Volatiles Derived from Plants Offer Solution against Antifungal Drug Resist
Despite advances in preventive, diagnostic, and therapeutic interventions, invasive fungal infections cause significant morbidity and mortality in immunocompromised patients. The burden of antifungal resistance in such high-risk patients is becoming a major concern.
Now, in an attempt to combat this, researchers at the VIB-KU Leuven Center for Microbiology in Belgium have developed a novel screening method for identifying antimicrobial properties in certain plant-derived volatile substances.
The research project, led by prof. Patrick Van Dijck, is rooted in the growing problem of antifungal drug resistance. Candida cells, for example, are quickly becoming tolerant to fluconazole, the most-used antifungal drug. Next to exploring experimental new techniques, scientists also seek to repurpose existing substances. Plant essential oils (EOs), metabolites obtained by steam distillation or cold citrus peel pressing, may offer interesting opportunities: they are made up of compounds that help protect the plant against microbial or herbivore attacks.
The team collected 175 different essential oils onstituting a collection of over one thousand different small molecules. The aim was to identify biologically active compounds present in these complex mixtures. They therefore developed a new class of assay that allowed to identify new volatile substances with antifungal activities over a distance.
Prof. Patrick Van Dijck (VIB-KU Leuven): “We screened our whole collection of EOs for vapor-phase mediated antifungal activity against two human fungal pathogens, Candida albicans and Candida glabrata. Interestingly, we found that approximately half of the EOs and their compounds had vapour-phase-mediated activity against bothCandida species. Surprisingly, C. glabrata, the most drug-resistant species of the two was on average even more susceptible. In contrast, none of the currently used antifungals showed any vapour-phase-mediated activity.”
Co-author Adam Feyaerts (VIB-KU Leuven): “Our findings are for instance a starting point for the development of molecules that could also be used in vaporizers. After all, volatiles can access otherwise hard to reach areas. Think of possibilities such as maintaining hygiene in hospitals or treat patients with lung infections. There are agricultural options too, such as preventing post-harvest contamination or protecting crops against pests.”