of logs or trees, but sometimes more or less central when growing on the tops of logs or branches; 1-7 x 1-3 cm; whitish; hairy to velvety; tough. Microscopic Features: Spores 7-11 x 2-4 µm; cylindric-ellipsoid; smooth; inamyloid. Basidia 4-sterigmate (Figure 2). Hymenial cystidia not found. Pileipellis a partially gelatinized, tangled cutis of elements 2.5-10 µm wide, smooth [51].

Figure 2: Medicinally important mushrooms. Pleurotus ostreatus. (Photographs were taken by Dr. Waill A. Elkhateeb. Location: Kuwabara, Nishi-Ku, Fukuoka City, Japan).

Pleurotus ostreatus biological activities

The genus Pleurotus mushroom as health promoter and environmental restorer is gaining more importance as compared to other medicinal mushrooms resulting in an upsurge in their R and D activities during the past two decades. The chemical nature of the bioactive compounds present in this mushroom includes: polysaccharides, lipopolysaccharides, proteins, peptides, glycoproteins, nucleosides, triterpenoids, lectins, lipids and their derivatives [52]. Fruiting bodies as well as active mycelia of Pleurotus species also possesses a number of therapeutic properties like anti-inflammatory, immunostimulatory and immunomodulatory, anticancer activity [53].

Food enrichment with minerals has been a method of increasing health benefits. This review, represent medicinal values of oyster mushroom were described especially Pleurotus ostreatus. Mushrooms are a fruiting body of macro fungi i.e. Basidiomycota that represents only a short reproductive stage in their life cycle. They have a long association with humankind, and provide profound biological and economic impacts. Starting from ancient times, mushrooms are consumed by man with delicacy, due to their good taste and pleasing flavor. Pleurotus ostreatus is an edible mushroom with high nutritional values and biomedical importance's, since it contains a large number of bioactive components that cause development of its therapeutic functions. The bioactive components that are present in Pleurotus ostreatus mushroom comprise: polysaccharides, lipopolysaccharides, proteins, peptides, glycoproteins, nucleosides, triterpenoids, lectins, lipids and their derivatives, in addition of its vital medicinal components beneficial for the human health. Furthermore, Pleurotus ostreatus possess several medicinal properties including; anti-arthritic, antitumor, immune-modulatory, antioxidant, anticancer, anti-inflammatory, antigenotoxic, hypo cholesterolaemic, anti-hyperglycaemic, anti-hypertensive, antiplatelet aggregating, antiviral and antimicrobial activities [54].

Edible Pleurotus ostreatus mushrooms are a source of dietary elements and antioxidants. The phenolic content, antioxidant activity and metal content of P. ostreatus grown on coffee husk, enriched with iron (Fe), zinc (Zn) and lithium (Li) were investigated by Vieira PA, et al. [55], the content of phenolic compounds was found to be different in mushroom enriched with Fe, Zn or Li. In DPPH test, a difference was observed in antioxidant activity; however, no difference in this activity was observed using β-carotene/linoleic acid test. The enrichment with minerals promoted decrease in the content of Fe in three enriched samples. Observed the accumulation of Li in the sample enriched with LiCl and P. ostreatus enriched with Fe, Zn or Li provided minerals such as K, P, Fe, Zn, Li and Cu. In addition, no heavy metals such as Ni, Cr and Cd were detected, and only low levels of Pb and Al were observed [56].

Pleurotus ostreatus (Jacq.) P. Kumm. (Basidiomycota) - Known as the oyster mushroom - is a mushroom species distributed on all continents, except for Antarctica [57]. Pleurotus ostreatus is a valuable mushroom of dietary importance. Pleurotus ostreatus rich in primary and secondary metabolites and chemical elements of physiological significance. One hundred grams of fresh fruiting bodies contains 15% of the recommended daily intake of vitamin C, 40% of niacin, riboflavin, and thiamin, and 0.5 mg of vitamin B12. Pleurotus ostreatus is also characterized by a high content of oleic acid (40%), linolenic acid (55%), and substances responsible for decreasing serum cholesterol levels. High contents of lovastatin, an approved hypolipidemic drug, and pleuran, an immunomodulating polysac-charide, have been found in fruiting bodies of Pleurotus ostreatus. It exhibits ant-atherosclerotic, hypoglycemic, anti-oxidant, anticancer and immunomodulatory properties. Due to its wide spectrum of biological activities, P. ostreatus is considered a medicinal mushroom [56]. Fruiting bodies and extracts of P. ostreatus have found applications in the treatment of civilization – related diseases, especially diabetes [35], arteriosclerosis and cancer. It is also a potential source of active ingredients in cosmetics and topically applied preparations.

