Chemical ​Composition and in ​Vitro ​Antibacterial ​Effect of Ziziphora clinopodioides ​Essential ​Oil

Background: Plants of genus Ziziphora are widely used as carminative, stomach tonic, expectorant and antiseptic in different parts of Iran. The aim of the current study was to determine chemical composition of Ziziphora clinopodioides essential oil and evaluate its antibacterial activity against common food-borne pathogens (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium and Escherichia coli O157:H7) with broth micro-dilution and agar disk diffusion methods. Methods: The chemical composition of the essential oil was identified and quantified using gas chromatograph coupled with mass spectrometer detector (GC-MS). The antibacterial activity of Z. clinopodioides essential oil was evaluated by micro-dilution method in BHI broth medium and agar disk diffusion assay. Results: According to results of GC-MS analysis, carvacrol (64.2%) followed by thymol (19.2%), p-cymene (4.8%) and ɣ-terpinene (4.6%) were the abundant components of the essential oil. The results revealed that the essential oil exhibited strong levels of antibacterial activity against all the tested microorganisms. Regarding the MIC and MBC values, S. typhimurium and E. coli O157:H7 were more resistance to the essential oil than the other bacteria. Conclusions: Our findings indicated that Z. clinopodioides essential oil had a potential to be applied as antimicrobial agent.