Therapeutic potential of aryl hydrocarbon receptor ligands derived from natural products in rheumatoid arthritis.

Rheumatoid arthritis is an autoimmune-mediated inflammatory disease, which is characterized by chronic synovitis, progressive bone destruction and reduced mobility. Aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor, has been shown to regulate the differentiation, activation and apoptosis of various cells involved in rheumatoid arthritis. The ligands of AhR such as tetrachlorodibenzo-p-dioxin, benzo[a]pyrene and 3,3'-diindolylmetheane are able to inhibit osteoclastogenesis and attenuate arthritis in mice. However, the long-term use of these compounds is associated with severe side effects, which limit their use as therapeutic agents in animals or humans. There is an urgent need to search for new AhR ligands that are effective and safe. This MiniReview discusses the potential therapeutic value of the AhR ligands derived from natural products.