Background and aims: Recent studies address an increase in dopamine levels in the brain of the mice with experimental autoimmune encephalomyelitis. Moreover, it is revealed that dopamine could regulate the immunity function of cells. In the present study, the therapeutic effect of chlorpromazine, as a dopamine antagonist, has been investigated on experimental autoimmune encephalomyelithis (EAE), which is a MS animal model. Furthermore. Moreover, its effects on T-helper cells responses has been evaluated.

Methods: In this experimental study, EAE was induced by guinea pig spinal cord homogenate and complete Freund’s adjuvant in male Wistar rats. Animals were placed in two therapeutic groups (n=7) Treatment with chlorpromazine (10 mg/kg-daily and intrapritoneally) was initiated when the treatment group developed a disability score) day 12). The control group just received a drug solvent (distilled water) with the same schedule. Signs of disease were recorded daily until the day 36 when the rats were sacrificed. Splenocytes were tested for proliferation by MTT test and cytokine production by ELISA.

Results: Chlorpromazine administration reduced the clinical features of EAE significantly after the occurrence of clinical symptoms. Moreover, Chlorpromazine inhibited the production of
pro-inflammatory IL-17 (P<0.01) significantly, and simultaneously increased the levels of
anti-inflammatory IL-10 (P<0.05) in treatment group compared to the control EAE rats. On the other hand, Lymphocyte proliferation significantly decreased (P<0.05) in the treatment group compared to that of the control group.

Conclusion: The results of this study show that chlorpromazine can reduce the inflammatory cytokines and control MS disease.