Abstract
Objective: This study was carried out to clarify the effects of the antidepressant fluoxetine, a selective serotonin reuptake inhibitor, for its potential use in autoimmune diseases like multiple sclerosis in a rat model of experimental autoimmune encephalomyelitis (EAE). Methods: The rat EAE model was induced by subcutaneous injection of guinea pig spinal cord homogenate. Rats received fluoxetine via daily intragastric administration, starting 2 weeks prior to immune induction (fluoxetine pretreatment). Clinical scores and pathological changes in EAE rats were analyzed. Changes in serum cytokine levels were assessed by ELISA. Results: Fluoxetine pretreatment significantly promoted remission in EAE. Histologically, fluoxetine-induced neuroprotection was accompanied by reductions in inflammatory foci and in the degree of demyelination in the spinal cord of EAE rats. The increase in serum IFN-γ in the EAE model was also suppressed by fluoxetine administration. Conclusions: These findings suggest that the prophylactic use of fluoxetine can relieve symptoms during remission in the acute EAE model, and these neuroprotective effects are associated with its anti-inflammatory effects.