scholarly journals Biopotency of vitamin E in barley

1984 ◽  
Vol 52 (2) ◽  
pp. 335-349 ◽  
Author(s):  
R. V. Juhani Hakkarainen ◽  
Jouko T. Työppönen ◽  
Saifeldin Hassan ◽  
Gösta Bengtsson ◽  
S. R. Lennart Jönsson ◽  
...  
Keyword(s):  
Vitamin E ◽  
Chemical Reduction ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Total Vitamin ◽  
Tissue Samples ◽  
Chemical Determination ◽  
The Individual ◽  
Dose Responses ◽  
Liver Storage

1. Investigations were carried out to establish the total biopotency of the natural vitamin E isomers in barley compared with that of DL-α-tocopheryl acetate.2. The chick was used as an experimental animal. Prevention of nutritional encephalomalacia (NE) and chick liver-storage and plasma-storage assays of vitamin E were the methods used in the study. The individual tocopherols and tocotrienols, both in the tissue samples and in the grain and barley oil, were analysed using high-pressure liquid chromatography (HPLC) with fluorescence detection. The diagnosis of NE was based on careful clinical and histopathological observations.3. It can be concluded from the results that full protection against NE in the chicks was obtained with a supplementation level of 7.5 mg DL-α-tocopheryl acetate/kg diet (i.e. a total vitamin E content of 11.20 mg/kg diet) or with a supplement of 8.7 g barley oil/kg diet (i.e. a total vitamin E content of 22.99 mg from barley oil/kg diet). This gave a biopotency factor of 0.49 for barley for prevention of NE of the chicks, as compared to that of DL-α-tocopheryl acetate.4. Using regression analysis a statistically linear relationship could be observed between the total dietary vitamin E level and the response, as measured by the total vitamin E content in the liver and plasma, both in the groups supplemented with DL-a-tocopheryl acetate and in the groups supplemented with corresponding amounts of vitamin E in barley oil. The liver and plasma responses to the total vitamin E in the barley-oil diet compared with those of the DL-a-tocopheryl acetate reference diet gave identical values for the regression coefficients, i.e. in both liver-storage and plasma-storage assays the value for slopes of dose-response lines was 0.37. This means that the biopotency of the total vitamin E in barley was 37% of that of dietary DL-a-tocopheryl acetate. Thus, barley is not as rich a source of vitamin E as could be supposed on the basis of the chemical determination of its total vitamin E content.5. It was possible to verify this experimentally established biopotency of 0.37 for the total vitamin E in barley by converting the chemically determined amounts of the vitamin E isomers in barley into DL-α-tocopheryl acetate equivalents by multiplying them with internationally accepted potency factors for the individual natural isomers (DL-α-tocopheryl acetate 1.00, D-α-tocopherol 1.49, D-β-tocopherol 0.60, D-gamma;-tocopherol 0.1 5, D-α-tocotrienol 0.37).6. In spite of the high proportion of α- and β-tocotrienols in the barley-oil diets (about 60% of the total vitamin E content), only traces of these isomers could be detected in the plasma and none could be detected in the liver. On the other hand, calculation of the individual hiopotencies for the different isomers in the barley-oil diet by comparing the dose responses, diet: liver, separately for each isomer with those of DL-α-tocopheryl acetate, resulted in biopotency values for α- and β-tocopherol which were twice as high as the internationally accepted conversion factors. These results of the present study tempted the authors to draw the conclusion that there may have been a chemical reduction of the α- and β-tocotrienols to the corresponding tocopherols before entering the liver.

scholarly journals Vitamin C and Vitamin E Mitigate the Risk of Pancreatic Ductal Adenocarcinoma from Meat-Derived Mutagen Exposure in Adults in a Case-Control Study

2019 ◽  
Vol 149 (8) ◽  
pp. 1443-1450 ◽  
Author(s):  
Donghui Li ◽  
Hongwei Tang ◽  
Peng Wei ◽  
Jiali Zheng ◽  
Carrie R Daniel ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Vitamin E ◽  
Vitamin C ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Case Control Study ◽  
Case Control ◽  
Ductal Adenocarcinoma ◽  
Dietary Vitamin ◽  
Total Vitamin ◽  
Control Study

