Resumo

Cladosporium carrionii is the most important pathogen of the genus Cladosporium, due to numerous cases of diseases caused by this fungus in worldwide, with a recognized agent of chromoblastomycosis, phaeohyphomycoses and allergic conditions. Infections caused by C. carrionii are chronic and appear as mycosis of the skin, subcutaneous tissues and nail. Toxic and unwanted effects of drugs of choice for treating fungal infections arouse the interest for research on medicinal plants with antifungal activity. Thus, this study aimed to evaluate the in vitro antifungal activity of essential oil of Cymbopogon nardus (citronella) and its major constituent, the citronellal. The minimum inhibitory concentrations (MICs) of citronella essential oil, citronellal and itraconazole (the standar antifungal used in the trials) were determined by the microdilution method. Assays of antifungal activity were performed by measure of radial growth at different time intervals, inhibition of conidial germination and assessment of morphological changes. The essential oil of C. nardus, the citronellal and intraconazole had their MICs set at 64 μg/mL, 32 μg/ mL e 32 μg/mL, respectively, and these values agreed for the two strains tested: C. carrionii LM- 01 and C. carrionii URM- 5109. Both the essential oil as citronellal induced inhibition of radial mycelial growth from a concentration- dependent manner; both induced significantly the amount of germinated conidial and microscopic morphological changes (decreased conidiation and structural changes in the hyphae of the tested strains) were observed after exposure to oil and also to citronellal. The results of our study encourage the determination of in vivo antifungal activity of citronella essential oil and citronellal, wich may represent a new possibility in the arsenal of products for treatment of mycoses caused by Cladosporium carrionii. Sponsory agency: CNPq