Brain-derived neurotrophic and immunologic factors: beneficial effects of riboflavin on motor disability in murine model of multiple sclerosis

OBJECTIVE(S): In the present study, C57BL/6 female mice (n=56) were used to explore the neuroprotective effects of riboflavin in motor disability of experimental autoimmune encephalomyelitis (EAE) as a model of multiple sclerosis. MATERIALS AND METHODS: The animals were assigned into 7 groups: sham-operated 1 (SO1), healthy mice receiving PBS (phosphate buffer saline); sham-operated 2 (SO2), healthy mice receiving PBS and riboflavin; sham treatment 1 (ST1), EAE mice receiving water; sham treatment 2 (ST2), EAE mice receiving sodium acetate buffer; treatment 1 (T1), EAE mice receiving interferon beta-1a (INFβ-1a); treatment 2 (T2), EAE mice receiving riboflavin; treatment 3 (T3), EAE mice receiving INFβ-1a and riboflavin. After EAE induction, scoring was performed based on clinical signs. Upon detecting score 0.5, riboflavin at 10 mg/kg of body weight and/or INFβ-1a at 150 IU/g of body weight administration was started for two weeks. The brain and spinal cord levels of brain-derived neurotrophic factor (BDNF), interleukin-6 (IL-6), and interleukin-17A (IL-17A) were studied using real-time PCR and ELISA methods. RESULTS: BDNF expression and protein levels were increased in the brain and spinal cord of the T3 group compared with the other groups (P<0.01). IL-6 and IL-17A expressions were increased in the brains of the T3 and T1 groups, respectively, compared to the other groups (P<0.01). The daily clinical score was reduced significantly by riboflavin in both effector and chronic phases of the disease compared with that of the controls (P<0.05). CONCLUSION: Our findings showed that riboflavin is capable of suppressing the neurological disability mediated by BDNF and IL-6.