Algerian Mentha pulegium L. leaves essential oil: Chemical composition, antimicrobial, insecticidal and antioxidant activities

- The antimicrobial activity of Algerian Mentha pulegium essential oil proved the effectiveness of this oil against several frequent infections.
- Algerian M. pulegium essential oil is effective against food pest Sitophilus granarius, appeared by high mortality rate compared to chemical pesticide (malathion).
- Algerian M. pulegium essential oil has a good radical scavenging ability near to synthetic oxidants.
- Algerian M. pulegium is a bioactive substitute for food hygiene and a natural replacement for harmful synthesized chemicals.

Essential oils are responsible for wide bioactivities, the reason why, this search is focused on the study of the chemical composition and the antimicrobial, insecticidal and antioxidant activities of Algerian Mentha pulegium L. leaves essential oil (EO). EO is obtained by steam distillation with a yield of 1.45 ± 0.01% and analyzed by gas chromatography coupled to mass spectrometry (GC/MS) where 39 compounds were identified. The analysis has revealed that EO contains pulegone (70.66%) and neo-menthol (11.21%), were the major compounds. Antimicrobial study showed good activity tested against 11 bacteria (3 g+ and 8 g-) and 2 yeasts, also showed good inhibitory (MIC) and bactericidal (MBC) properties.Insecticide assessment was carried out against food pest Sitophilus granarius (L.). Three toxicity tests of EO were performed using three different methods: contact, inhalation and ingestion. Also, assessment of the toxicity of M. pulegium EO was carried out using leaves at different status (fresh, dried and semi-dried) ground and non ground. Inhalation and ingestion methods were implemented on wheat seeds that showed high efficiency (100% mortality), and a lethal dose of (LD50 = 9.11 ± 2.53 μl/ml) was obtained using the contact method. Leaves in various statuses didn't show any efficiency except crushed ones. To compare the efficiency of EO, was assessed the toxicity test of chemical pesticide (malathion) against food pest S. grananarius which showed an average efficiency.The Antioxidant activity was defined using the scavenging test of free radicals (DPPH), while BHT and ascorbic acid were used as positive controls. The results of IC50 = 69.60 ± 1.72 μg/ml, showed a very good radical scavenging ability.As a result Algerian M. pulegium EO can be used in food and pharmaceutical industries.