Chemical Composition of <i>Salvia plebeian</i> R.Br. Essential Oil and its Larvicidal Activity against <i>Aedes aegypti</i> L

Abstract

Purpose: To evaluate the larvicidal activity of the essential oil of Salvia plebeian R.Br. (Labiatae) aerial parts against the larvae of Aedes aegypti L . Methods : The essential oil of S. plebeian aerial parts was obtained by hydro-distillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The essential oil was evaluated for larvicidal activity using World Health Organization (WHO) procedures, against the fourth larvae of A. aegypti within 24 h, and activity was recorded for various concentrations of the ranging from 12.5 – 200.0 μg/mL. Results : A total of 33 components of the essential oil of S. plebeian were identified. The major compounds of the essential oil were caryophyllene oxide (15.54 %), γ-eudesmol (14.03 %), τ-cadinol (10.21 %), calamenene (9.63 %), copaene (5.70 %), γ-cadinene (5.30 %), cadalene (5.28 %), α- muurolene (5.19 %), ledol (5.14 %) and α-cadinol (5.08 %). The essential oil exhibited larvicidal activity against A. aegypti at a median lethal concentration (LC50) of 46.26 μg/mL. Conclusion : The findings indicate that the essential oil of S. plebeian aerial parts has potentials for use in the control of A. aegypti larvae and may be useful in the search for newer, safer and more effective natural compounds as larvicides. Keywords : Salvia plebeian, Essential oil, Larvicidal activity, Aedes aegypti, Caryophyllene oxide, γ- Eudesmol, τ-Cadinol, Calamenene