Curcumin, an extract of the spice turmeric, is a natural product with potent anti-inflammatory properties that also exerts beneficial effects on cartilage metabolism. Scientists believe curcumin inhibits degradative enzymes such as metalloproteinases and cyclooxygenase-2 (COX-2) and reduces cartilage cell apoptosis (programmed cell death).
To study the effect of curcumin on cartilage breakdown in vitro (in the laboratory), a research team from the University of Nottingham established a model of cartilage inflammation that mimics the inflammatory events thought to occur in osteoarthritis. They induced cartilage degeneration with the pro-inflammatory mediator IL-1 beta. Then they co-treated some cultures with curcumin (0.1-100 µmol/L) for five days, subsequently measuring the amount of glycosaminoglycans (GAG) released from the cartilage in the culture media.
Curcumin significantly reduced the IL-1 beta-stimulated release of GAG back to control levels. Specifically, cartilage explants exposed to 100 µl curcumin reduced GAG release by an average of 20% to 27% when co-exposed to 10 and 25ng/ml IL-1 beta, respectively.
As a result, the authors suggested "curcumin antagonizes GAG release in vitro" and that "this model may be an effective in vitro system for evaluating the potential beneficial effects of botanical extracts."
Investigators indicated the need for more research to determine the "true efficacy and potential safety" of curcumin.