Characterization and Antifungal Activity of Essential oil of Cymbopogon citratus: Special Emphasis on Preliminary Fungicidal Mechanisms against Candida auris and Cryptococcus neoformans

In 2022, the World Health Organization published a list highlighting Candida auris and Cryptococcus neoformans as among the priority pathogens in need of new therapeutic alternatives. The essential oil of Cymbopogon citratus (EOCC) is used in folk medicine for its various properties, including antimicrobial activity. However, there are few reports of its activity against these yeasts and the possible action mechanism. EOCC was characterized by gas chromatography combined with mass spectrometry. Antifungal activity was determined by broth microdilution against C. parapsilosis ATCC 22,019, C. krusei ATCC 6258, C. auris 01256P, fluconazole-resistant C. albicans and C. neoformans strains. The possible mechanism of action of EOCC against C. auris and C. neoformans was investigated by flow cytometry and the alkaline comet assay. EOCC contained as major chemical compounds β-pinene (4.50%), neral (32.80%), geraniol (8.13%) and geranial (41.29%). EOCC had minimum inhibitory concentration (MIC50) of 32 to 256 µg/mL against Candida spp. and 32 to 128 µg/mL against C. neoformans. The antifungal effects of EOCC may be related to the high presence of neral and geranial detected in its phytochemical composition. The mechanism of action appeared to be related to mitochondrial dysfunction, an increase in reactive oxygen species and damage to fungal DNA, leading to apoptosis-like cell death.