Several studies highlight the presence of aluminum and diclofenac in water bodies around the world and their ability to induce oxidative stress and a negative effect on biomolecules in several aquatic species. However, studies evaluating the toxic effect of mixtures of these contaminants are scarce. The objective of this work was to determine the genotoxic, cytotoxic and embryotoxic effect of the mixture of aluminum and diclofenac at environmentally relevant concentrations on Cyprinus carpio. Juveniles of Cyprinus carpio were exposed to 0.31 μg L-1 of diclofenac, 24.45 mg L-1 of aluminum, and a mixture of both contaminants at the same concentrations for 12, 24, 48, 72 and 96 h. After the exposure time the liver, gills and blood were extracted and the following biomarkers were evaluated: micronucleus frequency, comet assay, caspase activity and TUNEL test. On the other hand, Cyprinus carpio embryos were exposed to diclofenac (0.31 μg L-1), aluminum (0.06 mg L-1) and their mixture at the same concentrations and exposure time. Microscopic observation was performed to evaluate embryonic development at 12, 24, 48, 72 and 96 h. Diclofenac (0.31 μg L-1) induces significant increases in micronucleus frequency with respect to control (p < 0.05), in all tissues. Aluminum (24.45 mg L-1) significantly increases DNA damage index in liver and blood cells with respect to control (p < 0.05). All treatments increase caspases activity in all tissues with respect to control (p < 0.05). Diclofenac increases the percentage of TUNEL-positive cells in liver and blood; while aluminum and the mixture increases it significantly in gills and blood with respect to the control (p < 0.05). The mixture significantly delays embryonic development, while aluminum and the mixture significantly increase teratogenic index with respect to control (p < 0.05). In conclusion, exposure to environmental concentrations of aluminium, diclofenac and their mixture induces genotoxic damage, cell death by apoptosis and negative effects on the development of Cyprinus carpio and the toxic response is modified by the interaction of the xenobiotics.

The present study was aimed to evaluate the effect of municipal wastewater of Tung Dhab drain to freshwater fish Labeo rohita through genotoxicity assays. The idea is to explore and standardize procedures for assessment of toxic impact of pollutant at the cellular level in aquatic species. Hence, chronic, non-renewal toxicity tests were performed with sublethal concentrations (17.7, 26.6 and 35.4 %) of wastewater for exposure durations of 15, 30 and 60 days. Recovery experiments were also performed for duration of 60 days. Higher micronuclei (MN) and binuclei (BN) frequencies were recorded in fluorescently stained liver cells as compared to frequencies obtained for gill cells and erythrocytes. The induced frequencies of MN, BN and nuclear abnormalities (NA) were found in the following order: MN (liver cells) > BN (liver cells) > BN (gill cells) > MN (gill cells) > NA (erythrocytes) > MN (erythrocytes). The results pointed towards the mutagenic nature of water quality of Tung Dhab drain and recommend the incorporation of the liver and gill cells as biomarkers of cytotoxicity over erythrocytes in chronic experiments during water monitoring programs.