Effect of pyrethroids, permethrin and fenvalarate, on the oxidative stress of Helicoverpa armigera

The cotton bollworm, Helicoverpa armigera is a polyphagous pest of several crops in Asia, Africa, and the Mediterranean Europe. Pyrethroid insecticides are used to control noxious insects in agriculture, forestry, households and horticulture. Therefore, the effect of permethrin and fenvalarate was evaluated on the oxidative stress in H. armigera. Lipid peroxidation, H2O2 content, and lactate dehydrogenase (LDH) activity increased and glutathione reductase (GR) activity decreased in a time- and dose-dependent manner in insecticide-fed larvae. However, catalase activity was not affected in insecticide-fed larvae. Larval growth decreased by ~ 64 and 70% in larvae fed on diets with sub-lethal doses of permethrin and fenvalarate. The results suggested that both the insecticides induced lipid peroxidation, H2O2, LDH leak, and altered antioxidant enzymes leading to oxidative stress in cells, which contribute to deleterious effects of these insecticides on the growth of H. armigera larvae, along with their neurotoxic effects