Dynamics of DHA and EPA supplementation: incorporation into equine plasma, synovial fluid, and surfactant glycerophosphocholines.

ABSTRACT

INTRODUCTION: Horses with asthma or osteoarthritis frequently receive ω-3 fatty acid supplements. Docosahexaenoic (DHA; 226) and eicosapentaenoic (EPA; 205) acids are essential ω-3 fatty acid precursors of anti-inflammatory mediators and components of structural glycerophospholipids (GPL) that act as reservoirs of these fatty acids. Analysis of the incorporation of dietary DHA + EPA into GPL pools in different body compartments has not been undertaken in horses. OBJECTIVES: We undertook a detailed study of dietary supplementation with DHA + EPA in horses and monitored incorporation into DHA- and EPA-containing glycerophosphocholines (GPC) 385, 386, 405, and 406 in plasma, synovial fluid (SF), and surfactant. METHODS: Horses (n = 20) were randomly assigned to the supplement or control group and evaluated on days 0, 30, 60, and 90. GPC in plasma, SF, and surfactant were measured by high-resolution mass spectrometry with less than 3 ppm mass error. Validation of DHA and EPA incorporation into these GPC was conducted utilizing MS2 of the [M + Cl]- adducts of GPC. RESULTS: Dietary supplementation resulted in augmented levels of GPC 385, 386, 405, and 406 in all compartments. Maximum incorporation into GPCs was delayed until 60 days. Significant increases in the levels of GPC 385, 405, and 406, containing docosapentaenoic acid (DPA; 225), also was noted. CONCLUSIONS: DHA and EPA supplementation results in augmented storage pools of ω-3 essential fatty acids in SF and surfactant GPC. This has the potential to improve the ability of anti-inflammatory mechanisms to resolve inflammatory pathways in these critical compartments involved in arthritis and asthma.