Zeinoxanthin, a crystalline carotenol from corn gluten.
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Carotenoids↗
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Antioxidant activities of carotenes and xanthophylls.
The purpose of this study was to assess the relative antioxidant activities of a range of carotenes and xanthophylls through the extent of their abilities to scavenge the ABTS(.+) radical cation. The results show that the relative abilities of the carotenoids to scavenge the ABTS(.+) radical cation are influenced by the presence of functional groups with increasing polarities, such as carbonyl and hydroxyl groups, in the terminal rings, as well as by the number of conjugated double bonds.
Antioxidants↗
The acute phase response and vitamin A status in malaria.
Plasma retinol and 5 carotenes were assayed by high performance liquid chromatography in Thai rural and urban malaria patients and matched control subjects. Plasma retinol was lower in the rural than in the urban controls and both groups of malaria patients had lower serum retinol concentrations than their respective controls. 29% (6/21) of the rural patients were biochemically deficient in retinol (less than or equal to 0.35 mumol/litre), suggesting severely depleted liver stores of vitamin A. The carotene data suggest that the intake of total carotenoids may be 50 to 100% greater than in the UK and that a much higher proportion of dietary beta-carotene is converted to vitamin A than in British adults. The concentrations of non-pro-vitamin A carotenoids in both groups of malaria patients were not compatible with vitamin A deficiency. The differences between patient and control median concentrations of pro-vitamin A (PVA) carotenoids were greater than those of non-PVA carotenoids, suggesting increased utilization of vitamin A in malaria. There was no evidence of clinical vitamin A deficiency in either of the communities studied; therefore, severely depleted stores of retinol are very unlikely. There is an alternative explanation for low plasma retinol levels in malaria patients because retinol is bound to the negative acute phase proteins, retinol binding protein and transthyretin. We suggest that the behaviour of retinol during infection indicates a rapid distribution into extravascular fluids and an increased availability to the tissues; i.e., it may be another beneficial effect of the acute phase response.
Acute-Phase Reaction↗
Liquid chromatographic determination of carotenoids in human serum using an engineered C30 and a C18 stationary phase.
A C30 stationary phase was specifically engineered for carotenoid separations, and carotenoid measurements using this column are compared with those obtained using a somewhat more conventional C18 column. Both methods were used to contribute measurements for the certification of carotenoids in Standard Reference Material 968b, Fat-Soluble Vitamins and Cholesterol in Human Serum. Analytes were extracted from the serum into hexane. Measurements on the C18 column were made using a gradient of acetonitrile, methanol, and ethyl acetate, which is described in detail elsewhere. Measurements on the C30 column were made using a gradient of water, methanol, and methyl tert.-butyl ether.
Carotenoids↗
Association between serum concentrations of micronutrients and lower urinary tract symptoms in older men in the Third National Health and Nutrition Examination Survey.
OBJECTIVES: To evaluate the association of serum micronutrients with lower urinary tract symptoms (LUTS). METHODS: We included 2497 men, 60 years old and older, who participated in the Third National Health and Nutrition Examination Survey from 1988 to 1994 and for whom serum concentrations of vitamins A, C, and E, carotenoids, and selenium had been measured previously. Cases were men with three or four of the following symptoms: nocturia, hesitancy, incomplete emptying, and weak stream, but who had never undergone noncancer prostate surgery. Controls were men without symptoms, who had never undergone noncancer prostate surgery. We adjusted for age and race in logistic regression models and used sampling weights. RESULTS: Serum concentrations of vitamin E (P = 0.03), lycopene (P = 0.06), and selenium (P = 0.03) were lower in men with LUTS compared with controls. Men in the top four quintiles of vitamin E, lycopene, and selenium had a nonstatistically significant 25% to 50% reduced odds of LUTS compared with men in the bottom quintile. Inverse associations were not seen for the other carotenoids or vitamin A. A high serum vitamin C concentration was associated with a lower odds of LUTS in current smokers, but with a nonstatistically significant greater odds in those who never smoked and in former smokers. CONCLUSIONS: Greater circulating concentrations of vitamin E, lycopene, and selenium, antioxidant micronutrients that are supported in published reports as protecting against prostate cancer, were observed also to be inversely associated with LUTS. The effect modification of the association with vitamin C by cigarette smoking warrants additional examination.
Aged↗
Longitudinal analysis shows serum carotenoid concentrations are low in children with cystic fibrosis.
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Carotenoids↗
Structure-reactivity relationship in the oxidation of carotenoid pigments of the pepper (Capsicum annuum L.).
