Effect of a dietary nutraceutical “STRUCTURE-Joint” on response of horses to intra-articular challenge with IL-1: implications for tissue adaptation to stress

Abstract

Abstract The purpose was to determine local (articular) and systemic effects of intra-articular interleukin-1 in horses supplemented with a dietary PUFA supplement [STRUCTURE-Joint (ST-J)]. Sixteen (16) healthy, mature, light breed horses were randomly assigned to diets containing 0 or 120 mL (n=8 per group) of ST-J for 30 days. On Days 0 (prior to beginning supplementation) and 27, recombinant equine interleukin-1β (reIL-1 β) (75ng) was injected into the left or right intercarpal joint to induce mild, transient synovitis. Synovial fluid was obtained by aseptic arthrocentesis at post-injection hour (PIH) 0 (immediately prior to IL-1 injection), 6, 12 and 72. ST-J supplementation for 30 days significantly increased synovial fluid nitric oxide, and resolvin D1 compared with the unsupplemented control group and significantly increased PGE2 levels and reduced joint circumference in the ST-J treated horses on Day 30 compared to the same group of horses on Day 0. There was also a significant increase in plasma hemoglobin, and free and total bilirubin, and decrease in plasma glucose. These data provide evidence for the usefulness of ST-J to modulate physiological variables with importance in exercise performance and tissue adaptation to exercise stress and further research on this product is warranted.