Natural Compound-based Formulations Inhibit Candida albicans and Non-albicans Colonization

Objectives: This study aimed to evaluate the colonization of Candida spp. biofilms by analyzing their structural characteristics after treatment with natural compound-based formulations.
Methods: Biofilms of Candida albicans, Candida glabrata, Candida krusei and, Candida tropicalis were grown in glass slides containing yeast nitrogen base medium supplemented with glucose for 2 h under monoculture conditions. After the 2h-incubation, the biofilms were subjected to the following treatments: 1) tt-farnesol + apigenin; 2) naringenin and, 3) control without compound. Miconazole was used as control. After 24 h-incubation, the glass slides were washed with sterile saline to remove non-adhered cells and the viable cells adhered to the glass were immersed in 2.5% glutaraldehyde solution for 2 h at room temperature, followed by serial dehydration with ethanol up to 100 % for 10 min and drying for 45 min. Biofilms were finally gold-coated in a metallizer device for SEM examination at 1000x magnification.
Results: SEM analysis showed that all Candida species were susceptible to both experimental formulations. After a single treatment with formulations 1 and 2, a small number of cells with fewer hyphae formation of C. albicans and non-albicans species were observed, revealing the great potential of the natural compounds to cause damage to the biofilms morphology and their colonization. The structure of biofilms of C. albicans, C. glabratta, C. krusei, C. tropicalis were not affected on control group compared with the other groups.
Conclusions: The findings highlight the reduction of Candida albicans and non-albicans biofilms after treatment with natural compound-based formulations and serve as a starting point to the characterization of novel therapies for Candida spp. infections.