Introduction: Oxidative stress and the production of Reactive Nitrogen (RNS) and Oxygen (ROS) Species play an important role in the pathogenesis and the progression of MS. This study aimed to investigate the effect of exercise on disease severity, NRF2 protein levels, and xanthine oxidase enzyme in the spinal cord during the chronic period of the disease.
Methods: Thirty female C57Bl/6 mice (6-8 weeks) were divided into three Voluntary Exercise, Experimental Autoimmune Encephalomyelitis (EAE), and Healthy Control groups. After induction of EAE by Myelin Oligodendrocyte Glycoprotein (MOG35-55) and after the mice showed a clinical score of one for two consecutive days, they performed one hour of voluntary exercise for four weeks and five days a week. Forty-eight hours after the last training session, the mice were anesthetized with Ketamine and Xylazine, and the spinal cord tissue was removed. The location of NRF2 proteins in the gray and white matter of the spinal cord was investigated by Immunohistochemistry, and xanthine oxidase was measured by xanthine oxidase assay kit according to the kit manufacturer's instructions and by ELISA method.
Results: Voluntary exercise increased NRF2 protein levels in the white matter (P=0.0001) and gray matter (P=0.0001) of the spinal cord and decreased xanthine oxidase levels in the spinal cord (P=0.001), and attenuated disease severity during the chronic period (P=0.01).
Conclusion: Voluntary exercise reduces oxidative stress and disease severity during the chronic period of the disease and would be a good strategy for controlling and treatment of MS disease.