ABSTRACT Background Previous studies have found that meat-derived mutagens increase, and vitamin C or E decrease, the risk of pancreatic cancer. Objective The aim of this study was to determine whether intake of vitamin C or E modulates the association between meat-derived mutagen exposure and risk of pancreatic cancer. Design We conducted a case-control study in 1321 patients with pathologically confirmed pancreatic ductal adenocarcinoma (PDAC) and 1061 healthy controls (aged 28–88 y). Cases and controls were frequency-matched by age, sex, and race/ethnicity. Mutagen intake was assessed using a meat preparation questionnaire. Intakes of vitamin C, E, and other dietary components were assessed via a food-frequency questionnaire in a subset of 811 cases and 818 controls. ORs and 95% CIs were estimated in multivariable-adjusted logistic regression models. Results The risk of PDAC was not associated with meat intake but was associated with consumption of well-done grilled or barbecued chicken (OR: 1.57; 95% CI: 1.18, 2.09; P = 0.001). Intake of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline was associated with increased PDAC risk (Ptrend = 0.047). Participants in the highest, as compared with the lowest, quintile of 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (PhIP) intake experienced a 38% increased risk of PDAC (95% CI: 1.00, 1.90; P = 0.048). Intakes of total vitamin C or E from food and supplements or from supplements alone were each inversely associated with PDAC risk. Stratified analyses showed differential associations for PhIP intake and PDAC risk, such that risk increased among individuals with lower intake of vitamin C or E and decreased among those with higher vitamin intake. Significant interactions of dietary vitamin C, dietary vitamin E, and total vitamin E with PhIP intake were detected (Pinteraction = 0.023, <0.001, and 0.013, respectively). Conclusions Consistent with experimental evidence, this study of 811 cases and 818 controls has shown that high intake of dietary vitamin C or E mitigates the risk of PhIP-related PDAC.

α-Tocopherol concentration and stereoisomer composition in plasma and milk from dairy cows fed natural or synthetic vitamin E around calving

2006 ◽  
Vol 73 (2) ◽  
pp. 227-234 ◽  
Author(s):  
Guillermo E Meglia ◽  
Søren K Jensen ◽  
Charlotte Lauridsen ◽  
Karin Persson Waller
Keyword(s):  
Vitamin E ◽  
Dairy Cows ◽  
Plasma Concentrations ◽  
Dietary Treatment ◽  
Tocopheryl Acetate ◽  
Tocopherol Concentration ◽  
Blood Concentrations ◽  
Oral Supplementation ◽  
Periparturient Period ◽  
The Individual

The aim of this study was to compare the effects of supplementing dairy cows with 1000 IU/day of all-rac-α-tocopheryl acetate (SynAc), RRR-α-tocopheryl acetate (NatAc), or RRR-α-tocopherol (NatAlc), from approximately 3 weeks before estimated calving until 2 weeks after calving, on the concentration of α-tocopherol and its stereoisomers (RRR-, RSS-, RRS-, RSR- and the four 2S-forms of α-tocopherol) in blood and milk. An unsupplemented group was included as control. Blood samples were collected at 3, 2 and 1 weeks before estimated calving, at calving, and 3, 7 and 14 days after calving, while milk samples were taken twice within 24 h after calving and at 7 and 14 days in milk. Overall, time and treatment had significant effects on plasma α-tocopherol with higher concentrations in NatAc than in the other groups. In addition, SynAc had higher concentrations than Control, and NatAlc tended to be higher than Control. The lowest plasma concentrations were observed at calving and 3 days after calving. Independent of treatment, the concentration was higher in colostrum than in milk day 7 and 14 after calving. Analyses of the stereoisomer distribution in plasma and milk showed that, irrespective of dietary treatment, RRR-α-tocopherol was the most predominant form, constituting more than 86%, whereas the remaining part of α-tocopherol was made up by the three synthetic 2R isomers, while the 2S isomers only contributed less than 1% of the total α-tocopherol. In control cows and cows supplemented with natural vitamin E, the proportion of RRR-α-tocopherol in plasma and milk constituted more than 98% of the total α-tocopherol. In conclusion, the results indicate that daily oral supplementation of dairy cows with RRR-α-tocopheryl acetate gives the highest blood concentrations of α-tocopherol in the periparturient period. Analyses of the distribution of the individual stereoisomers of α-tocopherol further indicate that the bioavailability of RRR-α-tocopherol relative to synthetic stereoisomers in cattle is considerably higher than officially accepted until now.

