Antioxidant and antibacterial activities of acetonitrile and hexane extracts of Lentinus tigrinus and Pleurotus djamour

Potential Medicinal Fungi from Freshwater Environments as Resources of Bioactive Compounds

Owing to their nutritional, culinary, and nutraceutical, mushrooms are worldwide consumed and appreciated. Moreover, many of these mushrooms are also known as medicinal mushrooms since they possess several pharmacological properties attributable to a huge number of bioactive compounds derived from their sporophores. Several studies are available in the literature about in vitro and in vivo mechanisms of actions of such bioactive compounds. Most of these surveys are focused on macrofungi belonging to the genera Pleurotus, Ganoderma, or specific taxa such as Agaricus bisporus, Agaricus blazei, Boletus eduliInonotus obliquus, Hericium erinaceus, Lentinula edodes, and Grifola frondose. On the other hand, there is a lack of information on the under investigated ecological group of freshwater fungi. These fungi play a very important role in freshwater environments and some of them, belonging to Basidiomycota, are also edible and largely consumed. In this review we collected information about the medicinal properties of freshwater macro- and micromycetes. Among them, macrofungi, such as Amanita vaginata, Armillaria mellea, Armillaria tabescens, Astraeus hygrometricus, Auricularia auricula-judae, Bjerkandera adusta, Bovista nigrescens, Calocybe gambosa, Candolleomyces candolleanus, Collybia dryophila, Coprinus comatus, Cyclocybe cylindracea, Hypsizygus ulmarius, Inonotus hispidus, Lactarius controversus, Lentinus tigrinus, and Schizophyllum commune, observed in riparian habitat, and microfungi, such as Penicillium aculeatum, P. chrysogenum, and Fusarium incarnatum, isolated from aquatic plants, have been reported to have antimicrobial, anticancer, anti-inflammatory, antioxidant, antidiabetic, immunomoludatory, hypoglycaemic, and other pharmaceutical activities. Such fungal species are noteworthy since they represent an important quote of biodiversity to preserve their fundamental ecological role and a possible solution for different health problems for humans and animal farms.

Volvariella volvacea (paddy straw mushroom): A mushroom with exceptional medicinal and nutritional properties

Volvariella volvacea, commonly referred to as paddy straw mushroom, is renowned for its remarkable medicinal and nutritional properties. This mushroom, part of the family Pluteaceae, thrives in tropical and subtropical regions and is highly esteemed for its distinctive flavor and substantial health benefits. The fruiting body of V. volvacea is a rich source of bioactive compounds, including antioxidant enzymes, terpenes, polypeptides, sugars, phenolics, and flavonoids. These compounds exhibit an extensive range of therapeutic activities such as anti-tumor, anti-microbial, antioxidant, anti-malarial, anti-cancer, anti-inflammatory, and anti-allergic effects. Nutritionally, V. volvacea is an excellent source of carbohydrates, proteins, fibers, ascorbic acid, and essential minerals. It also boasts a comprehensive profile of amino acids, including valine, arginine, glutamine, serine, aspartic acid, leucine, isoleucine, tyrosine, asparagine, lysine, cystine, proline, glycine, tryptophan, methionine, phenylalanine, threonine, and histidine. This review emphasizes the significant medicinal and nutritional potential of V. volvacea, advocating its inclusion as a functional food to enhance human health and well-being. By highlighting its diverse bioactive compounds and therapeutic benefits, this review aims to foster greater recognition and utilization of paddy straw mushroom in both dietary and medicinal applications.

In vitro Antibacterial Activity and Secondary Metabolite Profiling of Endolichenic Fungi Isolated from Genus Parmotrema

