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.