The additive and synergistic antimicrobial effects of select frankincense and myrrh oils – a combination from the pharaonic pharmacopoeia
Article first published online: 20 FEB 2012
© 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology
Letters in Applied Microbiology
Volume 54, Issue 4, pages 352–358, April 2012
How to Cite
de Rapper, S., Van Vuuren, S.F., Kamatou, G.P.P., Viljoen, A.M. and Dagne, E. (2012), The additive and synergistic antimicrobial effects of select frankincense and myrrh oils – a combination from the pharaonic pharmacopoeia. Letters in Applied Microbiology, 54: 352–358. doi: 10.1111/j.1472-765X.2012.03216.x
- Issue published online: 9 MAR 2012
- Article first published online: 20 FEB 2012
- Accepted manuscript online: 31 JAN 2012 02:59AM EST
- 2011/1950: received 18 November 2011, revised 19 January 2012 and accepted 19 January 2012
- antimicrobial activity;
Aims: The in vitro antimicrobial activity of three essential oil samples of frankincense (Boswellia rivae, Boswellia neglecta and Boswellia papyrifera) and two essential oil samples of myrrh and sweet myrrh (Commiphora guidotti and Commiphora myrrha), collected from different regions of Ethiopia, was investigated independently and in combination to determine their anti-infective properties.
Methods and Results: The microdilution minimum inhibitory concentration (MIC) assay was performed, whereby it was noted that generally Cryptococcus neoformans (MIC values in the range of 0·8–1·4 mg ml−1) and Pseudomonas aeruginosa (MIC values in the range of 0·5–1·3 mg ml−1) often appeared to be the most susceptible micro-organisms against oils of both Boswellia and Commiphora spp. When assayed in various combinations, the frankincense and myrrh oils displayed synergistic, additive and noninteractive properties, with no antagonism noted. When investigating different ratio combinations against Bacillus cereus, the most favourable combination was between B. papyrifera and C. myrrha. The composition of the oils was determined by gas chromatography coupled to mass spectrometry (GC–MS) to document the specific chemotypes used in the study, and the chemical profiles were found to be congruent with previously reported data.
Conclusions: The majority of interactions identified synergistic and additive effects, with strong synergism noted between B. papyrifera and C. myrrha.
Significance and Impact of the Study: Frankincense and myrrh essential oils have been used in combination since 1500 bc; however, no antimicrobial investigations have been undertaken to confirm their effect in combination. This study validates the enhanced efficacy when used in combination against a selection of pathogens.