Evaluation of bioactive compounds content and antioxidant properties of soil-growing and wood-growing edible mushrooms

Hypoglycemic Properties of Leccinum scabrum Extracts-An In Vitro Study on α-Glucosidase and α-Amylase Inhibition and Metabolic Profile Determination

Type-2 diabetes affects an increasing percentage of the world's population and its control through dietary management, involving the consumption of health-promoting foods or their derived supplements, is a common strategy. Several mushroom species have been demonstrated to be endowed with antidiabetic properties, resulting from their ability in improving insulin sensitivity and production, or inhibiting the carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase. This study aimed to investigate for the first time the hypoglycemic properties of the edible mushroom Leccinum scabrum (Bull.) Gray. Mushroom extracts were prepared through the microwave-assisted extraction (MAE) technique using green solvents with different polarity degrees. The inhibition activity of all the obtained extracts on both α-glucosidase and α-amylase was evaluated and the highest activity was observed for the EtOAc extract which showed an IC50 value about 60-fold lower than the reference compound 1-deoxynojirimycin (DNJ) on α-glucosidase (0.42 ± 0.02 and 25.4 ± 0.6 µg/mL, respectively). As expected on the basis of the literature data concerning both α-glucosidase and α-amylase inhibition, a milder inhibition activity on pancreatic α-amylase was observed. Preliminary in vivo tests on Drosophila melanogaster carried out on the most active obtained extract (EtOAc) confirmed the in vitro observed hypoglycemic activity. Finally, the EtOAc extract metabolic profile was determined through GC-MS and HRMS analyses.

Can the concentration of elements in wild-growing mushrooms be deduced from the taxonomic rank?

The mineral composition of wild-growing mushroom species is influenced by various environmental factors, particularly the chemical properties of the soil/substrate. We hypothesised that element uptake might also correlate with taxonomic classification, potentially allowing us to predict contamination levels based on mushrooms within the same taxonomic rank. This study compared the mineral composition (Ag, As, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Se, and Zn) of 16 saprotrophic mushroom species from 11 genera across 4 families and 2 orders. Among these were 13 edible and 3 inedible mushrooms, all collected from natural, wild stands in a forest in central-western Poland between 2017 and 2020. Phallus impudicus exhibited the highest mean content of Ba (together with Phallus hadriani) (6.63 and 8.61 mg kg-1, respectively), Ca (with Paralepista gilva and Stropharia rugosoannulata) (803, 735 and 768 mg kg-1, respectively), Cd (with Lycoperdon perlatum) (3.59 and 3.12 mg kg-1, respectively), Co (0.635 mg kg-1), and Fe (with P. hadriani and S. rugosoannulata) (476, 427 and 477 mg kg-1, respectively), while Macrolepiota mastoidea showed the highest content of Ag (1.96 mg kg-1), As (with Coprinus comatus) (1.56 and 1.62 mg kg-1, respectively) and Cu (with Macrolepiota procera and Chlorophyllum rhacodes) (192, 175 and 180 mg kg-1, respectively). Comparing the content of the analysed elements in the genera represented by at least two species, a similarity was observed, the same as the mean concentration in soil under these species. Soil characteristics could be a superior factor that overshadows the impact of the mushroom genus on the elements accumulation, obscuring its role as a determinant in this process. The results are not definitive evidence that belonging to a particular taxonomic rank is a prerequisite condition affecting the accumulation of all elements. A closer focus on this issue is needed.

Physiological changes and gene responses during Ganoderma lucidum growth with selenium supplementation

Ganoderma lucidum basidiomycota is highly appreciated for its health and nutrition value. In the present study, Ganoderma lucidum was cultivated as selenium transformation carrier, and the physiological changes and gene responses by selenium supplementation were revealed through high-throughput RNA-Seq technology. As a result, selenium supplementation increased the stipe length and the cap size, but decreased the cap thickness of G. lucidum. Mineral salt supplementation could greatly promote the formation of triterpene acids and selenium in G. lucidum. The highest yield was gained in the treatment with selenium content of 200 µg/g. Subsequently, the tissues of G. lucidum at budding and mature stages in this treatment group were sampled for transcriptome analysis and compared to those of a control group without selenium supplementation. A total of 16,113 expressed genes were obtained from the transcriptome of G. lucidum, and GO-annotated unigenes were mainly involved in molecular functions and KEGG-annotated ones were highly expressed in ribosomal pathway. Furthermore, genes involved in carbon metabolism pathway were most promoted by selenium at budding stage of G. lucidum, while gene expression was the highest in the pathway of amino acid biosynthesis at mature stage of G. lucidum. Specially, selenium-related genes in G. lucidum, such as GL23172-G, GL29881-G and GL28298-G, played a regulatory role in oxidoreductase, antioxidant activity and tryptophan synthesis. The results provide a theoretical basis for further study of selenium-enriched mushrooms and aid to development of Se-enriched foodstuff and health products made from fungi.

