Symbiotic Plant Peptides EliminateCandida albicansBothIn Vitroand in an Epithelial Infection Model and Inhibit the Proliferation of Immortalized Human Cells
The increasing number of multidrug-resistant microbes now emerging necessitates the identification of novel antimicrobial agents. Plants produce a great variety of antimicrobial peptides including hundreds of small, nodule-specific cysteine-rich NCR peptides that, in the legumeMedicago truncatula, govern the differentiation of endosymbiotic nitrogen fixing bacteria and,in vitro, can display potent antibacterial activities. In this study, the potential candidacidal activity of 19 NCR peptides was investigated. Cationic NCR peptides having an isoelectric point above 9 were efficient in killingCandida albicans, one of the most common fungal pathogens of humans. None of the tested NCR peptides were toxic for immortalized human epithelial cells at concentrations that effectively killed the fungus; however, at higher concentrations, some of them inhibited the division of the cells. Furthermore, the cationic peptides successfully inhibitedC. albicansinduced human epithelial cell death in anin vitrococulture model. These results highlight the therapeutic potential of cationic NCR peptides in the treatment of candidiasis.