Assessment of Antibacterial Activity and Toxicity of Mentha spicata, Mentha piperita, and Mentha pulegium Essential oils

Mentha species are valued for their health benefits, and their essential oils (EOs) are being studied as potential alternatives to synthetic products. This study aimed to evaluate the antibacterial activity and acute oral toxicity of EOs from Mentha spicata, Mentha piperita, and Mentha pulegium. EOs were obtained from the leaves of Mentha spicata and Mentha piperita, and the aerial parts of Mentha pulegium by hydrodistillation. The antibacterial efficacy of the EOs was assessed using disk diffusion and microdilution methods against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Micrococcus luteus) bacteria. Acute oral toxicity was evaluated following the Organization for Economic Cooperation and Development (OECD) Test No. 423 guideline. The EOs demonstrated varying degrees of antibacterial activity, with M. spicata EO exhibiting the highest efficacy, particularly against S. aureus with inhibition zone diameter of 16.67 mm. No sign of toxicity was observed at a dose of 2000 mg/kg for all three EOs, indicating a favourable safety profile. In conclusion, the bioactive EOs of M. spicata, M. piperita, and M. pulegium show promising antibacterial potential, suggesting their potential use as therapeutic alternatives for bacterial infections. Further evaluations are needed to confirm their safety for human use.