EVALUATION OF THE ANTIFUNGAL ACTIVITY OF EXTRACTS FROM DALEA PAZENSIS RUSBY

MELISA NEGRO; BEDOYA EINY; GABRIELA ORTEGA; MARIANA PERALTA,

Congreso; 2° Congreso de Ciencia, Biodiversidad y Sustentabilidad.; 2023

AUGM-UFMG

Dalea pazensis Rusby is an endemic species from Bolivia. Previous studies determined the presence of prenylated flavonoids in the benzene extract of its roots. It has been reported that this type of compound has antifungal activity. Candida albicans is a yeast capable of producing superficial and systemic mycoses called candidiasis. Multiple drug resistance (MDR) is the main mechanism responsible for resistance in clinical strains of Candida. The objective of this study was to evaluate the antifungal activity of rising polarity extracts obtained from the roots of D. pazensis, by determining the minimum inhibitory concentration (MIC) against clinical resistant strains of C. albicans. D. pazensis was collected in the town of Yotala, Department of Chuquisaca, Bolivia. Four extracts with organic solvents of increasing polarity were obtained from the dried roots: hexane, chloroform, ethyl acetate, and ethanol. 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 was measured at 540 nm in the presence of the four extracts. Those that were active at 500 µg/ml were then evaluated at the following concentrations: 31, 64, 125, and 250 µg/ml to determine the MIC. The chloroform extract turned out to be the most active, presenting the MIC at 125 µg/ml, with percentages of inhibition of CaS and CaR growth of 58.22% and 69.65%, respectively. Likewise, at 250 µg/ml, this extract inhibited the growth of both strains by more than 90%. For the hexane and ethyl acetate extracts, the MIC values were 250 µg/ml, inhibiting 70% and 50% respectively, against CaS and Car both strains. The ethanolic extract was not active at 500 µg/ml. According to these results, the medicinal potential of the extracts of D. pazensis was evidenced, against clinical strains of C. albicans sensitive and resistant to azoles. It is proposed to deepen the phytochemical and pharmacological investigations of the most active extracts from D. pazensis roots.