Polar extract of Curcuma longa protects cartilage homeostasis: possible mechanism of action.

BACKGROUND: Curcuma longa has been well documented for managing joint inflammation and pain. The present study investigated the effect of polar extract of C. longa (NR-INF-02) on cartilage homeostasis in human articular chondrocytes knee (NHAC-kn) cells to understand its plausible mechanism of action.

METHODS: Dysregulation of cartilage homeostasis was induced by IL-1β and H2 O2 . Modulating effects of NR-INF-02 on degradation markers viz., chondrocyte apoptosis, senescence, cytokine, eicosanoids, and cartilage synthesis markers viz., glycosaminoglycans and type II collagen degradation was evaluated in human articular chondrocytes knee (NHAC-kn) cells. Further, the effect of NR-INF-02 on lipopolysaccharide (LPS)-induced expression of NF-kB in RAW264.7 macrophages was investigated.

RESULTS: NR-INF-02 significantly attenuated IL-1β-induced chondrocyte cytotoxicity, apoptosis and release of chondrocyte degradation markers such as IL-6, IL-8, COX-2, PGE2 , TNF-α, ICAM-1 in NHAC-kn cells. Also, NR-INF-02 protected IL-1β-induced damage to synthesis markers such as glycosaminoglycans, type II collagen and further attenuated H2 O2 -induced chondrocyte senescence. In addition NR-INF-02 suppressed LPS-induced NF-kB expression in RAW264.7 cells.

CONCLUSIONS: NR-INF-02 protects cartilage homeostasis by maintaining the balance between synthesis and degradation of cartilage matrix.