Avaliação da atividade antifúngica, molecular docking e citotoxicidade do cymbopogon citratus e cymbopogon nardus frente a isolados clínicos de candida albicans na forma planctônica e biofilme.

Abstract

Brazil is a rich country on plant biodiversity, with native or well-adapted plants in abundance. Among these plants, some are used by communities, such as Cymbopogon citratus (DC). Stapf and Cymbopogon nardus (L) Rendle, these botanical specimens have in their secondary metabolism several phytochemical compounds with antifungal potential. C. albicans is a yeastlike fungus that causes many infections, among which healthcare -associated infections stand out as a problem with a great impact on public health, especially causing candidemia. The objective of this work was to evaluate antifungal activity, cytotoxicity and molecular docking of essential oils of C. citratus (Cc) and C. nardus (Cn) against clinical isolates of C. albicans in planktonic form and biofilm. Essential oils were extracted by hydrodistillation and constituents were identified by gas chromatography along with mass spectrometry. The MIC was determined by the broth microdilution method. The effect of the association of essential oil with amphotericin B was verified by the checkerboard test. The activity against the biofilm was determined through metabolism with XTT assay. Cytotoxicity assays were performed with VERO cells. Molecular docking was performed to predict the mode of oil interaction at the active yeast binding site. In the assay with planktonic cells MICs between 78.12 and 156.25 µg/mL were obtained for OECC, and for OECN 312.50 and 625 µg/ml. The checkerbo ard results showed synergism between OECC or OECN and amphotericin B. OECC inhibited biofilm metabolic activity by up to 81%, while OECN showed a reduction of up to 93%, both at a concentration of 2xMIC. The MTT assay of the essential oil of C. citratus showed cytotoxicity at tested concentrations above 250 µg/ml, while that of C. nardus did not show cytotoxicity up to a concentration of 1,000 µg/ml. In the molecular docking, interaction between some constituents and the SAP-5 protein was observed. The essential oils from the Cymbopogon specimens tested showed anti-Candida activity against planktonic and sessile cells, with potential for further application in therapy against infections caused by C. albicans.