Vitamin-E metabolism and its application

Effects of Supplementary Selenium and Vitamin E on the Growth Performance, Antioxidant Enzyme Activity, and Gene Expression of Sea Cucumber Apostichopus japonicus

A 60-day feeding experiment was conducted to evaluate the effects of single selenomethionine (Se) and its mixture with vitamin E (VE) on the growth, antioxidant enzyme activities, and gene expression of juvenile sea cucumber Apostichopus japonicus. The design of the experiment contained two factors and 5 × 2 levels by means of adding various levels of Se and VE in the feed, i.e., combination of 0, 0.3, 0.6, 0.9, or 1.2 mg Se kg^-1 and 0 or 200 mg VE kg^-1. The results revealed that the specific growth rate and weight gain rate were the highest in the group with 0.3 mg Se kg^-1 and 200 mg VE kg^-1, followed by the group with 0.6 mg Se kg^-1 without VE. Se significantly improved the activities of amylase and protease with VE also imposed positive effect on the amylase activity. Glutathione peroxidase (GPX) activity was highest in the group with 1.2 mg Se kg^-1 and lowest with the basal diet. The activity of catalase (CAT) was increased while glutathione reductase (GR) activity was decreased in response to the addition of Se. No significant interactive effects of Se and VE on the enzyme activities were found except superoxide dismutase (SOD) activity. While relative expressions of GPX, CAT, and SOD genes were significantly responsive to the addition of dietary Se, VE significantly promoted the gene expression of SOD. The results suggested that Se and VE might have beneficial effects on the growth and antioxidant responses of A. japonicus.

Effect of vitamin E on severity and duration of cyclic mastalgia: A systematic review and meta-analysis

OBJECTIVES

A systematic review was conducted to assess the effect of vitamin E on the severity and duration of Cyclic Mastalgia compared to vitamin B6, fish oil, herbal medicines and placebo.

DESIGN

A systematic review and meta-analysis of clinical trials.

METHODS

A search was carried out in PubMed, Cochrane Library, Embase, Scopus and Google Scholar and Persian databases for articles published from 1980 to 2018. The data obtained were analyzed in RevMan and reported in forest plots. The Odds Ratio (OR) was used to find the effect for the dichotomous data and the Standardized Mean Difference (SMD) for the continuous data. The heterogeneity of the studies was assessed using I² and the Random Effects Model was used instead of the Fixed Effects Model if I²>25%.

RESULTS

A total of 1051 titles and abstracts were extracted. Fourteen articles ultimately remained, and 11 of them were entered into the meta-analysis. The meta-analysis showed significant differences between vitamin E and placebo in the severity (SMD=-0.51; 95% CI=-0.21 to -0.82) and duration (MD=-1.47; 95% CI=-0.91 to -2.57) of cyclic mastalgia, although herbal medicines had a greater effect on the severity of mastalgia than vitamin E (SMD = 0.51, 95% CI = 0.06 to 0.96).

CONCLUSION

Although herbal medicines are more effective than vitamin E, vitamin E reduces both the severity and duration of the disorder compared to placebos, which only reduce its severity, and can therefore be considered a treatment with minimum side-effects. Due to the high heterogeneity of the studies, the researchers recommend further research on the subject using a standard tool based on the CONSORT statement.

The Response of Macro- and Micronutrient Nutrient Status and Biochemical Processes in Rats Fed on a Diet with Selenium-Enriched Defatted Rapeseed and/or Vitamin E Supplementation

The response of nutrient status and biochemical processes in (i) Wistar and (ii) spontaneously hypertensive (SHR) rats upon dietary intake of selenium- (Se-) enriched defatted rapeseed (DRS) and/or vitamin E fortification was examined to assess the health benefit of DRS in animal nutrition. Twenty-four individuals of each type of rat were used: The control group was fed with an untreated diet (Diet A). In Diets B and C, soybean meal was replaced with defatted DRS, which comprised 14% of the total diet. The selenized DRS application resulted in ~3-fold increase of Se content in the diet. Diet C was also fortified with the addition of vitamin E, increasing the natural content by 30%. The Se content of the blood and kidneys tended to increase in the DRS groups, where the changes were significant (P < 0.05) only in the case of SHR rats. The iodine (I) content and the proportion of iodide in rat livers indicated a lower transformation rate of iodide into organoiodine compounds compared to the control. Slight and ambiguous alterations in the antioxidative response of the rat were observed in the DRS groups, but the addition of vitamin E to the diet helped to moderate these effects.

Vitamin E-Induced Changes in Glutamate and GABA Metabolizing Enzymes of Chick Embryo Cerebrum

Vitamin E exists in eight different forms, four tocopherols and four tocotrienols. It forms an important component of our antioxidant system. The structure of Vitamin E makes it unique and indispensable in protecting cell membranes. α -tocopherol, one of the forms of Vitamin E, is also known to regulate signal transduction pathways by mechanisms that are independent of its antioxidant properties. Vitamin E compounds reduce the production of inflammatory compounds such as prostaglandins. Swollen, dystrophic axons are considered as the hallmark of Vitamin E deficiency in the brains of rats, monkeys, and humans. The present work aimed to study the Vitamin E- ( α -tochopherol acetate-) induced alterations of enzymes involved in metabolism of Glutamate and GABA during developmental neurogenesis of cerebrum. Therefore, cytosolic and crude mitochondrial enzyme activities of glutamine synthetase, aspartate transaminase, alanine transaminase, GABA transaminase, succinic Semialdehyde dehydrogenase, glutamic dehydrogenase, and α -Ketoglutarate dehydrogenase were analysed. Vitamin E induced significant changes in these enzymes thus altering the normal levels of glutamate and GABA during developmental neurogenesis. Such changes are surely to disturb the expression and/or intensity of neurotransmitter signaling during critical periods of brain development.

