Chemical and cytotoxic analyses of brown Brazilian propolis (Apismellifera) and its invitro activity against itraconazole-resistantSporothrix brasiliensis.

Abstract

This study aimed to evaluate the chemical composition and cytotoxic activity of brown Brazilian propolis and its invitro activity against itraconazole-resistant Sporothrix brasiliensis from animal sporotrichosis. Propolis was acquired commercially and prepared as a hydroalcoholic extract. Chemical analysis was evaluated by liquid chromatography coupled to mass spectrometry of ultra-efficiency. The cell viability was evaluated by MTT test in MDBK cells of 50 to 0.09μg/mL. For antifungal tests, twenty isolates of Sporothrix brasiliensis from dogs (n=11) and cats (n=9) with sporotrichosis were tested to itraconazole (16-0.0313μg/mL) and to propolis (3.125-0.09mg/mL) by broth microdilution technique (CLSI M38-A2), adapted to natural products. The results were expressed in minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). Itraconazole showed activity between MIC values of 0.25 to greater than 16μg/mL, and 88.9% (08/09) and 72.7% (08/11) of S.brasiliensis from cats and dogs, respectively, were considered itraconazole-resistant. All Sporothrix brasiliensis were sensitive to brown propolis between MIC values of 0.19-1.56mg/mL, including the itraconazole-resistant isolates, whereas the MFC values of propolis were from 0.78 to greater than 3.125mg/mL. Propolis maintained a medium to high cell viability between concentration of 0.78 to 0.09μg/mL, and p-coumaric acid was the major compound. Brown Brazilian propolis is a promising antifungal candidate against sporotrichosis and more studies need to be undertaken to evaluate its safe use to understand its efficacy.