Genotoxic effect of iron oxide (Fe2o3) nanoparticles on Allium cepa

Iron oxide (Fe2O3) nanoparticles (NP) are widely used, especially in clinical applications, as they are physically and chemically stable and considered environmentally safe. Due to their properties, they are important particles that have begun to find widespread use as a contrast agent in magnetic resonance imaging (MRI), in cell differentiation and detection, in the treatment of hyperthermia and in drug delivery. They are also used in sunscreens, cosmetics, electrical applicances, food products, defense and agriculture. Recent studies show that Fe2O3 NPs can be toxic and especially genotoxic in some species and test systems. Therefore, the aim of this study was to examine the genotoxic effects of Fe2O3 nanoparticles and microparticles (MP) using Allium cepa L. root tip cells, an indicator organism, by Allium and comet tests. Allium test was applied by treating Allium cepa L. root tips with 125, 250, 500 and 750 µg/mL concentrations of Fe2O3 NPs and MPs for 24, 48, and 72 hours. All the concentrations of both the nanoparticles and microparticles of Fe2O3 caused a decrease in the mitotic index compared to the negative control at 24, 48, and 72 h. These results reveal that both the NPs and MPs of Fe2O3 have nearly similar cytotoxic effects. Both the nanoparticles and microparticles of Fe2O3 increased the frequency of mitotic aberrations in Allium cepa L. root tip cells compared to their respective negative controls at all the treatment periods and concentrations. Fe2O3 NPs and MPs induced the formation of irregular prophase, C-metaphase, stickiness, bridge and star anaphase. In the comet assay, increased DNA damage was determined in some treatments of the both NPs and MPs of Fe2O3 in A. cepa L. root tip cells. On the other hand, genotoxic and clastogenic effects of Fe2O3 NPs were much higher than those of the Fe2O3 MPs. On the other hand, in the comet assay, MPs were more toxic than NPs. Taken together, this research revealed the cytotoxic, genotoxic and DNA damaging effect of both of the particles. All these results show that genotoxic potential of especially Fe2O3 NPs need to be further investigated by using different organisms and test systems for the safe usage of these particles.