Investigation of Chemical Compounds and Antibacterial Activity of Tarragon (Artemisia dracunculus) Essential Oil on Some Pathogenic Bacteria In Vitro

Tarragon (Artemisia dracunculus) as a valuable medicinal plant is extensively used in traditional medicine. Bacterial resistance to antimicrobial agents, is one of the important problems in medicine. The aim of this study was to identify the chemical compounds of Artemisia dracunculus essential oil and evaluation of its antibacterial activity on Listeria innocua, Staphylococcus epidermidis, Salmonella typhi, and Enterobacter aerogenes in vitro.
In this experimental study, the Artemisia dracunculus essential oil, was extracted using hydrodistillation method. The components of the essential oil, were identified by gas chromatography/mass spectrometry (GC/MS) device. Disk diffusion method was used to measure the diameter of the inhibition zone, and broth microdilution method was used to determine the minimum inhibitory concentration (MIC). The minimum bactericidal concentration (MBC), was determined using tubes or wells, where no color change was observed.
In this investigation, 18 compounds, were identified in Artemisia dracunculus essential oil. The major compound of the essential oil was p-Allylanisole. The diameter of inhibition zone for bacteria Listeria innocua, Staphylococcus epidermidis, Salmonella typhi, and Enterobacter aerogenes, were obtained 11.2, 14.2, 9.80 and 8.10 mm, respectively. MBC of Artemisia dracunculus essential oil for Staphylococcus epidermidis and Listeria innocua, was 9.2mg/ml and for Salmonella typhi and Enterobacter aerogenes, was 36.8 and 73.6mg/ml, respectively.
According to the results of this study, the Artemisia dracunculus essential oil has antibacterial effect, which is lower in comparison with antibacterial effect of vancomycin and gentamicin antibiotics. Therefore, further researches are required for clinical application of the essential oil.