Fluoxetine promotes remission in acute experimental autoimmune encephalomyelitis in rats.

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.