Antimicrobial activity of essential oil and aqueous and ethanol extracts of Teucrium polium L. subsp. gabesianum (L.H.) from Tunisia

The antimicrobial effects of essential oil, ethanol and aqueous extracts of Teucrium polium L. were investigated against 13 microorganisms. Extracts and essential oil were obtained from maceration, decoction and hydrodistillation respectively. Samples were tested for their antimicrobial activity using the disk diffusion, the agar dilution and the agar incorporation method. Essential oil was analysed using GC/MS, results showed that β-pinene (35.97%) and α-pinene (13.32%) were the main components. Furthermore, essential oil exhibited the highest antimicrobial activity, it was most effective against Proteus mirabilis, Staphylococcus aureus and Citrobacter freundei where inhibition zone ranged between 15 and 25 mm, and with the microbial inhibitory concentration (MIC) values of 0.078–0.156 mg/ml. The oil and ethanol extract showed the best antifungal activity against Microsporum canis, Scopulariopsis brevicaulis, and Trichophyton rubrum with the inhibition percentage (I%) ranging from 18.94 to 100%. However, none of the samples exhibited antifungal activity against Aspergillus fumigatus. In this study, the obtained results showed significant effects of essential oils and ethanol extracts of T. polium which may used as a substitute to the synthetic drugs against certain microbial diseases.