Foam cells antioxidant activity

Probucol. Probucol is an antioxidant that is effective in lowering LDL cholesterol. Whereas probucol was known to lower cholesterol after relatively simple clinical trials (160), its mechanism of action as an antioxidant in the treatment of atherosclerosis is quite novel. Probucol has been shown to have the abiUty to produce regression of atherosclerotic lesions in animal models (161). Probucol therefore represents a novel class of pharmaceutical agent for the treatment of atherosclerosis. This effect occurs mechanistically, in part, by preventing oxidation of LDL, a necessary step in foam cell formation. This antioxidant activity has been shown in laboratory experiments and its activity in lowering LDL cholesterol in human studies is well documented (162). 

The beneficial health eflfects attributed to the consumption of fruits and vegetables are related at least in part to their antioxidant activity. Of special interest is the inverse relationship between intake of dietary nutrients rich in flavonoids and cardiovascular diseases. This elfect is attributed to the flavo-noids capability to inhibit LDL oxidation, macrophage foam cell formation, and atherosclerosis. Fig. 7 summarizes some of our studies of total polyphenol concentration in several fmit juices or wines and the capacity of the juices, when compared on a similar total polyphenol concentration basis, to inhibit LDL oxidation. Pomegranate juice, red wine, and cranberry juice contained the... 

The production of inflammatory cytokines and cell adhesion molecules (CAMs) by the arterial endothelium are key cellular events involved in the development of atherosclerosis. Activation of the endothelium results in the release of vascular cytokines such as interleukin-1 (IL-la) and tumor necrosis factor alpha (TNF-a). These cytokines induce the expression of CAMs such as intracellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1), which, together with activated monocyte chemoattractant protein-1 (MCP-1), recruit monocytes through the vascular wall, where they are involved in foam cell formation. The nuclear transcription factor, NF-kB, is a mediator in TNF-a-induced expression of cell adhesion molecules and MCP. NF-kB is activated by an atherogenic diet (Liao et al. 1993) and oxidized LDL (Brand et al. 1997), and activation is inhibited by various antioxidants (Kunsch and Medford 1999). Therefore it is of particular interest that GEN attenuated NF-kB DNA binding and TNF-a release in human monocytes (Shames et al. 1999). A small, uncontrolled pilot study ( = 6) found that GEN, but not DAI, inhibited TNF-a-induced NF-kB activation in ex vivo human lymphocytes following consumption of 100 mg isoflavones/day for 3 weeks, as well as in cultured human... 

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