Background: Obesity is a risk factor for non-alcoholic fatty liver disease (NAFLD). The disease is associated with impairment of pro/antioxidant equilibrium and the inflammation in liver tissue. The aim of the work was to investigate the anti-inflammatory properties of the nanocrystalline cerium dioxide (nCeO(2)) on the rat model of NAFLD associated with monosodium glutamate (MSG)-induced obesity. Methods: The study was carried out on three groups of rats: control, MSG- and MSG + nCeO(2). They were injected with saline (control) or MSG. A month after born MSG- rats had been treated with water in a volume of 2.9 ml/kg, MSG + CeO2 groups - with CeO2 intragastrically (i.g.). The anthropometric and carbohydrate metabolism parameters, content of proinflammatory cytokines (interleukin (IL)-1 beta, IL-12Bp40, interferon-gamma (INF-gamma)) and anti-inflammatory cytokines (IL-4, IL-10, tumor growth factor-beta (TGF-beta)) were measured by ELISA. Results: We have demonstrated the anti- obesity effect of nanocrystalline cerium dioxide and for the first time its anti- inflammatory properties. Nanoparticles reduced the content of pro-inflammatory cytokines (IL-1 beta, IL-12Bp40) in rat serum and restored the level of anti- inflammatory cytokines (IL-4, IL-10, TGF-beta) to the control values. Conclusion: The precise mechanisms of this phenomenon remain to be unclear but we suppose they are at least partially associated with the strong anti- oxidant action of studied substance. Nanocrystalline cerium dioxide attenuates the inflammatory processes in rat blood that can prevent obesity complications and liver injury. (C) 2017 Elsevier Masson SAS. All rights reserved.