Potencial antifúngico do extrato de própolis verde frente a leveduras do gênero Candida.

Abstract

In recent years, there has been an increase in the incidence of fungal infections by species of Candida, generating a serious public health problem. Candidiasis is an opportunistic infection that produces lesions from superficial to invasive, where the use of drugs empirically produces resistance in the strains, making treatment difficult and making it necessary to choose new therapeutic options, in which propolis due to innumerable biological characteristics has a pharmacological future. Thus, the objective was to evaluate the antifungal potential of the hydroalcoholic extract of green propolis against yeasts of the genus Candida, by two methods of detection of susceptibility. Six species of Candida ATCC were used in the research, which were kindly provided by the Oswaldo Cruz Foundation, RJ, Brazil. Initially, the isolates reactivated in Sabouraud Dextrose Agar for 72 hours and subsequently the susceptibility profile of the green propolis hydroalcoholic extract and fluconazole, tested by disc diffusion reference methods (M44-A2) and microdilution in broth (M27-A3) of the CLSI. Candida species were considered as sensitive, dose-dependent and resistant sensitive, where the breakpoints of ≤ 62.5, 125-250 and ≥ 500 μg / ml were taken into account for both tests for the hydroalcoholic extract of propolis green and ≤ 8, 16-32 and ≥ 64 μg / ml for fluconazole, respectively. In both tests, 50% inhibition considered for the hydroalcoholic extract of green propolis in relation to fluconazole. All the reactivated isolates were feasible for determination of susceptibility, where, in relation to the disc diffusion test against the green propolis extract, all the isolates were dose-dependent at the concentration of 500 μg / ml. In contrast to fluconazole, only C. tropicalis was sensitive, the others presented resistance, both in front of the disc with a concentration of 64 μg/ml. In view of the microdilution methodology, the isolates of the parapsilosis complex, C. tropicalis (CIM and CFM of 15.63 μg / mL) and C. fumata (CIM and CFM of 62.5 μg/mL); C. albicans presented dose-dependent sensitivity (MIC and CFM of 125 μg/mL). In contrast to fluconazole, only C. tropicalis was sensitive with a MIC and CFM of 8 μg/mL, the isolates of the parapsilosis complex were sensitive as a dose-dependent dose with a MIC and CFM of 32 μg/mL and the others showed resistance with an MIC e CFM of 64 μg/mL, and CFM may not be determined. Comparing the methodologies only to C. fumata behaved in a similar way against the substances. It may be concluded that the extract in question had a considerable antifungal activity, against the evaluated microorganisms, due to the presence of phenolic compounds detected by HPLC, such as 2,5-dihydroxybenzoic acid, caffeic acid, catechin, myricetin and rutin; both tests were effective in determining the antifungal activity of the substances, however, microdilution is more reliable to detect the natural extracts, because the penetration mechanisms of the secondary compounds present in the extract are better distributed in the dilution technique.