Abstract
BackgroundArachidonic acid (ARA) is an essential fatty acid and a major constituent of biomembranes. It is converted into various lipid mediators, such as prostaglandin E2 (PGE2), which is involved in the development of rheumatoid arthritis (RA). However, the effects of dietary ARA on RA are unclear. Our objective was to clarify the effects of dietary ARA on an experimental rat arthritis model.MethodsLew rats were fed three contents of ARA diet (0.07%, 0.15% or 0.32% ARA in diet (w/w)), a docosahexaenoic acid (DHA) diet (0.32% DHA), or a control diet. After 4 weeks, arthritis was induced by injection of Freund’s complete adjuvant into the hind footpad. We observed the development of arthritis for another 4 weeks, and evaluated arthritis severity, fatty acid and lipid mediator contents in the paw, and expression of genes related to lipid mediator formation and inflammatory cytokines. Treatment with indomethacin was also evaluated.ResultsThe ARA content of phospholipids in the paw was significantly elevated with dietary ARA in a dose-dependent manner. Dietary ARA as well as DHA did not affect arthritis severity (paw edema, arthritis score, and bone erosion). PGE2 content in the paw was increased by arthritis induction, but was not modified by dietary ARA. Dietary ARA did not affect the contents of other lipid mediators and gene expression of cyclooxygenase (COX)-1, COX-2, lipoxgenases and inflammatory cytokines. Indomethacin suppressed arthritis severity and PGE2 content in the paw.ConclusionThese results suggest that dietary ARA increases ARA content in the paw, but has no effect on arthritis severity and PGE2 content of the paw in a rat arthritis model.Electronic supplementary materialThe online version of this article (doi:10.1186/1476-511X-14-3) contains supplementary material, which is available to authorized users.
Highlights
Polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA) and docosahexaenoic acid (DHA), are natural nutrients present in common foodstuffs and are physiologically important constituents of biomembranes
We reported that Arachidonic acid (ARA) supplementation in healthy Japanese elderly individuals increased plasma ARA but did not increase ARA-derived lipid mediators or clinical parameters, including inflammatory parameters such as C-reactive protein, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) [12]
To clarify the effects of dietary ARA on chronic inflammation and prostaglandin E2 (PGE2) status, we evaluated the effects of ARA at various doses on the severity of an adjuvant-induced arthritis (AIA) model in rats, and determined the contents of ARA and ARA-derived lipid mediators and the expression of genes related to these lipid mediators and inflammatory cytokines
Summary
Polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA) and docosahexaenoic acid (DHA), are natural nutrients present in common foodstuffs (e.g., egg yolk, meat, and fish oil) and are physiologically important constituents of biomembranes. ARA acts as the substrate for various lipid mediators, such as prostaglandins (PGs), leukotrienes, lipoxins (LX), endocannabinoids, and epoxyeicosatetranoates [1,2,3]. We recently studied the effects of dietary ARA on acute inflammation and reported that dietary ARA increased the ARA and LXA4 contents in the colon but did not affect the severity of inflammation or PGE2 content in a murine colitis model [14]. Arachidonic acid (ARA) is an essential fatty acid and a major constituent of biomembranes. It is converted into various lipid mediators, such as prostaglandin E2 (PGE2), which is involved in the development of rheumatoid arthritis (RA). Our objective was to clarify the effects of dietary ARA on an experimental rat arthritis model
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
