Flavonoid-Rich Fractions of Leaves Inhibit Biofilm Formation and Hyphae Growth.

This study evaluated the effect of the extract and fractions of on planktonic growth, biofilm formation, mature biofilm, and hyphae growth. Three strains (SC5314, ATCC 18804, and ATCC 10231) were tested. The crude extract and the fractions were obtained by exhaustive percolation and liquid-liquid partition, respectively. Phytochemical analyses of extract and fractions were performed using high-performance liquid chromatography coupled with a diode-array detector and mass spectrometry (HPLC-DAD-MS). A microdilution assay was used to evaluate the effect of the extract and fractions on planktonic growth, and crystal violet staining was used to measure the total biomass of the biofilm. Hyphae growth was analyzed using light microscopy. Thirteen flavonoids were identified, with a predominance of the flavonol-3--glycoside type based on quercetin, myricetin, and kaempferol. Flavonoid-rich fractions of leaves displayed antifungal activity and inhibited both biofilm formation and hyphae growth in all the tested strains, but were not effective on planktonic growth and mature biofilm. This study indicates that flavonoid-rich fractions from leaves interfere with the virulence of species and support the use of spp. in folk medicine to treat infections.