Lipoxygenase

Oxylipins constitute a family of oxygenated natural products which are formed from fatty acids by pathways involving at least one step of dioxygen-dependent oxidation. These small polar lipid compounds are metabolites of polyunsaturated fatty acids (PUFAs) including omega-3 fatty acids and omega-6 fatty acids. Oxylipins are formed by enzymatic or non-enzymatic oxidation of PUFAs.

In animal species, four main pathways of oxylipin production prevail: lipoxygenases (LOXs) pathway, cyklooxygenases (COXs) route, cytochrome P450 (CYPs) pathway, and reactive oxygen species (ROS) route. These pathways result in formation of many different oxylipin molecules which are important for number of processes in living organisms. The processes include inflammation, blood flow, energy metabolism, cellular life, cell signaling, or muscle contractions. Oxylipins have both pro- and anti-inflammatory roles.

A lipoxin (LX or Lx), an acronym for lipoxygenase interaction product, is a bioactive autacoid metabolite of arachidonic acid made by various cell types. They are categorized as nonclassic eicosanoids and members of the specialized pro-resolving mediator (SPM) family of polyunsaturated fatty acid (PUFA) metabolites. Like other SPMs, LXs form during an inflammatory response and act to resolve it. The first lipoxins identified were lipoxin A₄ (LXA₄) and lipoxin B₄ (LXB₄), followed by their respective epimers, the epi-lipoxins 15-epi-LXA₄ and 15-epi-LXB₄.