Chemical Composition and Bioctivity of the Giant Polypore or Black-Staining Mushroom, Meripilus giganteus (Agaricomycetes), from Serbia

ABSTRACT

In this study, we tested the methanolic and acetonic extracts of the edible species Meripilus giganteus for their medicinal properties. Here, we present the chemical composition, as well as the antimicrobial, antioxidant, antidiabetic, neuroprotective, and cytotoxic activities, of the aforementioned extracts. The chemical composition of the extracts was analyzed with high-performance liquid chromatography coupled with diode-array detection and tandem mass spectrometry. The studied extracts contained 13 minerals, 23 polyphenols, 11 organic acids, and 22 carbohydrates. Antimicrobial activity was tested by applying the microdilution assay, and the results ranged from 0.002 to 20 mg/mL. Antioxidant activity was studied with the DPPH assay (half-maximal inhibitory concentration = 673.42 and 712.31 μg/mL for the methanolic and acetonic extracts, respectively) and the reducing power assay (range, 0.042-0.099 μg/mL). Total phenolic content was determined as 4.86 mg gallic acid equivalents (GAE)/g for the methanolic extract and 5.06 mg GAE/g for the acetonic extract. The antidiabetic effect of the extracts was explored with the α-amylase and α-glucosidase assays, and the results ranged from 30.66% to 38.67% and from 11.06% to 17.08%, respectively. The neuroprotective properties of M. giganteus extracts were studied using the acetylcholinesterase inhibition assay, with results ranging from 4.54% to 9.31%. Cytotoxic activity was tested by applying the microtetrazolium assay, with results ranging from 196.24 to 322.83 μg/mL. Although some assays proved relatively limited activities of the M. giganteus extracts studied, they can still be considered as natural sources of bioactive compounds without side effects.