Insecticide resistance and glutathione S-transferases in mosquitoes: A review

Mosquito glutathione S-transferases (GSTs) have received considerable attention in the last 20 years because of their role in insecticide metabolism producing resistance. Many different compounds, including toxic xenobiotics and reactive products of intracellular processes such as lipid peroxidation, act as GST substrates. Elevated levels of GST activity have been reported in organophosphate, organochlorine and pyrethroid resistant mosquitoes. Particulary GST-based resistance is considered the major mechanism of DDT resistance in anopheline species. To date different GST enzymes structurally conserved have been identified suggesting that they may have an important role on common pathways of compound detoxification. In this review we describe the major characteristics of this enzyme family and the principal studies that have contributed to a better knowledge of its role in mosquito insecticide resistance. Finally some aspects on insect GST-based resistance and their implications in traditional biochemical assays for detecting and monitoring GST activity are discussed.