Antibacterial activities of the essential oil and hydroethanolic extract from Aeollanthus heliotropioides Oliv

<p>To contribute to control bacterial infections, we proposed evaluating the antibacterial activities and modes of action of <em>Aeollanthus heliotropioides </em>essential oil and its<em> </em>hydroethanolic extract. Solvent extracts and essential oil were obtained from the aromatic plant's aerial parts by hydroethanolic maceration and hydro-distillation. The analyses of the chemical composition were performed using gas chromatography coupled with mass spectrometry. The <em>microdilution method evaluated the in vitro antibacterial potential of the essential oil and solvent extracts</em>. The Inhibition of biofilms formation was carried out using a colorimetric biofilm microdilution assay with crystal violet as a dye. The effect of extract and essential oil on the release of nucleic acids was performed using a spectrophotometric method. The time-kill kinetic assay was assessed for hydroethanolic extracts and essential oil. The extraction yield was 0.1%, and the major compounds identified in the essential oil were linalool (43.47%) and cis-α-farnesene (42.67%). The phytochemical screening revealed flavonoids, saponins, phenols, triterpenes, catechin tannins, and quinones. Minimum Inhibitory Concentrations (MICs) ranged from 2.08 mg/mL to 10 mg/mL. Concerning the modes of action, the essential oil showed its bactericidal effect at 2 hours. The reduction of <em>Escherichia coli</em> biofilms formation was found at 0.21 mg/mL. The essential oil treatments resulted in a release of nucleic acids at a concentration of 2.1 mg/mL. These results justify using the essential oil and hydroethanolic extracts of <em>Aeollanthus heliotropioides</em> as a potential source of molecules with antibacterial activity.<strong></strong></p>