Many mediators of inflammation are derived from phospholipids and polyunsaturated fatty acids, including prostaglandins, leukotrienes, and platelet-activating factor. These mediators augment the vascular phase of inflammation and modify functions of inflammatory cells and cells of the immune system. Several growth factors or cytokines augment production of prostaglandin synthesis. The production of lipid-derived mediators may be inhibited by anti-inflammatory drugs and by modifying dietary polyunsaturated fatty acids.