Dos Reis EE, et al. [57], reported that mushrooms are a group of fungi with great diversity and ultra-accelerated metabolism. For this value, mushrooms have developed a protective mechanism consisting of high concentrations of antioxidants such as selenium, polyphenols, β-glucans, ergothioneine, various vitamins and other bioactive metabolites. The mushrooms of the Pleurotus genus have generated scientific interest due to their therapeutic properties, especially related to risk factors connected to the severity of coronavirus disease 2019 (COVID-19).  Mushrooms of the genus Pleurotus in general and P. ostreatus especially have antihypertensive, antihypercholesterolemic, antiatherogenic, antihyperlipidemic, antioxidant, anti-inflammatory, antihyperglycemic and antiviral properties. Since these properties interfere significantly in the risk factors for COVID-19 severity, the pharmacological potential of these mushrooms is evident. Because they are edible and widely produced in the world, they are easily accessible and could easily be incorporated into the diet, acting as a food supplement, or be used in the creation of pharmacological agents for direct use in treatment [57]. 

Atherosclerosis is an impairment of the artery walls made up of two membrane layers, intima and media. Oxidative stress, hypertension, and hypercholesterolemia are the three main factors that cause atherosclerosis. The edible genus Pleurotus mushrooms spp. has been proven to have valuable medicinal characteristics, and, they have been listed among “mushroom nutriceuticals” and categorized as both functional foods and medicinal mushrooms. Abidin MH, et al. [58], reported the benefits of Pleurotus spp. for the prevention and treatment of atherosclerosis via reduction of oxidative stress, hypertension, and hypercholesterolemia in terms of the therapeutic compounds responsible. This review revealed that at least ten different types of Pleurotus spp. have been reported to have anti-atherogenic capabilities, with six of them possessing high levels of anti-atherogenic compounds such as ACE inhibitor peptide, ergothioneine, chrysin, and lovastatin. Hence, it has been demonstrated that Pleurotus spp. has great potential for use as food or extracts from fruiting bodies or mycelium in an alternative therapy for atherosclerosis, through prevention and treatment of oxidative stress, hypertension, and hypercholesterolemia [58].

Shimeji mushrooms (Lyophyllum shimeji) description and ecology

Lyophyllum shimeji, commonly known as the hon-shimeji is an edible species of fungus in the family Lyophyllaceae that grows in pine forests, often near man-made roads. It is found in Japan, Sweden, Finland and Estonia. Shimeji mushrooms Lyophyllum shimeji belonging to; Kingdom: Fungi; Division: Basidiomycota; Class: Agaricomycetes; Order: Agaricales Family: Lyophyllaceae; Genus: Lyophyllum Species: Lyophyllum shimeji. Ecology: Lyophyllum shimeji grows in pine forests. Edibility: This species is considered edible.

Lyophyllum shimeji is an edible ectomycorrhizal fungus that is widely distributed in East Asia and also present in the northern regions of Europe. In Japan, L. shimeji is a culinary delicacy, considered amongst all edible mushrooms to have the best taste. Traditionally, fruiting bodies of L. shimeji have been collected from the wild but fruiting of L. shimeji is now relatively uncommon and cannot keep up with increasing consumer demand. As a result, methods for its cultivation are being developed for commercial production in Japan and other countries [59]. Description: Cap: 2-10 cm, convex, brown surface (Or white surface), decurved to plane margin with viscid surface (Figure 3). Hymenophore: Sub-decurrent, white, and close gills. The margin of the gills is serrete and lamellulae present. Stem: 2-7 cm tall and up to 3 cm wide, equal to sub-clavate, central, fused base in some cases. It is white and semi-stuffed. Flesh: White, not changing when exposed to air. Spore Print: White [60].

Figure 3: Medicinally important mushrooms. Lyophyllum shimeji. (Photographs were taken by Dr. Waill A. Elkhateeb. Location: Kuwabara, Nishi-Ku, Fukuoka City, Japan).

Lyophyllum shimeji biological activities

Shimeji mushrooms in general and Lyophyllum shimeji especially encompass a series of edible fungi species found mainly in Japan and other parts of Asia. They’re also present in North America and Europe. Shimeji mushrooms have gained popularity worldwide thanks to their delicious flavor. But up till now, not many people know that these fungi have several potential health benefits, including reducing blood pressure and cholesterol. The antibacterial activities of thirty mushroom species belonging to Basidiomycetes and Ascomycetes, cultivated on two liquid media, were evaluated against gram-positive (Bacillus subtilis and Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria by the disk diffusion method. Lyophyllum shimeji, showed antibacterial activity levels- from 9.5 mm in diameter of the inhibition zone to full inhibition of growth of the test bacteria [61]. 

