Brazilian propolis: correlation between chemical composition and antimicrobial activity

Abstract

The chemical composition of ethanol extracts from samples of Brazilian propolis (EEPs) determined by HPLC and their activity against Trypanosoma cruzi, Staphylococcus aureus, Streptococcus pneumoniae, Klebisiella pneumoniae, Candida albicans, Sporothrix schenckii and Paracoccidioides brasiliensis were determined. Based on the predominant botanical origin in the region of samples' collection, the 10 extracts were separated into three groups: A (B. dracunculifolia + Auraucaria spp), B (B. dracunculifolia) and C (Araucaria spp). Analysis by the multiple regression of all the extracts together showed a positive correlation, higher concentrations leading to higher biological effect, of S. aureus with p-coumaric acid (PCUM) and 3-(4-hydroxy-3-(oxo-butenyl)-phenylacrylic acid (DHCA1) and of trypomastigotes of T. cruzi with 3,5-diprenyl-4-hydroxycinnamic acid derivative 4 (DHCA4) and 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran (DCBEN). When the same approach was employed for each group, due to the small number of observations, the statistical test gave unreliable results. However, an overall analysis revealed for group A an association of S. aureus with caffeic acid (CAF) and dicaffeoylquinic acid 3 (CAFQ3), of S. pneumoniae with CAFQ3 and monocaffeoylquinic acid 2 (CAFQ2) and of T. cruzi also with CAFQ3. For group B, a higher activity against S. pneumoniae was associated DCBEN and for T. cruzi with CAF. For group C no association was observed between the anitmicrobial effect and any component of the extracts. The present study reinforces the relevance of PCUM and derivatives, especially prenylated ones and also of caffeolyquinic acids, on the biological activity of Brazilian propolis.

Keywords: Trypanosoma cruzi; bactericidal activity; chemical composition; fungicidal activity; propolis; statistical analysis.

Figure 1.

Concentration expressed in mg g⁻¹ dried extract (mean ± standard deviation) of individual components of the ethanol extracts of Brazilian propolis samples separated by botanical origin: (A) group A; (B) group B; (C) group C.

Figure 2.

Fungicidal activity of Brazilian propolis extracts (2, 4, 8 and 16 mg ml⁻¹) expressed as diameter of inhibition in mm: (a) Candida albicans; (b) Sporothrix schenckii; (c) Paracoccidiodes brasiliensis.

Figure 3.

Bactericidal activity of Brazilian propolis extracts expressed as MIC values in µg ml⁻¹: (a) Streptococcus pneumoniae; (b) Staphylococcus aureus.

Figure 4.

Effect of the Brazilian propolis extracts against bloodstream trypomastigotes of Trypanosoma cruzi after 1 day of treatment at 4°C. The bars represent the standard deviation of at least three independent experiments. The activity of EEP-01 was higher than that of EEP-02, EEP-04 and EEP-03 (P < 0.05); the activity of EEP-07 was higher than that of EEP-052, EEP-06 (P < 0.05); the activity of EEP-9 was higher than that of EEP-8, which has higher than that of EEP-10 (P < 0.05).