Omega-3 fatty acids and inflammatory processes

Long chain fatty acids influence inflammation through a variety of mechanisms;many of these are mediated by, or at least associated with, changes in fatty acidcomposition of cell membranes. Changes in these compositions can modify membranefluidity, cell signaling leading to altered gene expression, and the pattern of lipid mediatorproduction. Cell involved in the inflammatory response are typically rich in the n-6 fattyacid arachidonic acid, but the contents of arachidonic acid and of the n-3 fatty acidseicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can be altered through oraladministration of EPA and DHA. Eicosanoids produced from arachidonic acid have rolesin inflammation. EPA also gives rise to eicosanoids and these often have differingproperties from those of arachidonic acid-derived eicosanoids. EPA and DHA give rise tonewly discovered resolvins which are anti-inflammatory and inflammation resolving.Increased membrane content of EPA and DHA (and decreased arachidonic acid content)results in a changed pattern of production of eicosanoids and resolvins. Changing the fattyacid composition of cells involved in the inflammatory response also affects production ofpeptide mediators of inflammation (adhesion molecules, cytokines etc.). Thus, the fattyacid composition of cells involved in the inflammatory response influences their function;the contents of arachidonic acid, EPA and DHA appear to be especially important. Theanti-inflammatory effects of marine n-3 PUFAs suggest that they may be useful astherapeutic agents in disorders with an inflammatory component