Planta Med 2014; 80 - P1L48
DOI: 10.1055/s-0034-1394705

Antimicrobial activity of propolis from Beira Alta (Portugal) and analysis of the toxicity mechanism in fungi

RA Marques 1, F Baltazar 2, A Cunha 1, 3, R Oliveira 1, 3, CA Aguiar 1, 3
  • 1Department of Biology, University of Minho
  • 2ICVS – Life and Health Sciences Research Institute, University of Minho
  • 3CITAB – Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Minho

Propolis is a resinous and balsamic complex mixture produced by honey bees in their hives. This mixture has a wide range of biological properties for therapeutic applications, such as antibacterial and antifungal activities, which have been associated with the presence of high concentrations of compounds such as flavonoids, phenolic acids and phenolic aldehydes [1,2]. The spectra of antimicrobial activity vary with the geographic location of the hive, the local flora and the climate [3]. The objective of this study was to assess the antibacterial and antifungal activity of an ethanolic extract of a sample collected in Beira Alta (Pereiro; P10.EE), seeking to simultaneously contribute to the elucidation of cellular targets and mode of action. For antimicrobial activity 36 microorganisms were tested: 18 yeasts and 18 bacteria. The yeast Saccharomyces cerevisiae was selected as a biological model for the analysis of the toxicity mechanism. The propolis extract has antimicrobial activity, though apparently the antifungal activity was more relevant than the antibacterial one. Yeasts of the genus Candida (MIC = 750 µg/ml and higher) and Gram-positive bacteria (MIC as low as 500 µg/ml) displayed more sensitivity to the extract, which makes it interesting for further studies in order to isolate and characterize the bioactive compounds present in this sample of propolis. The P10.EE extract affected the inner mitochondrial membrane potential, also mutants affected in apoptosis and in the response to oxidative stress were more resistant to its toxicity, suggesting that the mode of action of the propolis sample tested may involve a direct action on the mitochondria. The results of this study are consistent with a mechanism of induction of programmed cell death by apoptosis.

Acknowledgements: This work is supported by national funds by FCT – Portuguese Foundation for Science and Technology, under the project PEst-OE/AGR/UI4033/2014.

Keywords: Propolis, antimicrobial activity

References:

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