Abstract
Many commonly known antioxidants, from probucol to vitamin E, are fat-soluble and have been shown to be most effective when administered with meals. Following meal consumption, these compounds are incorporated into intestinal lipoproteins, known as chylomicrons, and secreted into the circulation. These lipid-carrying particles are responsible for the transport of newly absorbed dietary fat for delivery to peripheral tissues. In the bloodstream, chylomicrons interact with heparin-releasable lipases common known as lipoprotein lipase and hepatic triglyceride lipase. Bothe lipases are anchored along the endothelial wall via heparan sulfate proteoglycans and have triglycerides as their preferred substrate. During this process, as dietary triglycerides are hydrolyzed and transported across the endothelium, we hypothesize that antioxidants carried in chylomicrons would be delivered directly to the arterial wall where they would be most effective in quenching reactive oxygen species generated by activated macrophages. Thus, the metabolism of postprandial lipoproteins is a key process in the defense against oxidative stress and may provide the path for effective antioxidant management. In this chapter, we will review the evidence in support of the hypothesis that postprandial lipoproteins may contribute to the delivery of fat-soluble antioxidants that are administered orally.