Biofortification of Three Cultivated Mushroom Species with Three Iron Salts—Potential for a New Iron-Rich Superfood

Mushrooms fortified with iron (Fe) can offer a promising alternative to counter the worldwide deficiency problem. However, the factors that may influence the efficiency of fortification have not yet been fully investigated. The aim of this study was to compare the effects of three Fe forms (FeCl₃ 6H₂O, FeSO₄ 7H₂O, or FeHBED) in three concentrations (5, 10, or 50 mM) for three mushroom species (Pleurotus eryngii, P. ostreatus, or Pholiota nameko) on their chemical composition, phenolic compounds, and organic acid production. The most effective metal accumulation of all the investigated species was for the 50 mM addition. FeCl₃ 6H₂O was the most favorable additive for P. eryngii and P. nameko (up to 145 and 185% Fe more than in the control, respectively) and FeHBED for P. ostreatus (up to 108% Fe more than in control). Additionally, P. nameko showed the highest Fe accumulation among studied species (89.2 ± 7.51 mg kg⁻¹ DW). The creation of phenolic acids was generally inhibited by Fe salt supplementation. However, an increasing effect on phenolic acid concentration was observed for P. ostreatus cultivated at 5 mM FeCl₃ 6H₂O and for P. eryngii cultivated at 5 mM FeCl₃ 6H₂O and 5 mM FeSO₄ 7H₂O. In the case of organic acids, a similar situation was observed. For P. ostreatus, FeSO₄ 7H₂O and FeHBED salts increased the formation of the determined organic acids in fruiting bodies. P. eryngii and P. nameko were characterized by a much lower content of organic acids in the systems supplemented with Fe. Based on the obtained results, we recommend starting fortification by preliminarily indicating which form of the element is preferred for the species of interest for supplementation. It also seems that using an additive concentration of 50 mM or higher is most effective.

A RESEARCH ON QUALITY EVALUATION OF EIGHT WILD EDIBLE MACROFUNGI COLLECTED FROM EAST MEDITERRANEAN REGION OF TURKEY

Eight edible macrofungal species ( Suillus collinitus, Rhizopogon roseolus, Lactarius sanguifluus, Lycoperdon molle, Ganoderma adspersum, Pleurotus cornucopiae, Lycoperdon perlatum, Macrolepiota procera ) grown in Osmaniye were studied. Besides the evaluation of fresh forms, the mushrooms were dried at 40˚C, and the color, texture, protein and mineral contents, and bioactivities (total phenolic content, (TPC) and antioxidant activities by DPPH, FRAP and ABTS techniques) were determined. The protein, macro and micro mineral contents of dried samples were in range of 11.31-55.31%, 132.75-50844.80 and 0.30-812.05 mg/kg, respectively. TPC of fresh samples were 10227.13-42216.89 mg gallic acid equivalent (GAE)/kg dry matter (DM) in methanolic solution, 3625.31-28809.99 mg GAE/kg DM in ethanolic solution, and decreased by drying process. ABTS method yielded higher results in fresh specimens, however DPPH method in ethanol and FRAP method in methanol were the superior in dried forms.

The antioxidant potential of different edible and medicinal mushrooms

Mushroom consumption has grown extraordinarily owing to their high nutritional value, desirable taste, and aroma. Mushrooms continue generating lots of interest chiefly in their consumption as food, as a cure for different ailments, as well as important goods for commerce throughout the globe owing to their dietary, antioxidant, and therapeutic values. Higher Ascomycetes and Basidiomycetes mushrooms have different properties with anticancer and immunological potential. They as well provide vital health benefits and display a wide-ranging continuum of pharmacological effects. The antioxidant activity of different mushrooms was reviewed for different radicals including DPPH, ABTS, OH, Nitrite, metals, and lipid peroxidation. The present review presents pharmacological activities of different species of edible and medicinal mushrooms. This review provides tangible evidence that these mushrooms are an excellent source of natural constituents and antioxidants with potential application in pharmaceuticals and in treating and managing different diseases.

