Biomarker responses in blood of Carassius auratus with exposure to copper oxide nanoparticles

Aim and Background: The engineered nanoparticles (NPs) are released and present in the environment during manufacturing, transport, use, and disposal operations, suggesting that a fundamental understanding of their mode and range of toxicity is needed. The NPs are able to cross biological membranes and access cells and tissues resulting in physiological disorders. Following environmental release, NPs are likely to represent a possible danger to aquatic life. The copper oxide NPs (n-CuO) are produced abundantly and widely applied in a range of products. Here, we aimed to evaluate the toxic effects of n-CuO in the blood of goldfish Carassius auratus under constant laboratory conditions. Methods: Animal models, goldfish, were treated with n-CuO at the sublethal concentrations namely 0.5, 1 2 mg/L for a period of 14 days, and then recovered for 21 days. After expiration of time period of treatments, blood samples were collected from caudal vein. In the blood sera, level of total antioxidant capacity (TAC), lactate dehydrogenase (LDH) and lysozyme activities were measured spectrophotometrically. Results and discussion: Our results revealed that n-CuO exposures could lower TAC value as a biomarker of oxidative stress, significantly. Additionally, LDH as a marker of cell death and lysozyme as a marker of non-specific immunity in the blood sera were found to be elevated. After recovery time, only lysozyme activity returned to normal level. Conclusion: The n-CuO exposures induced oxidative stress, cell death, and immunity in blood of goldfish, marked by altered biochemical markers.