Saibabu V, Fatima Z, Khan LA, Hameed S. Mechanistic Insights into the Anticandidal Action of Vanillin Reveal Disruption of Cell Surface Integrity and Mitochondrial Functioning.
Infect Disord Drug Targets 2021;
21:405-415. [PMID:
32614756 DOI:
10.2174/1871526520666200702134110]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/09/2020] [Accepted: 05/16/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND
Considering the emergence of multidrug resistance (MDR) in prevalent human fungal pathogen, Candida albicans, there is a parallel spurt in the development of novel strategies aimed to disrupt MDR. Compounds from natural resources could be exploited as efficient antifungal drugs owing to their structural diversity, cost effectiveness and negligible side effects.
OBJECTIVE
The present study elucidates the antifungal mechanisms of Vanillin (Van), a natural food flavoring agent against Candida albicans.
METHODS
Antifungal activities were assessed by broth microdilution and spot assays. Membrane and cell wall perturbations were studied by PI uptake, electron microscopy, plasma membrane H+ extrusion activity and estimation of ergosterol and chitin contents. Mitochondrial functioning was studied by growth on non-fermentable carbon sources, rhodamine B labeling and using retrograde signaling mutants. Gene expressions were validated by semi-quantitative RT-PCR.
RESULTS
We observed that the antifungal activity of Van was not only limited to clinical isolates of C. albicans but also against non-albicans species of Candida. Mechanistic insights revealed the effect of Van on cell surface integrity as evident from hypersensitivity against membrane perturbing agent SDS, depleted ergosterol levels, transmission electron micrographs and diminished plasma membrane H+ extrusion activity. In addition, spot assays with cell wall perturbing agents, scanning electron micrographs, delayed sedimentation rate and lower chitin content further substantiate cell wall damage by Van. Furthermore, Van treated cells underwent mitochondrial dysfunctioning via impaired retrograde signaling leading to abrogated iron homeostasis and DNA damage. All the perturbed phenotypes were also validated by RT-PCR depicting differential regulation of genes (NPC2, KRE62, FTR2 and CSM3) in response to Van.
CONCLUSION
Together, our results suggested that Van is promising antifungal agent that may be advocated for further investigation in therapeutic strategies to treat Candida infections.
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