The endolichenic fungi are an unexplored group of organisms for the production of bioactive secondary metabolites. The aim of the present study is to determine the antibacterial potential of endolichenic fungi isolated from genus Parmotrema. The study is continuation of our previous work, wherein a total of 73 endolichenic fungi were isolated from the lichenized fungi, which resulted in 47 species under 23 genera. All the isolated endolichenic fungi were screened for preliminary antibacterial activity. Five endolichenic fungi-Daldinia eschscholtzii, Nemania diffusa, Preussia sp., Trichoderma sp. and Xylaria feejeensis, were selected for further antibacterial activity by disc diffusion method. The zone of inhibition ranged from 14.3 ± 0.1 to 23.2 ± 0.1. The chemical composition of the selected endolichenic fungi was analysed through GC-MS, which yielded a total of 108 compounds from all the selected five endolichenic fungi. Diethyl phthalate, 1-hexadecanol, dibutyl phthalate, n-tetracosanol-1, 1-nonadecene, pyrrol[1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methyl) and tetratetracontane were found to be common compounds among one or the other endolichenic fungi, which possibly were responsible for antibacterial activity. GC-MS data were further analysed through Principal Component Analysis which showed D. eschscholtzii to be with unique pattern of expression of metabolites. Compound confirmation test revealed coumaric acid to be responsible for antibacterial activity in D. eschscholtzii. So, the study proves that endolichenic fungi that inhabit lichenized fungal thalli could be a source of potential antibacterial compounds.

Diversity and Ethno-Mycopharmacological Insights of Medicinal Mushrooms of the Bangus Valley of Jammu and Kashmir, India

The present study was carried out in various regions of Jammu and Kashmir, India, for the diversity and pharmacology of wild mushrooms. The valley is bestowed with alpine meadows and dense coniferous forest. Because of its isolation, security concerns, and line of control, most of these locations either have been little investigated or are entirely undiscovered. During the intensive survey of various locations, 20 mushroom species were collected from the surveyed areas. The ethno-mycological information was gathered from tribal communities and local herbalists (hakims). It was observed that 16 species were used against cold, constipation, liver and skin disorders, digestion problems, wound healing, and the like. However, these medicinal mushrooms are losing their relevance, so there is an urgent need to explore and preserve this knowledge for future use as medicine.

Antibacterial Activity of Culinary-Medicinal Polypore Mushroom Lentinus tigrinus (Agaricomycetes)

Medicinal mushrooms belonging to Lentinus spp. exhibit significant antibacterial activities, but little attention has been paid to their efficacy against the food-borne pathogen, Bacillus cereus. The present study for the first time quantitatively evaluated the antibacterial activity of different extracts from fruiting bodies of a well-authenticated Iranian native strain of medicinal mushroom, Lentinus tigrinus, against Gram-positive spore-forming bacterium B. cereus. The findings revealed that the acetone extract inhibited the growth of B. cereus at concentrations as low as 31.25 μg/ML, while it had no effect against Escherichia coli and Staphylococcus aureus even at 10,000 μg/ML. The rest of the bacteria were also susceptible to the acetone extract at concentrations greater than 5 mg/ML. Antibacterial activities of the methanol-ethyl acetate extract and the hot water extract were significantly weaker than that of the acetone extract, which contained high amounts of total phenols (5.83 ± 0.08 mg GAE/g, dw), while Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of functional groups, such as hydroxyl, carbonyl, amide, and amine. Further studies by scanning electron microscopy (SEM) confirmed obvious changes in the morphology of B. cereus in response to the acetone extract of L. tigrinus. This study may suggest that L. tigrinus could be a good natural source for isolating and purifying antibacterial compounds against B. cereus.

Bio-prospective potential of Pleurotus djamor and Pleurotus florida mycelial extracts towards Gram positive and Gram negative microbial pathogens causing infectious disease

BACKGROUND

The emergence of resistance to commonly used antibiotics by human infections occurred mostly due to their overuse, that prompted individuals to pursue novel and innovative treatments. The phytochemical characteristics, antibacterial activity, and cytotoxicity of MCF7 cells were evaluated in two Pleurotus spp. mycelial extracts in this work.

METHODS

Pleurotus djamor and Pleurotus florida mycelial extracts from pure cultures were tested for antibacterial activity by a well-diffusion assay and antimicrobial activity against mold fungi was evaluated for biomass inhibition. Mycelial extracts were obtained from dichloromethane extracts and their biophysical characteristics are analyzed by UV-vis spectrum and FTIR analysis. By spraying detection reagents onto TLC plates, the chemicals in dichloromethane extraction of chosen mushroom fungus mycelia were identified. Using the MTT test, the cytotoxic effect of dichloromethane extracts of selected mushroom fungi was evaluated on MCF7 Cell lines.

