The capacity of Lamiaceae essential oils, extracts and hydrolats against pathogenic biofilms

Abstract

The study aimed to analyse the potential of Lamiaceae essential oils, extracts, and hydrolats against bacterial biofilms. Bacterial cells Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus were exposed to Thymus vulgaris L. (thyme), Salvia officinalis L. (sage), Mentha × piperita L. (mint) essential oils, extracts, and hydrolats. The result of the minimal inhibitory concentration assessment shows the highest antibacterial potential for essential oils, followed by extracts and hydrolats respectively. The anti-biofouling capacity revealed that thyme essential oil has the highest potential for biofilm prevention for all tested bacteria, reducing up to 91% of biofilm, followed by mint (88%) and sage (87%) essential oil. While the thyme extract (84%), sage extract (83%) and hydrolat (77%) we less effective. The chemical composition of thyme essential oil showed a high percentage of monoterpene hydrocarbons and oxygenated monoterpenes, among which p-cymene and thymol were the most predominant. The bacterial cell membrane integrity assessment shows a significant increase in dead cells by increasing the concentration of thyme essential oil. The findings of our research indicate that the choice of herbal preparation significantly affects the active components, thereby influencing both antibacterial and anti-biofouling capabilities. Lamiaceae essential oils show great potential for biofilm management and represent a good candidate for antibacterial application in pharmacy, medicine, and industry.