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

Abstract

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 H₂O₂. 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 H₂O₂-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.