Toxic Effects of Imidacloprid, Copper Sulfate, and Their Combinations on Biomolecular and Oxidative/Antioxidant Biomarkers in the Tissues of Oreochromis niloticus

The wide-ranging use of heavy metals and pesticides worldwide and their irreversible accumulation in aquatic ecosystems is a major concern. As the range of household and agricultural chemicals increases, water pollution is trending from the toxic effects of a single agent to complex agent pollution that threatens aquatic ecosystems. The aim of this study was to investigate the effects of pesticides (imidacloprid, IMI) and metals (copper sulfate, CuSO ) on oxidative stress biomarkers, antioxidant enzymes, and biomolecular parameters. The present study on the individual and combined effects of Oreochromis niloticus copper sulfate (CuSO ; 1 ppm), imidacloprid (IMI; 10 and 50 ppm), and IMI + CuSO (IMI10 + CuSO , IMI50 + CuSO ) groups for 14 days. In this context, oxidative stress/antioxidant markers (SOD, CAT, GST, and GSH) and biomolecular markers including HSP70, 8-OHdG, PC, and TBARS levels were examined in fish liver and kidney tissues, which are detoxification organs. The results indicated that IMI and CuSO toxicity alone and in combination altered oxidative stress/antioxidant markers and biomolecular parameters; moreover, 14 days of exposure to the combination of CuSO and imidacloprid in particular exhibited a synergistic effect and caused oxidative toxicity. These findings highlighted the importance of evaluating mixtures of pesticides and metals and that the results show a remarkably synergistic effect. It can be concluded that these biomarkers are important indicators of physiological changes in living organisms.