Determination of Volatile Compounds of Mentha piperita and Lavandula multifida and Investigation of Their Antibacterial, Antioxidant, and Antidiabetic Properties

Abstract

<i>Mentha piperita</i> and <i>Lavandula multifida</i> are widely used in Moroccan traditional medicine for the treatment of diabetes and infectious diseases. The aims of this work were the determination of the chemical composition of <i>Mentha piperita</i> (MPEO) and <i>Lavandula multifida</i> (LMEO) essential oils and the evaluation of their antibacterial, antioxidant, and antidiabetic activities. The chemical composition was determined by GC-MS analysis. The antibacterial effects were evaluated against several bacterial strains using disc diffusion, MIC, and MBC methods. The antioxidant activity was evaluated <i>in vitro</i> using DPPH, H₂O₂, and xanthine oxidase, and the antidiabetic activity was estimated by the inhibitory effects of <i>α</i>-amylase, <i>α</i>-glucosidase, and lipase activities. GC-MS results showed that the main compounds of MPEO were menthone (29.24%), levomenthol (38.73%), and eucalyptol (6.75%). However, eucalyptol (28.11%), 2-bornanone (11.57%), endo-borneol (7.82%), and linalyl acetate (5.22%) are the major compounds of LMEO. The results exhibited important inhibitory effects against some bacterial strains with MIC = MBC = 0.39 mg/mL for MPEO against <i>Staphylococcus aureus</i> ATCC. However, LMEO exhibited remarkable antioxidant and antidiabetic activities compared to MPEO. Indeed, LMEO inhibited DPPH, H₂O₂, and xanthine oxidase with concentrations of 15.23, 21.52, and 8.89 <i>µ</i>g/mL, respectively. Moreover, LMEO exhibited <i>α</i>-amylase and <i>α</i>-glucosidase at IC₅₀ = 85.34 and IC₅₀ = 59.36 <i>µ</i>g/mL, respectively. The findings showed that both MPEO and LMEO exhibit promising biological properties. However, the application of these species or their main bioactive compounds requires further investigation.