Biomedical subjects

Edmond Rock

Publications and source records attributed to Edmond Rock.

At least 19 recordsLinked to original sources

PubMed2006

Growth arrest and decrease of alpha-SMA and type I collagen expression by palmitic acid in the rat hepatic stellate cell line PAV-1.

Liver fibrosis is characterized by an activation of hepatic stellate cells (HSC). During primary culture HSC evolve from a quiescent into an activated phenotype which is characterized by alpha-smooth muscle actin (alpha-SMA) up-regulation, increase in cell growth, and extracellular matrix secretion. HSC culture with trans-resveratrol can lead to deactivation of myofibroblast-like HSC. We used an HSC line, PAV-1, to check the role of retinol and palmitic acid in the deactivation process of HSC. Using mass and metabolic-based methods, Western blot and immunocytochemistry assays, we demonstrated that treatment with palmitic acid (75 muM) alone or in combination with retinol (2 muM) significantly decreased cell proliferation and alpha-SMA expression. We also established that the association of both compounds strongly decreased collagen type I expression. Our results suggest the potential use of palmitic acid alone or in combination with retinol to induce HSC deactivation.

Actins↗

PubMed2006

Magnesium and the inflammatory response: potential physiopathological implications.

The purpose of this review is to summarize experimental findings showing that magnesium modulates cellular events involved in inflammation. Experimental magnesium deficiency in the rat induces after a few days a clinical inflammatory syndrome characterized by leukocyte and macrophage activation, release of inflammatory cytokines and acute phase proteins, excessive production of free radicals. Increase in extracellular magnesium concentration, decreases inflammatory response while reduction in the extracellular magnesium results in cell activation. Because magnesium acts as a natural calcium antagonist, the molecular basis for inflammatory response is probably the result of modulation of intracellular calcium concentration. The priming of phagocytic cells, the opening calcium channel and activation of N-methyl-d-aspartate (NMDA) receptors, the activation of nuclear factor-kappa B (NFkappaB) have been considered as potential mechanisms. Moreover, magnesium deficiency induces a systemic stress response by activation of neuro endocrinological pathways. As nervous and immune systems interact bidirectionally, the roles of neuromediators have also been considered. Magnesium deficiency contributes to an exaggerated response to immune stress and oxidative stress is the consequence of the inflammatory response. Inflammation contributes to the pro-atherogenic changes in lipoprotein metabolism, endothelial dysfunction, thrombosis, hypertension and explains the aggravating effect of magnesium deficiency on the development of metabolic syndrome. Further studies are still needed to assess more accurately the role of magnesium in immune response in humans, but these experimental findings in animal models suggest that inflammation is the missing link to explain the role of magnesium in many pathological conditions.

Animals↗

PubMed2006

Entire potato consumption improves lipid metabolism and antioxidant status in cholesterol-fed rat.

BACKGROUND: Vegetables and fruits are rich sources of a variety of nutrients, including vitamins (E and C), trace minerals, and dietary fibers, and many other classes of biologically active compounds such as carotenoids and polyphenols, which are often assumed to protect against degenerative pathologies such as cardiovascular diseases. Although potato is considered as a starchy food, it is also included in the category of vegetables by its micronutrient content. AIM OF THE STUDY: In the present study, we investigated in the rat the effect of a potato-enriched diet on lipid metabolism and antioxidant protection. RESULTS: Feeding rats a potato-enriched diet for 3 weeks led to a significant decrease in cholesterol and triglyceride levels in plasma (respectively, -30%, P<0.0001 and -36%, P<0.05) and cholesterol level in liver (-42%, P<0.0001). Antioxidant status was also improved by potato consumption. TBARS levels in heart were decreased and vitamin E/triglycerides ratio in plasma was improved. CONCLUSIONS: Our present results suggest that consumption of cooked potatoes (consumed with skin) may enhance antioxidant defense and improve the lipid metabolism. These effects could be interesting for prevention of cardiovascular disease.

Animals↗

PubMed2006

Wheat lipoxygenase activity induces greater loss of carotenoids than vitamin E during breadmaking.

