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

Abstract

Objective: The aim of the present work is to evaluate the toxicity of titanium dioxide nanoparticles (TiO₂NPs) according to their doses and particle sizes. Materials and methods: The effect of five days oral administration of TiO₂NPs (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. Results: 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 TiO₂NPS (21 nm) had more adverse effect in all the selected biochemical parameters, genetic aberrations and histological investigations. Conclusions: Toxicity of TiO₂NPs increases in a dose-dependent manner and vice versa with particles size. The evaluated biomarkers are good indicators for TiO₂NPs toxicity. More detailed studies are required before the recommendation of TiO₂NP_S as food additives.

Keywords: Titanium dioxide nanoparticles; genotoxicity; liver histology; liver injury; oxidative stress.