The relationship between the degradation rate and structure of each pigment of the pepper carotenoid profile was studied in mixtures of dehydrated fruit with lipid substrates of differing degrees of unsaturation and in different proportions (20 and 40%). The differences in structural nature of the carotenoids present in the pepper fruit produce a variable rate of oxidation, resulting in nonuniform degradation. The yellow xanthophylls and beta-carotene have the highest rates of oxidation, with the ketocarotenoids and violaxanthin degrading at lower rates. Autoxidation is greater or lesser depending on the functional groups, which stabilize the radical intermediaries of the reaction. The behavior of capsanthin and capsorubin is that expected of carotenoids having structures that include keto groups: a markedly greater stability to autoxidation processes. This increases their antioxidant capacity, adding to their beneficial impact by reducing the proliferation of radical processes, which are detrimental to health.
Capsicum↗
Influence of dialysis on plasma lipid peroxidation products and antioxidant levels.
In patients with end-stage renal failure (ESRF), the incidence of atherosclerosis and cancer is increased. The importance of lipid peroxidation (LPO) products in the pathogenesis of these complications has recently been emphasized. The LPO products malondialdehyde (MDA) and hexanal, lipophilic antioxidants and erythrocyte glutathione (GSH) were estimated in 10 pediatric hemodialysis (HD) patients before and after HD and in 11 peritoneal dialysis (CPD) patients. Before HD, MDA was elevated [median (interquartile range): 384.5 (110 to 501) nM; normal < 150 nM], whereas plasma hexanal levels were normal in all patients [130.5 (88 to 222) nM; < 320 nM]. HD decreased MDA concentrations on average by 88% but did not change hexanal levels. CPD patients exhibited high plasma MDA concentrations [371 (287 to 468) nM], whereas hexanal was in the low normal range [56 (51 to 81) nM]. Antioxidants were normal in both groups and unchanged during HD. GSH decreased slightly during HD. We hypothesize that MDA may accumulate in ESRF due to reduced plasma clearance. Our results argue against a general increase of LPO in uremia.
Adolescent↗
Effect of increased fruit and vegetable intake on the susceptibility of lipoprotein to oxidation in smokers.
OBJECTIVE: To evaluate the effect of an increased dietary intake of fruit and vegetables on susceptibility of LDL to oxidation in smokers and nonsmokers. DESIGN: A descriptive and prospective study. SETTING: Joseph Fourier University, Grenoble. SUBJECTS: Volunteers were age and sex matched in the smoking and nonsmoking groups and were recruited by announcement. INTERVENTIONS: Increased intake of fruits and vegetables for two weeks providing 30 mg/day of carotenoids. MAIN OUTCOME MEASURES: Circulating levels of beta-carotene, lutein, lycopene, alpha-tocopherol; susceptibility of LDL to oxidation. Cu-Zn superoxide dismutase (Cu-Zn SOD), and Se glutathione peroxidase (Se-GSH-Px) activities and reduced (GSH) and oxidized (GSSG) glutathione. RESULTS: At entry (week 0: W0) smokers exhibited a lower plasma carotene level but the plasma parameters of oxidative stress and LDL oxidizability were not different from nonsmokers. After two weeks of increased intake of fruits and vegetables the circulating levels of carotenoids increased in smokers 23% and 11% in nonsmokers. At the same time the resistance of LDL to oxidation increased by 14% in smokers (P < or = 0.05) and by 28% in nonsmokers (P < or = 0.025). The mean whole blood GSH level was higher in smokers at entry but returned to a concentration similar to nonsmokers at the end of the study. CONCLUSION: This pilot study indicates that an increased, carotenoid rich food intake through its inhibitory effect on the susceptibility of LDL to oxidation may be an interesting approach to reduce the risk of atherosclerosis both in smokers and nonsmokers.
Adult↗
The charge delocalised beta,beta-carotene dication--preparation, structure elucidation by NMR and reactions with nucleophiles.
