Atividade antifúngica, antibiofilme e antioxidante do óleo essencial de Citrus deliciosa Tenore

Abstract

Plants and their metabolites have been used in folk medicine for years to treat various diseases. Plant essential oils are volatile, lipophilic, and aromatic substances, presenting several therapeutic properties, which have been extensively explored. Infectious diseases, as well as other diseases that involve an increase in the production of free radicals, have been increasingly worrying about the population. Especially due to the severity of these diseases, and the few therapeutic options, studies with natural substances appear as a new alternative for the treatment of these diseases. Given the above, this study aimed to evaluate the chemical composition, antifungal activity, antibiofilm, and antioxidant and toxicity, as well as the yield of essential oil of bergamot (Citrus deliciosa Tenore). The leaves of C. deliciosa Ten. were collected in São Francisco de Assis-RS, dried, and submitted to the hydrodistillation process to obtain the essential oil. The chemical composition of the essential oil was determined by gas chromatography. The antifungal activity against yeasts was carried out using the broth microdilution methodology and the antioxidant activity by the method of DPPH (2,2-diphenyl-1-picrylhydrazil) and FRAP (iron ion reduction power). The analysis of antibiofilm activity was performed using the violet crystal method. Cytotoxicity was assessed using the MTT methodology (3- (4,5-dimethyl-2-thiazolyl) -2,5-diphenyl-2H-tetrazolium bromide). The extraction of the essential oil of C. deliciosa Ten. obtained a yield of 0.97% ± 0.04. The chromatographic profile of the essential oil revealed 12 substances (making up 100% of the oil composition), being methyl N-methyl anthranilate (75.1%), γ-terpinene (13.8%) and dl-Limonene (7%) the majority substances. The oil of C. deliciosa had antifungal action against all tested yeasts, with promising action against Cryptococcus neoformans, Cryptococcus gattii, and Trichosporon asahii. This compound was also able to inhibit the biofilm production of Candida albicans, Candida glabrata, Candida parapsilosis, and T. asahii. In mature biofilms, the essential oil of C. deliciosa reduced the biomass of the biofilm of C. albicans, C. glabrata, and C. parapsilosis. The essential oil of bergamot showed weak antioxidant action. It did not show cytotoxicity in human mononuclear cells at the concentrations tested. It is hoped that these results may guide future studies to produce formulations of formulations that can be used in the treatment of biofilms caused by C. albicans, C. glabrata, C. parapsilosis, and T. asahii, as well as in candidiasis, cryptococcosis and/or trichosporonosis.