Integrated Evaluation of Mentha rotundifolia (L.) Huds Essential Oil: Physicochemical Characterization, Antibacterial...

This study aimed to evaluate the physicochemical characterization and antibacterial activity of the essential oil (EO) extracted from the leaves of Mentha rotundifolia (L.) Huds. Molecular interactions between bioactive ligand compounds, target bacterial proteins and DNA gyrase subunit B (GyrB), as well as an in silico ADMET prediction study, were also conducted. The EO was obtained by hydrodistillation of the plant leaves. The Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS) analysis revealed Rotundifolone (27.95%) and carvacrol (19.48%) as the major constituents. Other components identified included Piperitenone (6.09%), Cinerolon (4.73%), and Pulegone (4.47%). Antibacterial activity was assessed against six bacterial strains: Enterococcus faecalis CIP 103214, Salmonella Typhi CIP 5535, Staphylococcus aureus ATCC 9144, Bacillus cereus ATCC 33019, Streptococcus agalactiae IPM 24842, and Providencia alcalifaciens CIP 82.90T. The disk diffusion assay showed a strong inhibitory effect against E. faecalis (inhibition zone: 19.66 ± 0.3 mm), while the lowest minimum inhibitory concentration (MIC) was observed for B. cereus (0.58 ± 0.01 µL/mL). The time-kill kinetics assay showed a progressive inactivation of all tested bacterial strains after their exposure to EO for 8 h at MICs. Furthermore, Molecular docking showed remarkable affinities between EO components, target proteins and DNA gyrase subunit B (GyrB). Moreover, the in silico ADMET predictions provided preliminary insights into the safety-related properties of the major EO components. In addition, EO compounds have the potential to interact with bacterial structures. These findings highlight the in vitro antibacterial potential of the M. rotundifolia EO and suggest its promise as a natural source of bioactive compounds.