In vitro and in silico evaluation of the biological effects of essential oil from Artemisia campestris aerial parts against Culex pipiens (Diptera: Culicidae)

This work evaluates the insecticidal efficacy of Artemisia campestris L. essential oil aerial parts against Culex pipiens L., with emphasis on its toxicological, biochemical, enzymatic, and molecular effects. The essential oil (EO) was chemically characterized using gas chromatography–mass spectrometry (GC-MS). Bioefficacy was assessed using in vitro bioassays to evaluate larvicidal, adulticidal, repellent, and oviposition deterrent activities. The EO exhibited potent larvicidal and adulticidal activity, with LC50 values ranging from 125.91 to 45.52 ppm in larvae and from 0.387% to 0.185% in adults within 24–48 hours. Complete adult mortality was achieved at 2% concentration. Total repellency reached 100% at 8.67 µL/cm2, while OAI values (-0.40 to -0.91) indicated strong oviposition deterrence, especially at 8% EO. Biochemical analyses revealed significant alterations in morphological parameters and metabolic reserves, including reductions in total protein, lipid, and carbohydrate contents, suggesting impaired physiological function following LC50 exposure. Enzymatic assays showed a reduction of acetylcholinesterase (AChE) activity, indicative of neurotoxicity, and a marked induction of glutathione S-transferase (GST) activity, reflecting activation of detoxification mechanisms. To further elucidate the mode of action, molecular docking was performed to evaluate interactions between major phytoconstituents and selected enzymatic targets. Among the compounds identified, γ-curcumene and spathulenol exhibited high binding affinities toward AChE and GST, supporting their potential role as key bioactive agents.