The reaction between beta,beta-carotene and BF3-etherates has been investigated, leading to structural elucidation of the blue product, formed in appropriate organic solvents, as a symmetrical charge delocalised dication (lambda(max) 985 nm at room temperature in CHCl3) with considerable stability. The reaction, monitored by EPR studies at -25 degrees C, occurred via free radical intermediates. A C40H56BF3 intermediate was captured by EIMS. The detailed structure of the dication was established by COSY, HSQC, HMBC and 1D and 2D ROESY NMR techniques (600 MHz, CDCl3, -20 degrees C) leading to complete assignments of 1H and 13C chemical shifts and 3J(H,H) coupling constants. The effects of the two delocalised charges on chemical shift (charge distribution) and bond distance (3J(H,H)) were considered. The results are consistent with charge delocalisation mainly in the C-5-C-9 and C-5'-C-9' regions and with bond inversion to retro shifted double bonds in the central C-13-C-13' region. A convention for denoting the charge delocalisation and bond types is presented. The experimental results are discussed relative to previous theoretical calculations of the beta,beta-carotene dication structure. (All-E) and (15-Z)-beta,beta-carotene provided the same dication. The NIR spectra and stability of dications prepared in the same manner from the related carotenes 20,20'-dinor-beta,beta-carotene, heptapreno-beta,beta-carotene and nonapreno-beta,beta-carotene were examined for comparison. Reactions of the beta,beta-carotene dication with selected nucleophiles provided products including isocryptoxanthin, isocarotene and mutatochrome with H2O as nucleophile, and isocryptoxanthin methyl ether, 8-methoxy-7,8-dihydro-beta,beta-carotene and isocarotene with CH3ONa as nucleophile. The formation of these products is rationalised from the structure assigned to the dication.
Carotenoids↗
Antioxidant activity of carotenoids in phosphatidylcholine vesicles: chemical and structural considerations.
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Antioxidants↗
Carotenoid profiles of human plasma lipoproteins.
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Antioxidants↗
Evidence that dietary supplementation with carotenoids and carotenoid-rich foods modulates the DNA damage: repair balance in human lymphocytes.
Epidemiological evidence has shown that the habitual consumption of diets high in fruits and vegetables is associated with reduced risk of cancers. The challenge is to identify causal mechanisms of effect. The aim of the current study was to determine whether an increase in rate of removal of DNA single-strand breaks (SSB) following oxidative challenge could be provoked ex vivo in peripheral blood lymphocytes (PBL). The PBL were isolated from apparently healthy volunteers following dietary intervention with: (1) a mixed carotene capsule; (2) a daily portion of cooked minced carrots; (3) a matched placebo; (4) a portion of mandarin oranges; (5) vitamin C tablets. Single-cell gel electrophoresis was employed to measure baseline levels of SSB and DNA susceptibility to oxidative damage, and to monitor the number of SSB over 4 h, in both unchallenged and H2O2-treated PBL. The enzymatic capacity for repair of different types of DNA oxidative lesions was also measured using two related cell-free assays. There was no evidence that any of the dietary supplementation regimens altered baseline levels of SSB, provided any direct antioxidant protection or altered DNA repair capacity, with two exceptions: the number of SSB following exposure to H2O2 decreased more rapidly in PBL from volunteers given the mixed carotene capsules and repair patch synthesis activity in PBL increased from volunteers given the cooked carrots. These results suggest that carotenoids and carotenoid-rich foods can influence DNA damage:repair by modulation of discrete stages in the DNA repair mechanisms.
Adolescent↗
Frequency of fruit and vegetable consumption and coronary heart disease in France and Northern Ireland: the PRIME study.
Fruit and vegetable consumption is associated with low CHD risk in the USA and Northern Europe. There is, in contrast, little information about these associations in other regions of Europe. The goal of the present study was to assess the relationship between frequency of fruit and vegetable intake and CHD risk in two European populations with contrasting cardiovascular incidence rates; France and Northern Ireland. The present prospective study was in men aged 50-59 years, free of CHD, who were recruited in France (n 5982) and Northern Ireland (n 2105). Fruit and vegetable intake was assessed by a food-frequency questionnaire. Incident cases of acute coronary events and angina were recorded over a 5-year follow-up. During follow-up there was a total of 249 ischaemic events. After adjustment on education level, smoking, physical activity, alcohol consumption, employment status, BMI, blood pressure, serum total and HDL-cholesterol, the relative risks (RR) of acute coronary events were 0.67 (95% CI 0.44, 1.03) and 0.64 (95% CI 0.41, 0.99) in the 2nd and 3rd tertiles of citrus fruit consumption, respectively (P for trend <0.03). Similar results were observed in France and Northern Ireland. In contrast, the RR of acute coronary events for 'other fruit' consumption were 0.70 (95% CI 0.31, 1.56) and 0.52 (95% CI 0.24, 1.14) respectively in Northern Ireland (trend P<0.05) and 1.29 (95% CI 0.69, 2.4) and 1.15 (95% CI 0.68, 1.94) in France (trend P=0.5; interaction P<0.04). There was no evidence for any association between vegetable intake and total CHD events. In conclusion, frequency of citrus fruit, but not other fruits, intake is associated with lower rates of acute coronary events in both France and Northern Ireland, suggesting that geographical or related factors might affect the relationship between fruit consumption and CHD risk.
Acute Disease↗
Reduction in estimated vitamin A intake induced by new food composition tables in Japan, where vitamin A is taken mostly from plant foods.
