How does Chinese medicine target cytokine imbalance in rheumatoid arthritis?

Rheumatoid arthritis (RA) manifests as an imbalance between pro- and anti-inflammatory cytokines. Cytokine imbalance is suggested to play critical roles in the development of RA. Currently, various treatments for RA, including biological agents such as antibodies against inflammation mediators, or Chinese herbal medicines, intervene the disease by restoring the balance of cytokines. Chinese medicine (CM) can not only suppress the expression of pro-inflammatory cytokines, but also induce the expression of cytokines with anti-inflammatory and immunomodulatory effects. Thus, Chinese medicine can effectively reduce inflammatory cell infiltration into synovial tissue, pannus formation, and degradation of the extracellular matrix surrounding cartilage cells, thereby reducing subchondral bone damage. This paper reviews the changes of cytokine profiling during development of RA and discuss the mechanisms by which Chinese medicine restores the cytokine balance.