Chemical composition and antimicrobial activity of the essential oil of Lippia grandis Schauer (Verbenaceae) from the western Amazon

Lippia grandis Schauer is an aromatic plant that has been used as a spice in Brazilian culinary and in traditional medicine to treat liver disease, disorders of the stomach and throat infections. We determined the chemical composition of the essential oil of L. grandis and evaluated its potential for the treatment of clinically-important pathogenic micro-organisms. The essential oil was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), giving carvacrol (37.12%), ρ-cymene (11.64%), and thymol (7.83%) as the main components. The agar disk diffusion method of the essential oil was effective against 75% of the micro-organisms analyzed, in particular, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. The minimum inhibitory concentration was 0.57 mg/ml for E. faecalis and 1.15 mg/ml for all the other strains. The results indicate that the essential oil of L. grandis contains chemical compounds with good potential for the treatment of infections.