Vitamin E protects the insulin sensitivity and redox balance in rat L6 muscle cells exposed to oxidative stress

Abstract

Background The effect of reactive oxygen species (ROS) on insulin action is unclear. This study was carried out to explore the effect of prolonged low grade oxidative stress and vitamin E treatment on cultured rat L6 muscle cells. Methods L6 myotubes were incubated with vitamin E for 18 h and treated with H 2O 2 generating system for 12 h. Insulin stimulated glucose uptake, total antioxidant capacity and reduced glutathione concentration were measured. Results There was a marked decrease in insulin stimulated glucose transport in L6 cells exposed to H 2O 2 generating system. Pretreatment with vitamin E attenuates the effect of H 2O 2 on insulin action. Treatment with H 2O 2 caused a significant reduction in the levels of reduced glutathione and total antioxidant capacity, these alterations were reversed by vitamin E pretreatment. Vitamin E per se had no effect on insulin stimulated glucose transport in cells not exposed to oxidative stress. Conclusion In conclusion, our observations indicate that vitamin E improves the free radical defense system potential and prevents oxidative stress induced insulin resistance in rat L6 muscle cells.