Antimicrobial activity of propolis and essential oils and synergism between these natural products

Probst IS (1), Sforcin JM (1), Rall VLM (1), Fernandes AAH (2), Fernandes Júnior A (1)

(1) Department of Microbiology and Immunology, Botucatu Biosciences Institute, São Paulo State University (UNESP - Univ Estadual Paulista), Botucatu, São Paulo State, Brazil; (2) Department of Chemistry and Biochemistry, Botucatu Biosciences Institute, São Paulo State University (UNESP - Univ Estadual Paulista), Botucatu, São Paulo State, Brazil.

Abstract: In the present study, Apis mellifera propolis and essential oils (EOs) obtained from aromatic plants were evaluated as alternative antimicrobials. We aimed to establish the antimicrobial activity of ethanolic extracts of propolis (EEP) from Apis mellifera and of EOs from Caryophyllus aromaticus, Zingiber officinale, Cinnamomum zeylanicum andMentha piperita against 32 Staphylococcus aureus andEscherichia coli strains from human clinical specimens. The antimicrobials were diluted in agar and the minimal inhibitory concentrations (MIC) were found whereas MIC90% values were calculated. Time-kill curve assays using mixtures containing one quarter of MIC90% for EEP with all EOs as well cinnamon EO were performed. The cinnamon EO was found to be the most efficient, with MIC90% values of 1.22 and 0.96 mg x mL-1 respectively against S. aureus and E. coli, whereas MIC90% of EEP were 1.86 and 20.12 mg x mL-1 respectively against S. aureus andE. coli. The combinations of EEP with ginger and mint EOs, and cinnamon with ginger and clove EOs, showed synergistic effects. Consequently, further studies are necessary to confirm these activities in vivo and to evaluate the phytochemical characteristics of natural products.

Key words: Apis mellifera, aromatic plants, ethanolic extract of propolis, Staphylococcus aureus, Escherichia coli.

ACKNOWLEDGEMENTS

The authors thank The State of São Paulo Research Foundation (FAPESP) and Foundation for the Development of UNESP (FUNDUNESP) for the financial support. Thanks are also due to Prof. Dr. Ricardo de Oliveira Orsi who kindly provided the samples used in the assays.

COPYRIGHT

© CEVAP 2011

SUBMISSION STATUS

Received: November 16, 2011.

Accepted: February 11, 2011.

Abstract published online: February 16, 2011.

Full paper published online: May 31, 2011.

CONFLICTS OF INTEREST

There is no conflict.

FINANCIAL SOURCE

The State of São Paulo Research Foundation (FAPESP) and Foundation for the Development of UNESP (FUNDUNESP) provided the financial grants.

ETHICS COMMITTEE APPROVAL

The present study was approved by the Ethics Research Committee (CER) of the Botucatu Medical School, São Paulo State University (UNESP - Univ Estadual Paulista), Botucatu, São Paulo State, Brazil.

CORRESPONDENCE TO

ARY FERNANDES JÚNIOR, Departamento de Microbiologia e Imunologia, Instituto de Biociências, UNESP, Botucatu, SP, Brasil. Phone: +55 14 38116058. Email: ary@ibb.unesp.br.