An in vivo investigation of the effect of anthraquinones on the turnover of aggrecans in spontaneous osteoarthritis in the guinea pig.

We present details of a method which allows for the determination of chondroitin sulphate turnover in vivo using the guinea pig. Such methods have been utilised to examine the effects of diacetyl rhein, a compound with purported anti-osteoarthritic activity, and several related anthraquinone analogues on the turnover of chondroitin. Since the guinea pig develops spontaneous osteoarthritis, this may give useful information on the potential for such compounds to inhibit the progression of osteoarthritis. The results show that several of the anthraquinones are capable of reducing the turnover of chondroitin 4- but not 6-sulphate. This may indicate potential mechanisms for the breakdown of guinea pig cartilage aggrecans. We propose that these techniques could be useful for the screening of chemical agents with useful activity against osteoarthritis.