In vitro evaluation and comparison of anticancer, antimicrobial, and antifungal properties of thyme niosomes containing essential oil

Due to the inefficiency of current treatment methods in the treatment of various cancers, as well as increasing antibiotic resistance in bacteria and fungi, attention to the use of medicinal plants and their essential oils is increasing. However, leading barriers to the use of plant essential oils, such as rapid oxidation and high volatility, highlight the need for a drug delivery system to increase their efficiency. 

Therefore, this study aimed to investigate the antimicrobial, antifungal, and cytotoxic effects of free thyme essential oil (TEO) and compare it with its nanoniosomal form. Initially, the chemical component of TEO was analyzed by the gas chromatography method. Then, to improve biopharmaceutical properties and enhance the stability of TEO in light and volatility, nanoniosomes containing thyme essential oil synthesized by thin-film hydration method and their physicochemical properties such as size and zeta potential, morphology, encapsulation efficiency (EE%), and profile of in vitro release were investigated. 

The results showed that the nanoparticles had an average size of 97 nm with a zeta potential of -37 mV. Also, in the optimal formula, the EE% of essential oil in nanoniosomes and the maximum release rate of the TEO from nanosystem were 81% and 57%, respectively. On the other hand, it was found that the antibacterial and antifungal activity of TEO remarkably increased after encapsulation. Also, the cytotoxicity assay of TEO on cancer cells showed that blank nanoniosome had no cytotoxicity and besides, the IC50 of TEO in encapsulated form decreased by 1.75 times on MCF-7 cancer cells compared with its free form, which indicates an increase in its anti-cancer properties. 

Overall, encapsulation of thyme essential oil in optimal synthesized nano systems improved its anticancer and antimicrobial properties, which could be the beginning of a revolution in the treatment of cancer and microbial diseases using nano-encapsulated herbal remedies.