In biochemistry, Docosanoids are signaling molecules made by the metabolism of twenty-two-carbon fatty acids (EFAs), especially the omega-3 fatty acid, Docosahexaenoic acid (DHA) (i.e. 4Z,7Z,10Z,13Z,16Z,19Z-docosahexaenoic acid) by lipoxygenase, cyclooxygenase, and enzymes. Other docosanoids are metabolites of n-3 docosapentaenoic acid (i.e. 7Z,10Z,13Z,16Z,19Z-docosahexaenoic acid), n-6 DHA (i.e. 4Z,7Z,10Z,13Z,16Z-docosahexaenoic acid, and docosatetraenoic acid (i.e. 7Z,10Z,13Z,16Z-docosatetraenoic acid, DTA, or adrenic acid). Prominent docosanoid metabolites of DHA and n-3 DHA are members of the specialized proresolving mediator class of polyunsaturated fatty acid metabolites that possess potent anti-inflammation, tissue healing, and other activities (see specialized proresolving mediators).
Potently bioactive agents of the specialized proresolving mediator class include:
These DHA metabolites possess anti-inflammation and tissue-protection activities in animal models of inflammatory diseases; they are proposed to inhibit innate immune responses and thereby to protect from and to resolve a wide range of inflammatory responses in animals and humans. These metabolites are also proposed to contribute to the anti-inflammatory and other beneficial effects of dietary omega-3 fatty acids by being metabolized to them.
DHA can be converted non-enzymatically by free radical-mediated peroxidation to 8 different neurofuran regioisomers termed neuroprostanes and neurofuranes including 4-, 7-, 10-, 11-, 13-, 14-, 17-, and 20-series neurofurans/neuroporstanes for a total of 128 different racemic compounds. The most studied DHA-derived of these products are members of the 4-series, neurofuran 4-Fαneuroprostane and 4(RS)-ST-Δ6-8-neurofurane. These metabolites have been used mainly as biomarkers of oxidative stress that are formed in nerve tissues of the central nervous system.