Mechanism of Proanthocyanidins B2 in Alleviating Experimental Autoimmune Encephalomyelitis via Inhibition of Th17 Cells

EAE-induced mice received intraperitoneal injections of PC-B2 (50 mg/kg) from day 10 (post-symptom onset) until day 18, followed by sacrifice. Luxol fast blue staining, immunofluorescence, flow cytometry, ELISA, and Western blotting were employed to assess PC-B2’s effects on demyelination, inflammatory responses, and T-cell dynamics in the CNS and peripheral spleen.Results PC-B2 significantly alleviated spinal cord demyelination and reduced the secretion of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12, and IL-23) in both the CNS and spleen.

Furthermore, PC-B2 suppressed Th17 cell polarization and downregulated the expression of interferon regulatory factor 4 (IRF4) in Th17 cells.Conclusion These findings demonstrate that PC-B2 exerts therapeutic effects in EAE by inhibiting IRF4-mediated Th17 polarization, thereby reshaping the inflammatory microenvironment. This highlights PC-B2 as a promising candidate for MS treatment.