Fig. 4

Inhibitory effect of Cytinus hypocystis and Cytinus ruber extracts (at concentrations ranging from 125 to 250 μg/ml) and penta-O-galloyl-β-D-glucose (abbreviated as 5-O-gall in the graph; 31.25 μg/ml) on biofilm formation of S. epidermidis ATCC 35984. The inhibitory effect was assessed by measuring the total biofilm biomass by crystal violet staining after 24 h of incubation with the extracts. Control (CTRL) represents untreated bacteria. Concentrations are expressed in μg/mL. Dashed lines represent 50% reduction in biofilm biomass as compared to untreated controls. Data are reported as mean ± standard error of at least three independent experiments. ∗∗p < 0.01; ∗∗∗p < 0.001 (one-way ANOVA followed by Tukey-Kramer post hoc test)