Diversity of Pleurotus spp. (Agaricomycetes) and Their Metabolites of Nutraceutical and Therapeutic Importance.

Pleurotus spp. have been gaining popularity as a source for the creation of functional foods, nutraceuticals and novel pharmaceuticals. Despite Pleurotus is a specious genus including 208 legitimate species, only a few of them such as P. ostreatus are commercially accessible. The genetic and metabolic diversity of Pleurotus both at specific and subspecific level is therefore of main concern for many researchers. In addition to the conventional morphological approach, molecular and biochemical markers have been greatly contributing to investigate these issues. In this study, samples from six Pleurotus species (P. eryngii is represented by three varieties) were molecularly identified and the phylogeny was inferred to assess the relationships between the various taxa. Strains in pure culture obtained from 6 out of 7 species were cultivated as mycelium in vitro to investigate the metabolites by untargeted LC-MS/MS-based metabolomics. The results pointed out species-specific metabolite patterns and highlighted a clear difference between the P. eryngii group and P. ostreatus, although the latter appears more versatile depending on the strain. This is the first study pointing out and comparing different metabolite patterns in Italian samples of Pleurotus species, including P. eryngii varieties.

Characterization of Biological Activities of Methanol Extract of Fuscoporia torulosa (Basidiomycetes) from Italy.

This work investigated the antiradical, antibacterial, and antifungal properties of a methanol extract from Fuscoporia torulosa (PeruMyc1834) fruit body from Central Italy. The ITS partial sequence of the F. torulosa strain matched at a 100% rate those of various strains belonging to the species. Two complementary test systems, namely α,α-diphenyl-ß-picrylhydrazyl (DPPH) radical scavenging and ß-carotene/linoleic acid systems, were used. Free radical scavenging, measured by DPPH assay on methanol extract, showed an activity of 38.17 ± 2.74% of Trolox activity. The methanol extract of F. torulosa inhibited the growth of Gram-positive bacteria, particularly those belonging to the genus Bacillus (i.e., B. subtilis and B. cereus), better than Gram-negative bacteria. All the fungal isolates used in the present study for antifungal activity inhibited their growth when a concentration of 2.27 mg mL-1 of methanol extract was used (minimum inhibitory concentration from < 0.28 to 2.27 mg mL-1). This study established that the extracted antioxidant and antimicrobial compounds produced by F. torulosa can be exploited in treating diseases that affect humans, plants, and animals. There is a need to carry out further study to establish the chemical composition of the methanol extract.

Overview of the Biological Activities of a Methanol Extract from Wild Red Belt Conk, Fomitopsis pinicola (Agaricomycetes), Fruiting Bodies from Central Italy.

Fomitopsis pinicola (Sw.) P. Karst. (Fomitopsidaceae) is a medicinal mushroom with a variety of healthy properties. In this study we tested the radical scavenging activity and antimicrobial and anticancer potential of methanol extracts of F. pinicola from central Italy. Molecular identification confirmed that the samples were F. pinicola; a Basic Local Alignment Search Tool search showed a close match (99% sequence identity) with European isolates of this species. The free radical scavenging capacities, measured by DPPH assay, showed that the extract activity was 3.5% that of Trolox. The MTT test, evaluated after 72 hours of treatment with increasing doses of extract (5-500 µg · mL-1), considerably inhibited proliferation in a dose-dependent manner in 2 human tumor cell lines. This reduction was coupled with a relevant induction of apoptosis in the human leukemia THP-1 cell line after 24 hours of treatment, but a relevant toxic effect occurred in the human colon adenocarcinoma HT29 cell line. The genotoxic potential of the methanol extracts was studied by single-cell gel electrophoresis of normal human leukocytes exposed to 20 µg extract at 37°C for 30 minutes; no DNA damage was observed. The F. pinicola methanol extract was found to have varying degrees of antifungal effects against the pathogenic fungi tested (minimum inhibitory concentration from 23.63 to 66.81 µg · mL-1). The results show that the tested F. pinicola extract has strong antimicrobial and chemo-preventive activities, but is a poor antioxidant.