Antioxidant and anti-inflammatory properties of fungal mycelia and culture media

For centuries, mushrooms are used as fünctional foods or sources of natural medicine components.Besides the fruiting bodies, the mycelia and the culture media utilized in mushroom cultivation have been explored as potential sources of bioactive compounds, mostly due to the shorter incubation time and easier culture conditions, namely less required space, low probability of contamination and higher production of biomass, when compared to the fruiting bodies. Pleurotus eryngii (DC.) Quélis extensively studied and widely consumed, being acknowledged as a good dietary source of bioactive compounds. The less studied and consumed species Suillus bellinii (Inzenga) Watling was acknowledged for producing large amounts ofbiomass and exudates. To veriíy potential applications of the mycelia and culture media used to grow P. eryngü and >S'. bellinü, the phenolic acids and ergosterol contents, as well as their antioxidant and anti-inflarnmatory activities, were evaluated. The obtained results were further compared to those obtained with the Jfruiting bodies of wild samples (collected in Bragança, Portugal, in November 2015) of the same species.The mycelia were isolated fi-om sporocarps of each sample on different culture media (PDA,PDB and iMMN solid and liquid). Phenolic acids and ergosterol were determined by ultra-fast liquid chromatography coupled to a photodiode array detector (UFLC-PDA) or an ultraviolet detector (HPLC-UV), respectively. The antioxidant activity of the extracts was evaluated by four different assays: DPPH radical-scavenging activity, reducing power, R-carotene bleaching inhibition and thiobarbituric acid reactive substances (TBARS) assay.The anti-inflammatory effect was determined by measuring the down-regulation ofNO production in LPS-stimulated RAW264. 7 cells. S. bellinii mycelia showed higher contents of ergosterol and phenolic compounds and better leveis of antioxidant activity. On the other hand, P. eryngii mycelia, under specific culture conditions, showed higher anti-inflammatory activity (inclusively when compared to its fnüting bodies). Overall, mycelia and culture media can be use as potential altemative sources of bioactive compounds or as ingredients to be included in applications with antioxidant and anti-inflammatory activities.