beta-carotene and Hyperemia

Endothelial dysfunction is a fundamental step in the atherosclerotic disease process. Activation or injury of the endothelium leads to a variety of inflammatory disorders, including the release of microparticles. Endothelial progenitor cells may contribute to the maintenance of the endothelium by replacing injured mature endothelial cells.. We studied the influence of dietary fat on the release of endothelial microparticles (EMPs) and endothelial progenitor cells (EPCs) in elderly subjects.. Twenty healthy, elderly subjects (10 men and 10 women) consumed 3 diets following a randomized crossover design, each for 4 wk: a saturated fatty acid diet; a low-fat, high-carbohydrate diet; and a Mediterranean diet (MedDiet) enriched in monounsaturated fatty acids. We investigated total microparticles, EMPs from activated endothelial cells (activated EMPs), EMPs from apoptotic endothelial cells (apoptotic EMPs), EPCs, oxidative stress variables, and ischemic reactive hyperemia (IRH).. The MedDiet led to lower total microparticle, activated EMP, and apoptotic EMP concentrations and higher EPC numbers than did the other diets (P < 0.001). We detected lower superoxide dismutase activity (P < 0.001), a higher plasma β-carotene concentration (P < 0.001), and lower urinary isoprostane and plasma nitrotyrosine concentrations after consumption of the MedDiet than after consumption of the other 2 diets (P < 0.05). Furthermore, the occurrence of IRH was higher after consumption of the MedDiet than after consumption of the other 2 diets (P < 0.05).. Consumption of the MedDiet induces a reduction in endothelial damage and dysfunction, which is associated with an improvement in the regenerative capacity of the endothelium, in comparison with 2 other diets.

Topics: Aged; Apoptosis; Atherosclerosis; beta Carotene; Cell Count; Cross-Over Studies; Diet, Mediterranean; Dietary Fats; Endothelial Cells; Endothelium, Vascular; Fatty Acids, Monounsaturated; Female; Humans; Hyperemia; Isoprostanes; Male; Oxidative Stress; Regeneration; Stem Cells; Superoxide Dismutase; Tyrosine

The objective was to determine the effects of lycopene supplementation on endothelial function assessed by reactive hyperemia peripheral arterial tonometry (RH-PAT) and oxidative stress.. Healthy men (n=126) were randomized to receive placebo (n=38), 6 mg (n=41), or 15 mg (n=37) lycopene daily for 8-week.. Serum lycopene increased in a dose-dependent manner after 8-week supplementation (P<0.001). The 15 mg/day group had greater increase in plasma SOD activity (P=0.014) and reduction in lymphocyte DNA comet tail length (P=0.042) than the placebo group. Intragroup comparison revealed a 23% increase in RH-PAT index from baseline (1.45±0.09 vs. 1.79±0.12; P=0.032) in the 15 mg/day group after 8-week. hs-CRP, systolic blood pressure, sICAM-1 and sVCAM-1 significantly decreased, and β-carotene and LDL-particle size significantly increased only in the 15 mg/day group. Interestingly, the beneficial effect of lycopene supplementation on endothelial function (i.e., RH-PAT and sVCAM-1) were remarkable in subjects with relatively impaired endothelial cell function at initial level. Changes in RH-PAT index correlated with SOD activity (r=0.234, P=0.017) especially in the 15 mg lycopene/day group (r=0.485, P=0.003), lymphocyte DNA comet tail moment (r=-0.318, P=0.001), and hs-CRP (r=-0.238, P=0.011). In addition, changes in lycopene correlated with hs-CRP (r=-0.230, P=0.016) and SOD activity (r=0.205, P=0.037).. An increase in serum lycopene after supplementation can reduce oxidative stress which may play a role in endothelial function.

Topics: Adult; beta Carotene; C-Reactive Protein; Carotenoids; Dietary Supplements; DNA Damage; Endothelium, Vascular; Humans; Hyperemia; Lipoproteins, LDL; Lycopene; Male; Manometry; Middle Aged; Oxidative Stress; Particle Size; Superoxide Dismutase; Vascular Cell Adhesion Molecule-1

This study was performed on seven patients affected by the atrophic form of age-related macular degeneration (AF-ARMD). The patients under investigation belonged to a larger study aimed at evaluating the efficacy of rheopheresis treatment (RT) on the visual function of AF-ARMD patients. Following the protocol of the larger study, patients received RT twice a week, every two weeks, for a total of ten treatments, as well as high-dose supplementation with zinc and vitamins A, E and beta-carotene. Recruited patients underwent skin laser Doppler flowmetry coupled with skin iontophoresis of the endothelium-dependent vasodilator acetylcholine (ACh) and a test of skin post-ischemic reactive hyperemia, before and after the first RT (time 1: all seven patients) and the fifth RT (time 2: six patients). A significantly higher absolute (anova for repeated measures) and relative (percentage change from the baseline) skin blood flux response (SBFR) to ACh iontophoresis was observed after RT, compared to before RT at time 1 (679 +/- 43% and 436 +/- 78%, respectively; P < 0.05), as well as before RT at time 2 compared to before RT at time 1 (683 +/- 74% and 436 +/- 78%, respectively; P < 0.05). Absolute and relative SBFR to ischemia did not differ either after RT compared to before RT at time 1, or before RT at time 2 compared to before RT at time 1. These findings are consistent with an acute and subacute beneficial effect of RT on skin microvascular endothelial function in the studied AF-ARMD patients.

Topics: Acetylcholine; Aged; beta Carotene; Endothelium, Vascular; Female; Humans; Hyperemia; Iontophoresis; Laser-Doppler Flowmetry; Macular Degeneration; Male; Microcirculation; Middle Aged; Pilot Projects; Plasmapheresis; Skin; Vasodilator Agents; Vitamin A; Vitamin E; Vitamins; Zinc