Riboflavin may ameliorate neurological motor disability but not spatial learning and memory impairments in murine model of multiple sclerosis

Summary: Background & aims: Riboflavin has an important role in myelin formation. This experimental study assesses the interactions between the effects of riboflavin and interferon beta-1a (INF-β1a) on motor disability, spatial learning and memory, and brain-derived neurotrophic factor (BDNF) in experimental autoimmune encephalomyelitis (EAE). Methods: In the present research C57BL/6 mice (n = 56) were divided into sham and treatment groups. Riboflavin was administrated (10 mg/kg/day) orally for two weeks alone and/or combined with INF-β1a at 150 IU/g of body weight. After the induction of EAE, the animals were investigated for the clinical signs. Spatial learning and memory were assessed through the standard Morris water maze (MWM). The brain and spinal cord levels of BDNF were studied using real-time polymerase chain reactions and enzyme-linked immunosorbent assay. The data were analyzed using one-way ANOVA, repeated measures, and generalized estimating equations model. Results: The results in the brain revealed that BDNF mRNA expression (P < 0.01) and protein levels (P < 0.05) increased in the EAE mice treated with the combination of riboflavin and INF-β1a compared to the treated groups with riboflavin or INF-β1a. Clinical scores were reduced in groups treated with riboflavin compared to other groups. EAE mice treated with riboflavin swam significantly faster in MWM compared to other groups (P < 0.05). No significant differences were found between EAE and healthy mice in other spatial learning and memory evaluating variables. Conclusion: The data highlighted the synergistic role of riboflavin and INF-β1a in improving the disability but not spatial learning and memory mediated by BDNF in EAE. Keywords: Riboflavin, Experimental autoimmune encephalomyelitis, Brain-derived neurotrophic factor, Memor