Sinomenine suppresses collagen-induced arthritis by reciprocal modulation of regulatory T cells and Th17 cells in gut-associated lymphoid tissues.

•Sinomenine, administered orally, markedly attenuates the clinical signs of CIA.•Sinomenine regulates the balance of Th17/Treg cells in intestinal lymph node.•Sinomenine induces the migration of Treg cells from gut to joint.