The preventive effect of two nutraceuticals on experimentally induced acute synovitis

BACKGROUND: Nutraceuticals are often used when managing equine osteoarthritis, but scientific evidence of their efficacy is lacking.

OBJECTIVES: To study the preventive effect of two new nutraceuticals after experimental induction of synovitis compared to positive and negative control treatment.

STUDY DESIGN: Blinded, controlled, randomised experiment.

METHODS: Twenty-four healthy Standardbred horses were randomly allocated to supplement AT (multi-ingredient, 28 days), supplement HP (collagen hydrolysate, 60 days), meloxicam (4 days) or placebo (60 days). Synovitis was induced in the right intercarpal joint by intra-articular injection of 0.5 ng lipopolysaccharide of E. Coli, while treatments were continued. Blood and synovial fluid were sampled before treatment, immediately prior to LPS-injection, and at 8, 24 and 48 hours post-injection. Synovial fluid samples were analysed for total nucleated cell count (TNCC), total protein (TP) and selected biomarkers (PGE2, IL-6, GAGs, CPII, MMP). Lameness was scored by visual examination and pressure plate analysis immediately prior to LPS-injection, and at 8, 24 and 48 hours post-injection. Clinical examinations were performed before treatment, immediately prior to LPS-injection, at 2, 4 and 6 hours post-injection, and then twice daily during the test period.

RESULTS: Before treatment and intra-articular challenge, there were no statistical differences between treatment groups for any of the parameters. After intra-articular challenge, the placebo group showed statistically higher synovial fluid TP, TNCC and PGE2 compared to the meloxicam group whereas the model did not induce a relevant amount of lameness. Both nutraceuticals resulted in statistically lower synovial fluid TP, TNCC and PGE2 compared to placebo. No statistical differences in IL-6, GAGs, CP-II and MMPs were observed between treatment groups. No adverse effects were observed.

MAIN LIMITATIONS: Despite laboratory evidence of synovitis, lameness was too mild to detect.

CONCLUSION: Preventive administration of these nutraceuticals showed anti-inflammatory effects in this validated synovitis model and therefore further studies on clinical applicability are warranted. This article is protected by copyright. All rights reserved.