Design of Nanoemulsions Containing Essential Oil of Artemisia Kopetdaghensis: Investigation of Antioxidant Properties and Antimicrobial Activity on Two Isolates from Clinical Specimens

The Artemisia plant is known by its scientific name, which is the exclusive species of Kopeh Daghi in Iran. The present study aimed to design a nanoemulsion of the essential oil of Kopeh Daghi and investigate its antimicrobial activity on the gram-negative bacteria Escherichia coli and the gram-positive bacteria Staphylococcus aureus.

At first, the essential oil extraction was performed using a Clevenger. Nanoemulsion was prepared by a spontaneous method using Tween 80 as oil in water. The size of nanoparticles was determined using the dynamic light scattering method. The antioxidant and antibacterial effects of Nanoemulsion at a concentration of 15% of essential oil were investigated.

In the current research, 38 compounds were identified in the species of Artemisia kopetdaghensis, of which Davanone, with 28.89%, was the most effective substance. The results of the antioxidant test demonstrated that pure essential oil (IC₅₀= 7.05 mg/ml) and Nanoemulsion containing essential oil (IC₅₀= 46.51 mg/ml) had the highest antioxidant activity, respectively. Furthermore, regarding the inhibition of bacterial growth, Nanoemulsion was the most effective in Staphylococcus aureus with a non-growth zone diameter of 8 mm. In Escherichia coli, pure essential oil was the most effective, with a non-growth zone diameter of 9 mm.

In general, the antibacterial properties of 15% nanoemulsion were better compared to 15% essential oil. Moreover, Nanoemulsion containing the medicinal plant essential oil had more antioxidant properties compared to 15% essential oil