Exploring the biological activities of the Origanum majorana essential oil nanoemulsion: antimicrobial, antibiofilm, antioxidant and anticancer activities

Abstract

The current study was aimed at preparing a nanoemulsion of the essential oil (EO) from Origanum majorana (O. majorana) and examining its different biological activities. Based on gas chromatography-mass spectrometry (GC-MS), the biologically effective ingredients in Origanum majorana essential oil (OEO) were identified. Additionally, transmission electron microscope (TEM) imaging was used to determine the shape and size of the prepared OEO nanoemulsion (ONE). The antimicrobial activities for OEO, ONE, and their combination were also assessed for numerous standard strains of pathogenic microbes. Furthermore, the capabilities of OEO, ONE, and their combination to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) were employed for a comparative evaluation of their antioxidant potential. Moreover, the potential cytotoxic effects of ONE on the Wi-38 normal line as well as its anticancer activity towards the Pc-3 and HepG-2 cancerous cell lines were investigated following the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Analysis of the TEM images also showed droplets with a spherical shape, a constant size of 49.2–60.6 nm, and a calculated polydispersity index (PDI) of 0.183. Moreover, our findings illustrated the inhibitory effect of OEO, ONE, and their combination against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) biofilm formation. Upon completion of this research, we obtained biologically safe ONE with a characteristic tiny particle size and valuable antimicrobial, antibiofilm, as well as antioxidant activities.