Benzoylacetonitrile as a novel anti-inflammatory compound on attenuating microglia and encephalitogenic T cell activation in experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is an autoimmune disorder and characterized by immune-mediated neuroinflammation and demyelination triggered by the CNS resident immune cells, microglia (MG), and CNS infiltrating pathogenic T cells. Experimental autoimmune encephalomyelitis (EAE) is an animal model of MS, and MG activation and pathogenic Th1/Th17 cell infiltration is responsible for EAE development and progression. We previously demonstrated that benzoylacetonitriles exerted neuro-immunomodulatory activity and identified compound 7a (referred to henceforth as BTA) as promising analog. Here, we investigated whether BTA possessed effects on modulating inflammatory responses in EAE and assessed its effects on MG activation and pathogenic Th1/Th17 differentiation and CNS infiltration in EAE. Our results showed BTA ameliorated disease severity in the chronic C57BL/6 EAE model. Further studies demonstrated BTA suppressed MG activation, attenuated CNS Th1/Th17 infiltration, and inhibited peripheral Th1/Th17 differentiation in EAE. Using protein array, we confirmed BTA inhibited MG activation by suppressing inflammatory cytokines/chemokine production. Furthermore, BTA suppressed Th1/Th17 polarization in vitro, indicating a direct suppressive effect of BTA on Th1/Th17 differentiation. Finally, our results showed that BTA prevented disease relapse in the relapsing-remitting SJL EAE model. In conclusion, our study demonstrates BTA possessed protective and therapeutic effects by ameliorating disease severity in the chronic EAE and mitigating relapse in the relapsing-remitting EAE, respectively. Further analysis revealed BTA exerted effects on inhibiting MG activation and Th1/Th17 differentiation, demonstrated by in vivo and in vitro studies. Altogether, our results suggest the benzoylacetonitrile scaffold could be developed as a novel therapeutic agent for MS/EAE treatment.