Antimicrobial and antineoplasic activity of Pleurotus ostreatus

Bioactive Metabolites from the Fruiting Body and Mycelia of Newly-Isolated Oyster Mushroom and Their Effect on Smooth Muscle Contractile Activity

Higher basidiomycetes are recognized as functional foods due to their bioactive compound content, which exerts various beneficial effects on human health, and which have been used as sources for the development of natural medicines and nutraceuticals for centuries. The aim of this study was to evaluate and compare the biological potential of basidiocarp and mycelial biomass produced by submerged cultivation of a new regionally isolated oyster mushroom. The strain was identified with a high percentage of confidence (99.30%) as Pleurotus ostreatus and was deposited in the GenBank under accession number MW 996755. The β-glucan content in the basidiocarp and the obtained mycelial biomass was 31.66% and 12.04%, respectively. Three mycelial biomass and basidiocarp extracts were prepared, and the highest total polyphenol content (5.68 ± 0.15 mg GAE/g DW and 3.20 ± 0.04 mg GAE/g DW) was found in the water extract for both the fruiting body and the mycelium biomass. The in vitro antioxidant activity of the extracts was investigated, and it was determined that the water extracts exhibited the most potent radical scavenging activity. The potential ability of this new fungal isolate to affect the contractile activity (CA) of dissected smooth muscle preparations (SMP) was examined for the first time. It was found that oyster mushrooms likely exhibit indirect contractile effects on the gastric smooth muscle (SM) cells.

Pleurotus Genus as a Potential Ingredient for Meat Products

Edible mushrooms are considered an important source of nutritional and bioactive compounds. In this review, the findings of macronutrients, bioactive compounds, antioxidant activity, and antimicrobials against foodborne pathogens of some Pleurotus spp., as well as their potential use as an ingredient in the meat industry are discussed. The results show that Pleurotus spp. are an important source of proteins and amino acids, carbohydrates, minerals, and vitamins. Additionally, the presence of some bioactive components, such as polysaccharides (α-glucans, β-glucans, and so on), proteins/enzymes and peptides (eryngin, pleurostrin, and others) phenolic acids (p-coumaric, chlorogenic, cinnamic, ferulic, gallic, protocatechuic, and others) and flavonoids (chrysin, naringenin, myricetin, quercetin, rutin, or the like) has been demonstrated. Several works evidenced the use of Pleurotus spp. in some meat and meat products (patties, sausages, paste, and suchlike) as a novel ingredient in order to improve their chemical composition and functional health promoting properties, as well as to increase their physicochemical and sensory attributes. In conclusion, the use of Pleurotus is a promissory strategy for the development of natural additives rich in nutritional and bioactive components for meat and meat product formulation.

Validating Anti-Infective Activity of Pleurotus Opuntiae via Standardization of Its Bioactive Mycoconstituents through Multimodal Biochemical Approach

Mushrooms produce a variety of bioactive compounds that are known to have anti-pathogenic properties with safer and effective therapeutic effects in human disease prognosis. The antibacterial activity of ethanol and methanol extracts of Pleurotus opuntiae were checked against pathogenic microorganisms viz. Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis NCIM 2300, Proteus vulgaris NCIM 5266, Serratia marcescens NCIM 2078, Shigella flexeneri NCIM 5265, Moraxella sp. NCIM 2795, Staphylococcus aureus ATCC 25923 by agar well diffusion method at different concentrations of the extracts. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts was determined by INT (Iodonitrotetrazolium chloride) colorimetric assay. Extracts were standardized by thin layer chromatography (TLC) in different solvent systems. The Retention factors (Rf) of different compounds were calculated by high performance TLC (HPTLC) fingerprinting at UV 254, 366, and 540 nm before and after derivatization. The ethanol and methanol extracts of P. opuntiae showed bactericidal activity against all the test pathogens at MIC values of 15.6 to 52.08 mg/mL and 20.81 to 52.08 mg/mL respectively. Whereas the MBC values for ethanol and methanol extract of P. opuntiae against all pathogens were recorded as 26.03 to 62.5 mg/mL and 125 mg/mL respectively. Preliminary mycochemical screening of both the extracts revealed high contents of bioactive compounds. Amongst all the solvent systems used in TLC, the best result was given by chloroform + hexane (8:2) which eluted out 5 different compounds (spots). HPTLC results revealed spots with different Rf values for all the 24 compounds present. Thus, it can be inferred from the present investigation that the mycoconstituents could be an alternative medication regimen and could play a role in new drug discoveries against different infections. Further, the antimicrobial components of these mushrooms can be transformed to bioengineered antimicrobial coatings for surfaces, drug and other hybrid systems for public health implications in combating persistent infections.

