Invitro Determination of Chemical Compounds and Antibacterial Activity of Lavandula Essential oil against some Pathogenic Microorganisms

Introduction: The lavender is one of the most widely used medicinal plants in Iran, which has been used in traditional medicine since the past. This study aimed to identify the chemical compounds and antibacterial activity of Lavandula sublepidota essential oil which is an endemic species in Iran. Materials & Methods: In this study, chemical compounds of Lavandula sublepidota essential oil were identified using gas chromatography. The inhibition zone diameter of the Lavandula sublepidota essential oil on Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and Escherichia coli was identified on a concentration of 12.5, 25, 50, and 100 mg/ml, respectively, by disk and well diffusion methods. Common antibiotics, including Ampicillin, Enrofloxacin, Gentamicin, and Kanamycin were used to compare the microbial inhibition zone diameters. Moreover, minimum inhibitory concentration (MIC) (diluted in liquid) and minimum bactericidal concentration of the aforementioned microorganisms were determined in this study. Findings: In total, 99.41% of the essential oil compounds were identified using gas chromatography. Linalool was found to be the most abundant among the identified compounds (43.3%). The most sensitive and resistant bacteria to Lavandula sublepidota essential oil were S. aureus and P. aeruginosa with inhibition zone diameter of 30.70±0.40 and 10.10±0.68 in a concentration of 100 mg/ml, respectively. Moreover, the MICs of P. aeruginosa, S. aureus, B. cereus, and E. coli were estimated at 32, 8, 16, and 16 mg/ml, respectively. Discussion & Conclusions: The results of this study revealed that Lavandula sublepidota essential oil has an acceptable antibacterial activity against the pathogenic microorganisms. However, gram-positive bacteria obtained higher antimicrobial activity of the essential oil, compared to gram-negative bacteria. It is recommended that further studies be conducted to investigate the clinical application of Lavandula sublepidota essential oil.