Myricetin Disturbs the Cell Wall Integrity and Increases the Membrane Permeability of .

The fungal cell wall and membrane are the principal targets of antifungals. Herein, we report that myricetin exerts antifungal activity against by damaging the cell wall integrity and notably enhancing the membrane permeability. In the presence of sorbitol, an osmotic protectant, the minimum inhibitory concentration (MIC) of myricetin against increased from 20 to 40 and 80 μg/ml in 24 and 72 h, respectively, demonstrating that myricetin disturbs the cell wall integrity of . Fluorescence microscopic images showed the presence of propidium iodidestained cells, indicating the myricetin-induced initial damage of the cell membrane. The effects of myricetin on the membrane permeability of cells were assessed using crystal violet-uptake and intracellular material-leakage assays. The percentage uptakes of crystal violet for myricetin-treated cells at 1×, 2×, and 4× the MIC of myricetin were 36.5, 60.6, and 79.4%, respectively, while those for DMSO-treated cells were 28.2, 28.9, and 29.7%, respectively. Additionally, myricetin-treated cells showed notable DNA and protein leakage, compared with the DMSO-treated controls. Furthermore, treatment of cells with 1× the MIC of myricetin showed a 17.2 and 28.0% reduction in the binding of the lipophilic probes diphenylhexatriene and Nile red, respectively, indicating that myricetin alters the lipid components or order in the cell membrane, leading to increased membrane permeability. Therefore, these data will provide insights into the pharmacological worth of myricetin as a prospective antifungal for treating infections.