Re-evaluation of the vitamin E requirements of juvenile tilapia (Oreochromis niloticus ✕ O. aureus)

2001 ◽  
Vol 72 (3) ◽  
pp. 529-534 ◽  
Author(s):  
S. Y. Shiau ◽  
L. F. Shiau
Keyword(s):  
Lipid Peroxidation ◽  
Vitamin E ◽  
Oreochromis Niloticus ◽  
Control Diet ◽  
Dietary Treatment ◽  
Dietary Lipid ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Feeding Trial ◽  
Protein Deposition

AbstractA 10-week feeding trial was conducted to re-evaluate the level of dietary vitamin E (DL- α-tocopheryl acetate) that was adequate for juvenile tilapia Oreochromis niloticus ✕ O. aureus given diets containing two dietary lipid concentrations. Purified diets with eight levels of vitamin E (0, 25, 50, 75, 100, 150, 200, 400 mg/kg diet) at either 50 or 120 g lipid per kg were each given to three replicate groups of tilapia (mean weight: 0·69 (s.e.0·02) g) reared in a closed, recirculating system. Food efficiency and protein deposition were significantly (P < 0·05) higher in fish given 50 mg vitamin E per kg diet and 75 mg/kg diet in the 50 and 120 g lipid per kg groups respectively, compared with fish given the unsupplemented control diet. Mortality of fish was not affected by dietary treatment. Weight gain and liver microsomal ascorbic acid-stimulated lipid peroxidation data analysed by broken-line regression indicated that the optimum dietary vitamin E requirements in juvenile tilapia are 42 to 44 mg vitamin E per kg and 60 to 66 mg vitamin E per kg in 50 and 120 g lipid per kg diets, respectively.

scholarly journals Effects of protein and vitamin E on haemoglobin formation in rats

1968 ◽  
Vol 22 (4) ◽  
pp. 751-755 ◽  
Author(s):  
J. Bunyan ◽  
J. Green ◽  
M. A. Cawthorne
Keyword(s):  
Vitamin E ◽  
Dietary Supplement ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Deficient Diet ◽  
Growth Depression ◽  
Low Protein ◽  
Protein Diets ◽  
Severe Growth ◽  
Haemolysis Test

1. Young rats were given, for 9 weeks, vitamin E-deficient diets containing either 20% or 10% casein, with and without a dietary supplement of 350 ppm D-α-tocopheryl acetate. For the next 5 weeks the casein content of the low-protein diets was decreased to 7%.2. The low-protein diets induced severe growth depression.3. The dialuric acid-induced haemolysis test showed that the rats given the 20% casein vitamin E-deficient diet were depleted of vitamin E, but that the rate of depletion on the lowcasein diet was slower.4. Haemoglobin levels were slightly decreased by the 10% casein diets after 9 weeks, but this difference was not found after 14 weeks, comparing 20% and 7% casein. Dietary vitamin E had no effect on haemoglobin levels or erythrocyte counts.

Effects of Dietary Carnosine and Vitamin E on Antioxidant and Oxidative Status of Rats

2008 ◽  
Vol 78 (45) ◽  
pp. 230-237 ◽  
Author(s):  
Wissam Ibrahim ◽  
Vickie Tatumi ◽  
Che-Chung Yeh ◽  
Chuen Bin Hong ◽  
Ching Kuang Chow
Keyword(s):  
Vitamin E ◽  
Antioxidant Status ◽  
Conjugated Dienes ◽  
Oxidative Status ◽  
Tocopheryl Acetate ◽  
Protein Carbonyls ◽  
Dietary Vitamin ◽  
Sprague Dawley ◽  
Deficient Diet ◽  
Sprague Dawley Rats

The purpose of this study was to determine if moderate levels of carnosine supplement, alone or in combination with vitamin E, enhance antioxidant status and/or provide protection against oxidative stress. Fiftyfour one-month-old male Sprague-Dawley rats were fed a basal vitamin E-deficient diet supplemented with either 0, 200, or 1000 mg L-carnosine, and either 0, 10, or 100 IU vitamin E (as all rec-α-tocopheryl acetate) per kg diet for 15 weeks. The antioxidant and oxidative status were assessed in the skeletal muscle, liver, and blood. Dietary vitamin E, but not carnosine, increased levels of vitamin E, decreased tissue peroxidizability, prevented incidence of myodegeneration, and reduced erythrocyte hemolytic stress. The levels of conjugated dienes, protein carbonyls, ascorbic acid, and nonprotein sulfhydryls, and activities of catalase, glutathione (GSH) peroxidase, and aldehyde dehydrogenase were not significantly altered by dietary carnosine or vitamin E. The results obtained suggest that supplementation of carnosine at levels of up to 1000 mg/kg diet does not significantly affect the antioxidant and oxidative status of rats.

scholarly journals Effect of Dietary Supplementation with Vitamin E and Selenium in Thoroughbred Horses on the Concentration of F2-isoprostanes in the Blood Plasma as a Marker of Lipid Peroxidation

