GC-MS Profiling, In Vitro and In Silico Antibacterial and Antioxidant Potential of Origanum elongatum Essential Oil: Novel Source against Phytopathogenic Bacteria

This study highlights the regulatory potential antibacterial and antiradical of Origanum elongatum essential oil (EO), an endemic medicinal plant of Morocco used for its various properties. The chemical composition of the EO was characterized using gas chromatography-mass spectrometry (GC-MS). The antibacterial activity against different agricultural phytopathogens was determined by disc diffusion and microatmosphere methods, as well as by the determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC), while the antioxidant activity was evaluated by DPPH and FRAP assays. To complement the experimental analyses, a molecular docking approach was used to predict and elucidate the mechanisms of action of the identified bioactive compounds, both for their antioxidant and antibacterial properties. The GC-MS analysis revealed a chemical composition dominated by the major compounds: p-cymene-2-ol (25.31%), thymol (23.88%), and gamma-terpinene (19.26%). Furthermore, antibacterial analyses performed using different methodological approaches (disc diffusion, microatmosphere, MIC, and MBC) showed significant inhibitory activity against all phytopathogens tested. Moreover, O. elongatum EO exhibited interesting antioxidant ability with an IC50 value of 168.25 +/- 1.14 mu g/mL for DPPH assay and EC50 value of 164.22 +/- 1.04 mu g/mL for FRAP assay. Furthermore, in silico molecular docking demonstrated further insights into the interactions between the oil's active components and bacterial targets, supporting its mode of action. This indepth characterization highlights the potential of O. elongatum EO as a natural alternative for the biocontrol of plant pathogens. It opens new perspectives for developing natural solutions to protect crops against plant diseases.