Anticancer, antioxidant, and antibacterial effects of nanoemulsion of Origanum majorana essential oil

Background and Objectives: This study aimed to develop a natural nanoemulsion with antibacterial and anticancer prop- erties. Materials and Methods: The chemical composition of the Origanum majorana essential oil was investigated using GC–MS analysis. Besides, the successful loading of the essential oil in the nanoemulsion was confirmed using ATR-FTIR analysis. Moreover, nanoemulsion’s anticancer, antioxidant, and antibacterial activities were investigated. Results: Terpinen-4-o1 (46.90%) was identified as the major compound in the essential oil. The nanoemulsion with a 149 ± 5 nm droplet size and zeta potential of -11 ± 1 mV was prepared. The cytotoxic effect of the nanoemulsion against A-375 human melanoma cells (IC = 139 μg/mL) showed significantly more potency than A-549 human lung cancer cells (IC = 318 μg/mL). Interestingly, growth of Staphylococcus aureus (Gram-positive) and E. coli (Gram-negative) bacteria after treatment with 4800 μg/mL of nanoemulsion were obtained at 12 ± 2 and 6 ± 1%, respectively. However, the IC of nanoemulsion against E. coli (580 μg/mL) was not significantly different (P 0.05) from S. aureus (611 μg/mL). value Conclusion: A straightforward preparation method, high stability, and multi-biological effects are the main advantages of the prepared nanoemulsion. Therefore it could be considered for further investigation in vivo studies or complementary medicine.