Determination of the antimicrobial and antioxidant capacity of Mentha dumetorum essential oil

This study evaluated the antimicrobial and antioxidant properties of Mentha dumetorum essential oil. The oil was extracted by steam distillation and analyzed using GC-MS. The major components identified were linalool (21.76%), linalyl acetate (20.76%), elemol (11.63%), eucalyptol (7.99%), and α-terpineol (7.82%). Antimicrobial activity was tested using agar well diffusion and microdilution methods against seven bacterial and three yeast strains. The oil exhibited strong antibacterial and antifungal activities, with inhibition zones ranging from 8.56-12.04 mm and 19.41-22.88 mm, respectively. Minimum inhibitory concentration values confirmed significant activities against Staphylococcus epidermidis and Candida species. Antioxidant activities were assessed using 2,2-diphenyl-1-picrylhydrazyl, 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), as well as copper(II) and iron (III) ions, reducing antioxidant power activity assays. Radical scavenging activity was relatively weak compared to Trolox, while reducing power was significant, especially in copper(II) and iron(III) ions, reducing antioxidant power activity analyses. These findings suggest that the bioactive constituents of M. dumetorum contribute to its antimicrobial and antioxidant reducing potential. The oil shows promise as a natural antimicrobial agent and may enhance oxidative stability in pharmaceutical, cosmetic, or food applications. Further studies should investigate toxicological safety, pharmacological efficacy, and potential synergistic effects with existing antimicrobial drugs. KEY WORDS: Agar well, Antimicrobial activity, Essential oil, Mentha dumetorum, Minimum inhibitory concentration Bull. Chem. Soc. Ethiop. 2026, 40(5), 1091-1103 DOI: https://dx.doi.org/10.4314/bcse.v40i5.11