The current study was undertaken to provide solutions to optimize the unsaponifiable antioxidants content of bread. We report a complete description of changes in wheat carotenoids and vitamin E content from grain to bread and highlight the most important processing steps affecting their level in wheat bread. Major carotenoids losses occurred during kneading. A close correlation (r(2) = 0.97; P = 0.05) was found between carotenoid pigment losses and lipoxygenase (LOX) activity, both parameters depending on wheat genotype. The use of wheat species exhibiting high carotenoid contents and low LOX activity was shown to preserve significant carotenoid level in the bread. No relation was found between vitamin E losses during doughmaking and LOX activity. In addition, moderate kneading resulted in higher vitamin E retention in comparison with carotenoids (12% and 66% losses, respectively). It is concluded that carotenoids are more susceptible to oxidation by endogenous lipoxygenase than vitamin E during breadmaking. This study showed that bread nutritional quality, in terms of antioxidant content, could be improved by selecting suitable cereal genotypes, if this potential is preserved by milling and baking processes.

Bread↗

PubMed2006

Inulin attenuates atherosclerosis in apolipoprotein E-deficient mice.

Effects of different inulin-type fructan fractions were studied on atherosclerotic plaque formation in male apo E-deficient mice. Thirty-two mice were randomly divided into four groups and received either a semi-purified sucrose-based diet (control group), or diets in which sucrose was replaced in part by various inulin-type fructans (10 g/100 g): long-chain inulin, oligofructose, or an oligofructose-enriched inulin for 16 weeks. The presence of atherosclerotic plaques was assessed by histomorphometry in the aortic sinus. The apo E-deficient mice fed long-chain inulin or an oligofructose-enriched inulin had about 35 % and 25 % less atherosclerotic lesion area compared with the control group, respectively. Feeding long-chain inulin significantly reduced plasma cholesterol concentrations (P<0.001), and the three inulin-type fructans reduced triacylglycerol (TAG) concentrations compared with the control group (P<0.001). Both the long-chain inulin and an oligofructose-enriched inulin significantly lowered hepatic cholesterol concentrations compared with the control diet (P<0.05). Hepatic TAG concentrations were significantly lower in all three groups fed the fructan-supplemented diets v. the control group (P<0.0001). The results of the present study suggest that inhibition of atherosclerotic plaque formation is more potent in the presence of long-chain inulin, either alone or in combination with oligofructose (an oligofructose-enriched inulin), and that this probably is related to changes in lipid metabolism.

Animals↗

PubMed2006

In vivo antioxidant activity of procyanidin-rich extracts from grape seed and pine (Pinus maritima) bark in rats.

BACKGROUND: In vitro evidence exists for the potential antioxidant benefits of procyanidin-rich extracts, but in vivo studies are scarce. We have evaluated the effects of selected procyanidin-rich extracts on oxidative stress in rats in condition of prolonged consumption of these compounds and also after single administration i.e. in postprandial conditions. METHODS: Rats were fed for 8 weeks with diets supplemented with either a grape seed extract (GE), a pine bark extract (PE), or a high-degree polymerized pine bark extract (HPE). An additional study was performed in order to assess the postprandial effect of these extracts on plasma antioxidant capacity. The ferric-reducing antioxidant power (FRAP) and thiobarbituric acid-reactive substances (TBARS) were determined in plasma. For lipid peroxidation study of heart tissue, homogenates were prepared and TBARS were measured after lipid peroxidation induced by FeSO4-ascorbate. RESULTS: After 8 weeks of dietary treatment, total antioxidant capacity in plasma was significantly higher in the GE and PE groups as compared with the other two groups. Plasma TBARS concentrations and heart susceptibility to peroxidation were not significantly different between the groups. In the postprandial state, by comparing plasma antioxidant capacity 2 hours after ingestion of the different procyanidin-rich extracts (500 mg/kg body weight), we observed that FRAP values were higher in the procyanidin-rich extracts groups as compared with the control group. Moreover, plasma FRAP concentration was significantly higher in the GE group as compared with the other groups. CONCLUSION: The results of the present experiment constitute positive evidence for an in vivo antioxidant effect at the plasma level of procyanidin-containing plant extracts.

Animals↗

PubMed2005

Lycopene but not lutein nor zeaxanthin decreases in serum and lipoproteins in age-related macular degeneration patients.

