Pomegranate fruit extract can block enzymes that lead to cartilage destruction in osteoarthritis (OA), according to a recent study conducted at Case Western Reserve University, and partly funded by grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the U.S. Department of Health and Human Services' National Institutes of Health.

A team of researchers, led by Tariq M. Haqqi, Ph.D., put the extract's known anti-inflammatory properties "to the test" in cartilage samples from people with OA. They found that it inhibited the production of enzymes called "matrix metalloproteinases" (MMPs), which play a key role in cartilage cell turnover, degradation, and destruction in OA.

The cartilage samples were prepared in the laboratory and stimulated with a protein that causes the production of MMPs. Variable concentrations (6.25 mg/L to 50 mg/L) of pomegranate fruit extract were added to the cultures that maintained the samples. When the cultures were examined 24 hours later, the MMPs were significantly reduced at all but the lowest concentration of the extract, and at the highest concentration of the extract, MMPs were almost completely blocked. This suggests that something in the extract may be able to stop cartilage destruction.

The research team recommends additional studies to investigate the extract's potential cartilage protective effects in living specimens. The studies would aim to identify the active agents in the extract, and find out whether the body would use them with the same results as seen in these lab tests. The researchers conclude, "These novel results suggest that pomegranate fruit extract or compounds derived from it may inhibit cartilage degradation in OA, and may also be a useful nutritive supplement for maintaining joint integrity and function."

Irreversible cartilage destruction is a hallmark of OA, a joint disorder which affects millions of people, especially older adults. People with OA often turn to herbal or supplemental treatments, but many of these have not been carefully studied for safety and efficacy. Conventional medicines for OA may help with pain and inflammation, but are not known to stop disease progression and joint destruction.

The National Center for Complementary and Alternative Medicine also supported this study.

The mission of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the Department of Health and Human Services' National Institutes of Health, is to support research into the causes, treatment, and prevention of arthritis and musculoskeletal and skin diseases; the training of basic and clinical scientists to carry out this research; and the dissemination of information on research progress in these diseases. For more information about NIAMS, call the information clearinghouse at (301) 495-4484 or (877) 22-NIAMS (free call) or visit the NIAMS Web site at http://www.niams.nih.gov.

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Haqqi TM, et al. Punica granatum L. extract inhibits IL-1β-induced expression of matrix metalloproteinases by inhibiting the activation of MAP kinases and NF-κB in human chondrocytes in vitro. J. Nutrition 2005;135:2096-2102.