Myrtle Essential Oil-Loaded Alginate Nanoparticles: A Dual Therapeutic Approach for Cytotoxicity Against Skin Cancer Cells and Antibacterial Effects on Common Pathogens

The skin, being the body's largest organ, is not only susceptible to one of the most prevalent forms of cancer but also vulnerable to a myriad of pathogens, including bacteria. Myrtle essential oil (EO) has been shown to possess both anticancer and antimicrobial properties. This study aimed to investigate the efficacy of alginate nanoparticles containing myrtle EO on melanoma (A375) and epidermoid carcinoma (A431) cell lines, as well as on some common bacteria, including Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.

Initially, myrtle EO was analyzed using Gas Chromatography-Mass Spectrometry. Subsequently, alginate nanoparticles were prepared via the ionic-gelation method and characterized by dynamic light scattering, Zeta potential, and attenuated total reflectance-Fourier transform infrared spectroscopy. Encapsulation efficacy was then determined using UV-Vis spectrometry. Both cytotoxicity assessment (MTT assay) and evaluation of antibacterial effects (microdilution assays) were conducted using the 96-well plate format.

The major compounds identified in myrtle EO were α-pinene, 1,8-cineole, linalool, linalool acetate, and geranyl acetate. The alginate nanoparticles exhibited a size of 160 ± 9 nm, a SPAN of 0.96, and a Zeta potential of -26 ± 2 mV. The encapsulation efficacy was determined to be 78.4%. It was found that the nanoparticles demonstrated cytotoxicity against A375 and A431 cells with IC50 values of 211 µg/mL and 308 µg/mL, respectively. The most potent antibacterial effect was observed against S. aureus (IC50: 266 µg/mL).

The alginate nanoparticles containing myrtle EO, which exhibited notable cytotoxicity against melanoma and epidermoid carcinoma cells as well as potent antibacterial effects, show promise for further investigation in vivo studies.