Evaluating the toxic oral doses of iron oxide nanoparticles in mice

Iron nanoparticles (α-Fe2O3) are used in a wide range of biological and medicinal applications, including the delivery of specific drugs, other pharmaceutical and agricultural ones. Its toxic effects, risk assessment and safety are still being researched. Hence, in this investigation, 28-day repeated doses for assessing the acute and sub-acute oral toxicity were conducted on (α-Fe2O320-40) nanoparticles with special reference to target histopathologically, the neurobehavioral and alteration in mice brain and liver. The acute LD50 was 14.74 g/kg orally, using Dixon’s method, as well as recording the toxicity signs, such as lethargy, rapid respiration, subcutaneous hemorrhage, plioerection, tremor, and itching. Oral repeated doses for 28 days of α-Fe2O3 nanoparticles (75 and 150 mg/kg) led significantly to decrease head pocking, considerable lengthening of negative geotaxis performance, and to a significant decline in open-field activity, compared to the control group. α-Fe2O3 nanoparticles at dose 300mg/kg orally in the 7th and 14 days of treatment led to significantly increase mice body weight compared to the control group. The nanoparticles α-Fe2O3 at dose 75, 150 and 300mg/kg after 28 days of treatment cause in liver vacuolar degeneration of hepatocytes, congestion of sinusoids, central vein, and necrosis, while in brain, it causes necrosis, gliosis, congestion of blood vessels, thrombus formation and neuronophagia. We conclude that the higher doses and longer exposure to nanoparticles α-Fe2O3 show significant toxicity effects represented by neurobehavioral and histopathological changes.