POLYPHENOLIC FLAVONOIDS INHIBIT MACROPHAGE-MEDIATED OXIDATION OF LDL AND ATTENUATE ATHEROGENESIS

Macrophage-mediated oxidation of LDL, a hallmark in early atherosclero sis, depends on the oxidative state of the LDL, and that of the macrop hages. The LDL oxidative state is determined by the balance between th e LDL polyunsaturated fatty acids and cholesterol, which are prone to oxidation, and the LDL associated antioxidants. Dietary consumption of nutrients rich in polyphenols, such as red wine or liquorice results in LDL enrichment with these polyphenolic flavonoids, and hence, subse quent LDL oxidation is reduced. In addition, enrichment of LDL with po lyphenols results in a marked decrease in the susceptibility of the li poprotein to aggregation (another lipoprotein atherogenic modification ). The oxidative status of the macrophages depends on the balance betw een cellular oxygenases and antioxidants. Macrophage enrichment with p olyphenolic flavonoids in vitro or in vivo also reduce macrophage oxid ative state, and subsequently cell-mediated oxidation of LDL. The pres ent review article summarizes our current data on these aspects of the antiatherogenic potential of polyphenolic flavonoids. (C) 1998 Elsevi er Science Ireland Ltd. All rights reserved.