EFFECTS OF THE ORGANOPHOSPHATE INSECTICIDE FENTHION ON THE ANTIOXIDANT DEFENSE SYSTEM AND LIPID PEROXIDATION OF GALLERIA MELLONELLA L.

In this study, the potential of different sublethal concentrations (2.00, 4.00, 6.00, 8.00, 10.00, 20.00, 50.00, and 100.00 mu g/100 g diet) of fenthion, an organophosphorus insecticide, to create oxidative stress and their effect on the antioxidant enzymes and lipid peroxidation of the larvae of the model organism Galleria mellonella were investigated. The activities of catalase (CAT) and super-oxide dismutase (SOD) and the contents of malondialdehyde (MDA) and protein were determined using spectrophotometric methods. Fenthion caused a reduction in protein contents but an increase in the MDA content and CAT activity. Lower fenthion doses resulted in an increase in SOD activity, whereas higher fenthion doses significantly decreased SOD activity. Thus, the toxicity of fenthion due to oxidation was determined to result from the oxidative stress caused by the effect on activities of antioxidant enzymes such as CAT and SOD.