COX-2 inhibitors and metabolism of essential fatty acids

Area of Science:

• Cardiovascular Pharmacology
• Biochemistry

Background:

• Selective COX-2 inhibitors carry risks of myocardial infarction and stroke.
• These risks are linked to the inhibition of prostacyclin (PGI2), lipoxins, resolvins, and endothelial nitric oxide (eNO).
• Aspirin inhibits both COX-1 and COX-2, affecting various eicosanoids and fatty acids.

Purpose of the Study:

• To explore the mechanisms behind COX-2 inhibitor-induced cardiovascular risks.
• To investigate the potential of combining essential fatty acids (EFAs) with COX-2 inhibitors to mitigate these risks.

Main Methods:

• The study discusses the biochemical pathways involving COX enzymes, eicosanoids, and essential fatty acids.
• It contrasts the effects of selective COX-2 inhibitors with aspirin on fatty acid metabolism and eicosanoid formation.
• The analysis focuses on the roles of dihomo-gamma-linolenic acid (DGLA), arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

Main Results:

• Selective COX-2 inhibitors reduce beneficial vasodilatory and anti-aggregatory compounds like PGI2 and PGE1.
• Aspirin's broader inhibition leads to increased intracellular levels of DGLA, AA, EPA, and DHA.
• DGLA, AA, and EPA are precursors to vasodilators and anti-aggregators that prevent thrombus formation.
• EPA exhibits anti-arrhythmic properties, while EPA, DHA, DGLA, and PGE1 possess anti-inflammatory actions.
• EPA, DHA, and AA enhance eNO formation, contributing to anti-atherosclerotic effects.

Conclusions:

• Combining essential fatty acids (EFAs) with COX-2 inhibitors may prevent thrombotic cardiovascular events.
• This combination strategy could counteract the pro-thrombotic and inflammatory effects associated with selective COX-2 inhibition.