Flavonoids and trypanocidal activity of Bulgarian propolis.

Acetone and ethanol extracts of two Bulgarian propolis samples (Bur and Lov) were investigated by high temperature high resolution gas chromatography coupled to mass spectrometry (HT-HRGC-MS), and their activity against Trypanosoma cruzi was evaluated. The ethanol extracts--Et-Bur and Et-Lov--showed similar composition, with a high content of flavonoids, and strong inhibitory activity against T. cruzi proliferative epimastigotes, which were more susceptible than trypomastigotes. In the presence of blood, the activity of Et-Bur or Et-Lov against trypomastigotes was similar to that of the standard drug, crystal violet. Both extracts also showed similar and significant activity against Staphylococcus aureus and Candida albicans, while being inactive against Escherichia coli. The acetone extract, Ket-Bur, was more active than Et-Bur against both forms of T. cruzi.