The antioxidative capacity of four basidiomycetous fungal species from Fruška Gora provenance as a potential biochemical indicators of environmental disturbance

In the last decades, basidiomycetous fungal species became of great importance as sources of natural bioactive molecules. Moreover, macrofungal species have been also used as a good bioecological indicator of contamination of ecosystem in biodiversity monitoring examinations, determining conditions of soil, wood species and air. Biochemical parameters of oxidative stress in four macrofungal species were analyzed for their antioxidative capacity referring of possibility of disturbance of Fruška Gora Provenance and its forest ecosystem by environmental (e.g. climate) changes above Vojvodina region. Organic extracts (70% methanol and 100% chloroform), made of four lignicolus fungal species (Panus tigrinus, Fomes fomentarius, Agrocybe aegerita, Omphalotus olearius) from natural Fruška Gora Provenance were examined directly for their antioxidative capacity by 3 tests in vitro: DPPH•assay, FRAP assay and total phenol content determination. The highest radical scavenging capacity (RSC) and the lowest IC 50 value (129,22 µg/ml) in DPPH• assay was noticed in the extract of F. fomentarius, while the extract of A. aegerita showed ≈ 13 times higher value (1746,38 µg/ml) indicating lower antioxidant potential. O. olearius extract showed the highest antioxidative capacity in all tests obtained. However, F. fomentarius species showed higher value in FRAP test (69,1 mg equivalent of ascorbic acid/g dw) and total phenol content (240,55 mg equivalent of galic acid/g dw) then P. tigrinus and A. aegerita species in the same tests, showing its stronger antioxidative defense against oxidative stress. Positive correlation (r=0.98) between total phenol content and ferric reducing power of fungal extractst indicated the possibility that phenols are major active constituents in obtained antioxidative activity. According to results for DPPH• assay, two fungal species, P. tigrinus and A. aegerita indicate possibility that different, nonphenolic secondary metabolites can be responsible for high IC 50 value and strong anitoxidative reaction. The obtained results suggest that all analyzed fungi from natural Fruška Gora Provenance are of potential interest as a good bioecological indicator for Fruška Gora Provenance which ecosystem is in balance, as opposed to the obvious climate changes.