Essential oils from Murraya koenigii (L.) Spreng. and their phytochemicals as an environmental-friendly agent against pests of medical importance

Mosquitoes are vectors that can cause serious negative impacts, including disease transmission, and altered ecosystem dynamics. In this research, phytochemical screening and toxicity of the essential oil derived from Murraya koenigii (L.) Spreng. leaves (Mk-EO) were evaluated against Aedes aegypti (Linn.) and Culex quinquefasciatus Say. The Mk-EO phytochemical screening revealed the presence of 16 chemicals, including Estragole (74.4%) as the main compound. Furthermore, the larvicidal activity showed a dose-dependent mortality rate across different instar larvae of filarial and dengue vectors. The action on larvae was vigorous at the peak dose (1000 ppm) of Mk-EO. The lethal concentration (LC50) values against Ae. aegypti and Cx. quinquefasciatus were 503 and 513 ppm, respectively. Furthermore, the Mk-EO (500 ppm) significantly reduced the rate of α- and β-esterase activity and increased the rate of detoxifying enzymes glutathione-S-transferase (GST) and cytochrome P450 (CYP450). The repellent activity of Mk-EO was observed to be higher at 1000 ppm against Ae. aegypti (76%) and Cx. quinquefasciatus (76%) with a longer repellent period of up to 210 min. Severe midgut toxicity was observed, causing significant damage to midgut cells in both mosquito species. The screening against the non-target predators revealed that Mk-EO was harmless at a higher concentration (1200 ppm) compared to the chemical insecticide Temephos (1 ppm). Additionally, the in silico prediction of major metabolites of Mk-EO on the honey bee and aquatic models indicated minimal toxicity. Overall, Mk-EO serves as an environmentally friendly insecticidal agent against dengue and filarial vectors while also being nontoxic to aquatic predators. [Display omitted] •Chemical screening of essential oil from Murraya koenigii (Mk-EO) derived maximum peak area at Humulene.•Larvicidal activity of Mk-EO (1000 ppm) was maximum at the dose of 1000 ppm against dengue and filarial mosquito larvae.•Lethal dosage of Mk-EO (500 ppm) significantly affects the midgut enzymes of mosquito larvae.•Lethal dosage of Mk-EO (1000 ppm) displayed significant repellent activity up to 210 minutes.•Non-target screening against the mosquito predators displayed that the Mk-EO was harmless as compared to Temephos.