Vitamin E protects the insulin sensitivity and redox balance in rat L6 muscle cells exposed to oxidative stress.
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 H2O2 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 H2O2 generating system. Pretreatment with vitamin E attenuates the effect of H2O2 on insulin action. Treatment with H2O2 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.


CONCLUSIONS
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.
Vinayaga Moorthi
R
R
Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry-605 006, India.
Bobby
Zachariah
Z
Selvaraj
N
N
Sridhar
M G
MG
D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D032342:Muscle Cells / Q000187:drug effects* / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014810:Vitamin E / Q000494:pharmacology*
D007328:Insulin; D017382:Reactive Oxygen Species; D014810:Vitamin E; D005947:Glucose