Kaempferol Alleviates the Interleukin-1β-Induced Inflammation in Rat Osteoarthritis Chondrocytes via Suppression of NF-κB

Background: This study was designed to examine the anti-inflammatory and anti-osteoarthritis (OA) effects of kaempferol in rat articular chondrocytes stimulated with interleukin-1 beta. Material/Methods: Rat articular chondrocytes cultures were treated with interleukin-1 beta alone or with kaempferol (25, 50, 100, and 200 mu M) and interleukin-1 beta. The effect of kaempferol on chondrocyte cells viability was measured by MTT assay. The effect on prostaglandin E2 (PGE2) and nitric oxide (NO) level were also assessed using the ELISA and Griess reagent, respectively, for kaempferol activity. Moreover, the expression of iNOS, Cox-2 and activation of NF-kappa B under influence of kaempferol was also assessed by Western blot. Results: Kaempferol treatment (up to 100 mu M) in a concentration-dependent way caused reduction in the interleukin-1 beta-stimulated formations of PGE2 and NO. Kaempferol also upregulated the expression of iNOS and Cox-2 in interleukin- 1 beta-stimulated rat OA chondrocytes. Additionally, kaempferol was found to inhibit the IkBa degradation and NF-kappa B activation in rat chondrocytes stimulated with interleukin-1 beta. Conclusions: Kaempferol significantly caused reduction in interleukin-1 beta-stimulated pro-inflammatory mediators in rat OA chondrocytes by inhibiting the NF-kappa B pathway. These results suggest that kaempferol had significant anti-inflammatory and anti-arthritis effects. Thus, kaempferol, as a novel therapeutic active agent, may prevent, stop, or retard the progression of OA.