CHEMICAL COMPOSITION AND ANTIBACTERIAL ACTIVITY OF ESSENTIAL OIL FROM Melissa officinalis leaves

This study was designed to determine chemical composition and antibacterial activity of essential oil from Melissa officinalis leaves. The essential oil was obtained by hydro-distillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Antibacterial activity was evaluated by micro-dilution and disk-diffusion methods. The GC-MS analysis of the essential oil revealed 48 compounds in which D-Limonene, Cyclohexanone, 2-Methyl-5-isopropenyl-2cyclohexenone,Geraniol and 2-Cyclohexen-1-one, 2-methyl-5-(1-methylethenyl)-, (R)(CAS) and α-Terpinolene, β-Pinene were the main compounds. Results of disk diffusion method showed inhibition zones of 25.88, 21.33, 16.44 and 12.33 mm respectively against B. cereus, S. aureus, E. coli andS. enterica. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of Melissa officinalis essential oil against the mentioned bacterial species were respectively 1.04, 3.64, 4.42 and 25 and 1.3, 4.68, 8.33, 25mg/ml. Our findings show significant antibacterial activity for this herbal essential oil which suggests its capacity as a natural food preservative against food-born pathogens.