AmBisome and amphotericin B inhibit the initial adherence of Candida albicans to human epithelial cell lines, but do not cause yeast detachment

Abstract

Background: Candida biofilms with reduced susceptibility to conventional antifungals are sensitive to lipid formulations of amphotericin B (AMB). We examined the effect of the liposomal AMB formulation, AmBisome, and free AMB on the adherence of C. albicans to HeLa cervical carcinoma and HSC-3 oral squamous cell carcinoma cells. Material/Methods: HeLa and HSC-3 cells were incubated with three oral isolates of C. albicans either in the presence of AmBisome or AMB, or pre-incubated with yeasts and subsequently exposed to the drug. The effect of the drugs on the viability of HeLa and HSC-3 cells was determined by an Alamar Blue assay . Results: Following a 1-h incubation in the presence of AmBisome, at 1-256 μg/ml, the adherence of C. albicans to HeLa and HSC-3 cells was reduced considerably. For example at 16 μg/ml, adherence was diminished by ~66% in HeLa and by ~36% in HSC-3 cells. The susceptibility of cell-associated Candida to antifungals was decreased markedly. The reduction in adherence was between 3.3 and 13.7%, when compared to the drug-free controls. AmBisome was not toxic in the range 1-256 μg/ml, while free AMB was not toxic at 1 and 4 μg/ml to HeLa cells and at 1, 4 and 16 μg/ml to HSC-3 cells. Conclusions: AmBisome inhibited candidal attachment when present during the adherence phase but did not cause detachment of cell-associated yeasts. The effect of AmBisome on candidal adherence to HSC-3 cells was less inhibitory than that observed with HeLa cells. Candidal adherence to epithelial cells is significantly reduced when antifungal polyenes are present during the adherence phase , while cell-associated Candida is resistant to antifungals in terms of adherence. © Med Sci Monit, 2009