<i>Tetraclinis articulata</i> Essential Oil: From Chemotaxonomy to Nanoformulation and Antibacterial Evaluation

This investigation undertook a comprehensive exploration of the essential oil (EO) derived from Tetraclinis articulata leaves, harvested in Blida (Algeria). It was structured in three phases: (i) profiling the phytochemical composition of the EO, (ii) developing and characterizing a novel nanoemulsion-based delivery system, and (iii) evaluating, for the first time, its antibacterial efficacy. Analytical characterization using GC-MS and GC-FID revealed the predominance of α-pinene (32.9%), camphor (27.8%), and d-limonene (5.6%). A significant metabolic flux was observed within the biosynthetic pathways around camphor, bornyl acetate, and α-pinene, leading to the formation of other compounds. The formulated nanoemulsion exhibited remarkable physicochemical properties, characterized by its optical clarity, nanoscale droplet size (34.2 nm), and robust stability during a 7-month storage period. Antibacterial assessments conducted via disc-diffusion and broth microdilution methods against 10 foodborne bacterial strains demonstrated substantial inhibitory activity of the EO. More importantly, the formulated nanoemulsion significantly enhanced the antibacterial performance of the encapsulated EO against eight of the tested microorganisms. Collectively, these findings not only enrich the phytochemical and ecological understanding of T. articulata but also underscore the potential of EO-based nanoemulsions as promising candidates for the development of next-generation natural antibacterial agents tailored for food preservation and safety applications.