Protective effects of Paederia scandens extract on rheumatoid arthritis mouse model by modulating gut microbiota

Paederia scandens (Lour.) Merr. (P. scandens) has been traditionally used to treat the pain of rheumatism. The purpose of this study was to investigate the possible influences of P. scandens on the progression of rheumatoid arthritis (RA), inflammatory responses and gut bacterial communities in RA mouse model. collagen-induced arthritis (CIA) mice were orally administered with P. scandens extract (PSE) for 24 days. Then, pro-inflammatory cytokine levels in the serum were measured, and gut microbiota was examined with Illumina HiSeq. Compared with the vehicle group, PSE significantly inhibited paw swelling and reduced arthritis score. Histological examination of ankle soft tissue of demonstrated PSE effectively inhibited the tissue fibrosis and inflammatory cell infiltration. The increased serum levels of TNF-α, IL-1β, IL-6, IL-7, and IL-23 in RA mice were significantly suppressed by PSE. Moreover, PSE treatment help restore gut microbial ecosystem altered in RA mice including decreasing relative abundance of inflammatory related microorganisms, Desulfovibrio, Mucispirillum, Helicobacter, and Lachnospiraceae. These results suggest that PSE has therapeutic effects in RA mice with CIA, showing the potential as anti-arthritis reagent.