title: Repellents inhibit P450 enzymes in Stegomyia (Aedes) aegypti.
abstract: The primary defence against mosquitoes and other disease vectors is often the application of a repellent. Despite their common use, the mechanism(s) underlying the activity of repellents is not fully understood, with even the mode of action of DEET having been reported to be via different mechanisms; e.g. interference with olfactory receptor neurones or actively detected by olfactory receptor neurones on the antennae or maxillary palps. In this study, we discuss a novel mechanism for repellence, one of P450 inhibition. Thirteen essential oil extracts from Colombian plants were assayed for potency as P450 inhibitors, using a kinetic fluorometric assay, and for repellency using a modified World Health Organisation Pesticide Evaluations Scheme (WHOPES) arm-in cage assay with Stegomyia (Aedes) aegypti mosquitoes. Bootstrap analysis on the inhibition analysis revealed a significant correlation between P450-inhibition and repellent activity of the oils.
authors.affiliation: Department of Biological Chemistry, Rothamsted Research, Harpenden, United Kingdom.
authors.forename: Gloria Isabel
authors.initials: GI
authors.lastname: Jaramillo Ramirez
authors.forename: James G
authors.initials: JG
authors.lastname: Logan
authors.forename: Elisa
authors.initials: E
authors.lastname: Loza-Reyes
authors.forename: Elena
authors.initials: E
authors.lastname: Stashenko
authors.forename: Graham D
authors.initials: GD
authors.lastname: Moores
mesh_terms: D000330:Aedes / Q000187:drug effects*; D000818:Animals; D065607:Cytochrome P-450 Enzyme Inhibitors; D003671:DEET / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D007302:Insect Repellents / Q000494:pharmacology*; D009822:Oils, Volatile / Q000494:pharmacology; D011817:Rabbits
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D004791:Enzyme Inhibitors; D007302:Insect Repellents; D009822:Oils, Volatile; D003671:DEET