Enhancing Antibacterial Action of Origanum vulgaris Essential Oil Through Emulsions

During recent years, plant essential oils have come more into the focus of phytomedicine. Especially the antimicrobial and antioxidant activities of essential oils. The essential oil from the common herb Origanum vulgaris may be an effective treatment against dangerous and sometimes drug-resistant bacteria. Our research was centered on creating emulsions that were able to enhance the antimicrobial activity of Origanum vulgaris essential oil against pathogenic bacteria. Emulsions were prepared by making stock solutions of 100 mg/mL of Origanum vulgaris essential oil in four solvents 1. Ethanol 2. DMSO 3. Tween 20 (200 mg/mL in ethanol) 4. Tween 20 (200 mg/mL and Sunflower oil 100 mg/mL in ethanol). A sample of 100µL of each of the four stock solutions was diluted in 900µL of distilled water to form solutions or emulsions. Samples of these solutions were utilized as samples for serial dilutions. A macro-broth-dilution technique was used to determine the susceptibility of the bacteria to the essential oil of Origanum vulgaris. The MBC was determined by sub-culturing a 0.01-mL volume of the medium drawn from the culture tubes after 48h on Mueller Hinton Agar and incubated further for bacterial growth. Our research confirms that emulsions generated by Tween 20 reduced the MBC by 50%. In fact, a quantity of 0.25 mg/mL (encapsulated in micelles) showed equal or improved activity than did the pure solubilized compound at a concentration of 0.5 mg/mL.