Gas Chromatography-Mass Spectrometry Profiling, Antioxidant and Antibacterial Evaluations of Essential Oils Extracted from Mentha piperita and Mentha pulegium

Abstract

Synthetic food preservatives protect against oxidation and pathogens but can harm consumer health. Plant-based bioactive components like phenolic acids, flavonoids, and essential oils (EOs) are crucial for safe alternatives. The study investigated the chemical composition and biological activities of EOs extracted from Mentha piperita and Mentha pulegium. Essential oils from both plant species were extracted using hydro-distillation method. Gas chromatography-mass spectrometry (GC-MS) profiling was performed to determine the EOs' constituents. The EOs were assessed for antioxidant properties using three assays, while their antibacterial activity was evaluated against Escherichia coli and Staphylococcus aureus. Molecular docking and dynamic simulation studies were performed to elucidate the interaction between EO constituents and target enzymes. The results revealed that the main components in M. piperita and M. pulegium EOs were isomintlactone (35.55%) and pulegone (74.04%), respectively. The EOs of M. piperita and M. pulegium exhibited remarkable antioxidant activity, with inhibitory concentration (IC50) values of 3.24±0.22 and 3.51±0.22 mg/mL, respectively, in the 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) assay. Strong antibacterial efficacy was observed with a minimum inhibitory concentration (MIC) of 4% for M. pulegium and moderate effects for M. piperita with MIC values of 0.5% against Staphylococcus aureus and its ATCC29213, and 1% against Escherichia coli and its ATCC25922. Molecular docking and dynamic molecular simulations showed that the identified chemical constituents in the test EOs have a good affinity to the target enzymes. These findings suggest that M. piperita and M. pulegium EOs are promising natural sources of antioxidant and antibacterial agents, potentially valuable in food preservation and health applications.