Neurotoxic effect of titanium dioxide nanoparticles: Biochemical and pathological approach in male wistar rats

Abstract

Objective: Titanium dioxide nanoparticles (TiO2 NPs) are widely used in pharmaceutical, cosmeceutical, biomedical and industrial applications. The adverse effects of TiO2 NPs are also increasing alarmingly. The purpose of this study is to investigate the toxicity of TiO2 NPs on biochemical and histological changes in different regions of brain in adult male Wistar rats. Methods: Two different doses of TiO2 NPs (50 mg/kg b. w and 100 mg/kg b. w) administered orally for 14 d along with one control group, each group consisting of six animals. Standard biochemical methods were adopted for the estimation of enzymes alkaline phosphatase, 5' nucleotidase, ATPases and gamma-glutamyl transpeptidase. Trace elements calcium, sodium, potassium and magnesium as well as metals like iron, zinc and copper were also estimated. Results: When compared with the control group, the enzymes ATPases, ALP, 5'-NT and GGT activities were significantly decreased in both the TiO2 NPs treated groups. Ca, Na, Fe, Cu and TiO2 contents were significantly increased in both the experimental groups, while the K, Mg and Zn contents decreased. However, the changes in the parameters studied were more in 100 mg treated group (p<0.001) when compared to the 50 mg treated group (p<0.05and p<0.01). Moreover, it is also evident that different regions responded differently due to TiO2 NPs exposure. The changes were maximum in the cerebral hemisphere (p<0.001) followed by medulla oblongata (p<0.001) and cerebrum (p<0.05). Conclusion: The results clearly imply that TiO2 NPs could impair the electrochemical gradient, ionic homeostasis and membrane stability in different regions of the rat brain.