Curcumin Turns Down Inflammation Coming from Chondrocytes

OBJECTIVE AND DESIGN: This study aims to investigate the effects of curcumin (Cur) on the extracellular matrix protein metabolism of articular chondrocytes and on their production of inflammatory mediators.

METHODS: Human chondrocytes in alginate beads and human cartilage explants were cultured in the absence or in the presence of interleukin (IL)-1beta (10(-11) M) and with or without Cur (5-20 microM). Nitric oxide (NO) synthesis was measured by the Griess spectrophotometric method; prostaglandin (PG) E(2) by a specific radioimmunoassay; and IL-6, IL-8, aggrecan (Agg), matrix metalloproteinase (MMP)-3, and tissue inhibitor of metalloproteinase (TIMP)-1 by specific enzyme-amplified immunoassays. Proteoglycan degradation was evaluated by the release of (35)S-glycosaminoglycans (GAG) from human cartilage explants.

RESULTS: In alginate beads and cartilage explant models, Cur inhibited the basal and the IL-1beta-stimulated NO, PGE(2), IL-6, IL-8, and MMP-3 production by human chondrocytes in a concentration-dependent manner. The TIMP-1 and the Agg productions were not modified. In the basal condition, (35)S-GAG release from cartilage explants was decreased by Cur.

CONCLUSIONS: Curcumin was a potent inhibitor of the production of inflammatory and catabolic mediators by chondrocytes, suggesting that this natural compound could be efficient in the treatment of osteoarthritis.