Larvicidal activity of Zanthoxylum oxyphyllum Edgew. extract against Culex pipiens

The increasing incidence of synthetic pesticide resistance in Culex pipiens, a principal vector for lymphatic filariasis, demands the immediate advancement of sustainable mosquitocides. This current research shows the larvicidal effectiveness, molecular processes, and environmental safety of the plant extract Zanthoxylum oxyphyllum (ZOM). Metabolite profiling using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) showed the presence of flavonoid glycosides such as fortunellin and linarin, phenolic derivatives, and nitrogenous metabolites. ZOM showed larvicidal action against day-2 third-instar C. pipiens that depended on the dose and the period. The LC50 and LC90 values decreased from 43.14 (30.78–60.45) ppm and 132.46 (94.52–185.65) ppm at 12 h to 36.16 (26.06–50.16) ppm and 99.163 (71.48–137.56) ppm at 24 h, which showed that the activity of the treatment increased with time. Compared to untreated controls, ZOM-treated larvae had lower levels of both alkaline phosphatase (0.03797 vs. 0.00282 U mg−1 protein) and acetylcholinesterase (0.00396 vs. 0.00153 U mg−1 protein) activity. Standardized acute toxicity testing, as per OECD 2025 recommendations, aids in showing that ZOM does not harm the non-target indicator species Danio rerio. These results may confirm that ZOM is an effective, target-specific, and environmentally acceptable option for sustainable vector control programs against mosquitoes.