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Background and Objective: Thyme essential oil is strong antifungal, anti-parasitic and antibacterial due to presence phenolic thymol and carvacrol. Encapsulation is used in order to increase the solubility, protection against oxidation and evaporation and also to improve the effectiveness of essential oils. This study was performed in order to loading Thymus essential oil (Thymus daenensis Celak and Zataria multiflora species) into liposomal vesicles and evaluation of antifungal activity of Zataria multiflora specie encapsulated with nano-systems.
Methods: In this descriptive – laboratory study, liposomes containing Thymus essential oil- were prepared using thin film hydration method. After size reduction, nano-particle was characterized in term of morphology, size, zeta potential and chemical interactions. Effect of phospholipids types, cholesterol content and species of Thymus were investigated on encapsulation efficiency. Finally, the antifungal activity of essential oil of Zataria multiflora specie loaded liposome was evaluated the minimum fungicidal concentration, minimum inhibitory concentration and zone of inhibition against Trichophyton mentagrophytes.
Results: Thymus essential oil loaded into liposome with over 80% efficiency. Optimal formulation contained of 10% cholesterol, 90% soybean phosphatidylcholine phospholipid with 3% of polyethylene glycol and also Thymus essential oil with concentration of 0.5 mg/ml. Nanoparticles were anionic with spherical shape and size less than 100 nm. There was no chemical interaction between liposomes and essential oil. Prepared formulation was chemically stable and the essential oil had not retained during encapsulation. Medicinal-nano system of Zataria multiflora specie was effective in inhibition of the growth of Trichophyton mentagrophytes.
Conclusion: The preparation of optimal liposomal formulation containing Thymus essential oil is affected by the type and amount of phospholipid, and it was completely independent of the species of Thymus. Also, Encapsulation increases the anti-fungal activity of essential oil of Zataria multiflora.

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Background and Objective: Ciprofloxacin is effective against a wide range of bacteria, particularly Enterobacteriaceae. However, studies have shown that the resistance of Escherichia coli to ciprofloxacin is enhanced. Thyme is one of the medicinal plants whose essential oil has anti-microbial effects. This study was aimed to investigate the antimicrobial properties of local Thyme essential oil alone and in combination with ciprofloxacin on Escherichia coli mutant strain with intermediate resistance.
Methods: In this descriptive laboratory study, Thyme plants (10 samples) were collected from Lorestan Province, west of Iran during 2016. Theses samples belonged to T. eriocali species. Plant essential oil was extracted by distillation method with Clevenger equipment. The antimicrobial properties of local thyme were determined by measuring minimum inhibitory concentration (MIC) of it alone and in combination with ciprofloxacin using sequential dilution method (macrodilution and microdilution methods) in Escherichia coli strains. Minimum bactericidal concentration (MBC) was measured by cultivation method. The interaction between essential oil and ciprofloxacin was determined by calculation of fractional inhibitory concentration index (FICI).
Results: MIC of essential oil for wild type strain MG1655 and mutant strain RE6 was 8 and 10 µl/ml, respectively. MBC was equal to MIC. 0.4 µl/ml of essential oil decreased 45 fold the MIC of ciprofloxacin in mutant strain and produced synergistic interaction (FICI=0.06).
Conclusion: Thyme essential oil in concentration less than its MIC in combination with ciprofloxacin via synergistic interaction reduces antibiotic MIC and antibiotic resistance.