Platelet activating factor - a molecular link between atherosclerosis theories

The most common causes of death in westernized societies remain heart disease and stroke. For this reason the prevention of atherosclerosis is a major objective of modern medicine. Platelet-Activating Factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a crucial mediator in the inflammatory response. PAF is synthesized by several types of cells, including platelets, monocytes, macrophages, foam cells and endothelial cells upon activation. Many experimental data reveal that atherogenic activities of oxidized LDLs can be attributed to PAF and PAF-like lipids, which render these molecules the initiators of atherosclerosis. Several theories have been formulated for atherosclerosis. The purpose of this review is to highlight the significance of PAF and PAF-like lipids during the early stages of atherosclerosis. Secondly to link the biological action of PAF molecules to the most accepted, current hypotheses of atherosclerosis. Thirdly to propose a mechanism for the initiation and propagation of atherosclerosis by PAF. The mechanism we propose offers a new biochemical approach and may help to explains the beneficial effects of the Mediterranean diet. Mediterranean foods contain a significant number of lipid-like components with anti-PAF action in vitro. The comsumption of PAF antagonist from Mediterranian foods inhibits the development of atherosclerosis. Such observations suggest that our hypothesis serves as a sound basis for further research.