2008 ◽  
Vol 77 (3) ◽  
pp. 335-340
Author(s):  
H. Härtlová ◽  
R. Rajmon ◽  
A. Dörflerová ◽  
L. Zita ◽  
D. Řehák ◽  
...  
Keyword(s):  
Vitamin E ◽  
Blood Plasma ◽  
Plasma Concentrations ◽  
Tocopheryl Acetate ◽  
Control Group ◽  
Individual Values ◽  
Large Variability ◽  
Thoroughbred Horses ◽  
The Individual ◽  
Experimental Group

The objective of this study was to assess the effect of vitamin E and selenium (Se) supplementation on the plasma levels of F2-isoprostanes as a marker of oxidative stress in horses in their training period. Twelve healthy 3-year-old English thoroughbred horses were divided into two groups: control (n = 6) and experimental (n = 6). Feeding rations were adapted to a moderate workload. The horses of the experimental group received supplements of DL-α-tocopheryl acetate E (2 250 mg/day/horse) and of sodium selenite (0.5 mg/day/horse). The plasma concentrations of both antioxidants and F2-isoprostanes were monitored on days 0, 44 and 70. After 70 days of supplementation, the concentrations of selenium in the experimental group were significantly higher (P < 0.05) compared to the beginning of the experiment (mean ± SE: 135.81 ± 10.19 μg l -1 vs. 98.70 ± 10.88 μg l -1), as well as to the control group (day 0: 101.78 ± 11.06 μg l -1, day 70: 108.18 ± 7.77 μg l -1). In the horses of the experimental group, plasma α-tocopherol levels significantly increased from the 44th day of supplementation compared to the beginning of the study as well to the control group (5.23 ± 0.52 mg l -1 vs. 2.45 ± 0.25 mg l -1 or 3.46 ± 0.34 mg l -1, respectively). The plasma concentration of F2-isoprostanes tended to be lower in the experimental group at the end than at the beginning of monitoring (156.8 ± 12.89 pg l -1 vs. 170.3 ± 60.8 pg l -1), although the control group showed the opposite trend (181.2 ± 15.67 pg l -1 vs. 137.0 ± 47.05 pg l -1). Nevertheless, none of these differences were significant because of the large variability of the individual values. It can be stated that supplementation of the diet used with selenium and vitamin E caused a non-significant decrease of F2-isoprostane concentration in the blood plasma only, and a significant increase of plasma concentrations of these antioxidants. The variation of isoprostane levels probably reflected rather the individual responses of the horses' organisms to the training workload.

Separation of RRR-α-Tocopherol by Chiral Chromatography

2020 ◽  
Vol 103 (5) ◽  
pp. 1288-1292
Author(s):  
Brendon D Gill ◽  
Harvey E Indyk
Keyword(s):  
Vitamin E ◽  
Chromatographic Separation ◽  
Chromatographic Method ◽  
Tocopherol Content ◽  
Hplc Method ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Accurate Estimation ◽  
Chiral Column ◽  
Compliance Testing

Abstract Background α-Tocopherol can exist as eight possible stereoisomers due to the presence of three chiral carbons. Regulations and industry guidelines necessitate that dietary vitamin E intakes be based on the vitamin E activity of RRR-α-tocopherol. Food products fortified with synthetic all-rac-α-tocopherol or all-rac-α-tocopheryl acetate during manufacturing will require chiral separation of the α-tocopherol stereoisomers for accurate estimation of vitamin E activity. Objective The development of an HPLC method utilizing a chiral column for the chromatographic separation of RRR-α-tocopherol from other α-tocopherol stereoisomers. Method Normal phase liquid chromatographic separation using a polysaccharide-based chiral column with fluorescence detection of α-tocopherol stereoisomers. Results The described chromatographic method achieves baseline resolution of RRR-α-tocopherol from its stereoisomers. Method selectivity, precision, and robustness were evaluated and acceptable performance was achieved. Conclusions The chromatographic method was found to be suitable for application where both RRR-α-tocopherol content and total α-tocopherol content are required for routine compliance testing. Highlights A robust and precise chomatographic method for the baseline resolution of RRR-α-tocopherol from its stereoisomers was acheived.

scholarly journals Influence of sources of dietary vitamin E on the maternal transfer of α-tocopherol to fetal and neonatal guinea pigs as determined by a stable isotopic technique

