Vitamin E prevents extensive lipid peroxidation in patients with hypertension

Abstract

Oxidative modification of low-density lipoprotein (LDL) increases atherogenic potential to induce the accumulation of lipids and cells in the vascular wall. Previous studies reveal that hypertensive patients have a higher susceptibility to LDL oxidation. As animal models indicate that vitamin E protects LDL from oxidation, here we study the influence of vitamin E on the resistance of LDL to oxidation (lag time) in 47 subjects (31 normotensive, 16 hypertensive) before and after oral administration of vitamin E (400 IE) daily for two months. LDL was isolated and oxidised by incubation with copper ions. The time course of oxidation was measured by continuous photometric monitoring of diene formation at 234 nm. At the beginning of this study, normotensive subjects showed a lag time of 108 +/- 26 minutes and hypertensive patients a lag time of 85 +/- 24 minutes (P<0.05). Vitamin E caused a significant increase in the lag time in both groups: normotensive subjects 128 +/- 33, hypertensives patients 114 +/- 27 minutes (P<0.01). At completion of the study, lag times in both groups were similar (P=not significant). The data presented here suggests that vitamin E protects against the increased risk of vascular disease in patients with hypertension by reducing the susceptibility to oxidative modification of LDL. Vitamin E may therefore act as an inhibitor of atherogenesis.

Oxidative stress and serum paraoxonase activity in experimental hypothyroidism: effect of vitamin E supplementation

“…12,13 Vitamin E is a widely studied antioxidant molecule and several authors have proposed that vitamin E supplementation could be useful in disturbances that are associated with oxidative stress. [14][15][16][17] In the present study, our aim was to evaluate the oxidant and antioxidant status and serum paraoxonase activity in hypothyroidism and to examine the effects of vitamin E on this clinical state. To our knowledge there is no previous report of investigation of either serum paraoxonase/arylesterase activities or antioxidant effects of vitamin E supplementation in hypothyroidism.…”

Vitamin E supplementation does not prevent ethanol-reduced hepatic retinoic acid levels in rats

“…Vitamin E (VE) is a potent antioxidant and has been shown to effectively decrease in vitro and in vivo susceptibility to lipid peroxidation [12-14]. Research has documented synergistic interactions between vitamins A and E against lipid peroxidation in vitro , with the combination offering reciprocal protection against oxidation [15].…”

Design for a study to determine optimal dosage of ascorbic acid and alpha-tocopherol in humans

“…(2) Time from intake of AA supplements to (Brockes et al 2003;Winklhofer-Roob et al 1995;Steinberg and Chait 1998). The concentration of RBC AT is then approximately 30 mmol/g Hb (Brown et al 1997).…”