Sublethal effects of the pyrethroid insecticide deltamethrin on oxidative stress parameters in green toad (Bufotes viridis L.).

Pyrethroids are synthetic insecticides widely used in agriculture, public health, and veterinary medicine. Deltamethrin, a type II pyrethroid insecticide, has attracted particular attention because of its frequent use. The mechanisms of the toxicity of most pesticides (including pyrethroids) in nontarget organisms is linked to the production of free radicals, oxidative stress induction, increased lipid peroxidation, and disruption of the total antioxidant potential. The aim of the present study was to investigate the effects of acute toxicity of 3 different concentrations (8, 16, and 32 mg/kg body wt) of orally applied deltamethrin after 96 h of treatment. Some of the front-line oxidative stress parameters as well as cholinesterase (ChE) activity and cytochrome P4501A (CYP1A) expression in the liver, muscle, skin, and gastrointestinal tissue of the adult green toad Bufotes viridis were determined. Compared with the control group, the activity of catalase and glutathione reductase was increased in the liver and skin, while the concentration of sulfhydryl groups was reduced. In the liver and muscle, concentrations of thiobarbituric reactive substances were increased, as well as liver CYP1A expression. In the muscle and skin, glutathione-S-transferase activity was higher in treated toads. The oxidative stress parameters examined were affected by different deltamethrin concentrations. We conclude that the assessed parameters represent good biomarkers of pesticide-induced oxidative stress. Environ Toxicol Chem 2017;36:2814-2822.