Mechanism of action of quinoline-based ionic liquids against the pathogenesis of the fungal pathogen, Candida albicans.

Quinoline-based ionic liquids (ILs) are being evaluated for their potential antifungal activity, making them promising alternatives to traditional antifungal therapies. The peculiar properties, characteristic of the utilization of ILs, including their solvation effect, greatly influence their broad-spectrum activity against a wide range of fungal species. Thus, in this study, for the first time, to the best of our knowledge, we aim at exploring the mechanistic action of the previously synthesized quinoline-based IL, 1-hexadecylquinolin-1-ium bromide, [C16quin]Br, against the pathogenesis of the critical pathogenic fungus, Candida albicans. The impact of this compound was evaluated on C. albicans growth and biofilm formation using various biological assays. The antifungal activity and prevention of the yeast-to-hyphae transition, which is essential for virulence and biofilm formation, were demonstrated using light microscopy studies. Ultraviolet absorbance at 260 and 280 nm showed that when fungal cells were treated with IL, nucleic acid and proteinaceous material leaked out, suggesting a physically damaged cell membrane, which was further validated by scanning electron microscopy. By evaluating the solubility of fluconazole, a commercially available antifungal medication, and contrasting it with traditional solvents such as dimethyl sulfoxide, the study also stipulates the potential of [C16quin]Br as a drug carrier, contributing to replenishing the otherwise dry antifungal pipeline.