Nutraceutical Potential and Processing Aspects of Oyster Mushrooms (PleurotusSpecies)

Background:

Oyster mushrooms (Pleurotus species) have gained considerable attention of food technologist and nutritionist for their nutraceutical properties. Oyster mushrooms are considered as functional foods due to their richness in functional food ingredients. In recent times, consumption of these mushrooms has increased considerably due to their numerous health benefits. These are potential sources of bioactive components, which are sufficient enough for prevention and treatment of various lifestyle diseases. There are about 200 different species in the genus Pleurotus and these are commonly referred to as “oyster mushrooms”.

Objective:

The study aimed to grasp a collective information on nutraceutical and processing aspects of highly perishable but nutritious oyster mushroom

Results:

Pleurotus ostreatus is the most commonly consumed species all over the world due to its superior flavor, taste and nutraceutical properties. It acts as a source of natural antioxidants which might be beneficial for human health in preventing or reducing oxidative damage. Nutritionally, these species are rich sources of proteins, dietary fibres, β-glucan, vitamin B-complex, vitamin C and minerals. They contain higher proportions of certain amino acids such as methionine, cystine and aspartic acid than other edible mushrooms. Oyster mushrooms have been reported to possess hypocholesterolemic, anti-bacterial, anti-diabetic, anti-oxidant, anti-arthritic, anti-carcinogenic, hepatoprotective, anti-viral activities and act as natural resources of immunotherapy activities. The use of these mushrooms can overcome the deficiency of protein in the developing countries where there is unavailability or unacceptability of good quality proteins from animal sources because of religious restrictions.

Conclusion:

Because of the occurrence of abundant nutritional ingredients and other bioactive components in P. ostreatus, they have a great scope as a potential source for the development of functional or specialty foods for value addition of deficient foods so as to alleviate the nutritional deficiency diseases from society.

The use of fermented buckwheat to produce L-carnitine enriched oyster mushroom

l-Carnitine is an essential compound that shuttles long chain fatty acids into mitochondria. The objective of this study was to produce l-carnitine enriched oyster mushroom (Pleurotus ostreatus) using common buckwheat fermented by Rhizopus oligosporus. Mushroom grown on common buckwheat medium contained 9.9–23.9% higher l-carnitine (186.3 mg/kg) than those grown on basal medium without any buckwheat addition. Those grown on fermented common buckwheat medium contained the highest l-carnitine content (201.2 mg/kg). Size index and lightness of mushroom pileus (L*) were also the highest (100.7 and 50.6, respectively) for those grown in medium added with fermented common buckwheat (20%, w/w). Antioxidant activities of both mushroom extracts (1.5 mg/mL) showed the same level as 38.7% for mushroom grown in media added with common buckwheat or fermented common buckwheat. At the treatment concentration of 300 μg/mL, viabilities of murine macrophage cell line Raw 264.7 cells treated with ethanol extract of oyster mushroom grown on buckwheat medium ranged from 58.9 to 67.8%. The oyster mushroom grown on buckwheat and fermented buckwheat medium can be used as one of the substitutes for meat based diets.

