Assessment of titanium dioxide nanoparticles toxicity via oral exposure in mice: effect of dose and particle size.

The aim of the present work is to evaluate the toxicity of titanium dioxide nanoparticles (TiONPs) according to their doses and particle sizes. The effect of five days oral administration of TiONPs (21 and 80 nm) with different doses (50, 250 and 500 mg/kg body weight) was assessed in mice via measurement of oxidative stress markers; glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and nitric oxide (NO), liver function indices; aspartate and alanine aminotransferases (AST and ALT), chromosomal aberrations and liver histopathological pattern. The results revealed drastic alterations in all the measured parameters and showed positive correlation with the gradual dose increment. In addition, the smaller particle size of TiONPS (21 nm) had more adverse effect in all the selected biochemical parameters, genetic aberrations and histological investigations. Toxicity of TiONPs increases in a dose-dependent manner and vice versa with particles size. The evaluated biomarkers are good indicators for TiONPs toxicity. More detailed studies are required before the recommendation of TiONP as food additives.