Extracts from Flammulina velutipes Inhibit the Adhesion of Pathogenic Fungi to Epithelial Cells

Recently, extracts from natural sources have been tested for their antifungal properties. In this aspect, Flammulina velutipes extracts possess a significant amount of branch-chained carbohydrates with mannose moieties that, hypothetically, can reduce the adhesion.

In this study, we assessed the capacity of extracts from F. velutipes (wild-type AQF-1 and ATCC 34574 as the reference strain) to inhibit the adhesion of S. schenkii and C. albicans to epithelial cells.

The aqueous extracts from F. velutipes strains were obtained by sonication, total carbohydrate and protein was analyzed by Dubois and Lowry methods respectively. Effect of the extracts (50, 100 and 150 μg/mL) on the fungi adhesion to host cells was evaluated after 1 h interaction, and the percentage of inhibition of adhesion was measured. After of interaction the cytoskeleton from cell was analyzed with phalloidin-FITC.

The extract from strain AQF-1 (50, 100 and 150 μg/mL) inhibited the adhesion of: S. schenkii in a dose-dependent manner (4.9, 7.5 and 12.7%, respectively) and C. albicans in a dose-independent manner (5.2%). The percentage of inhibition by extracts from the strain ATCC34574 at the same concentrations, shown that are dose independent for both fungi: 3.9% for S. schenkii and 2.6% for C. albicans.

The extracts from F. velutipes inhibit the adhesion of pathogenic fungi to host cells. The mechanism molecular is unknown; however, is probably an interaction between the polysaccharides from extracts with the fungi receptors. This aspect is currently analyzed.

The yields of mycelium from two strains of F. velutipes and the extract from it were similar.Extracts from both strains have inhibited adhesion of S. schenkii and C. albicans to epithelial cells in vitro, but the extract from strain AQF-1 was more effective.The extracts have not prevented damage to epithelial cells caused by pathogenic fungi. Abbreviation Used: YPG: Yeast peptone glucose, DMEM: Dulbecco's Modified Eagle's medium, FITC: Fluorescein isothiocyanate.