Biological potential of extracts of the wild edible Basidiomycete mushroom Grifola frondosa

Abstract

Partially purified polysaccharides (FP) and hot alkali extract (FNa) obtained from fruiting bodies of the wild basidiomycete Grifola frondosa were examined for their antimicrobial, antioxidant and cytotoxic activity. The structural properties of FP and FNa samples were investigated by FT-IR and high resolution 1H- and 13C-NMR spectroscopy. From a group of various G- and G+ bacteria the antibacterial effects were highest against the G + B. cereus. FNa was the better antioxidant shown by the lower EC50 values of DPPH scavenging ability, ferric-reducing antioxidant power and ferrous ion-chelating ability. Ferric-reducing antioxidant power and ferrous ion-chelating ability were mostly linked to total polysaccharides, total- and beta-glucan content, as well as total protein content. Both extracts displayed a moderate dose dependent antiproliferative action towards malignant human breast cancer MDA-MB-453, cervical adenocarcinoma HeLa and myelogenous leukemia K562 cells not observed in the non cancer derived MRC-5 fibroblasts. The highest effect was found in HeLa cells for FP extract. The mean diameter of Ca-alginate bead loading FP was 960.7 mu m while the mean diameter of beads encapsulating FNa extract was 1051.7 mu m.