An herbal formula attenuates collagen-induced arthritis via inhibition of JAK2-STAT3 signaling and regulation of Th17 cells in mice.

Wenjinghuoluo prescription, a traditional Chinese medicine compound treatment of rheumatoid arthritis characterized by wind-cold-dampness arthralgia, contains five herbs, namely, C. cassia Presl., Cinnamomum cassia Presl., Paeonia lactiflora Pall., Saposhnikovia divaricate (Turcz.) Schischk., and Clematis chinensis Osbeck. We have reported that WJHL could inhibit the production of inflammatory mediators in immune cells. This study explored the effect and mechanism of WJHL on collagen-induced arthritis mice. WJHL could significantly improve clinical arthritic conditions; inhibit bone erosion and osteophyte formation in joints; decrease expression of proinflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-17); reduce protein expression levels of JAK2, p-JAK2, STAT3, p-STAT3 and gene expression levels of JAK2, STAT3, IL-17A, RORγt mRNA; elevate osteoprotegerin and Foxp3 mRNA levels and lower Th17 cell proportions in splenocytes. Results suggest that WJHL, specifically regulating the JAK2/STAT3 pathway and Th17 cells, may be a promising herbal medicine candidate for the treatment of RA.