Antibacterial activity of essential oil of Juniperus communis L.

Abstract

Many herbal raw materials have been used for centuries as a means of treating various types of diseases. Herbal preparations in pharmaceutical forms for oral and external use show a wide range of effects, among which one of the most important antimicrobials. The effect of such herbal preparations on various microorganisms is the subject of many scientific research today, which is mainly fueled by the fact that the high use of antibiotics in more than half a century has led to resistance to microorganisms. Enriched with new results and knowledge of chemistry and the activity of active ingredients derived from plants, today we are experiencing a growing use of herbs in various industries. The Republic of Srpska has a great potential of woody greenery as a possible raw material for the production of essential oils. Therefore, the aim of this study is to define antibacterial effect of juniper berries (Juniperus communis L.) essential oil, obtained by the hydrodestilation process in industrial production conditions. A boiler with capacity of 2000 liters has been used in the hydrodistillation process (hydromodule1:3), the temperature was 102°C, pressure of 0.5 bar, and the time of hydrodistillation process was 2 hours. The yield of essential oil was 1.3 %.The antibacterial effect of the essential oil of the juniper berries was tested using the agar diffusion method on the reference cultures of Salmonella enterica WDCM 00030, Pseudomonas aeruginosa WDCM 00024, Escherichia coli WDCM 00013, Staphylococcus aureus WDCM 00032, Bacilus cereus WDCM 00151- (CEST- Coleccion Espanola De CultivosTipo, Espana), as well as clinical isolates of Providenciastuarti, coagulase positive staphylococci, streptococcus group D and Salmonella spp. from the collection of microbiological laboratory of the Veterinary Institute “Dr Vaso Butozan” Banja Luka.
The juniper berries essential oil in a concentration of 20 μl showed antibacterial activity only on the clinical isolate of coagulase-positive staphylococci with an inhibition zone of 12.00 mm, while at a concentration of 100 μl it was shown antibacterial activity on all investigated pathogens (with an inhibition zone of 8.33 mm to 18.00 mm), except on P.aeruginosa and E. coli. The research results indicate to better effect of essential oils compared to reference antibiotics.