Eicosapentaenoic acid also may decrease the expression of proinflammatory cytokines and the enzymes and metabolites involved
in their signaling pathways.18 This includes IL-1, TNF-α, COX-2, and PGE2. In vitro examination in our laboratory has confirmed the effect on IL-1 and PGE2 in canine cells (R.P. Middleton; S.S. Hannah: Unpublished data, 2004).
Osteoarthritis is a disease characterized by an imbalance in catabolic and anabolic factors affecting the degradation and
synthesis of the extracellular matrix. New techniques are allowing researchers to characterize this disease and evaluate potential
therapeutic agents at the cellular and molecular level. Proinflammatory mediators and inflammatory cytokines play a central
role in the gene-expression changes and resulting biochemical changes seen in the arthritic articular chondrocyte. Oral eicosapentaenoic
acid administration has effectively managed osteoarthritis in several species. The continued identification of the molecular
mechanisms involved in osteoarthritis not only increases our understanding of the disease, but helps researchers identify
and understand nutritional interventions.
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