2003 ◽  
Vol 89 (4) ◽  
pp. 455-466 ◽  
Author(s):  
N. Hidiroglou ◽  
R. Madere ◽  
L. R. McDowell ◽  
P. L. Toutain
Keyword(s):  
Vitamin E ◽  
Guinea Pigs ◽  
Relative Bioavailability ◽  
Tissue Type ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Natural Form ◽  
Stable Isotopic ◽  
Relationship Of ◽  
Isotopic Technique

The accepted biological potencies of vitamin E (United States Phamacopeia, 1985) for 1 mg all-rac-α-tocopheryl acetate (synthetic form) is 1·00 IU and that of 1 mg (RRR)-α-tocopheryl acetate (natural form) is 1·36 IU. In the present study, a stable isotopic (2H) technique was employed to evaluate the bioavailability of natural v. synthetic forms of vitamin E and to determine whether the potency of the forms is the stated relationship of 1·36:1·00 (RRR)-α-tocopheryl acetate:all-rac-α-tocopheryl acetate. Sixty female in-bred guinea pigs received either 40 or 80 mg vitamin E/kg diet with equal levels of (RRR)-α-tocopheryl acetate and all-rac-α-tocopheryl acetate throughout gestation and lactation. At late-term pregnancy (day 50 or 60) and during early lactation, dams and their corresponding fetuses or neonates were killed and various tissues collected for subsequent α-tocopherol analysis. Vitamin E analysis of fetal and neonatal tissues indicated a substantial transfer of 2H-labelled α-tocopherol across the placenta and through the mammary gland. Total α-tocopherol concentrations were significantly influenced by tissue type and dose level, but not by stage of gestation or lactation. The relative bioavailability (d3:d6) across fetal and neonatal tissues was on average 1·81:1·00, with a range from 1·62:1·00 to 2·01:1·00. Maternal tissues had a mean ratio of 1·77:1·00. A higher relative bioavailability (P≤0·05) was observed with natural compared with synthetic α-tocopherol as shown by a higher d3:d6 ratio in all tissues examined. Vitamin E was highest in colostrum on day 2 then declined through to day 5. Results from this present experiment further question the accepted biological potencies of natural:synthetic α-tocopheryl acetate of 1·36:1·00.

EFFECT OF DIETARY SELENIUM ON GLUTATHIONE PEROXIDASE ACTIVITY IN PIGLETS

1979 ◽  
Vol 59 (1) ◽  
pp. 67-75 ◽  
Author(s):  
E. R. CHAVEZ
Keyword(s):  
Vitamin E ◽  
Peroxidase Activity ◽  
Basal Diet ◽  
Growing Pigs ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Live Animal ◽  
Dietary Selenium ◽  
Level Of Activity ◽  
High Level

Two experiments were conducted to measure the effect of dietary selenium on glutathione (GSH) peroxidase activity in plasma and body organs of growing pigs. In experiment 1, 12 piglets weaned at 2 wk and 18 weaned at 4 wk were fed for a period of 5 wk either a selenium-deficient basal diet or the same diet supplemented with 0.1 ppm selenium as sodium selenite. Three levels of dietary vitamin E supplemented as dl-alpha-tocopheryl acetate were also included in this experiment in a factorial arrangement with selenium. Vitamin E was shown to have no effect on GSH-peroxidase activity. In contrast, dietary selenium exerted a significant effect on the activity of the seleno-enzyme in the plasma, pancreas, heart, lungs and kidneys of piglets. The kidneys showed the highest GSH-peroxidase activity of the organs studied. Supplemental selenium resulted in a marked increase in plasma GSH-peroxidase activity of the piglets weaned at 2 wk, and maintained a high level of activity for those weaned at 4 wk. Pancreatic activity of this enzyme in selenium-deficient animals showed a drop to about one-third the activity observed in selenium-supplemented piglets after a 5-wk period. GSH-peroxidase in heart muscle showed the same response that was observed in the pancreas. The reduction in activity of this enzyme in lungs and kidneys was much greater than in pancreas and heart. No measurable amounts of GSH-peroxidase were observed in the liver of piglets either with or without selenium supplementation. In experiment 2, six pairs of male-female piglets weaned at 2 wk of age were fed either a selenium-deficient or a selenium supplemented diet. During the 20-wk period, selenium-supplemented piglets showed an average GSH-peroxidase activity in plasma 8.2-fold higher than selenium-deficient animals. After 2 wk, selenium-deficient piglets showed an extremely low activity of the seleno-enzyme in the plasma. Thus, the measurement of GSH-peroxidase in plasma of the live animal appears to be a reliable index of nutritional selenium status in piglets.

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