BACKGROUND: Epidemiological studies have established that a low serum concentration of carotenoids was associated with risk of Age-Related Macular Degeneration (ARMD). The aim of this study was to determine carotenoid levels in serum and in different lipoprotein fractions in patients diagnosed for ARMD and in matched control group. METHOD: Thirty-four ARMD patients and 21 control subjects from Brest area (France) have been included to this study. Lipoproteins have been separated from serum by gradient density ultracentrifugation. We measured concentration of carotenoids and tocopherols in serum and in different lipoprotein fractions by HPLC. RESULTS: No difference was observed between ARMD patients and control subjects in total serum carotenoids. Individual carotenoid levels showed that only lycopene was decreased significantly in serum, LDL and HDL fractions in patients (P<0.05). Concentrations in serum and lipoparticle fractions of lutein and zeaxanthin, the major pigments present in macula were not modified between both groups. CONCLUSIONS: Lycopene, as liposoluble antioxidant nutrient, is the only carotenoid altered in ARMD patients. It cannot be excluded that this effect is related to different dietary habits, but we hypothesise that lower lycopene status could result also from specific antioxidant protection of lutein and zeaxanthin by lycopene.

Adult↗

PubMed2005

Effect of copper supplementation on indices of copper status and certain CVD risk markers in young healthy women.

Western diets containing suboptimal Cu concentrations could be widespread. A link between marginal Cu deficiency and CVD has been suggested. The objective of the present study was to investigate the effect of Cu supplementation on both Cu status and CVD risk factors in healthy young women. Sixteen women with a mean age of 24 (sd 2) years participated in a randomised crossover study of three 4-week periods with 3-week washouts between periods. During each intervention period, subjects received 0, 3 or 6 mg elemental Cu/d as CuSO4 in addition to their habitual diet. Blood samples were taken to assess the effect of supplementation on putative markers of Cu status. The content of plasma lipids, lipoprotein (a), apo and certain haemostatic factors, as putative indices of CVD, was also analysed. Daily supplementation with 3 mg Cu significantly increased (P < 0.05) serum Cu concentration and the activity of erythrocyte superoxide dismutase, although there was no further significant increase after an intake of 6 mg Cu/d. The concentration of the fibrinolytic factor plasminogen activator inhibitor type 1 was significantly reduced (P < 0.05) by about 30 % after supplementation with 6 mg Cu/d. No other marker of Cu status or CVD risk factor was affected by Cu supplementation. The results indicate that supplementation with 3 or 6 mg Cu/d may improve Cu status in these healthy young women. Increased Cu intake could reduce the risk of CVD and atherosclerosis in man by promoting improved fibrinolytic capacity.

Adult↗

PubMed2005

Proteomic analysis reveals changes in the liver protein pattern of rats exposed to dietary folate deficiency.

Epidemiologic and experimental studies showed that folate deficiency is associated with increased risk of degenerative diseases by enhancing abnormal one-carbon metabolism. We studied the changes in the proteome of liver, the main tissue of folate storage and metabolism, in a rat model of dietary folate depletion. Four-month-old rats were fed for 4 wk an amino acid-defined diet without folate and compared with pair-fed rats given the same diet adequately supplemented with folic acid. Folate deprivation decreased plasma and hepatic folate concentrations dramatically, while increasing homocysteinemia significantly. Using 2-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight MS, we identified 9 spots corresponding to differentially expressed proteins in the liver of folate-deficient rats compared with controls. Among those spots, 4 had a significantly increased volume, whereas the volume of the 5 other spots was decreased. Upregulated proteins included glutathione peroxidase (GPx) 1 and peroxiredoxin 6, 2 enzymes involved in the response to oxidative stress, and MAWD binding protein (MAWDBP), which has been associated with cancer. MAWDBP was simultaneously identified as a second spot with a lower isoelectric point (pI) that vanished almost completely after folate deficiency. Decreased abundance was also observed for cofilin 1, a protein linked to tumorigenesis, and for the GRP 75 precursor and preproalbumin, both of which are responsive to oxidative stress and/or inflammation. Moreover, an enzyme activity assay and/or Western blot analysis of GPx-1 and MAWDBP confirmed the proteomic findings. Our results show that folate deficiency modifies the abundance of several liver proteins consistently with adaptive tissue responses to oxidative and degenerative processes.

Amino Acids↗

PubMed2004

In vivo and in vitro evidences that carotenoids could modulate the neutrophil respiratory burst during dietary manipulation.

