Effects of UV Stress in Promoting Antioxidant Activities in Fungal Species Тrametes versicolor (L.) Lloyd and Flammulina velutipes (Curtis) Singer.

Trametes versicolor and Flammulina velutipes, after submerged cultivation, with intermittent exposure to ultraviolet light (UV), were studied for Total Phenolic content (TP) and Total Proteins (TPR) contents and antioxidant properties against free radicals. The TP and TPR were determined by a spectrophotometric method and Lowry's assay, respectively. Liquid chromatography with mass spectrometry (LC-MS/MS) was used to quantify polyphenols. Different in vitro assays determined the antioxidant activities of the extracts. Mycelia extract from F. velutipes after 14 days and filtrate from T. versicolor after 21 days of incubation gave the highest TP 59.60 ± 0.14 and 50.03 ± 0.66 mg GAE/g d.w., respectively. Mycelia extract from T. versicolor after 28 days of incubation had the highest TPR (183.53 ± 2.84 mg BSAE/g d.w.). The LC-MS/MS analysis indicated that p-hydroxybenzoic and protocatechuic acids are the most abundant. Trametes versicolor filtrate after 14 days and F. velutipes filtrate after 21 days (71.29 ± 0.54% and 73.5 ± 1.81, respectively) had the highest scavenging activity in SOA. Correlation analysis indicated that all extracts' antioxidant (AO) potential strongly correlated with TP (R2 = 0.83-1.0). The data confirmed that stress factors such as UV exposure could stimulate the production of secondary metabolites and natural AOs, especially phenolic acids in test fungi.

Mushroom Species Stereum hirsutum as Natural Source of Phenolics and Fatty Acids as Antioxidants and Acetylcholinesterase Inhibitors.

Many lignicolous mushroom species are used as a food supplement and may represent an alternative treatment of Alzheimer's disease (AD). This study aimed to evaluate acetylcholinesterase inhibition (AChEI) of Stereum hirsutum together with antioxidant activity (AO) and cytotoxic activity against HepG2 cells. Different extracts (water, ethanol, methanol, polysaccharide) were analyzed, with respect to their mineral composition and chemical content. Ethanol extract was the most potent in AChEI (98.44 %) and demonstrated cytotoxic activity (91.96 % at 900.00 µg/mL), while the highest AO was demonstrated for polar extracts (methanol and water) as well. These activities may be attributed to determined phenolics (hydroxybenzoic and quinic acid) and fatty acids (FA), while biflavonoid amentoflavone may be responsible for cytotoxic activity. The most prevalent FA was linoleic (40.00 %) and the domination of unsaturated FA (UFA) (71.91 %) over saturated (26.96 %) was observed. This is the first report of AChEI of S. hirsutum extracts and first detection of amentoflavone. Due to high amount of UFA and well-expressed AChEI, this species can be considered as a potent food supplement in the palliative therapy of AD.

Comparison of Two Schizophyllum commune Strains in Production of Acetylcholinesterase Inhibitors and Antioxidants from Submerged Cultivation.

In recent years, fungi have been recognized as producers of acetylcholinesterase (AChE) inhibitors, agents important for the prevention of Alzheimer's disease (AD). This study aimed to examine the AChE inhibitory, the antioxidative and antibacterial activity of two different Schizophyllum commune strains that originated from Serbia (SRB) and Italy (IT). Submerged cultivation of grown mycelia (M) and fermentation broth (F) of ethanol (EtOH) and polysaccharide (PSH) extracts lasted for 7, 14, 21 and 28 days. For AChE activity Ellman method was performed, while for antioxidative activity, sevendifferent assays were conducted: DPPH, ABTS, FRAP, SOA, OH, NO together with total phenolic content. Antimicrobial screen, LC-MS/MS technique and FTIR measurements were performed. Different isolates exhibited different AChE activity, with PSH being the strongest (SRB, M, 28 days IC90 79.73 ± 26.34 µg/mL), while in EtOH extracts, IT stood out (F, 14 days, IC50 0.8 ± 0.6 µg/mL). PSH extracts (7 days) exhibit significant antioxidative activity (AO), opposite to EtOH extracts where 14 and 21days periods stood out. Only tw extracts showed antibacterial activity. Following LC-MS/MS analysis p-hydroxybenzoic and gallic acids were the most abundant phenolics. PSH extracts demonstrated remarkable results, making this study debut and introducing S. commune as a valuable resource of AChE inhibitors.