Modulation of articular chondrocyte activity by pirfenidone.

Pirfenidone is under investigation as an anti-inflammatory and anti-fibrotic agent in several organs including lung. Since important features of arthritic conditions include inflammation and long-term damage to articular cartilage, we have investigated whether PD can suppress chondrocyte responses to bacterial lipopolysaccharide (LPS) and interleukin 1 (IL-1); modulators that induce a cascade of inflammatory responses that lead to articular joint tissue damage. PD (0 - 5microM) showed no effect on cell number or viability when incubated with high density primary equine chondrocyte cultures for a 24 hr period. PD did not stimulate nitric oxide (NO) release by chondrocytes when added alone but LPS and IL-1-induced NO release was inhibited by PD, in a dose-dependent manner. PD did not significantly influence GAG release from cartilage matrix nor did it stimulate or suppress the GAG releasing actions of LPS or IL-1. We conclude that PD is capable of attenuating the cytokine-induced production of the inflammatory mediator, NO by chondrocytes, without stimulating matrix glycosaminoglycan loss from cartilage. PD may have potential as an anti-inflammatory agent in the joint.