Comparison of antibacterial effect of Thymbra spicata’s essential oils with common therapeutic antibiotics

Human beings have always used plants to cure diseases. Recently, some researches have revealed that Thymbra spicata’s essential oils contains Carvacrol and Thymol both of these compounds have anti-bacterial effects. In this study, we aimed to investigate the anti-bacterial properties of the essential oil of Thymbra spicata a native plant of Ilam province.

Plant was collected from the Zagros mountains, Ilam province, Iran. After identification, essential oils were obtained using Clevenger. Different concentrations of the oils were prepared and inhibitory effect noted on 10 pathogenic bacteria by disc diffusion results were compared with the effect of selected antibiotics and also with DMSO which was used as control. MIC and MBC were determined.

The maximum zones of inhibition was observed on E. faecalis 2321 in 500 µl/ml of essential oil, and the minimum zone of inhibition was related to S. typhi in the same concentration. In addition, the results obtained using MIC and MBC showed that the minimum MIC (7 µl/ml) was seen on the growth of E. faecalis 2321 and the maximum MIC (60 µl/ml) was related to S. typhi and S. aureus 1885.

The results revealed that Thymbra spicata’s essential oil had a stronger inhibitory effect on the micro-organisms under investigation than the commonly used antibiotics. The average zone of inhibition showed that there was no significant difference between the inhibition zone of gram positive and gram negative bacteria. Keywords: Thymbra spicata, essential oil, antibacterial, antibiotic.