Genotoxicity and oxidative stress induced by the orally administered nanosized nickel and cobalt oxides in male albino rats

Background: Nanoparticles (NPs) are extensively used in many areas of our daily life. Thus, human exposure to a mixture of the NPs is likely to occur. However, most of the previous studies have investigated the toxicity of the individual NPs. Therefore, the current study investigated the genotoxicity and oxidative stress induced by an acute oral administration of the nano-sized nickel oxide (NiO) and/or cobalt oxide (CO3O4) in the brain, liver, and kidney of the rats. Results: After 1 day of an administration with NiO-NPs or Co3O4-NPs, at the dose levels of 0.5 and 1.0 g/kg, remarkable elevations in malondialdehyde (MDA) levels, percentage of DNA damage (%DNA), tail length (TL), and tail moment (TM), accompanied by marked reductions in the levels of zinc (Zn), glutathione (GSH) as well as the activities and expression levels of the superoxide dismutase (SOD) were recorded in all the studied groups, as compared to the controls. The changes in the levels of all the studied parameters were in a time- and dose-dependent manner. Excessive productions of the reactive oxygen species (ROS) associated with the genomic DNA fragmentation were observed in the experimental groups, as compared to the controls. However, in the groups administered with NiO-NPs and Co3O4-NPs together, the alterations in all the studied parameters were improved as compared to those administered NiO-NPs or Co3O4-NPs solely. Conclusion: The NiO-NPs and Co3O4-NPs antagonized each other leading to an alleviation of the genotoxicity induced by each of them.