Chemical composition of Mentha suaveolens and Pinus halepensis essential oils and their antibacterial and antioxidant activities

ABSTRACT

Objective: To determin the chemical compounds of Mentha suaveolens (M. suaveolens) and Pinus halepensis (P. halepensis) essential oils (Eos) and evaluate their antioxidant and antibacterial activities. Methods: The chemical composition of P. halepensis and M. suaveolens EOs was determined by GC-MS analysis. The antioxidant activity was evaluated using DPPH, ABTS and FRAP assays. The antibacterial effect was tested against 6 bacterial strains using the well diffusion method and micro-dilution assay. Results: The major components of P. halepensis EOs were β-caryophyllene (28.04%), myrcene (23.81%) and α-pinene (12.02%). However, piperitenone oxid (56.28%), piperitenone (11.64%) and pulegone (6.16%) were the major components of M. suaveolens EOs. M. suaveolens EOs showed remarkable antioxidant activities compared with P. halepensis EOs, showing antioxidant capacity values of IC50=(64.76±2.24) μg/mL, IC50=(82.73±3.34) μg/mL, and IC50=(93.35±4.45) μg/mL, revealed by DPPH, ABTS and FRAP assays, respectively. However, P. halepensis EOs showed interesting antibacterial effects against all bacterial strains. The most sensible strains to P. halepensis EOs were Staphylococcus aureus [(34.00±0.50) mm], Listeria monocytogenes [(31.00±1.50)] mm and Proteus mirabilis [(29.00±2.25)mm]. Furthermore, the lowest minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were revealed by P. halepensis EOs against Staphylococcus aureus [MIC=MBC=0.125% (v/v)] and Listeria monocytogenes [MIC=MBC=0.25% (v/v)]. Conclusions: P. halepensis and M. suaveolens EOs contain bioactive compounds that could have potential applications against bacterial infections and oxidative stress related diseases as well as for food conservation. However, further investigations are necessary to isolate and investigate the action mechanisms of these bioactive compounds.