Resumo

Nowadays there are several medicines widely employed on antimicrobial therapy. However, because of the increase of the multidrug-resistant microorganisms, the research for new therapeutic alternatives is growing. In this scenario, the propolis, a natural product made by bees from resins exudates and plant parts, is the one among the most studied recognized by many biological activities. The aim of this study was to evaluate the antimicrobial activity of propolis from Minas Gerais State, Brazil, correlating with physic-chemistry indicators. For this purpose, fifteen samples of green, brown and black propolis were collected from different regions and submitted to hydroalcoholic extraction. The antifungal activity of these extracts was analyzed against two species of yeasts, Candida albicans ATCC 36802 e Candida krusei ATCC 6258, relevant human pathogens, by Minimum Inhibitory Concentration (MIC) methodology. The physico-chemical indicators evaluated were: dry extract (w ⁄v), wax percentage (%), oxidation index (seconds) and phenolic and flavonoid compounds index (w⁄w). Of the 15 samples, 87% showed positive antifungal activity against C. albicans and 54% against C. krusei , with MIC values ranging from 250 to 1000 &mug⁄mL. Only two propolis samples showed the same MIC values for both yeasts evaluated. The physico-chemical indicators showed a great variation among samples, and the mean and standard deviation (sd) of these parameters were: dry extratc 15,12% (sd=5,75), wax index 3,02% (sd=2,57), oxidation index 1,0 s (sd=0), phenolic and flavonoid compounds, which showed a strong positive correlation, 2,27% (sd=1,02) and 0,80% (sd=0,4), respectively. These results demonstrate the relevant activity of propolis from different origins against yeasts, and contribute to novel formulations for treatment of infections caused by these pathogens, mainly for topic use.