Increasing the Fungicidal Action of Amphotericin B by Inhibiting the Nitric Oxide-Dependent Tolerance Pathway
AmB-induced superoxide radical accumulation, membrane permeabilization, and loss of proliferative capacity can be increased by blocking nitric oxide radical production using L-NAME. Exponential yeast cultures were treated with different concentrations of AmB in the presence or absence of 200 mM L-NAME for 3 h. (a) Levels of superoxide radical detected by dihydroethidium (DHE) fluorescence and flow cytometry. (b) Membrane permeabilization events detected by propidium iodide (PI) fluorescence and flow cytometry. (c) Number of CFU/mL in Log-scale, assessed by plating assays and CFU counting. Means and standard errors of the means (SEMs) of at least 3 independent biological experiments () are presented. Black bars represent treatment with AmB alone; white bars represent treatment with AmB supplemented with 200 mM L-NAME. Two-way ANOVA followed by Tukey multiple comparison test was performed to analyse significant differences between the two treatments. and represent and , respectively. Multiplicity-adjusted values are presented in the text.