Russians N, et al. [62], revealed that the IC50 values of ethyl acetate extracts of Lyophyllum shimeji and white oyster mushroom Pleurotus ostreatus in inhibiting the growth of HCT-116 cell line were 111.09 and 239.46 ppm, respectively. In addition, the ethyl acetate extract of shimeji mushroom is considered to be more effective in inhibiting the HCT-116 cell line proliferation and needs to be investigated further, especially as an anti-colorectal cancer agent. Lyophyllin and LAP isolated from Lyophyllum shimeji revealed activity against Physalospora piricola [63]. Ribosome-inactivating proteins are enzymes that eliminate adenosine residues from rRNAs, which results in the inactivation of ribosomes. Various mushrooms have been reported to possess these enzymes, which infer a wide range of bioactivities such as anti-HIV1 reverse transcriptase, antiproliferative as well as antifungal activities and the most potent was Lyophyllum shimeji [63].

White Lyophyllum shimeji is a healthy edible mushroom product. It is the Queen in edible fungi and is popular in overseas market. White Shimeji contains Lysine and leucine, which can effectively complement the proline and sulfur-containing amigo acids in egg milk products and meat. In this way, people can achieve balanced nutrition and absorb better. White Shimeji also contains β-1,3-D glucan. in publication the relationship between bioactivity and structure of glucan, proved that β-1,3-D glucan has anti-tumor activity, anti-radiation effect, and anti-inflammatory effect [64].

Jung JW, et al. [65], studied the anti-effects of protein extract from Lyophyllum shimeji as well as its molecular mechanism of action on KB human oral squamous cell carcinoma and resulted that treatment with extract from Lyophyllum shimeji reduced cell viability of KB oral squamous cell carcinoma in a dose-dependent manner. Formation of a DNA ladder was observed by treatment with extract from L. shimeji. Furthermore, the studied confirmed that dead cell staining was significantly increased by extract from L. shimeji. Thus, L. shimeji could be considered as a potential safe and effective chemotherapy agent for the treatment of oral cancer. In addition, these results suggest that extract from L. shimeji induces cell apoptosis through a mitochondrial caspase-dependent pathway in KB humans oral squamous cell carcinoma [65].

Many studies conducted on Pholiota microspore; Pleurotus ostreatus and Lyophyllum shimeji mushrooms are represented in the current review and showed that these edible mushrooms exhibit the potential as a vital therapeutic food. Though, more studies for deep exploration are still required. Pholiota microspore; Pleurotus ostreatus and Lyophyllum shimeji species showed some vital biological activities such as antitumor, antioxidant, and antihyperlipidemic activities, anti-inflammatory, anti-hyperlipidemia, antibacterial, anti-viral, anti-aging, anti-arthritic, immune-modulatory, antigenotoxic, hypo cholesterolaemic, anti-hypertensive

Future investigations and research are required for bio prospect new medicinal and edible mushrooms for different biological activities efficacy and after that active biomolecules are isolated. The current review recommends further exploration to get a full profile of the active components obtained from these genera and species.

The authors acknowledge the National Research Centre (NRC) of Egypt for providing all needed facilities and logistics for the study.

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14. Elkhateeb WA, Daba GM. The fascinating bird’s nest mushroom, secondary metabolites and biological activities.‏ International Journal of Pharma Research and Health Sciences. 2021;9(1):3265-3269. doi: 10.21276/ijprhs.2021.01.01.
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23. Elkhateeb WA, Daba GM. Highlights on unique orange pore cap mushroom favolaschia sp. and beech orange mushroom cyttaria sp. and their biological activities. Open Access Journal of Pharmaceutical Research. 2021;5(3): 1-6. doi: 10.23880/oajpr-16000246.
24. Elkhateeb WA, Daba GM. Highlights on the wood blue-leg mushroom clitocybe nuda and blue-milk mushroom lactarius indigo ecology and biological activities. Open Access Journal of Pharmaceutical Research. 2021;5(3):1-6. doi: 10.23880/oajpr-16000249.
25. Elkhateeb WA, Daba GM. Highlights on the golden mushroom cantharellus cibarius and unique shaggy ink cap mushroom coprinus comatus and smoky bracket mushroom bjerkandera adusta ecology and biological activities. Open Access Journal of Mycology & Mycological Sciences. 2021;4(2):1-8. doi:10.23880/oajmms-16000143.
26. Thomas PW, Elkhateeb WA, Daba G. Truffle and truffle-like fungi from continental Africa. Acta mycological. 2019;54(2):1-15.
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32. Elkhateeb WA, Daba GM. Therapeutic values of ganoderma oregonense and ganoderma pfeifferi, mushrooms: A Review. Open Access Journal of Pharmaceutical Research. 2023;7(1):1-6. doi:10.23880/oajpr-16000276.
33. Elkhateeb WA, Daba GM. Vitamin D enriched edible mushrooms: A review. Open Access Journal of Mycology & Mycological Sciences. 2023;6(1)1-6. doi: 10.23880/oajmms-16000170.
34. Elkhateeb WA, Galappaththi MC, El-Ghwas DE, Daba G. The anti-diabetic potential of mushrooms: A review. Current Trends in Biotechnology and Pharmacy. 2023;17(4):1415-1424. doi:10.5530/ctbp.2023.4.77.
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