Edible Mushrooms as a Natural Source of Food Ingredient/Additive Replacer

Although mushrooms have been exploited since ancient times because of their particular taste and therapeutic properties, the interest in edible species as a source of ingredients and bioactive compounds is recent. Their valuable nutritional contents in protein, dietary fiber and bioactive compounds make them ideal candidates for use in foods in efforts to improve their nutritional profiles. This trend is in line with the consumer's growing demand for more plant-based foods. The present review paper explores different studies focused on the use of common edible mushrooms as an ingredient and additive replacer by using them in fresh, dried, or even extract forms, as meat, fat, flour, salt, phosphates, and antioxidant replacers. The replacement of meat, fat, flour, and salt by mushrooms from commercial species has been successful despite sensorial and textural parameters can be affected. Moderate concentrations of mushrooms, especially in powder form, should be considered, particularly in non-familiarized consumers. In the case of antioxidant and antimicrobial properties, results are variable, and more studies are necessary to determine the chemical aspects involved.

Fungi and Algae as Sources of Medicinal and Other Biologically Active Compounds: A Review

Many species of fungi including lichenized fungi (lichens) and algae have the ability to biosynthesize biologically active compounds. They produce, among others, polysaccharides with anticancer and immunostimulatory properties: (1) Background: This paper presents the characteristics of the most important bioactive compounds produced by fungi and algae; (2) Methods: Based on the example of the selected species of mushrooms, lichens and algae, the therapeutic properties of the secondary metabolites that they produce and the possibilities of their use are presented; (3) Results: The importance of fungi, especially large-fruited mushrooms, lichens and algae, in nature and human life is discussed, in particular, with regard to their use in the pharmaceutical industry and their nutritional value; (4) Conclusions: The natural organisms, such as fungi, lichenized fungi and algae, could be used as supplementary medicine, in the form of pharmaceutical preparations and food sources. Further advanced studies are required on the pharmacological properties and bioactive compounds of these organisms.

Enhancing the nutritional and functional properties of Pleurotus citrinopileatus mushrooms through the exploitation of winery and olive mill wastes

Treatment and disposal of wineries and olive-oil mills waste is usually associated with complex processes, which are often of limited wide-scale applicability. Olive-leaves plus two-phase olive mill waste (OLW) or grape marc plus wheat straw (GMW) were assessed as substrates for the cultivation of the choice edible mushroom Pleurotus citrinopileatus. GMW led to increased mushroom biological efficiency and shorter production cycles. Antioxidant activities, triterpenic acids, free amino acids, lovastatin and ergosterol were significantly higher in fruitbodies from GMW; the latter compound was positively correlated with squalene concentrations in substrates. Glucans, resveratrol and fatty acids content showed minor differences among mushrooms from the three substrates examined, whereas ergothioneine was significantly higher in fruitbodies grown on OLW. High correlations were noted for oleanolic, ursolic and amino acid content in mushrooms and their respective substrates. Moreover, FTIR spectra revealed variations in fruitbodies content in bioactive compounds which were associated with the substrates used.

Contribution of Bioactive Compounds to the Antioxidant Capacity of the Edible Mushroom Neolentinus lepideus

Neolentinus lepideus is a fungus consumed by rural communities in Central America and Asia due to its rich flavor; however, little information on its chemical composition is available. With this in mind, the objective of this work was to determine the content of vitamin E and C, ergosterol, and phenolic compounds of this fungus, as well as its antioxidant capacity. The quantified bioactive compounds were two isoforms of vitamin E, highlighting α-tocopherol (3370.35 mg/100 g dry weight, DW) and ergosterol (11.70 mg/100 g DW). The total phenolic content was 164.80 mg gallic acid equivalents/100 g, and nine phenolic compounds were identified (protocatechuic, p-hydroxybenzoic, caffeic, vanillic, ferulic, salicylic, p-anisic, trans-cinnamic acids, and scopoletin). The highest antioxidant capacity was detected in the lipophilic extract with TEAC (27688 μmoles Trolox equivalents/100 g). These results suggest that lipophilic compounds are among the main bioactive compounds in N. lepideus, and they might exhibit the highest radical scavenging properties in non-polar extracts.

