Arachidonic acid bioactive lipids

Capdevila, J.H., Falck, J.R., Harris, R.C. 2000. Cytochrome P450 and arachidonic acid bioactivation. Molecular and functional properties of the arachidonate monooxygenase. J. lipid Res. 41 163-181. 

Aldehydes The oxidative breakdown of polyunsaturated fatty acids generates a number of aldehydes, which are highly bioactive and well characterized molecules. Aldehydes are longer-lived than free radicals, and are able to attack targets extra or intracellularly (for review see Esterbauer et al., 1991). Among the different aldehydes formed during lipid and LDL oxidation, malondialdehyde and 4-hydroxyl alkenals, in particular 4-hydroxynonenal (4-HNE), have been intensively studied. 4-HNE results from the oxidation of arachidonic acid and, to a lesser extent, linoleic acid (Esterbauer et al., 1991). 4-HNE and related hydroxyalkenals react rapidly... 

Conversely, arachidonic acid is also metabolized by various enzymes of the LOX pathway (Fig. 6.IB), to produce bioactive lipid mediators. The chief enzymes of the LOX pathway are the 5-LOX, 12-LOX, and the 15-LOX enzymes, whose names are derived from the position in which molecular oxygen is inserted by the enzyme species into the arachidonic acid backbone. The major bioactive products of the 5-LOX pathway are the leukotrienes (LT). Leuko-trienes are formed from arachidonic acid presented to the 5-LOX enzyme by the... 

There are many unanswered questions about the dual role that ether lipids serve as membrane components and as cellular signaling molecules. Although it is clear that arachidonic acid is closely associated and tenaciously retained by ether lipids in membranes, even in essential fatty acid deficiency, much remains to be elucidated about the enzymatic systems and regulatory controls that affect the release of this sequestered pool of arachidonic acid for its subsequent conversion to bioactive eicosanoid metabolites. The significance of ether lipids as a dietary nutrient has received little attention even though they occur in a variety of foods and it is known that ether lipid supplements are readily incorporated into cellular lipids. 

Smith, KJ and Skelton, H (2002) Arachidonic acid-derived bioactive lipids their role and the role for their inhibitors in dermatology. J Cutan Med Surg, 6, 241-256. 

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