Antibacterial Effects of Essential Oils of Lavandula and Rosemary on Staphylococcus aureus: In vitro and Animal Model
Antibacterial Effects of Essential Oils of Lavandula and Rosemary on Staphylococcus aureus: In vitro and Animal Model
Nader Kazemi,1,*Mahdi Arfaei,2Sahar Rasouli,3
1. Nanobiotechnology Research Center, Zanjan Branch, Islamic Azad University, Zanjan, Iran. 2. Department of Biology, Faculty of Basic Sciences, Zanjan Branch, Islamic Azad University, Zanjan, Iran. 3. Department of Biology, Faculty of Basic Sciences, Zanjan Branch, Islamic Azad University, Zanjan, Iran.
Introduction: Infectious diseases are one of the most common diseases around the world which impose enormous financial burden on society. Staphylococcus aureus is an important cause of nosocomial infections and multidrug resistance. Although synthetic antibiotics have been able to play an important role in treatment of infectious diseases in past decades, however problems related to microbial resistance of antibiotics have caused that the medical plants to be considered as an alternative.
Methods: In this study, essential oil was prepared from dried leaves of the Lavandula angustifolia and Rosmarinus officinalis, then anti-bacterial activities of the essential oil for Staphylococcus aureus was experimented, first by the method of well diffusion in agar, and later the amount of the MIC and MBC of the essential oils were measured by broth dilution method. In animal model study, first 5×105 CFU/ml of bacteria was intraperitoneally injected and after 24 hours, 0.5ml (as MBC concentration of each the essences) of essential oils, to female BALB/c mice was intraperitoneally injected. Then, the counting of bacterial colonies in spleen were determined with cultivation on Mueller Hinton agar after 7 days as the standard protocol.
Results: The experiment results concerning the determination of growth inhibition diameter in agar showed that the maximum of growth inhibition diameter is related to the essential oil of Lavandula angustifolia (30 mm), and the minimum of growth inhibition diameter is related to essential oil of Rosmarinus officinalis (10 mm) at the highest concentration (400 mg/ml). In conditions of in vivo, spleen supernatant cultivation, the average number of bacteria for Lavandula angustifolia and Rosmarinus officinalis essential oil were 2×102 CFU/ml and 6×102 CFU/ml respectively. These results showed significantly decrease in number of bacteria in all experimental groups (p˂0.5) compared to control group.
Conclusion: In general, the results of evaluations in experimental conditions and the animal model showed that the essential oils of Lavandula angustifolia and Rosmarinus officinalis have the effective antibacterial activity against mentioned bacteria and can be useful to treatment of nosocomial infections.