A comprehensive review on phenolic compounds from edible mushrooms: Occurrence, biological activity, application and future prospective

Phenolic compounds are minor metabolites usually present in mushroom species. Because of their potential advantages for human health, such as antioxidant and other biological activities, these bioactive components have been gaining more interest as functional foods, nutraceutical agents for providing better health conditions. This review aims to comprehensively discuss the recent advances in mushroom phenolic compounds, including new sources, structural characteristics, biological activities, potential uses and its industrial applications as well as the future perspectives. Phenolic acids as well as flavonoids are considered the most common phenolics occurring in mushroom species. These are responsible for its bioactivities, including antioxidant, anti-inflammatory, antitumor, antihyperglycaemic, antiosteoporotic, anti-tyrosinase and antimicrobial activities. Several edible mushroom species with good phenolic content and show higher biological activity were highlighted, in a way for its futuristic applications. Trends on mushroom research highlighting new research areas, such as nanoformulation were discussed. Furthermore, the use of phenolic compounds as nutraceutical and cosmeceutical agents as well as the future perspectives and recommendations were made.

Antioxidant Properties and Industrial Uses of Edible Polyporales

The content of antioxidant compounds varies within fungal species, and the Polyporales order has been recognized for this property. Numerous antioxidant compounds have been identified in Polyporales fungi, including phenolic compounds, β-glucans, ergosterol, ergothioneine, vitamin C, and tocopherols. Each compound contributes differently to the antioxidant potential of fungi. Besides the health benefits for rural communities caused by fungi consumption, their antioxidant composition attracts the food, cosmetic, and pharmaceutical industries’ interest. In this context, the present review compiles, analyzes, and discusses the bioactive composition of edible fungi of the Polyporales order and its contribution to total antioxidant capacity.

Phenolic Acids-Rich Fractions from Agaricus bitorguis (Quél.) Sacc. Chaidam ZJU-CDMA-12 Mycelia Modulate Hypoxic Stress on Hypoxia-Damaged PC12 Cells

Hypoxia is a common pathological process in various clinical diseases. However, there is still a lack of effective anti-hypoxia active substances. Agaricus bitorguis (Quél.) Sacc Chaidam (ABSC) is a rare wild edible macrofungus that grows underground at high altitudes. Herein, intracellular phenolic acids-rich fractions (IPA) were extracted from ABSC ZJU-CDMA-12, and the structural characterization and anti-hypoxia activity of IPA on PC12 cells were elucidated as well. The results of HPLC-Q-TOF-MS illustrated that five kinds of IPA were isolated from ABSC, including (−)-epicatechin gallate, arabelline, yunnaneic acid D, 2′-O-p-hydroxybenzoyl-6′-O-trans-caffeoylgardoside,4′-O-methylgallocatechin-(4->8)-4′-O-methylepigallocatechin. IPA extracted from ABSC proved to show anti-hypoxia activity on hypoxia-damaged PC12 cells. Hypoxia enhanced reactive oxygen species (ROS) generation and reduced the mitochondrial membrane potential (ΔΨm) in PC12 cells, resulting in the inhibition of survival and induction of apoptosis in PC12 cells. Measurements of 100 μg/mL and 250 μg/mL IPA could significantly reduce hypoxia-induced damage in PC12 cells by decreasing overproduced intracellular ROS, improving ΔΨm, and reducing cell apoptosis rate. Our findings indicated that the IPA from ABSC potentially could be used as novel bioactive components applied to anti-hypoxia functional foods or medicines.

