Brazilian propolis: Physicochemical properties, plant origin and antibacterial activity on periodontopathogens

Propolis samples collected in the dry and rainy seasons, from an experimental apiary located in a cerrado vegetation region in Brazil were used in this study. Microscopic analysis showed the presence of 31 pollen types, secretory hairs (genus Baccharis) and fragments of plant epidermis. The oxidation rates and the wax content of the samples after physicochemical analyses were in agreement with the Cuban Guideline NRAG 870-88. A high performance liquid chromatography analysis showed a similar pattern of chromatograms, characterized by the presence of ten phenolic compounds. There was no significant difference in the profile of phenolic compounds and also in the total flavonoid concentration in propolis samples collected in different seasons. Antibacterial assays were performed by the method of dilution of an ethanol extract of propolis (EEP) in agar (v/v%) and showed that all 16 A. actinomycetemcomitans strains tested were inhibited by propolis concentrations of 0.1% to 0.25%, and did not grow at all at 0.5%. The growth inhibition of six Fusobacterium spp. and 16 black-pigmented anaerobes was observed at concentrations of 0.05% to 0.1%, and no growth was observed at 0.25%. There was no effect of seasonality on the inhibitory activity of propolis. The antibiotics tetracycline and meropenem were used as positive controls. Copyright (C) 2003 John Wiley Sons, Ltd.