A plausible mechanism for the protective effects of
curcuminoids against OA is the potent anti-inflammatory effects of this phytopharmaceutical . Most of the anti-inflammatory properties of curcuminoids are
due to the inhibition of NF-κB, and effect that leads to the suppression of several key regulators of inflammation such as cyclooxygenase-II, activator protein-1,
JNK, MAPK and PI3K/Akt.Curcuminoids can effectively reduce the release of pro-inflammatory cytokines such as tumor necrosis factor- α, interleukin-1β (IL-1β), IL-6, macrophage chemotactic protein-1 and prostaglandin E2. These anti-inflammatory properties have been verified in cultured chondrocytes . Moreover, inhibition of NF-κB by curcuminoids blocks the catabolic actions of down-stream products, most importantly matrix metalloproteinase (MMP) enzymes. By inhibiting MMPs, curcuminoids promote extracellular matrix accumulation and prevent cartilage degradation . Finally, there is evidence indicating that curcuminoids that increase chondrocyte survival through down-regulation of inflammation-induced apoptosis