Evidence for inhibition of cholinesterases in insect and mammalian nervous systems by the insect repellent deet.

Vincent Corbel (1, 2) , Maria Stankiewicz (3) , Cedric Pennetier (1, 4) , Didier Fournier (5) , Jure Stojan (6) , Emmanuelle Girard (7, 8) , Mitko Dimitrov (5) , Jordi Molgó (7, 8) , Jean Marc Hougard (2) , Bruno Lapied (4)

1 LIN - Laboratoire de Lutte contre des Insectes Nuisibles
2 CREC - Centre de Recherche Entomologique de Cotonou
3 Institute of General and Molecular Biology [Torun]
4 RCIM - Récepteurs et Canaux Ioniques Membranaires
5 Groupe de Biotechnologie des Protéines
6 Medical Faculty, Institute of Biochemistry
7 NBCM - Laboratoire de neurobiologie cellulaire et moléculaire
8 INAF - Institut de Neurobiologie Alfred Fessard

ABSTRACT: BACKGROUND: N,N-Diethyl-3-methylbenzamide (deet) remains the gold standard for insect repellents. About 200 million people use it every year and over 8 billion doses have been applied over the past 50 years. Despite the widespread and increased interest in the use of deetin public health programmes, controversies remain concerning both the identification of its target sites at the olfactory system and its mechanism of toxicity in insects, mammals and humans. Here, we investigated the molecular target site for deet and the consequences of its interactions with carbamate insecticides on the cholinergic system. RESULTS: By using toxicological, biochemical and electrophysiological techniques, we show that deet is not simply a behaviour-modifying chemical but that it also inhibits cholinesterase activity, in both insect and mammalian neuronal preparations. Deet is commonly used in combination with insecticides and we show that deet has the capacity to strengthen the toxicity of carbamates, a class of insecticides known to block acetylcholinesterase. CONCLUSION: These findings question the safety of deet, particularly in combination with other chemicals, and they highlight the importance of a multidisciplinary approach to the development of safer insect repellents for use in public health.

Domaines: Neurosciences [q-bio.NC]

Vincent Corbel, Maria Stankiewicz, Cedric Pennetier, Didier Fournier, Jure Stojan, et al.. Evidence for inhibition of cholinesterases in insect and mammalian nervous systems by the insect repellent deet.. BMC Biology, 2009, 7 (1), pp.47. ⟨10.1186/1741-7007-7-47⟩. ⟨hal-00409532⟩