Extracellular polysaccharide production by a strain of Pleurotus djamor isolated in the south of Brazil and antitumor activity on Sarcoma 180

Polysaccharides with medicinal properties can be obtained from fruiting bodies, mycelium and culture broth of several fungus species. This work was carried out in batch culture using a stirred tank reactor with two different initial glucose concentrations (40-50 g/L) and pH values (3.0-4.0) to enhance extracellular polysaccharides production by Pleurotus djamor UNIVILLE 001 and evaluate antitumor effect of intraperitonial administration of Pleurotus djamor extract on sarcoma 180 animal model. According to factorial design, the low pH value (pH 3.0) led to a gain of 1.6 g/L on the extracellular polysaccharide concentration, while glucose concentration in the tested range had no significant effect on the concentration of polysaccharide. With 40 g/L initial glucose concentration and pH 3.0, it was observed that yield factor of extracellular polysaccharide on substrate (YP/S = 0.072) and maximum extracellular polysaccharide productivity (Q(Pmax) = 11.26 mg/L.h) were about 188% and 321% respectively higher than those obtained in the experiment performed at pH 4.0. Under these conditions, the highest values of the yield factor of biomass on substrate (YX/S = 0.24) and maximal biomass productivity (Q(Xmax) = 32.2 mg/L.h) were also reached. In tumor response study, mean tumor volume on the 21th day was 35.3 cm(3) in untreated group and 1.6 cm(3) in treated group (p = 0.05) with a tumor inhibition rate of 94%. These impressive results suggests an inhibitory effect of P.djamor extract on cancer cells.

Production of bioactive compounds with antitumor activity against sarcoma 180 by Pleurotus sajor-caju

This work studied the influence of culture medium composition and pH on exopolysaccharide (EPS) production by Pleurotus sajor-caju and validates the antitumor activity of the produced EPSs and of the mycelial biomass (intracellular polysaccharides [IPSs]) against Sarcoma 180 (S180) cells. The effect of the initial concentrations of (NH₄)₂SO₄, yeast extract and soy peptone on EPS production by P. sajor-caju was studied in shake flasks. A bioreactor was used to evaluate the pH values and the initial CaCO₃ and glucose concentrations. Extracts of EPSs (PE1) and IPSs obtained through two different separation processes (PM1 and PM2) were tested on mice inoculated with S180 cells. A medium containing 2.5, 1.0, and 1.0 g/L of (NH₄)₂SO₄, yeast extract and soy peptone, respectively, provided the highest EPS concentration (0.6 g/L). The use of pH 4.0, 1.0 g/L CaCO₃ and 20 g/L initial glucose concentration enhanced EPS productivity (3.84 g/L per hour). The PE1 extract promoted the highest reduction of S180 growth (86%), followed by the PM2 extract (80%); growth reduction was dose-independent for both substances. This work provides information about culture medium and conditions that enhanced the production of extracellular polysaccharides by P. sajor-caju. The results can contribute to the search for new bioactive products bringing novel aspects to the medical and pharmaceutical areas.

Production, purification and characterisation of polysaccharides from Pleurotus ostreatus with antitumour activity

BACKGROUND

Mushroom polysaccharides play an important role in functional foods because they exhibit biological modulator properties such as antitumour, antiviral and antibacterial activities. The present study involved the production, purification and characterisation of intracellular and extracellular free and protein-bound polysaccharides from Pleurotus ostreatus and the investigation of their growth-inhibitory effect on human carcinoma cell lines.

RESULTS

Several fermentation parameters were obtained: batch polysaccharide productivities of 0.013 ± 8.12 × 10⁻⁵ and 0.037 ± 0.0005 g L⁻¹ day⁻¹ for intracellular and extracellular polysaccharides respectively, a maximum biomass concentration of 9.35 ± 0.18 g L⁻¹ , P(max) = 0.935 ± 0.018 g L⁻¹ day⁻¹, µ(max) = 0.218 ± 0.02 day⁻¹, Y(EP/X) = 0.040 ± 0.0015 g g⁻¹ and Y(IP/X) = 0.014 ± 0.0003 g g⁻¹ . Some polysaccharides exhibited superoxide dismutase (SOD)-like activity of 50-200 units. Fourier transform infrared analysis of the polysaccharides revealed absorption bands characteristic of such biological macromolecules. Cytotoxicity assays showed that both intracellular and extracellular polysaccharides exhibited antitumour activity towards several tested human carcinoma cell lines in a dose-dependent manner.

