Forsythoside B ameliorates neuroinflammation via inhibiting NLRP3 inflammasome of glial cells in experimental autoimmune encephalomyelitis mice

Abstract

Neuroinflammation mediated by glial cells plays a crucial role in demyelination in experimental autoimmune encephalomyelitis (EAE), a multiple sclerosis (MS) model. Forsythoside B (FTS·B), a natural phenylethanoid glycoside isolated from the dried fruits and leaves of Forsythia suspensa (Thunb.) Vahl, has been found to have antioxidant, anti-apoptotic, and anti-inflammatory properties. However, there is currently no report or research on the effectiveness of FTS·B treatment for EAE. The aim of this study was to investigate the neuroprotective properties of (FTS·B) on EAE and reveal its potential mechanisms. Myelin oligodendrocyte glycoprotein-induced EAE mice were randomly categorized into the control, EAE model, and FTS·B treatment groups. Behavioral testing, pathology, immunohistochemistry, immunofluorescence staining, and western blot analysis of spinal cord tissue were used to determine the effects and mechanisms of FTS·B on EAE in mice. We found that FTS·B treatment could significantly alleviate and reduce the clinical symptoms and morbidity of EAE, respectively. In addition, FTS·B administration reduced inflammatory response and demyelination by inhibiting glial cell activation in the spinal cord of EAE mice. Further experiments confirmed that FTS·B inhibited the formation of NLRP3 inflammasome in microglia and astrocytes, thereby suppressing neuroinflammation and GSDMD-mediated pyroptosis. Altogether, these results suggest that FTS·B treatment attenuates central neuroinflammation and pyroptosis by inhibiting NLRP3 inflammasome of glial cells in EAE mice.