Anti-inflammatory activity of chondroitin sulfate: new functions from an old natural macromolecule

Chondroitin sulphate (CS) is recommended by the European League Against Rheumatism as a symptomatic slow-acting drug for the treatment of osteoarthritis on the basis of numerous clinical trials and meta-analyses. Furthermore, recent clinical trials have also demonstrated the possible structure-modifying effects of CS. This review focuses on recent experimental results and data available in the scientific literature regarding the anti-inflammatory properties of CS with a view to understanding the molecular basis responsible for its activity. Several animal studies have demonstrated that orally administered CS significantly inhibited hind paw oedema, synovitis and destruction of the articular cartilage in a dose-dependent manner. Furthermore, CS proved to have a beneficial effect in slowing down the development of adjuvant arthritis and in reducing disease markers, findings which support its beneficial activity in humans as a chondroprotective drug. Finally, several in vitro studies have focused on the hypothesis that CS may reduce inflammatory processes by acting on the nuclear translocation of NF-κB, which is closely associated with the blood biomarkers of inflammation, primarily IL-1, IL-6 and C-reactive protein.