Mycelia from Pleurotus sp. (oyster mushroom): a new wave of antimicrobials, anticancer and antioxidant bio-ingredients

Abstract

Introduction: There has been an upsurge of interest in mushrooms, such as Pleurotus species, as an important source of bioactive compounds. Mycelia-submerged culture represents a promising approach to search new safe and healthy myco-products with standardized quality in addition to mushroom fruiting bodies. Methods: The study examined the in vitro antimicrobial, antitumor and antioxidant activities of a hotwater extract from Pleurotus sp. mycelium. The antimicrobial activity was screened through the activation of the microbial autolytic system of four bacteria and four yeast strains. The anti-proliferative effects on NB4 human leukemia cells were measured by flow-cytometry analyses. The antioxidant activity was investigated by the scavenging of DPPH and ABTS radicals, the reducing power and the inhibition of lipid peroxidation. Results: The extract activated the microbial autolytic system of eight strains: 7 autolyzing strains with intensity values (Is) ranging from 2.7% in Candida sp. to 36.1% in Saccharomyces cerevisiae. Thus, the microbial autolytic system of the strains tested (including Gram-positive and gram-negative bacteria as well as yeasts) could be activated in vitro by mycelial extract. Pleurotus extract reduced the viability of NB4 leukemia cells, particularly at the concentration of 200 μg/mL to 82% compared to control cells, and induced apoptosis demonstrated by an increase in annexin V-FITC+ cells (25% at 200 μg/mL). At 10 mg/mL, the extract showed the most potent scavenging effects for DPPH and ABTS radicals (96% and 55%, respectively) and the inhibition of lipid peroxidation (52%). The mushroom extract at 5 mg/ mL manifested reducing power of 1.105. Although carbohydrates (76.8%, w/w) appear to be the most important bioactive compounds, secondary metabolites, like phenolics, would also contribute to the antioxidant, antimicrobial and anti-proliferative activities. Conclusion: The hot-water extract obtained from Pleurotus mycelium, in light of its in vitro antimicrobial, antitumor and antioxidant effects could be considered a good candidate for developing nutraceuticals and for designing innovative myco-therapeutics and phytocosmetics applications.

Characterization of the Nutritional Composition of a Biotechnologically Produced Oyster Mushroom and its Physiological Effects in Obese Zucker Rats

“…[ 9 ] The multidirectional health‐promoting effects of mushrooms of the Pleurotus genus result from the presence of secondary metabolites, which have been isolated from both oyster mushroom fruiting bodies and mycelia. [ 10 ] The bioactive compounds identified in Pleurotus include polysaccharides, chitinous substances, amino acids, fatty acid esters, sterols, and polyphenols. These bioactive substances exhibit anti‐atherosclerotic, anti‐inflammatory, hepatoprotective, and anti‐oxidative properties.…”

Bioactive compounds and medicinal properties of Oyster mushrooms (Pleurotus sp.)

“…Application of a pleuran-based cream as an adjunctive therapeutic to patients with atopic dermatitis has produced good results. The latest scientific reports confirm the usefulness of different oyster mushroom species as a raw material for the cosmetics industry (Taofiq et al, 2016;Wu et al, 2016;Morris et al, 2017).…”

“…The multidirectional health-promoting and therapeutic effects of mushrooms of the Pleurotus genus result from the presence of secondary metabolites, which have been isolated from both oyster mushroom fruiting bodies and mycelia (Morris et al, 2017). The bioactive compounds identified in Pleurotus mushrooms can be divided into those with a high and those with a low molecular weight.…”

Green potential ofPleurotusspp. in biotechnology

“…Secondary metabolites isolated from Pleurotus fruiting body and mycelia show strong, versatile health-promoting and therapeutic effects. Valuable bioactive compounds from oyster mushrooms can be divided into two groups with high and low molecular weight (Morris et al, 2017; Golak-Siwulska et al, 2018). A bundle of reports concerning oyster mushrooms brings to light the new substances with such properties as an antibiotic, antitumor, antiviral, and anticholesterolic activities (Selegean, Putz & Rugea, 2009).…”