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Abstract

Overcoming the phenomenon of insecticides resistance in malaria vectors in Sub-Saharan tropics remains a great challenge to stop the burden of malaria disease. We tested the efficacy of Zingiber officinale as an alternative insecticide to synthetic pesticides and as a vector control tool against Anopheles coluzzii, the main malaria vector in Cameroon. The biotoxicity of Z. officinale essential oil on aquatic stages of An. coluzzii was assessed using WHO guidelines, and the essential oil active compounds were identified using Gas Chromatography coupling Mass Spectrometry (GC-MS). The essential oil of Z. officinale revealed an ovicidal and larvicidal property against developmental stages of An. coluzzii. A median inhibitory concentration (IC50) of 17.81 ppm was obtained for eggs hatching potentials, while LC50 of 12.20, 12.12, 12.77 and 13.67 were obtained after exposure to first, second, third and fourth instars larvae respectively. All larval stages exhibited similar and full susceptibility to Z. officinale essential oil at 25 ppm. Overall, the essential oil extraction yield was 0.301% and 26 compounds were identified from their retention indices and mass spectra. Hydrocarbon monoterpenes (24.52%), oxygenated monoterpenes (44.93%) and hydrocarbon sesquiterpenes (30.54%) constituted the major classes of the essential oil. β-curcumene (15.24%), geranial (15.16%), camphene (13.79%), neral (11.88%) and α-zingiberene (6.18%) were the most abundant oil compounds. In summary, Z. officinale essential oil revealed important ovicidal and larvicidal properties and stands as a promising tool to manage the phenomenon of insecticides resistant vectors in malaria endemic regions.