Guirlanda C, A. F. Moura M. Use of the Versatility of Fungal Metabolism to Meet Modern Demands for Healthy Aging, Functional Foods, and Sustainability

Aging-associated, non-transmissible chronic diseases (NTCD) such as cancer, dyslipidemia, and neurodegenerative disorders have been challenged through several strategies including the consumption of healthy foods and the development of new drugs for existing diseases. Consumer health consciousness is guiding market trends toward the development of additives and nutraceutical products of natural origin. Fungi produce several metabolites with bioactivity against NTCD as well as pigments, dyes, antioxidants, polysaccharides, and enzymes that can be explored as substitutes for synthetic food additives. Research in this area has increased the yields of metabolites for industrial applications through improving fermentation conditions, application of metabolic engineering techniques, and fungal genetic manipulation. Several modern hyphenated techniques have impressively increased the rate of research in this area, enabling the analysis of a large number of species and fermentative conditions. This review thus focuses on summarizing the nutritional, pharmacological, and economic importance of fungi and their metabolites resulting from applications in the aforementioned areas, examples of modern techniques for optimizing the production of fungi and their metabolites, and methodologies for the identification and analysis of these compounds.

Reduction of Salt and Fat in Frankfurter Sausages by Addition of Agaricus bisporus and Pleurotus ostreatus Flour

The reduction of fat and salt and the incorporation of fiber-rich compounds in frankfurters is a trend to improve their nutritional profile. The objective of this study was to evaluate the partial replacement of 30 and 50% of pork backfat and 50% of salt by adding edible mushroom flour (2.5 and 5%) from Agaricus bisporus (Ab) and Pleurotus ostreatus (Po) on physicochemical, microbiological and sensory properties of frankfurters sausages during cold storage. The addition of flours increased the moisture, and the dietary fiber contents in frankfurters, keeping the amino acid profile. Lipid oxidation remained under acceptable values despite not antioxidant effect was observed by mushrooms flours. Only spore-forming bacteria were found during cold storage. Color and texture was modified by addition of mushroom, being the Ab samples darker, while Po flour addition resulted in softer and less cohesive sausages. Although lower color, flavor, and taste scores were given to the mushroom samples than the control, they ranked in the acceptable level confirming that the inclusion of 2.5 and 5% of Ab and Po flours in fat- and salt-reduced frankfurter sausages resulted a feasible strategy to enhance the nutritional profile these products.

Antioxidant and antibacterial activity of Trametes polyzona (Pers.) Justo

Polypores are cosmopolitan mushrooms, widely investigated for their beneficial properties in combatting multidrug resistant pathogens. The present study focuses on the need for new, naturally sourced antimicrobial and antioxidant compounds from mushrooms. The antioxidant and antibacterial activity of the phenolic extract of strains of Trametes polyzona (Pers.) Justo, were investigated. Strains of T. polyzona were analyzed for total phenolic content, Trolox antioxidant equivalent, DPPH radical scavenging and antibacterial activities. The amplification of the ribosomal DNA-ITS fragments from DNA of selected mushrooms was carried out using ITS1 and ITS4 primers. The antibacterial activity of phenolic extracts of T. polyzona was comparable to the antibiotics, ceftazidime and erythromycin. T. polyzona extracts inhibited the growth of the different strains of K. pneumoniae, E. coli, S. aureus, and S. enterica tested in this study. The results of the study demonstrate that, T. polyzona can be a potential source of antimicrobial and antioxidant compounds.

Transcriptional profiling of Auricularia cornea in selenium accumulation

Auricularia cornea is a widely cultivated edible fungus with substantial nutritive value. This study aimed to enrich the multifunctional bionutrient element selenium in A. cornea to improve its quality and explore the accumulation of selenium in the fungus using high-throughput RNA-Seq technology. In general, the treatment group with a 100 µg/g supply of selenium outperformed the other treatment groups in terms of high yield, rich crude polysaccharides and a high total selenium concentration. Additional evidences demonstrated the budding and mature phases were two typical growth stages of A. cornea and were important for the accumulation of selenium. Therefore, the budding and mature phase tissues of A. cornea in the treatment group with a 100 µg/g supply of selenium were used for transcriptome analysis and compared to those of a control group that lacked additional selenium. A total of 2.56 × 105 unigenes from A. cornea transcriptome were assembled and annotated to five frequently used databases including NR, GO, KEGG, eggNOG and SwissProt. GO and KEGG pathway analysis revealed that genes involved in metabolic process and translation were up-expressed at the budding stage in response to selenium supplementation, including amino acid metabolism, lipid metabolism, ribosome. In addition, the differential gene expression patterns of A. cornea suggested that the up-expressed genes were more likely to be detected at the budding stage than at the mature stage. These results provide insights into the transcriptional response of A. cornea to selenium accumulation.