Genotoxicity of zinc oxide nanoparticles: an in vivo and in silico study.

Zinc oxide (ZnO) NPs are being used worldwide in consumer products and industrial applications. Based on predefined pathways, this study synthesized and characterized the nanostructures of ZnO NPs. The genotoxic effects of these nanomaterials were evaluated using a short-term in vivo bioassay, the somatic mutation and recombination test (SMART) in Drosophila melanogaster. In addition, a systems biology approach was used to search for known and predicted interaction networks between ZnO and proteins. The results observed in this study after in vivo exposure indicate that ZnO NPs are genotoxic and that homologous recombination (HR) was the main mechanism inducing loss of heterozygosis in the somatic cells of D. melanogaster. The results of in silico analysis indicated that ZnO is associated with the nuclear factor-kappa-beta (NFKB) protein family. In accordance with this model, ZnO exposure decreases the levels of NFKB inhibitory protein in the cell, consequently increasing NFKB dimers in the nucleus and inducing DNA double strand breaks (DSB) repair via HR. This excess level of HR can be observed in the SMART results. Assessing the mutagenic/recombinagenic effect of nanomaterials is essential in the development of strategies to protect human and environmental integrity.