BACKGROUND: The primary role of polymorphonuclear neutrophils (PMNs) is to destroy pathogenic microorganisms after phagocytosis by producing reactive oxygen species (ROS) and toxic molecules. However, PMNs produce sufficient amounts of ROS during an oxidative burst to be autotoxic and detrimental to their own functions and to possibly cause DNA damage, protein and lipid oxidation and cell membrane destructuration. OBJECTIVE: The aim of this study was to investigate in vivo the role of the antioxidant capacities of carotenoids in modulating ROS content in PMNs during oxidative burst. Moreover to investigate the direct or indirect effect of carotenoids, the modification of PMN ROS content was explored after in vitro supplementation with beta-carotene or lycopene, chosen taking account of their vitamin A and no vitamin A precursor effect, respectively. DESIGN: In vivo study: Venous blood was collected from 10 healthy male volunteers and ROS production from phorbol myristate acetate (PMA)-stimulated PMNs was determined, by flow cytometry using the fluorescent dye dihydrorhodamine 123, at baseline, after 3 weeks of carotenoid depletion (carotenoid intake limited to 25% of usual intake) and after 5 weeks of carotenoid repletion (30 mg beta-carotene, 15 mg lycopene and 9 mg lutein per day). In vitro study: ROS content in PMA-stimulated PMNs isolated from carotenoid depleted subjects and controls was quantified after an in vitro enrichment with beta-carotene (1 micromol/L) or lycopene (0.3 micromol/L). RESULTS: In vivo carotenoid depletion increased PMN H2O2 content after PMA activation by 38% (p < 0.05 vs baseline),while supplementation for 5 weeks restored basal H2O2 generation (p < 0.05 vs depletion). Although H2O2 measurement in PMNs from non-depleted subjects was not affected by an in vitro supply with beta-carotene or lycopene, a significant decrease in H2O2 content by 78.9 % and 81.2%, respectively, was observed in PMNs from carotenoid depleted subjects (p < 0.01 vs depleted control subjects). CONCLUSIONS: The carotenoid ROS quenching capacities control both in vivo and in vitro the PMNs ROS generation and probably protect these cells against DNA, membrane lipid and protein damages during oxidative burst. Moreover, these effects appear independent from the metabolic conversion of carotenoids to vitamin A.

Antioxidants↗

PubMed2004

Lyophilized carrot ingestion lowers lipemia and beneficially affects cholesterol metabolism in cholesterol-fed C57BL/6J mice.

BACKGROUND: Several lines of evidence indicate that diet rich in fruit and vegetable can protect against cardiovascular diseases by acting on cholesterol metabolism and on oxidative stress. AIM OF THE STUDY: The aim of this study was to assess whether daily carrot consumption (provided as lyophilized powder) could differentially influence the consequences of cholesterol supplementation on lipid metabolism and oxidative stress in C57BL/6J mice. METHODS: Fourteen mice were randomized in four groups. Mice were fed either control diets (without or with 0.25% cholesterol added) or lyophilized carrot enriched diets (20% wt/wt without or with 0.25 % cholesterol added) for 4 weeks. Cholesterol and triglycerides in plasma and in liver were measured at the end of the experimental period. Fecal excretion of sterols was evaluated. Vitamin E and carotenoid concentrations were also determined. Several biomarkers relative to oxidative stress such as FRAP (Ferric Reducing Ability of Plasma) and isoprostanes were investigated. RESULTS: Feeding the carrot diet resulted in a decrease of cholesterol (-41%) and triglycerides (-49 %) in plasma and in the liver (-41% and -39%, respectively) in animals fed cholesterol-supplemented diets. Carrot diet induced an increase of total neutral sterols fecal excretion, which inhibits digestive cholesterol absorption. Carrot diet increased antioxidant status in cholesterol-fed mice as related by the 16% higher FRAP values. Although vitamin E was not affected by carrot diet, vitamin E/TG ratio was significantly higher in animals fed carrot diets. The carrot diet induced an increase of vitamin E in the heart in both cholesterol-free and cholesterol-supplemented mice suggesting a higher protection of this tissue. CONCLUSION: This study shows that carrot ingestion decreases lipemia and improves antioxidant status in mice. Such results suggest that carrot intake may exert a protective impact against CVD linked to atherosclerosis. It is likely that these effects could be due to the synergistic effect of fiber and associated antioxidants.

Animals↗

PubMed2004

Health effect of vegetable-based diet: lettuce consumption improves cholesterol metabolism and antioxidant status in the rat.

