Background: Vitamin E has been reported to have a beneficial effect on nonalcoholic fatty liver disease (NAFLD); however, the underlying mechanism of action has not yet been clearly defined.
Aim: We aimed to evaluate the effects and mechanisms of vitamin E on lipid and glucose homeostasis both in vivo and in vitro.
Methods: An NAFLD model was established in C57BL/6 mice fed a 30% fructose solution for 8 weeks. Subsequently, NAFLD mice were given vitamin E (70 mg/kg) for 2 weeks. In addition, L02 cells were treated with 5 mM fructose and 100 nM vitamin E to explore the potential mechanisms of action.
Results: Vitamin E reversed the impaired glucose tolerance of fructose-treated mice. Histopathological examination showed that liver steatosis was significantly relieved in vitamin E-treated mice. These effects may be attributed to the upregulation of nuclear factor erythroid-2-related factor 2 (Nrf2), carboxylesterase 1 (CES1), and downregulated proteins involved in lipid synthesis by vitamin E treatment. In vivo, vitamin E also significantly reduced lipid accumulation in fructose-treated L02 cells, and the Nrf2 inhibitor ML385 reversed the protective effects of vitamin E.
Conclusion: These data indicated that the therapeutic effects of vitamin E on lipid and glucose homeostasis may be associated with activation of the Nrf2/CES1 signaling pathway.
Keywords: Carboxylesterase 1; Fructose; Glucose homeostasis; Lipid; Nonalcoholic fatty liver disease; Vitamin E.