Visceral fat increase and signals of inflammation in adipose tissue after administration of titanium dioxide nanoparticles in mice

Titanium dioxide nanoparticles (TiO₂ NP) are present in several daily use products, and the risks associated with their bioaccumulation must be stablished. Thus, an evaluation of several toxicological-related effects was conducted after intraperitoneal injection of TiO₂ NPs in mice. Mice were divided into two groups, which received 2 mg kg⁻¹ day⁻¹ of TiO₂ NPs or vehicle saline. Assessments of body and organ weight as well as biochemical, hematological, and histopathological analyses were performed in order to evaluate adverse effects. The results showed that treatment resulted in an increased visceral and abdominal fat deposition, as well as a mononuclear inflammatory infiltrates in the abdominal fat tissue. The TiO₂ NPs induced significant decrease in the weight gain and splenomegaly. Additionally, TiO₂ NP-treated mice showed altered hematological parameters and significant liver injuries, which were characterized by histopathological and biochemical changes. Our results also indicated that TiO₂ NPs were absorbed and significantly accumulated in the spleen, liver, and kidney. These results showed the ability of TiO₂ NPs to infiltrate different organs and to induce inflammation and liver and spleen damage with visceral fat accumulation. The data obtained are useful for the governmental authorities to legislate and implement regulations concerning the use and the production of this kind of material that might be hazardous to the living beings, as well as to the environment.