BACKGROUND & AIMS: It is often assumed that fruits and vegetables contribute to protect against degenerative pathologies such as cardiovascular diseases. Besides epidemiological observations, scientific evidences for their mechanism of action are scarce. In the present study, we investigated the mean term and post-prandial effects of lettuce ingestion on lipid metabolism and antioxidant protection in the rat. RESULTS: Feeding rats a 20% lettuce diet for 3 weeks resulted in a decrease cholesterol LDL/HDL ratio and a marked decrease of liver cholesterol levels (-41%). Concurrently, fecal total steroid excretion increased (+44%) and apparent absorption of dietary cholesterol was significantly depressed (-37%) by the lettuce diet. Lettuce diet also displayed an improvement of vitamin E/TG ratio in plasma and limited lipid peroxidation in heart as evidenced by TBARS. In post-prandial experiment, lettuce intake significantly increased both ascorbic acid and alpha-tocopherol plasma levels which contribute to improve plasma antioxidant capacity within 2 h of consumption. Other lipid-soluble antioxidants (lutein and vitamin E) may also improve the plasma antioxidant capacity. CONCLUSION: Lettuce consumption increases the total cholesterol end-products excretion and improves antioxidant status due to the richness in antioxidants (vitamins C, E and carotenoids). In our model, lettuce clearly shows a beneficial effect on lipid metabolism and on tissue oxidation. Therefore regular consumption of lettuce should contribute to improve protection against cardiovascular diseases.

Animals↗

PubMed2004

The effect of age on vitamin E status, metabolism, and function: metabolism as assessed by labeled tocopherols.

The effects of age on vitamin E metabolism were studied in 97 healthy 20-75-year-old male nonsmoking Austrian volunteers of the VITAGE project. After a single oral intake of 30 mg d(6)-RRR-alpha- and d(2)-RRR-gamma-tocopheryl acetate, blood and 24-hour urine was collected. Deuterated tocopherols in plasma and deuterated urinary metabolites were analyzed by GC-MS. A first evaluation revealed a similar uptake of d(6)-alpha- and d(2)-gamma-tocopherol during the first 6 hours, and then d(2)-gamma-tocopherol started to decrease. Urinary d(2)-gamma- carboxyethyl hydroxychroman metabolites (CEHCs) exceeded those of d(6)-alpha-CEHCs by about 10 times. There was no effect of age. Thus, there might be no need for a higher vitamin E intake for healthy elderly nonsmoking men.

Absorption↗

PubMed2004

Effects of vitamin E depletion/repletion on biomarkers of oxidative stress in healthy aging.

The effects on ex vivo LDL resistance to oxidation and biomarkers of in vivo oxidative stress in response to 3-month dietary vitamin E restriction to 25% of recommended intake and 2-month unrestricted dietary intake and supplementation with 800 IU/d were studied in 100 healthy, nonsmoking 20-75-year-old volunteers. Significant changes in vitamin E status were associated with decreases and increases, respectively, in LDL resistance to oxidation in the depletion and supplementation period and with decreases in lipid peroxidation and oxidative DNA modification in the supplementation period. Healthy aging was not associated with enhanced susceptibility to oxidation in the depletion period.

Adult↗

PubMed2004

Does aging affect the response of vitamin E status to vitamin E depletion and supplementation?

A vitamin E depletion/supplementation study was conducted in 100 healthy 20-75-year-old volunteers. The responses of vitamin E status to 3-week dietary vitamin E restriction to approximately 25% of recommended intake and 2-month unrestricted dietary intake plus 800 IU/d of RRR-alpha-tocopherol were studied as a function of age. Plasma alpha-tocopherol concentrations were closely related to cholesterol concentrations, which increased with age (P < 0.001). Upon dietary restriction, plasma alpha-tocopherol concentrations decreased significantly (P < 0.001) but independently of age. Plasma alpha-tocopherol responses to supplementation increased significantly with age, but this effect disappeared after standardization for cholesterol. gamma-Tocopherol concentrations decreased to less than 30% of baseline.

Adult↗

PubMed2003

Effect of carrot intake on cholesterol metabolism and on antioxidant status in cholesterol-fed rat.

BACKGROUND: Vegetables are major dietary sources of fibers and antioxidants such as carotenoids, polyphenols and vitamin C which contribute to explain their protective effects against cardiovascular diseases. AIM OF THE STUDY: We investigated in the rat the effects of a 3-week supplementation of the diet with carrot (15% dry matter) on lipid metabolism and antioxidant status. RESULTS: A significant decrease of cholesterol level in liver (-44%; P= 0.0007) was observed together with a reduction of the level of liver triglycerides (-40%; P= 0.0005). Fecal total steroids excretion increased by 30% upon feeding the carrot diet as compared to the control. The secretion of bile acids was maintained, whereas the cholesterol apparent absorption was reduced in rats fed carrot diet. Carrot consumption also improved the antioxidant status. It significantly decreased the urinary excretion of thiobarbituric acid reactive substances (TBARS), reduced the TBARS levels in heart, increased the vitamin E plasmatic level and tended to increase the ferric reducing ability of plasma (FRAP) as compared to the controls. The carrot diet provided carotenoid antioxidants: 5.1 mg beta-carotene, 1.6 mg alpha-carotene and 0.25mg lutein per 100 g diet. No carotenoids were found in plasma whereas the three carotenoids were detected in the plasma of the rats fed the carrot diet at 125, 41, 43 nmol/L respective concentrations. beta-Carotene was also detected in liver and heart. CONCLUSION: Carrot consumption modifies cholesterol absorption and bile acids excretion and increases antioxidant status and these effects could be interesting for cardiovascular protection.

