Essential oils from Lippia origanoides Kunth. and Mentha spicata L.: chemical composition, insecticidal and antioxidant activities

Abstract

This work describes the chemical composition of the essential oils extracted from fresh leaves of Lippia origanoides Kunth. and Mentha spicata L. and their antioxidant and insecticidal activities. The essential oils were extracted by steam distillation using a modified Clevenger apparatus and subsequently analyzed by gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. The antioxidant activities were determined by the β-carotene-linoleic acid method and by sequestration of the 2,2-diphenyl-1-picryl-hidrazila radical. The concentrations of the essential oils and the synthetic standard, butylated hydroxyltoluene, were 25, 50, 100, 150, 200, 250, 300 and 500 μg mL-1. Insecticidal activity was analyzed by non-preference with choice and no choice against the aphid Myzus persicae Sulzer. Gas chromatography analysis of the essential oil from Lippia origanoides Kunth. revealed carvacrol (41.51%), p-cymene (18.36%), γ-terpinene (17.03%) and thymol (4.86%) as major constituents, and the essential oil from Mentha spicata L. contained piperitona (81.18%), piperitenone (14.57%) and limonene (1.47%) as the principal components. The essential oils and the standard exhibited dose-dependent antioxidant activities at the concentrations tested. The essential oils were shown to be potential agents in the integrated management of the aphid Myzus persicae Sulzer.