Chemical composition and larvicidal activity of Ocimum species essential oils from the south of the Paranaense forest (Argentine) against Aedes aegypti (Diptera: Culicidae) larvae

Abstract

Aedes aegypti plays a predominant role in the transmission of a variety of diseases, such as yellow fever, dengue fever, malaria, Zika and Chikungunya disease. The reduction of chemicals available for vector control due to the increase in mosquito resistance to insecticides and their negative impact on the human health and the environment have driven the focus of the problem towards the identification and evaluation of sustainable alternatives to synthetic insecticides. The essential oils from the leaves of Ocimum campechianum, Ocimum ovatum, and Ocimum selloi were analyzed by GC/MS and GC/FID and investigated for its larvicidal activity against A. aegypti larvae. In the chromatographic analyses showed that the main compounds were elemicin (22.8%), methyl eugenol (33.4%), and methyl eugenol (46.5%), respectively. The susceptibility tested on essential oils was performed according to the World Health Organization protocol. The highest larvicidal potential was displayed by O. ovatum, followed by O. campechianum and O. selloi, with LC50 values of 47.5, 95.5 and 141.2 ppm, respectively. The rapid and efficient larvicidal activity of these three essential oils led us to consider these results as promising for the search of a potentially effective earth-friendly larvicide against the A. aegypti vector.