Polyphenols, the main antioxidants of diet, have shown anti-inflammatory, antioxidant and anticarcinogenic activities. Here, we compared the effects of four polyphenolic compounds on ROS production and on the levels of matrix metalloproteinase (MMP)-2 and -9, which represent important pathogenetic factors of breast cancer. THP-1 differentiated macrophages were activated by LPS and simultaneously treated with different doses of a green tea extract (GTE), resveratrol (RSV), curcumin (CRC) and an olive fruit extract (oliplus). By using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, we found that all of the tested compounds showed antioxidant activity in vitro. In addition, GTE, RSV and CRC were able to counteract ROS production induced by H₂O₂ in THP-1 cells. As assessed by a zymographic analysis of THP-1 supernatants and by an “in-gel zymography” of a pool of sera from patients with breast cancer, the antioxidant compounds used in this study inhibited both the activity and expression of MMP-2 and MMP-9 through different mechanisms related to their structures and to their ability to scavenge ROS. The results of this study suggest that the used antioxidants could be promising agents for the prevention and complementary treatment of breast cancer and other diseases in which MMPs play a pivotal role.

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.

The aim of this study was to evaluate the antioxidant properties of the products derived from the biodegradation of lignin by the ligninolytic enzymes present in an aqueous extract of the mushroom P. eryngii. A mixture obtained after the incubation of lignin for 18 h with P. eryngii extract was tested in vitro for its total polyphenol content, reducing power, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl (OH) radical-scavenging activities. The results showed that the enzymatic treatment of lignin enhanced its antioxidant performance. The biocompatibility of the products of lignin biodegradation and their ability to scavenge reactive oxygen species (ROS) were also tested on the astrocytic cell line DI-TNC1. The results obtained indicated that a lignin mixture incubated for 18 h does not affect cell viability or inhibit the H₂O₂-induced ROS production. These results suggest that the enzymatic degradation of lignin represents an efficient and ecofriendly approach to obtain lignin derivatives potentially useful for antioxidant applications.