IN VIVO EVALUATION OF CYTOTOXIC AND GENOTOX-IC RESPONSES INDUCED BY TITANIUM DIOXIDE NANOPARTICLES (TIO2-NPS) IN GOLDFISH (CARASSIUS AURATUS).

Abstract

Titanium dioxide nanoparticles (TiO2-NPs) are widely used in industrial and consumer products,1 raising concerns about their ecotoxicological effects, especially in aquatic environments. With the expansion of nanotechnology, artificial particles are increasingly released into the environment and, due to their structure, often different from natural substances, they tend to persist and degrade slowly, posing risks to organisms lacking natural defense mechanisms.2 Once released, it can be absorbed by aquatic organisms and enter the food chain. Prior studies, such as Rocco et al.3, have shown that TiO2-NPs exposure causes DNA damage and genomic instability in zebrafish. This study aimed to assess in vivo cytotoxic and genotoxic effects in goldfish (Carassius auratus), exposed to 10 μg/L TiO2-NPs for 14 and 21 days. A control group (NC) was maintained without exposure. Three assays were per- formed: eosin Y staining for cell viability, NBT test for ROS pro- duction, and TUNEL test for DNA fragmentation. The results showed a significant reduction in cell viability, especially at the end of the longest exposure period (21 days), with a decrease of 78.6% compared to 96% observed in NC. In addition, a significant production of ROS was observed in the treated samples, with an increase of 27.98% at 14 days and 36% at 21 days. Similarly, a sig- nificant increase in DNA fragmentation was recorded, equal to 24% at 14 days and 28% at 21 days, compared to controls, which show a fragmentation of 13% and 15%, respectively. Furthermore, another aspect observed was the color change of the livery of the exposed specimens, which showed a change from a reddish- orange to blackish shades, suggesting a possible visible effect of prolonged exposure. These data indicate that exposure to TiO2- NPs causes cytotoxic and genotoxic effects in goldfish, effects that become more evident with the prolongation of exposure time. The increase in oxidative stress, DNA damage and the granting of cell viability suggests that these nanoparticles, can have a significant biological impact. The consistency between the results of the three tests strengthens the hypothesis of a potential ecotoxicological risk and underlines the importance of a more rigorous regulatory monitoring of the release of TiO2-NPs in environment