IDENTIFICATION OF BIOACTIVE EXTRACTS WITH ANTIFUNGAL ACTIVITY FROM Dalea boliviana Britton

NEGRO MELISA FABIANA; ORTEGA MARIA GABRIELA; SILVA MARIA FERNANDA; PERALTA MARIANA ANDREA

MENDOZA

Congreso; XL Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2022

Dalea boliviana Britton is a native species from Argentina. Previous studies determined the presence of prenylated flavonoids in the hexane extract of its roots. These compounds have been reported as antifungals against Candida albicans. This yeast is capable of producing superficial and systemic mycoses called candidiasis. Multiple drug resistance (MDR) is the primary mechanism responsible for resistance in clinical strains of Candida. The objective of this study was to evaluate the antifungal activity of extracts obtained with solvents of increasing polarity from the roots of D. boliviana against clinical strains of Candida albicans, and to determine the minimum inhibitory concentration (MIC) for those extracts that were more active. D. boliviana was collected in the department of Humahuaca, province of Jujuy, Argentina. From the dried roots, four extracts were obtained with organic solvents according to the following polarity order: hexane (DbH), chloroform (DbC), ethyl acetate (DbA), and ethanol (DbE). Soxhlet was used as the extraction methodology. The antifungal activity of the extracts was evaluated by microdilution in a 96-well plate (according to CLSI standards), on two clinical strains of C. albicans, one resistant (CaR) and the other sensitive (CaS) to azoles. The optical density at 540 nm was measured in the presence of the four extracts at a concentration of 500 µg/ml. At the concentration evaluated, the DbH, DbA, and DbE extracts showed growth inhibitions of less than 50% for both strains, while DbC inhibited the growth of CaS and CaR by 67% and 71%, respectively. The chloroform extract turned out to be the most active, so 125 and 250 µg/ml concentrations were evaluated to determine its MIC. At 250 µg/ml, it inhibited 57% and 55% for CaS and CaR, respectively, establishing this concentration as the MIC for DbC. These results allowed evidence, of the DbC extract medicinal potential, against clinical strains of C. albicans even those azole-resistant. It is proposed to deepen the phytochemical and pharmacological investigations of this extract.