Chemical composition and larvicidal efficacy of essential oils from three artemisia species endemic to the Mediterranean region against Culex pipiens (L.), insecticide-resistant vector: in vivo and in silico studies

Abstract

Objective This study aims to evaluate the larvicidal efficacy of essential oils extracted from three North African endemic Artemisia ( A ) species against the Culex pipiens mosquito, a major vector of emerging or re-emerging viruses that pose a threat to public and veterinary health in Africa, using both in vivo and in silico approaches. Methods Third- and fourth-instar larvae were exposed to varying concentrations of essential oils from the selected Artemisia species. Lethal concentrations LC 10 , LC 50 , and LC 90 for each essential oil were determined through probit analysis. The susceptibility of C. pipiens was also compared to that of the standard insecticide, temephos, under controlled laboratory conditions. Additionally, in silico studies, including molecular docking and dynamics simulations, were conducted on the major chemical constituents to further interpret and explain the in vivo results. Results Gas chromatography analyses revealed that the essential oil of A. negrei was dominated by β-thujone (29.02%) and camphor (14.68%). In A. herba-alba Asso, α-thujone (49.19%) was the predominant compound, followed by terpinen-4-ol (9.82%). The essential oil of A. campestris was mainly characterized by camphor (33.07%) and 1,8-cineole (5.26%). A. negrei exhibited the highest larvicidal activity against C. pipiens , followed by A. campestris. In contrast, the essential oil of A. herba-alba Asso, despite its richness in oxygenated monoterpenes, showed the lowest larvicidal effectiveness. In silico investigations revealed that the examined compounds had promising binding affinities within the receptor’s active site, comparable to those of the reference insecticide, temephos. Conclusions The results of this study suggest that A. negrei , an endemic species from Morocco, holds significant potential for managing C. pipiens populations and provides a promising alternative to chemical insecticides.