“The therapeutic potential of cannabidiol (CBD), the major nonpsychoactive component of cannabis, was explored in murine collagen-induced arthritis (CIA).
CBD was administered after onset of clinical symptoms, and in both models of arthritis the treatment effectively blocked progression of arthritis. CBD was equally effective when administered i.p. or orally.
Clinical improvement was associated with protection of the joints against severe damage.
Taken together, these data show that CBD, through its combined immunosuppressive and anti-inflammatory actions, has a potent anti-arthritic effect in CIA.”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC16904/
“In the present study, we report that CBD has a beneficial therapeutic action on established CIA, and we explore its mode of action.” http://www.pnas.org/content/97/17/9561.long