Study on Different Mechanisms of Gastric Damage after Oral Administration of Titanium Dioxide Nano- and Microparticles

Abstract

The study was performed with male Wistar rats who individually received nano (NPs) or fine (FPs) titanium dioxide (TiO2) particles with an attractive food for 7 days. Two doses of TiO2 NPs (200 and 400 mg/kg) and one dose of TiO2 FPs (200 mg/kg) were used. The macroscopic status of the gastric mucosa as well as the pro-and antioxidant activity of the adherent mucus layer were examined. Our experiments showed that a chronic (7-day) oral administration of TiO2 nanoor microparticles increased the area of erosive lesions and the amount of mucosal hemorrhages with respect to control. However, the damage mechanisms in the group “TiO2 FPs 200 mg/kg” were different from those in the groups “TiO2 NPs 200 mg/kg” and “TiO2 NPs 400 mg/kg”. The oxidative damage of glycoproteins occurred in the gastric mucus of animals who received TiO2 NPs; this led to degradation of the adherent mucus layer and deterioration of its protective properties. Therewith, a dose-dependent reaction was not observed at the indicated doses of TiO2 NPs. The oxidative damage of glycoproteins was not found in the gastric mucus of animals who received TiO2 FPs; erosive lesions and mucosal hemorrhages could be induced by TiO2 FPs as the mechanical and chemical agent that does not provoke oxidative stress at the indicated dose. Our study demonstrated that the use of TiO2 in any form for increasing the attractivity of foodstuffs can be harmful for the digestive tract.