Planta Med 2019; 85(18): 1462
DOI: 10.1055/s-0039-3399829
Main Congress Poster
Poster Session 1
© Georg Thieme Verlag KG Stuttgart · New York

Gas chromatography-based metabolomics in the identification of potential anti-quorum sensing compounds in commercial essential oils

K Mokhetho
1   Tshwane University of Technology,, Department of Pharmaceutical Sciences, Private Bag X680, Pretoria 0001, South Africa
,
M Sandasi
1   Tshwane University of Technology,, Department of Pharmaceutical Sciences, Private Bag X680, Pretoria 0001, South Africa
2   Tshwane University of Technology,, SAMRC Herbal Drugs Research Unit, Faculty of Science, Private Bag X680, Pretoria 0001, South Africa
,
A Ahmad
1   Tshwane University of Technology,, Department of Pharmaceutical Sciences, Private Bag X680, Pretoria 0001, South Africa
,
Kamatou GP
1   Tshwane University of Technology,, Department of Pharmaceutical Sciences, Private Bag X680, Pretoria 0001, South Africa
,
A Viljoen
1   Tshwane University of Technology,, Department of Pharmaceutical Sciences, Private Bag X680, Pretoria 0001, South Africa
2   Tshwane University of Technology,, SAMRC Herbal Drugs Research Unit, Faculty of Science, Private Bag X680, Pretoria 0001, South Africa
› Author Affiliations
Further Information

Publication History

Publication Date:
20 December 2019 (online)

 

The increase in antimicrobial drug resistance has prompted researchers to find alternative ways to combat bacterial infections. Alternative drug targets such as anti-quorum sensing (AQS) have been identified as possible ways to reduce the risk of developing drug resistance. The aim of the research was to investigate the AQS activity of 40 commercial essential oils against Chromobacterium violaceum and identify potentially active constituents using an untargeted metabolomics approach. Chemical profiling of the oils was performed by gas chromatography coupled to mass spectrometry (GC-MS). The AQS activity was determined using the microdilution assay and spectrophotometric quantification of violacein production in Chromobacterium violaceum. Orthogonal projections to latent structures-discriminant analysis (OPLS-DA) was applied to the data in SIMCA-P+ 14.0, to investigate correlation between AQS activity and the essential oil chemistry. Possible biomarkers were identified using the S-plot. The essential oils with noteworthy AQS activity (percentage inhibition ≥ 90%) at 0.25 mg/ml were Cymbopogon sp., Citrus limon, Eucalyptus dives, Eugenia caryophyllus, Mentha sp., Myrtus communis and Pinus ponderosa. Using OPLS-DA models, eugenol, geraniol, geranial, menthol and pulegone were identified as putative biomarkers that may be associated with the activity observed. The results demonstrate the ability of essential oils to interfere with bacterial quorum sensing thus providing a possible alternative drug target to combat infections. Furthermore, with the aid of chemometrics, it was possible to identify potential bioactive constituents in essential oils with AQS ability.