Beneficial effect of vitamin E administration on nitric oxide function in subjects with hypercholesterolaemia

Abstract

1. Vitamin E administration improves endothelial function in hypercholesterolaemic animals but, generally, has not been found to do so in man. The aim of this study was to determine whether vitamin E administration improves basal or stimulated function of the nitric oxide (NO) dilator system in patients with hypercholesterolaemia. 2. Seven subjects aged 47+/-3 (+/-S.E.M.) years with moderately elevated serum cholesterol concentrations (6.0+/-0.1 mmol/l) were given 4 weeks of placebo therapy followed by 500 i.u. of vitamin E twice daily for 4 weeks. Endothelium-dependent and -independent vasodilatation were assessed by intrabrachial infusion of acetylcholine and sodium nitroprusside, and forearm blood flow was measured by strain-gauge plethysmography. Basal NO function was assessed by infusion of NG-monomethyl-L-arginine. 3. Plasma alpha-tocopherol concentration was enhanced after administration of vitamin E (34.6+/-1.8 to 86.9+/-9.6 micromol/l; P<0.001). In addition, vitamin E administration significantly increased acetylcholine-mediated vasodilatation whether the results were expressed in terms of changes in absolute forearm blood flow (P<0. 01), forearm vascular resistance (P<0.05) or forearm blood flow ratios (P<0.001). Similarly, absolute forearm blood flow (P<0.05), forearm vascular resistance (P<0.01) and forearm blood flow ratio (P<0.01) responses to NG-monomethyl-L-arginine were augmented by vitamin E therapy. Sodium nitroprusside responses were unaltered. 4. These results indicate that 4 weeks therapy with 1000 i.u. of vitamin E daily improves basal and stimulated NO-related endothelial function in subjects with hypercholesterolaemia.

Oxidative Stress in Cardiovascular Disease: A New Avenue Toward Future Therapeutic Approaches

“…The primary component of vitamin E, alpha-tocopherol, has been proposed as the most prevalent antioxidant in protecting LDL [87]. Vitamin E has been shown to decrease LDL oxidation [88,89] and to improve endothelial function [90,91]. The WHO/MONICA Study provided some of the first supportive evidence for the role of vitamin E in coronary artery disease, suggesting that an individual's vitamin E plasma concentration may be indicative of ischemic heart disease mortality [92].…”

Strategies to reduce oxidative stress in cardiovascular disease

“…Vitamin E has been shown to decrease LDL oxidation [128,129] and to improve endothelial function [130,131]. Similarly vitamin C administration has been shown to improve endothelium-dependent vasodilation [53,132,133].…”

The Boyd Orr Lecture: Nutrition interventions in aging and age-associated disease

“…Some large clinical trials have found no benefits from vitamin E supplementation for patients with established disease (Table 3). However, mounting evidence indicates that supplemental levels of vitamin E have a great potential in preventing the development of cardiovascular disease through several mechanisms, The Heart Outcomes Prevention Evaluation Study (1999) Palumbo et al (2000) including reducing the susceptibility of LDL to oxidation (Jialal et al 1995), reducing the expression of chemokines and adhesion molecule expression and monocyte adhesion (Wu et al 1999), decreasing smooth muscle proliferation (Azzi et al 1995), improving vessel relaxation (Keaney et al 1993;Green et al 1998;Neunteufl et al 1998), and decreasing platelet aggregation (Steiner, 1999). It appears that dietary vitamin E supplements are more effective in preventing the development of the disease rather than curing the established lesions in patients with cardiovascular disease.…”