Maternal dietary omega-3 fatty acid intake increases resolvin and protectin levels in the rat placenta

Abstract

Placental inflammation is associated with several pregnancy disorders. Inflammation is limited by anti-inflammatory and proresolving mechanisms, the latter partly mediated by resolvins and protectins derived from omega-3 polyunsaturated fatty acids (n-3PUFA). We examined effects of dietary n-3PUFAs on levels of resolvins, protectins, and lipoxygenase (ALOX) enzymes in the rat placenta. Rats consumed standard (Std) or high n-3PUFA (Hn3) diets from day 1 of pregnancy; tissues were collected on day 17 or 22 (term = day 23). Maternal Hn3 diet increased resolvin and protectin precursors, 18R/S-HEPE ( P < 0.001), and 17R/ S-HDHA ( P < 0.01) at both days. Resolvins (17R-RvD1 and RvD1) increased at day 22 ( P < 0.001) after Hn3 consumption, coincident with higher Alox15b and Alox5 mRNA expression, while RvD2 increased at both days ( P < 0.05). Protectins, PD1, and 10S,17S-DiHDHA increased over late gestation ( P < 0.001), coincident with higher Alox15 mRNA expression ( P < 0.001) and further increased with Hn3 diet ( P < 0.05). Maternal systemic and placental proinflammatory mediators were not suppressed by Hn3 diet; systemic IL1 , placental Il1 , and Il6 mRNA expression increased marginally with Hn3 at day 22 ( P < 0.001), while Ptgs1 ( Cox1 ) expression increased both days ( P < 0.05). Our data indicate that maternal n-3PUFA supplementation enhances expression of enzymes in the n-3PUFA metabolic pathway and increases placental levels of resolvins and protectins. Copyright © 2013 by the American Society for Biochemistry and Molecular Biology, Inc.