Apoptotic cell death of human leukaemia U937 cells by ubiquinone-9 purified fromPleurotus eryngii

Cell death induction by mycelium extracts from Pleurotus spp. on cervical cancer cell lines

Mushrooms have health benefits, including anti-tumoral properties. We evaluated the cytotoxic and cell death induction effects of water-soluble extracts of Pleurotus ostreatus and Pleurotus eryngii mycelium in the cervical cancer cell lines HeLa (HVP18⁺) and SiHa (HVP16⁺) as well as the non-tumoral cell line HaCaT. Both Pleurotus extracts presented similar protein patterns from 190 to 10 kDa and displayed protease activity on a gelatine substrate. The mycelium extracts of both Pleurotus strains induced a dose-dependent cytotoxic effect on HPV⁺ cells IC₅₀ 65 µg), whereas HaCaT cells were less susceptible (IC₅₀ 90 µg). The cytotoxic effect at the IC₅₀ concentration was not associated with apoptosis, the activation of Caspases-3/7 was not significantive; only P. eryngii induced a moderate (1.2-fold) increase in SiHa cells. Pleurotus extracts induced autophagy, mainly in SiHa cells (4.3-fold). Neither extracts induced changes in p53 protein expression, suggesting that the cytotoxic effect could be due to p53-independent pathways.

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.

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.

Asperpyrone F, a new dimeric naphtho-γ-pyrone from the edible fungus Pleurotus ostreatus

A new dimeric naphtho-γ-pyrone, asperpyrone F (1), along with six known ones, asperpyrones B (2) and C (3), fonsecinones A (4) and B (5), aurasperones A (6) and E (7), have been isolated from the solid culture of the edible fungus Pleurotus ostreatus. The structures of 1-7 were determined mainly by NMR and MS experiments. The absolute configuration of compound 1 was assigned via the circular dichroism (CD) data analysis. Compounds 1-7 showed modest antioxidant and immunomodulatory activities. All compounds were isolated from the fungus P. ostreatus for the first time.

New apoptosis-inducing sesquiterpenoids from the mycelial culture of Chinese edible fungus Pleurotus cystidiosus

Two new bisabolane-type sesquiterpenoids, pleuroton A (1) and pleuroton B (2), and three clitocybulol derivatives, clitocybulol D (3), clitocybulol E (4), and clitocybulol F (5), were obtained from the mycelial culture of edible fungus Pleurotus cystidiosus O. K. Mill by repeated column chromatography over RP-18, Sephadex LH-20, and silica gel. Their structures were determined according to nuclear magnetic resonance data, high-resolution electron impact mass spectrometry, and circular dichroism spectra. These new sesquiterpenoids exhibited significant cytotoxicity against two human prostate cancer DU-145 and C42B cells in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The median inhibitory concentration (IC50) of compounds 1, 2, 3, 4, and 5 was 174, 28, 233, 162, and 179 nM, respectively, against the DU-145 cell and was 104, 52, 163, 120, and 119 nM, respectively, against the C42B cell. Especially, pleuroton B (2) exhibited the strongest cytotoxity among these sesquiterpenoids, which was confirmed by the colony formation assay. Furthermore, pleuroton B (2) could trigger the apoptosis of DU-145 cells through the detection of apoptosis cells using annexin V-FITC staining by flow cytometry, the observation of condensed nuclei in the apoptosis cells, and the western blot analysis for the expression of apoptosis-related proteins Bcl-2, Bak, and Bax. Analysis of structure-activity relationships of these sesquiterpenoids revealed that the unusual functional moiety of pleuroton B should contribute to its significant bioactivity. These results display the pharmacological potential of P. cystidiosus.

Gene cloning and biochemical characterization of eryngase, a serine aminopeptidase of Pleurotus eryngii belonging to the family S9 peptidases

Pleurotus eryngii serine aminopeptidase that has peptide bond formation activity, redesignated as eryngase, was cloned and expressed. Eryngase has a family S9 peptidase unit in the C-terminal region having a catalytic triad of Ser, Asp, and His. In the phylogenetic relations among the subfamilies of family S9 peptidase (S9A, prolyl oligopeptidase; S9B, dipeptidyl peptidase; S9C, acylaminoacyl peptidase; S9D, glutamyl endopeptidase), eryngase existed alone in the neighbor of S9C subfamily. Mutation of the active site Ser524 of the eryngase with Ala eliminated its catalytic activity. In contrast, S524C mutant maintained low catalytic activity. Investigation of aminolysis activity using l-Phe-NH2 as a substrate showed that S524C mutant exhibited no hydrolysis reaction but synthesized a small amount of l-Phe-l-Phe-NH2 by the catalysis of aminolysis. In contrast, wild-type eryngase hydrolyzed the product of aminolysis l-Phe-l-Phe-NH2. Results show that the S524C mutant preferentially catalyzed aminolysis when on an l-Phe-NH2 substrate.

Cloning and functional characterization of TCRP1, a novel gene mediating resistance to cisplatin in an oral squamous cell carcinoma cell line

To explore the mechanisms of chemotherapy resistance, we previously established a multi-drug resistant cell line, Tca8113/Pingyangmycin (Tca8113/PYM) and identified differential expression in known genes and ESTs using microarray analysis. From among those ESTs we have now identified a novel gene producing an mRNA of 1834 nucleotides translated into a protein having 235 amino acids. This gene was denominated as tongue cancer resistance-associated protein 1 gene (TCRP1, accession number: EF363480). We further determined its functional characteristics. The results demonstrate that TCRP1 mediates a specific resistance to cisplatin in Tca8113 cells by reducing the cisplatin-induced apoptosis. This suggests that TCRP1 might be a novel molecular target to develop agents to reverse cisplatin-induced chemoresistance.