Chemical Composition andIn VitroAntibacterial Activity ofMentha spicataEssential Oil against Common Food-Borne Pathogenic Bacteria
The aim of the present study was to investigate chemical composition and antibacterial activity of essential oil from the leaf ofMentha spicataplant against common food-borne pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium, andEscherichia coliO157:H7). Chemical composition of the essential oil was identified by gas chromatography coupled with mass spectrometer detector (GC-MS). The antibacterial activity of the essential oil was evaluated by broth microdilution method and agar disk diffusion assay. According to the result of GC-MS analysis, 18 components were identified, accounting for 99.89% of the whole essential oil. The main components were carvone (78.76%), limonene (11.50%),β-bourbonene (11.23%),cis-dihydrocarveol (1.43%),trans-caryophyllene (1.04%), menthone (1.01%), menthol (1%), and terpinen-4-ol (0.99). The essential oil exhibited moderate level of antibacterial activity against all test microorganisms. In general, Gram-positive bacteria were more susceptible toM. spicataessential oil than Gram-negative bacteria.L. monocytogeneswas the most sensitive of the microorganisms to the antibacterial activity ofM. spicataessential oil (inhibition zone = 22 mm and MIC and MBC = 2.5 µL/mL). Based on our results, the essential oil ofM. spicataplant collected from Kermanshah province, west of Iran, has a potential to be applied as antibacterial agent.