RESULTS

Mycelial extracts of P. djamor and P. florida exhibited significant antimicrobial effect on the bacterial and fungal pathogens tested. Dichloromethane mycelial extracts were obtained using soxhlet extraction which response positive for various phytochemical analysis. Detection of metabolites in thin layer chromatography using spray reagents documented one of few first accounts on flavonoids, anthroquinone and terpenoid compounds in P. djamor and P. florida. P. djamor and P. florida had dose-dependent antiproliferative activity against MCF7 cells, with an inhibitory impact of 55.72% and 64.47% percent at 125 μg/mL, respectively.

CONCLUSION

The study has reported the identification with the potent biological activity of some of the key bioactive components present in DCM extracts from the mycelia of P. djamor and P. florida.

Antimicrobial activity, chemical composition and cytotoxicity of Lentinus crinitus basidiocarp

Lentinus crinitus (L.) Fr. (Basidiomycota: Polyporales) is a wild mushroom with several biotechnological applications; however, there are few studies on its chemical composition and antimicrobial activity. Therefore, this study aims to evaluate the chemical composition, cytotoxicity, and antimicrobial activity of L. crinitus basidiocarp. For that, its nutritional value (AOAC procedures) and its composition in some hydrophilic and lipophilic compounds (chromatographic techniques) were assessed. Moreover, the potential hepatotoxic effects were evaluated using a primary cell culture obtained from porcine liver, and its growth inhibitory capacity was also evaluated against four human tumour cell lines (spectrophotometric assays). The antimicrobial activity was evaluated by microdilution against eight bacteria and fungi. The basidiocarp has a high content of carbohydrates and, therefore, a relatively high energetic value. It is also rich in soluble sugars, β-tocopherol, phenolic acids, mainly p-hydroxybenzoic acid, and organic acids, mainly malic acid. L. crinitus did not show cytotoxicity in non-tumour cells, but it did not inhibit the growth of human tumour cell lines either. The basidiocarp has a wide antimicrobial activity, inhibiting the growth of different species of bacteria and fungi. It showed minimum bactericidal and fungicidal concentration values similar to or lower than those verified by commercial antibiotics or food additives used as preservatives. The antimicrobial activity was more evident against Listeria monocytogenes, Salmonella enterica, and Penicillium ochrochloron, followed by Aspergillus ochraceus and Trichoderma viride, when compared to the controls. The results obtained in this study showed that L. crinitus basidiocarp has great potential to be used by the industry without toxicity risks.

Polysaccharides of mushroom Pleurotus spp.: New extraction techniques, biological activities and development of new technologies

The biodiversity of mushrooms Pleurotus spp. is impressive due to its complexity and diversity related to the composition of chemical structures such as polysaccharides, glycoproteins and secondary metabolites such as alkaloids, flavonoids and betalains. Recent studies of polysaccharides and their structural elucidation have helped to direct research and development of technologies related to pharmacological action, production of bioactive foods and application of new, more sophisticated extraction tools. The diversity of bioactivities related to these biopolymers, their mechanisms and routes of action are constant focus of researches. The elucidation of bioactivities has helped to formulate new vaccines and targeted drugs. In this context, in terms of polysaccharides and the diversity of mushrooms Pleurotus spp., this review seeks to revisit the genus, making an updated approach on the recent discoveries of polysaccharides, new extraction techniques and bioactivities, emphasising on their mechanisms and routes in order to update the reader on the recent technologies related to these polymers.

Investigation of Antioxidant/Oxidant Status and Antimicrobial Activities of Lentinus tigrinus

In the present study, antioxidant and antimicrobial potential of the Lentinus tigrinus (Bull.) Fr. mushroom was determined. Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) of the mushroom were measured with Rel Assay kits. Antimicrobial activities were tested on 9 standard bacterial and fungal strains (Staphylococcus aureus, Staphylococcus aureus MRSA, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Candida albicans, Candida krusei, and Candida glabrata) with a modified agar dilution method. It was determined that the TAS value of L. tigrinus was 1.748 ± 0.071, TOS value was 19.294 ± 0.237, and OSI was 1.106 ± 0.031. It was also found that mushroom extracts generally exhibited higher activity on Candida albicans, C. krusei, and C. glabrata. In conclusion, it was suggested that L. tigrinus can be used as a natural source due to its antioxidant and antimicrobial activities.