CONCLUSION

The polysaccharides of P. ostreatus exhibited high SOD-like activity, which strongly supports their biological effect on tumour cell lines. The extracellular polysaccharides presented the highest antitumour activity towards the RL95 carcinoma cell line and should be further investigated as an antitumour agent.

Hericium erinaceus mushroom extracts protect infected mice against Salmonella Typhimurium-Induced liver damage and mortality by stimulation of innate immune cells

The present study investigated the antibacterial effect of four extracts from the fruitbody of the edible medicinal mushroom Hericium erinaceus (hot water extract, HWE; microwave/50% ethanol extract, MWE; acid extract, ACE; and alkaline extract, AKE) against murine salmonellosis. The extracts had no effect on Salmonella ser. Typhimurium growth in culture. Nor were the extracts toxic to murine macrophage cells, RAW 264.7. HWE and MWE stimulated uptake of the bacteria into the macrophage cells as indicated by increased colony-forming unit (CFU) counts of the contents of the lysed macrophages infected with Salmonella Typhimurium for 30 and 60 min. Two hours postinfection, the bacterial counts increased in the macrophages, but 4 and 8 h postinfection the HWE- and MWE-treated cells showed greater activity against the bacteria than the control. HWE- and MWE-treated noninfected macrophages had altered morphology and elevated inducible nitric oxide (NO) synthase (iNOS) mRNA expression. In the presence of S. Typhimurium, iNOS mRNA expression was further increased, accompanied by an increase in NO production. Histology assays of the livers of mice infected with a sublethal dose (1 × 10(4) CFU) of S. Typhimurium showed that HWE and MWE, administered by daily intraperitoneal injection, protected against necrosis of the liver, a biomarker of in vivo salmonellosis. The lifespans of mice similarly infected with a lethal dose of S. Typhimurium (1 × 10(5) CFU) were significantly extended by HWE and MWE. β-Glucan, known to stimulate the immune system, was previously found to be present in high amounts in the active extracts. These results suggest that the mushroom extract activities against bacterial infection in mice occur through the activation of innate immune cells.

Anti-Cancer Effects of Protein Extracts from Calvatia lilacina, Pleurotus ostreatus and Volvariella volvacea

Calvatia lilacina (CL), Pleurotus ostreatus (PO) and Volvariella volvacea (VV) are widely distributed worldwide and commonly eaten as mushrooms. In this study, cell viabilities were evaluated for a human colorectal adenocarcinoma cell line (SW480 cells) and a human monocytic leukemia cell line (THP-1 cells). Apoptotic mechanisms induced by the protein extracts of PO and VV were evaluated for SW480 cells. The viabilities of THP-1 and SW480 cells decreased in a concentration-dependent manner after 24 h of treatment with the protein extracts of CL, PO or VV. Apoptosis analysis revealed that the percentage of SW480 cells in the SubG₁ phase (a marker of apoptosis) was increased upon PO and VV protein-extract treatments, indicating that oligonucleosomal DNA fragmentation existed concomitantly with cellular death. The PO and VV protein extracts induced reactive oxygen species (ROS) production, glutathione (GSH) depletion and mitochondrial transmembrane potential (ΔΨ_m) loss in SW480 cells. Pretreatment with N-acetylcysteine, GSH or cyclosporine A partially prevented the apoptosis induced by PO protein extracts, but not that induced by VV extracts, in SW480 cells. The protein extracts of CL, PO and VV exhibited therapeutic efficacy against human colorectal adenocarcinoma cells and human monocytic leukemia cells. The PO protein extracts induced apoptosis in SW480 cells partially through ROS production, GSH depletion and mitochondrial dysfunction. Therefore, the protein extracts of these mushrooms could be considered an important source of new anti-cancer drugs.