The insect repellent DEET (N,N-diethyl-3-methylbenzamide) increases the synthesis of glutathione S-transferase in cultured mosquito cells

Abstract

DEET (N,N-diethyl-3-methylbenzamide) is the active ingredient used in many commonly used insect repellents, but its mode of action remains poorly understood. Efforts to identify properties that could lead to the development of more effective active ingredients have distinguished among DEET's repellent, deterrent, and insecticidal activities. We used an Aedes albopictus mosquito cell line to evaluate DEET's toxicological properties in the absence of sensory input mediated by the olfactory system. When cells were treated with DEET and labeled with [(35)S]methionine/cysteine, a single 25-kDa protein was induced, relative to other proteins, on SDS-polyacrylamide gels. The 25-kDa band from DEET-treated cells was enriched in peptides corresponding to glutathione S-transferase D10 and/or theta in the Aedes aegypti genome. Consistent with the increased expression of the labeled protein, DEET-treated cells had increased glutathione S-transferase activity, and the radiolabeled band bound to Sepharose 4B containing reduced glutathione. By analyzing partial tryptic digests, we established that DEET induces the homolog of A. aegypti glutathione S-transferase, class theta, corresponding to protein XP_001658009.1 in the NCBI database. This specific effect of DEET at the subcellular level suggests that DEET induces physiological responses that extend beyond recognition by the peripheral olfactory system.

Effects of Subchronic Exposure toN,N-Diethyl-m-toluamide on Selected Biomarkers in Common Carp (Cyprinus carpioL.)

“…The effect of DEET on formation of oxidative stress was studied especially in insect [43] and rats [44–46]. Antioxidant enzymes, that is, GPx, GR, CAT, and SOD, keep the oxidative status in the cell.…”

DEET Efficacy Increases With Age in the Vector Mosquitoes Anopheles gambiae s.s. and Aedes albopictus (Diptera: Culicidae)

“…In this context, the increased susceptibility to DEET observed in old females may be attributed to decreases in the efficacy of detoxification mechanisms. Consistently, mosquito aging has been shown to be associated with decreases in the concentration of enzymes involved in DEET detoxification ( Mourya et al 1993 , Hellestad et al 2011 ). These decreases have been observed in both insecticide-resistant and susceptible old mosquitoes and are also responsible for increased susceptibility to insecticides ( Hazelton and Lang 1983 , Mourya et al 1993 ).…”

Differentiation of action mechanisms between natural and synthetic repellents through neuronal electroantennogram and proteomic in Aedes aegypti (Diptera: Culicidae)

“…Some research published had extracted Ae. aegypti proteins, however, the proteins found were not the same since the reports focused on different objectives 74 – 76 . Moreover, considering the electroantennography it can be confirmed that synthetic repellents displayed a different action mechanism in comparison with natural-based compounds.…”

“…However, detoxification proteins like Aldo-keto reductase, glutathione-S-transferase, glutaredoxin, and nicotinate phosphoribosyltransferase displayed upregulation 54,72,73 . These proteins easily react with molecules containing ketone, ester, aldehydes, electrophilic carbon groups, present in geranyl acetate, α-bisabolol, and nerolidol repellent molecules 74 (Fig. S10).…”