Chemical composition and antibacterial activity of essential oils extracted from plants cultivated in Mexico

Samples of lavender, rosemary and laurel essential oils obtained from plants cultivated in Mexico were analysed by GC-MS using a non polar capillary column. Characterisation of individual components was performed using a commercial mass spectrometry library, and 53 components were identified. The analysis of bioactive compounds highlighted a 5 and 2-fold increased quantity of potent antibacterial 1,8-cineole (46.5%) and camphor (12.3%) in lavandin “provence”, compared to the French cultivars. It also showed a 3- and 2-fold increase in camphor and linalool concentration in rosemary and laurel compared to the average level, making them promising alternatives for medicinal treatment. Strains of Gram-positive and Gram-negative bacteria were analyzed for their susceptibility to these essential oils using the agar disc diffusion method and their antimicrobial activity was demonstrated. To our knowledge, this is the first report on antibacterial activity of lavender essential oil, recently added to the Mexican pharmacopeia, against Mycobacterium smegmatis (Mc Rv 3782 PW2).