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