A revised edition of the standard tables of food composition was implemented in Japan in 2005; one of the major revision points is the change of retinol activity equivalents for pro-vitamin A carotenoids. This preliminary analysis was conducted to examine whether the revision affects the estimation of vitamin A intake; and if so, to what extent. Accordingly, a field survey was conducted to collect 24-h duplicates of daily foods of citizens, and 26 adult women volunteered. Application of the procedures in the new and previous standard tables of food composition gave 537 microg retinol activity equivalent and 704 microg retinol equivalence, respectively, for daily vitamin A intake. Thus, the changes in retinol activity equivalents induced substantial reduction (by 24%) in estimation of vitamin A intake among the Japanese population, for whom pro-vitamin A carotenoids in plant foods are the major sources (76%) for vitamin A, and retinol accounts for only 35% (on the retinol activity equivalent basis).
Adult↗
Variability in the intercomparison of food carotenoid content data: a user's point of view.
The availability of reliable information on food composition is essential both for the evaluation of diet and for nutritional research to relate diet to health or disease. In this article, we compare the total and individual carotenoid contents and the retinol equivalents in fruits and vegetables reported in several food composition tables and HPLC studies. The impact of the variability in carotenoid intake was evaluated on the basis of Spanish National Consumption Statistics and on the values for a standard diet. We identify, from a user's point of view, errors concerning identification of the items and the terms used to refer to the compounds. Food composition tables overestimate (by 2 to 48%) the retinol equivalent intake, whereas they underestimate (by 30 to 50%) the total carotenoid intake according to HPLC data. We study the effect of these main sources of error, their impact on dietary assessment and on the classification of relevant contributors, and the possible consequences with respect to proper diet in terms of nutritional assessment and epidemiological studies. Given the different dietary habits among populations and the fact that certain items may be over- or underestimated in databases, the use of a single database may be misleading as to the rate of carotenoid consumption and the "true" nutrient intake in a given population, thus weakening the reliability of the study and resulting in erroneous conclusions.
Carotenoids↗
Diurnal and seasonal variation of five carotenoids measured in human serum.
We studied within-person variation over time in serum concentrations of five carotenoids. In a diurnal study involving 33 subjects, only the 1700 h blood samples demonstrated carotenoid concentrations different from the original 0800 values. Correlations between serum concentrations of the same carotenoids drawn 1 d apart ranged from 0.93 to 0.98. In a seasonal study involving 29 subjects, no systematic trends were observed for serum concentrations of these carotenoids. Correlations between concentrations of the same carotenoids drawn 1 y apart ranged from 0.57 to 0.82. Concentrations of different carotenoids within an individual tended to be correlated with each other. Obtaining one blood sample from subjects is a relatively imprecise way to estimate their usual serum concentrations of carotenoids. If an epidemiological study was to be based on only one determination of serum carotenoids, within-person variability in serum concentrations would attenuate true regression coefficients by 4-13% and would increase the required numbers of study subjects by 19-65%.
Adult↗
Amount of fat in the diet affects bioavailability of lutein esters but not of alpha-carotene, beta-carotene, and vitamin E in humans.
BACKGROUND: Fat-soluble vitamin E and carotenoids are regarded as being protective against chronic diseases. Little is known about the effect of dietary fat on the bioavailability of these compounds. OBJECTIVE: The objective of this study was to assess the effect of the amount of dietary fat on plasma concentrations of vitamin E and carotenoids after supplementation with these compounds. DESIGN: During two 7-d periods, 4 groups of 14-15 volunteers received daily, with a low-fat hot meal, 1 of 4 different supplements: vitamin E (50 mg), alpha- plus beta-carotene (8 mg), lutein esters (8 mg lutein), or placebo. The supplements were provided in a low- or high-fat spread supplied in random sequence during either of the 2 experimental periods. RESULTS: As anticipated, plasma concentrations of vitamin E, alpha- and beta-carotene, and lutein were significantly higher in the supplemented groups than in the placebo group. The amount of dietary fat consumed with the hot meal (3 or 36 g) did not affect the increases in plasma concentrations of vitamin E (20% increase with the low-fat spread and 23% increase with the high-fat spread) or alpha- and beta-carotene (315% and 139% with the low-fat spread and 226% and 108% with the high-fat spread). The plasma lutein response was higher when lutein esters were consumed with the high-fat spread (207% increase) than with the low-fat spread (88% increase). CONCLUSION: Optimal uptake of vitamin E and alpha- and beta-carotene requires a limited amount of fat whereas the amount of fat required for optimal intestinal uptake of lutein esters is higher. 2000;71:-93.
Adolescent↗