Abstract: Objective To Observe the effect of estrogen on myelin and axonal injury in the central nervous system(CNS) of experimental autoimmune encephalomyelitis（EAE） mice. Methods 40 mice EAE models were induced with MOG35-55 peptide, all animal ovarectomized. They were divided into treatment group and control group. Treatment group was treated by estrogen. Two groups were compared by clinical symptom scores. The myelin and axonal injury of the brain and spinal cord were studied by Luxol Fast Blue（LFB）-H&E and Bielschowsky staining. The expression of MBP and GAP-43 were examined by quantitative real-time PCR and western-blot. Results Clinical symptom score and incidence of treatment group were lower than that in the control group. Luxol Fast Blue（LFB）-H&E, Bielschowsky staining, quantitative real-time PCR and western-blot showed that myelin and axonal injury was decreased in treatment group. Conclusion Estrogen could decrease myelin damage and promote axonal regeneration to treat EAE mice.

Key words: experimental autoimmune encephalomyelitis, estrogen, myelin damage, axonal regeneration, multiple sclerosis