In vitro activity of baicalein against Candida albicans biofilms

Candidiasis can be associated with the formation of biofilms on bioprosthetic surfaces. The intrinsic resistance of Candida albicans biofilms to the most commonly used antifungal agents has been demonstrated. Here we examined the effect of baicalein (BE) on C. albicans biofilm formation. Confocal laser scanning microscopy showed that C. albicans biofilm was inhibited and growth was predominantly composed of yeast cells and pseudohyphae. The effect of inhibition was dose-dependent. Over 70% inhibition of biofilms was observed at BE concentrations between 4 mu g/mL and 32 mu g/mL. Moreover, BE was active against different growth stages of biofilms, with 89% and 52% inhibition when BE was added at 0 h and 24 h of the incubation period, respectively. The water-hydrocarbon two-phase assay showed a decrease in cell surface hydrophobicity in the BE-treated groups compared with the control group. Consistent with this, real-time reverse transcriptase polymerase chain reaction (RT-PCR) results showed that BE-treated cells expressed lower levels of CSHI mRNA than cells grown in the absence of BE. Our data provide useful information for the development of new strategies to reduce the incidence of device-associated infections. (c) 2008 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.