by David Douglas

Last Updated: 2007-11-28 15:06:12 -0400 (Reuters Health)

NEW YORK (Reuters Health) – Water-soluble C60 fullerene prevents the degeneration of articular cartilage in a rabbit model of osteoarthritis (OA) through the downregulation of chondrocyte catabolic activity, according to Japanese researchers.

"C60 is characterized as a strong radical sponge," lead investigator Dr. Kazuo Yudoh told Reuters Health. "This agent has a high reactivity with oxygen free radicals and potential activity as a free radical scavenger."

Dr. Yudoh of St. Marianna University School of Medicine, Kawasaki, and colleagues investigated the activity of C60 fullerene in human chondrocytes in vitro and in a rabbit model of OA.

In the in vitro study, C60 inhibited the catabolic stress-induced production of matrix metalloproteinases 1, 3, and 13, the researchers report in the October issue of Arthritis and Rheumatism. It also down-regulated matrix production, apoptosis, and premature senescence in the chondrocytes.

Intra-articular injection into the knee joint of rabbits with OA significantly reduced articular cartilage degeneration. The effect was dose dependent and the results were superior to those achieved with sodium hyaluronidase.

Moreover, the combination of hyaluronidase and C60 provided results beyond that achieved with either agent alone.

The study, continued Dr. Yudoh, indicates that "C60 fullerene may be useful as a protective agent against the oxygen free radical-induced pathological features in a variety of diseases."

"Now, we are focusing on the inhibitory effect of C60 on inflammatory arthritis such as rheumatoid arthritis."

Arthritis Rheum 2007;56:3307-3318.