Avaliação da atividade antifúngica do extrato etanólico de Annona crassiflora Mart. frente as cepas de Candida albicans

Abstract

Given the high prevalence of oral candidiasis, as well as the limitations of commercially available synthetic antifungals, either in terms of side effects, availability, and degree of susceptibility of Candida albicans strains in patients, especially immunosuppressed patients, if necessary the search for new products for the treatment of the disease. Plant extracts may be promising therapeutic agents. Thus, it is essential to intensify research in order to make better use of biodiversity to combat fungal infections. The aim of this study was to evaluate the antifungal activity of ethanolic extract of Annona crassiflora Mart., facing the strains of Candida albicans. Determination of Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC), interference on microbial growth kinetics, mechanisms of action on the fungal cell wall and membrane, antifungal activity on the biofilm, cytotoxic effects on human erythrocytes. In antifungal activity assays, the ethanolic extract of A. crassiflora Mart showed MIC and MFC ranging from 256 µg/mL to 1024 µg/mL. In the microbial death kinetics assay, the extract showed fungicidal activity by inhibiting the growth of yeast tested at the end of the 24 h period, without being time dependent and with growth inhibition effectiveness directly proportional to the concentration used. It has been observed that the mechanism of action is not by damage to the cell wall, nor via exogenous ergosterol metabolism. It has also been shown that the extract is not cytotoxic in human erythrocytes. Anti-biofilm action was shown by reducing the number of viable microorganisms in mature biofilm. From the results obtained, it follows that the ethanolic extract of A. crassiflora Mart may represent a new therapeutic option in the control of C. albicans.