Diacerein suppresses the increase in plasma nitric oxide in rat adjuvant-induced arthritis.

We investigated the effects of rhein, an active metabolite of diacerein, on the interleukin-1alpha-stimulated production of nitric oxide (NO) in rabbit articular chondrocytes, and the effects of diacerein on NO production in rat adjuvant-induced arthritis. At doses of 10 and 30 microM, rhein significantly inhibited the interleukin-1alpha-stimulated NO production in chondrocytes. In the rat adjuvant-induced arthritis model, diacerein was administered for 21 days, starting at the time of adjuvant injection. Paw swelling and plasma NO level were measured in order to assess the effect of diacerein on arthritis and NO biosynthesis in the whole body. At doses of 30 and 100 mg/kg/day, diacerein significantly suppressed the development of adjuvant-induced arthritis and the increase in plasma NO. These results suggest that the inhibitory effect of diacerein on rat adjuvant-induced arthritis is partly related to its reduction of the NO production induced by adjuvant-induced arthritis.