Animals↗

PubMed2003

Comparison of the postprandial chylomicron carotenoid responses in young and older subjects.

BACKGROUND: The plant carotenoids may contribute to the beneficial health effect of fruits- and vegetables-rich diet. Epidemiological studies consistently associated high plasma carotenoids status with reduced age-related diseases. However, the data concerning the bioavailability of carotenoids in the elderly are scarce. OBJECTIVE: To test whether there is an age effect on carotenoid bioavailability. DESIGN: Eight young (20-35 y) and eight older (60-75 y) healthy adults ingested three different meals containing 40 g triacylglycerols (TG) and vegetable sources of carotenoids. These sources were either 188 g carrot purée which provided 30 mg betacarotene as the main carotenoid, or 61 g tomato purée providing 30mg lycopene, or 260 g cooked chopped spinach providing 30 mg lutein. TG and carotenoids were assayed in chylomicrons (CM) collected for 9 h postprandially. RESULTS: There was no major effect of age on the postprandial CM/TG response (0-9 h area under the curve (AUC)). There was no major effect of age on the postprandial CM all- trans beta-carotene, cis betacarotene, alpha-carotene, and lutein responses. Adjustment of these responses by the CM TG responses did not reveal any age effect. While there was no significant effect of age on the CM lycopene response, the CM TG-adjusted lycopene response was significantly lower (-40 %) in the older than in the younger subjects (P < 0.04). The cis-trans ratios of CM betacarotene were not significantly different between the old and the young subjects. There was no significant effect of age on the ratio of CM retinyl-palmitate to the sum of alpha-carotene and beta-carotene measured after the carrot meal. CONCLUSIONS: The bioavailability of lycopene is apparently impaired in the old,while there is no major difference in the bioavailability of beta-carotene, alpha-carotene and probably lutein. There is also no major effect of age on the cis-trans isomerization of beta-carotene during absorption, and in the intestinal conversion of provitamin A carotenoids into vitamin A.

Adult↗

PubMed2003

Effects of vitamin E and carotenoid status on oxidative stress in health and disease. Evidence obtained from human intervention studies.

Vitamin E and carotenoids are known to act as antioxidants both in vitro and in vivo. In this review we present a series of studies in healthy subjects and in patients who exhibit either acute or chronic oxidative stress. In the EU-Commission funded VITAGE project we investigated the status and effects of vitamin E and carotenoids on oxidative stress in 300 healthy volunteers. Depletion studies limiting dietary vitamin E or carotenoid intake to approximately 25% of the dietary reference intakes and subsequent repletion by supplementation with either large doses of vitamin E or intermediate doses of carotenoids showed significant changes in ex vivo LDL oxidizability, total plasma peroxide concentrations and urinary 8-oxo-7,8-dihydro-2(')-deoxyguanosine excretion. Patients on chronic hemodialysis present with oxidative stress in the presence of normal vitamin E but impaired vitamin C status and, due to anemia, need to be treated with parenteral iron. We studied the effects of a single oral dose of vitamin E taken 6 h prior to intravenous infusion of 100 mg iron, which exceeded the iron-binding capacity of transferrin. Vitamin E significantly reduced and in combination with a single dose of vitamin C completely abrogated acute oxidative stress induced by the iron load. Patients with cystic fibrosis are exposed to chronic oxidative stress due to an overproduction of reactive oxygen species as a result of neutrophil-dominated lung inflammation and impaired antioxidant status. Biochemical vitamin E and carotenoid deficiencies could be fully corrected even in the presence of fat malabsorption using intermediate doses of either RRR alpha-tocopherol or all-rac alpha-tocopheryl acetate and water-miscible all-trans beta-carotene. Long-term supplementation reduced ex vivo LDL oxidizability, in vivo lipid peroxidation and lung inflammation.

Aging↗