Identification of potential anti-quorum sensing compounds in essential oils: a gas chromatography-based metabolomics approach

Quorum sensing is a form of bacterial cell-to-cell communication, which plays an important role in bacterial pathogenicity. Due to increasing drug resistance, quorum sensing has been identified as a potential target to reduce the risk of developing drug resistance. The current study aims at investigating the antiquorum sensing activity of 40 commercial essential oils of therapeutic relevance. The agar well diffusion method, microdilution assay and spectrophotometric quantification of violacein production, assessed antiquorum sensing in Chromobacterium violaceum. Gas chromatography coupled to mass spectrometry (GC-MS) profiled essential oil constituents. A correlation between antiquorum sensing activity and essential oil chemistry was investigated in SIMCA-P + 14.0. The essential oils that displayed remarkable antiquorum sensing activity (inhibition 90%) at 0.25 mg/ml were; Cymbopogon sp., Citrus limon, Eucalyptus dives, Eugenia caryphyllus, Mentha sp., Myrtus communis and Pinus ponderosa. Eugenol, geraniol, geranial, menthol and pulegone were identified as putative biomarkers correlated to the active oils.