Abstract: Objective：To compare the effect of TiO₂ nanoparticles on antioxidant function and element content of liver and kidney tissues in young and adult rats. Methods: Forty-ight SD male rats, half in 4-eek (youth) old and half in 9-eek (adult) old rats, were randomly divided into 8 groups, which were exposed to TiO₂ nanoparticles ［(75±15) nm, anatase］ through intragastric administration at 0, 10, 50 and 200 mg/kg body weight every day for 30 days. The liver and kidney tissues were collected for antioxidant function and element content analysis. Results: 200 mg/kg TiO₂ nanoparticles exposure significantly increased the liver total superoxide dismutase (T-OD) activity and the kidney reduced glutathione (GSH)/oxidized glutathione (GSSG) ratios in young rats, and significantly decreased the liver Mo, Co, Mn and P contents and the kidney Rb and Na contents in young rats. 200 mg/kg TiO₂ nanoparticles exposure significantly increased GSH/GSSG ratios and Rb contents and decreased Na contents in the liver of adult rats. No significantly difference was found in antioxidant indexes and elements content in the kidney of adult rats between three experimental groups and control group. Conclusion: TiO₂ nanoparticles can enhance the antioxidant capacity and decrease the elements content in rat liver and kidney tissues. The liver is the more sensitive target organ and the young animals are more susceptible to TiO₂ nanoparticles toxicity by the oral routes.

Key words: Nanoparticles, Titanium dioxide, Safety, Hepatotoxicity, Nephrotoxicity