Larvicidal activity of Zanthoxylum acanthopodium essential oil against the malaria mosquitoes, Anopheles anthropophagus and Anopheles sinensis

Background: Zanthoxylum acanthopodium has insecticidal effect in Chinese traditional medicine. In this study, the essential oil from the dried Zanthoxylum plant was used as a larvicidal compound against the malaria mosquitoes, Anopheles anthropophagus and Anopheles sinensis. Methods: Compounds in the Zanthoxylum essential oil were investigated by gas chromatography and mass spectroscopy (GC-MS). The larvicidal bioassays of the whole oil, as well as the main compounds in the oil (estragole and eucalyptol) were performed using WHO method. Results: In total, 63 main compounds (99.32%) were found in the oils, including estragole (15.46%), eucalyptol (10.94%), beta-caryophyllene (5.52%), cis-linalool oxide (3.76%), cis-limonene oxide (3.06%). A dose-dependent effect on mortality was recorded with increasing concentrations of essential oil and compounds increasing mortality of the larvae. Larvicidal bioassays revealed that 24 h LC50 of the whole essential oil was 36.00 mg/L and LC90 was 101.49 mg/L against An. anthropophagus, while LC50 was 49.02 mg/L and LC90 was 125.18 mg/L against An. sinensis. Additionally, 24 h LC50 of estragole were 38.56 and 41.67 mg/L against An. anthropophagus and An. sinensis, respectively, while the related LC90 were 95.90 and 107.89 mg/L. LC50 of eucalyptol were 42.41 and 45.49 mg/L against An. anthropophagus and An. sinensis, while the related LC90 were 114.45 and 124.95 mg/L. Conclusion: The essential oil of Z. acanthopodium and its several major compounds may have potential for use in the control of malaria mosquitoes.