Evaluation of Physicochemical and Antimicrobial Properties of Nanoliposomes Containing Kakuti (Ziziphora Clinopodioides) Essential Oil

The encapsulation of essential oils in nanoliposomes is an effective method for protecting them from light, oxygen and chemical degradation. In this study, nanoliposomes containing kakuti essential oil were prepared from different concentrations of lecithin-cholesterol (60:0, 50:10, 40:20 and 30:30 mg) by thin-layer hydration-sonication method. The GC-Mass spectroscopy method was used to study essential oil composition and the results showed that Pulegone (49.05%) was the main component of essential oil. Particle size, poly dispersity index (PdI), zeta potential, and the encapsulation efficiency were evaluated to determine the physical properties. Antibacterial activity of nanoliposomes against E. coli O157H:7 were investigated using a disk diffusion agar method, the minimum inhibitory concentration (MIC) and minimum bactricidal concentration (MBC). The size of particles and PdI were in the range of 88.60-121.97 nm and 0.114-0.169, respectively. The results showed that using the highest concentration of cholesterol for preparing of nanoliposomes containing essential oil increased the size and PdI, but reduced the encapsulation efficiency. Cholesterol concentration did not have a significant effect on zeta potential, and only the sample containing 30 mg of cholesterol had a higher zeta potential. MIC and MBC of cholesterol-free nanoliposomes containing essential oils were 14 and 14 μg/ml and for the control sample (free essential oil) were 15 and 30 μg/ml, respectively. The antimicrobial activity of nanoliposomes decreased with increasing cholesterol levels in the samples. The results of this study showed that nanoliposomes could be a suitable carrier for kakuti essential oil to control the growth of E. coli.