Effect of vitamin E on dorsal root ganglion neuronal death and nerve regeneration after nerve injury in rats

Abstract

Introduction: After nerve injury, there is degeneration of nerve fibers called Wallerian degeneration followed by nerve regeneration.

However, the recovery is limited by slow axonal regeneration and neuronal cell death. To improve the regeneration, many drugs have been testing. Vitamin E has antioxidant property which can reduce oxidative stress. In the past, several studies have shown the benefits of vitamin E in nervous system disorders in which oxidative stress plays a causal role. Oxidative stress is also found after nerve injury. Therefore, vitamin E may be beneficial to nerve injury. The aim of this study was to test the effect of vitamin E on dorsal root ganglion neuronal death and nerve regeneration after nerve injury in rats. Material and method: studyl Crushing the left sciatic nerve, vitamin E was given via gavage in a dose of 100, 500 and 1,000 mg/kg/day for 10 days. L4 DRG neurons was counted The next study used the same nerve injury model with vitamin E 500 mg/kg/day treatment for 3 weeks. Then, the functional recovery of sciatic nerve was tested by measuring foot prints for calculating the Sciatic functional index (SFI) and measure morphometry of sciatic nerve. Results: studyl Vitamin E 500 and 1,000 mg/kg/day significantly reduced neuronal cell loss in DRG (p<0.01) compared with 100 mg/kg/day and control group. Study 2 showed that vitamin E 500 mg/kg/day did not significantly improve the functional recovery. However, in the nerve morphometry study, fiber density in segment 2 and 3 and myelinated nerve fiber in segment 3 were significantly increased in the vitamin E group (p<0.05) compared with the control group which indicated the nerve regeneration. Conclusion : These data show the benefits of vitamin E on nerve injury by reducing neuronall cell loss and enhancing nerve fiber regeneration.