In this study the antioxidant and neuroprotective activity of an enriched polysaccharide fraction (EPF) obtained from the fruiting body of cultivated P. eryngii was evaluated. Proximate composition (moisture, proteins, fat, carbohydrates and ash) was determined using the AOAC procedures. The EPF was extracted by using, in sequence, hot water and alkaline extractions followed by deproteinization and precipitation with cold ethanol. Total α- and β-glucans were quantified using the Megazyme International Kit. The results showed that this procedure allows a high yield of polysaccharides with a higher content of (1-3; 1-6)-β-D-glucans. The antioxidant activity of EPF was detected from the total reducing power, DPPH, superoxide, hydroxyl and nitric oxide radical scavenging activities. The EPF was found to scavenge DPPH, superoxide, hydroxyl and nitric oxide radicals with a IC50 values of 0.52 ± 0.02, 1.15 ± 0.09, 0.89 ± 0.04 and 2.83 ± 0.16 mg/mL, respectively. As assessed by the MTT assay, the EPF was biocompatible for DI-TNC1 cells in the range of 0.006–1 mg/mL and, at concentrations ranging from 0.05 to 0.2 mg/mL, significantly counteracted H₂O₂-induced reactive oxygen species production. This study demonstrated that polysaccharides extracted from P. eryngii might be used as functional food to potentiate the antioxidant defenses and to reduce oxidative stress.

Cardiovascular diseases represent the main cause of death. A common feature of cardiovascular disease is thrombosis resulting from intravascular accumulation of fibrin. In the last years, several fibrinolytic enzymes have been discovered in many medicinal or edible mushrooms as potential new antithrombotic agents. This study aimed to compare the fibrin(ogen)olytic activity of crude extracts from the fruiting bodies of four cultivated edible mushrooms: Lentinula edodes, Pleurotus ostreatus, Pleurotus eryngii, and Agrocybe aegerita. Fibrin(ogen)olytic activity was assessed by fibrin plate, spectrophotometric assay and electrophoretic analysis (SDS-PAGE and zymography). The highest activity was detected for P. ostreatus followed by P. eryngii, L. edodes and A. aegerita. Results indicated that enzymes exhibited maximum activity at pH 6–7 and 30–40 °C, respectively. Enzyme activity was inhibited by serine and metalloprotease inhibitors. We proposed a new index called the Specific Fibrin(ogen)olytic Index (SFI), which allows specification of the proportion of the total proteolytic capacity due to the fibrin(ogen)olytic activity. These data suggest that the extracts from fruiting bodies or powdered mushrooms can be used as functional ingredients for the development of new functional foods that may act as thrombolytic agents responding, at the same time, to the increasing demand for safe, healthy and sustainable food.

The fungi belonging to the genus Pleurotus can be cultivated in different substrates and represent excellent producers of several extracellular enzymes. In this study, we analyzed eleven hydrolytic enzymes of the P. eryngii and P. ostreatus secretomes, which were collected at three different growth stages after 23 days (mycelial colonization of about 50% of the substrate), 34 days (100% colonization of the substrate) and 50 days (after the first flush). Mushrooms were axenically cultivated on the same substrate. The results demonstrate that proteases, lipases, amylases, α-glucosidase, cellulases (endoglucanase, β-cellobiohydrolase and β-glucosidase) and hemicellulase (xylosidase, glucuronidase, arabinosidase and mannosidase) activities were higher in the secretomes from P. eryngii than those from P. ostreatus. Time course analysis revealed for both species a similar enzymatic activity profile, in which in the early stages of mycelium development, both species use starch as the main carbon source. Protease and lipase activities increased and remained constant during the subsequent formation of fruiting bodies, whereas cellulase and hemicellulase activities decreased after the complete mycelial colonization of the substrate. The zymographic analysis suggested the presence in the secretomes of proteolytic activities belonging to different classes. In conclusion, both mushroom species released into the secretomes a broad spectrum of hydrolytic enzymes potentially useful in various biotechnological fields.