Apicultural products like propolis and pollen have gained increased attention for their therapeutic properties. The aim of this study was to assess antibacterial properties of Egyptian propolis and pollen extracts or their mixtures which were extracted by different ethanol/water concentrations against 6 food-borne pathogenic, as well as 4 lactic acid bacterial (LAB) strains. Antibacterial activity of the extracts was evaluated by disc diffusion and microdilution method. The synergistic action of the extracts with LAB was assayed by the disc diffusion method on free agar and on agar containing sub-inhibitory concentrations of tested extracts. The obtained results indicated that the tested extracts have antibacterial activities against foodborne pathogenic bacteria. MICs of extracts for food-borne pathogenic bacteria ranged between 20-12.5 mg ml−1. Meanwhile, there was no recorded MIC against LAB strains. Moreover, some LAB strains have been stimulated at lower concentrations of extracts. The antibacterial activity of propolis extracts was higher than pollen extracts which may be due to high levels of phenolic and flavonoid compounds in propolis. In synergism assay, the antibacterial activity of some tested LAB strains have been remarkably improved by the presence of some extracts of propolis and pollen or their mixtures.
Key words: Propolis, Pollen, Antibacterial, Synergism, Antagonism, Phenolic compounds
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