Abstract: The combined toxicity of Fe3O4 nanoparticles (nano-Fe3O4) and CdCl2 in the liver of mice was reported. The organ coefficient, histopathological changes, serum biochemical parameters and oxidative stress responses were determined in the liver of mice after oral administration of nano-Fe3O4 and/or CdCl2 for 7 d. The results show that nano-Fe3O4 and CdCl2 mutually competitively inhibit Fe and Cd uptake in the liver. Oral nano-Fe3O4 (50 mg/kg BW) does not induce obvious injury in mice. In contrast, oral CdCl2 (2.0 mg/kg BW) causes signigicant oxidative damage in the liver. Co-administration of nano-Fe3O4 with CdCl2 significantly attenuates CdCl2-induced damage in the liver through reduction of oxidative stress. The inhibition of Cd-induced deprivation of tissue Fe and decrease in Cd accumulation after co-administration of nano-Fe3O4 with CdCl2 might play two key roles in the protective effect of nano-Fe3O4 on CdCl2-induced oxidative damage. Nano-Fe3O4 may be used as a perfect MRI contrast agent and drug carrier for patients with Cd poisoning, since it not only acts as an MRI contrast agent or drug carrier, but also simultaneously attenuates Cd-induced toxicity.

Key words: nano-Fe3O4, Cd, joint toxicity, liver