Effect of occupational lead exposure on α- and γ-tocopherol concentration in plasma

OBJECTIVES

Changes in enzymatic antioxidant activity are frequently observed in workers occupationally exposed to lead. Few studies have investigated the influence of lead on the non-enzymatic antioxidant system. The aim of our study was to assess the influence of occupational exposure to lead on the plasma concentration of two hydrophobic forms of vitamin E: α-tocopherol and γ-tocopherol.

METHODS

A sample of 401 healthy men, aged 19-62, participated in the study. In total, 340 of these subjects were employed at the Mine and Metallurgical Plant in southern Poland. The workers who were occupationally exposed to lead were divided into quartiles (groups of 85 subjects). The lead concentrations in the blood of the subjects in the control group and in the lead exposure quartiles correspond to the following ranges: 10-72 μg/l (control group); 82-206 μg/l (Q1); 209-308 μg/l (Q2); 308-394 μg/l (Q3) and 395-644 μg/l (Q4), respectively.

RESULTS

Significant differences were observed only for the plasma concentration of γ-tocopherol, which differed between the control group and Q1 (by 24.1%, p=0.0368), between Q1 and Q3 (by -18.8%, p=0.0115) and between Q1 and Q4 (by -25.7%, p=0.0002). Multiple linear regression analysis showed that the statistically significant, predictive properties of the γ-tocopherol plasma concentration were as follows: triglycerides (β=0.440)> age (β=0.131)> whole cholesterol (β=0.117)> blood lead concentration (β=-0.108). For α-tocopherol, significant prognostic properties were triglycerides and total cholesterol (β=0.485 and β=0.399, respectively).

CONCLUSIONS

Occupational exposure to lead is strongly correlated with the concentration of γ-tocopherol but not α-tocopherol.

The influence of alpha-tocopherol supplementation on plasma concentration of this vitamin and insulin in sedentary or physically trained rats

Male young growing rats of Wistar strain (n = 54) were fed a vitamin E deficient diet for 3 days of adaptation period and then 10 days of experimental period. After adaptation half of the rats ran, once per a day, on a treadmill with a rate of 2.0 m/s for 15 minutes for the following 10 days. Animals were given orally 0, 0.5, 1.0 or 4.0 mg/d/rat of alpha-tocopherol. The aim of the study was to evaluate the influence of physical training on tocopherol and insulin concentrations in the blood plasma of rats treated with different doses of vitamin E. The concentrations of alpha-tocopherol (HPLC-UV method used) and insulin (rat insulin specific RIA method used) were estimated in the blood plasma. Lower concentration of vitamin E in physically trained animals was observed, which may suggest increased needs of organisms for antioxidants, as a result of increased free radical production. In trained rats a lower concentration of plasma insulin was also observed. This effect is probably related to improvement in insulin action observed in organisms under physical exercise. The most significant impact on plasma alpha-tocopherol was due to its supplementation level. The treatment of rats with different doses of alpha-tocopherol was found to be not related to insulin concentration in plasma. A significant increase in feed conversion factor was noted in vitamin E treated animals. The obtained results suggest that the increased requirement of trained rats for antioxidants might be covered by alpha-tocopherol supplementation.

Vitamin E decreased the activity of acetylcholinesterase and level of lipid peroxidation in brain of rats exposed to aged and diluted sidestream smoke

INTRODUCTION

The biological systems of both smoker and passive smoking suffer changes caused by toxic compounds from cigarette smoke such as inflammation, lipid peroxidation, and deficiency of vitamin E. The aim of the present study was to evaluate the effect of vitamin E on acetylcholinesterase (AChE) activity and the lipid peroxidation level in the brain of rats in the model of exposure to aged and diluted sidestream smoke (ADSS).

METHODS

Adult male Wistar rats (200-300 g) were exposed to ADSS for 4 weeks and treated with vitamin E (50 mg/kg/day) loaded by gavage. In the first, second, third, and fourth weeks, animals were concomitantly exposed to the smoke of 1, 2, 3, and 4 cigarettes/day, respectively. The duration of each exposure was 15 min, daily.

RESULTS

For rats exposed to ADSS, the AChE activity and lipid peroxidation level increased in the striatum, cerebral cortex, and cerebellum. In contrast, the activity of AChE and the level of lipid peroxidation decreased in the smoke group treated with vitamin E.

CONCLUSIONS

The results suggest that the rats exposed to ADSS and treated with vitamin E significantly reduced the raised activity of AChE and level lipid peroxidation from the brain structures studied. The study, therefore, concludes that vitamin E could be considered as a therapeutic agent in this type of exposure.

Nutritional status of patients with biliary atresia and autoimmune hepatitis related to serum levels of vitamins A, D and E

CONTEXT

Chronic liver disease may induce to malabsorption of lipids and fat-soluble vitamins, leading to injury of nutritional status.

OBJECTIVES

To evaluate the nutritional status of pediatric-age patients with autoimmune hepatitis and biliary atresia related to serum levels of vitamins A, D and E and the disease severity.

METHODS

This controlled transverse study, evaluated the patients with autoimmune hepatitis and biliary atresia and a reference group paired by sex and age. The patients underwent anthropometric evaluation, alimentary inquiry and determination of serum levels of vitamins A, D and E by high performance liquid chromatography. The Mann-Whitney test, Spearman correlation coefficients and variance analysis (ANOVA) were utilized for data treatment, regarding significant difference if P<0.05.

RESULTS

The highest nutritional deficit was observed in patients with biliary atresia, mainly with cholestasis. The serum levels of vitamins A and E for the reference group changed as a function of age. The serum levels of vitamins A, D and E were higher in reference group than in patients with biliary atresia and autoimmune hepatitis together or separately. There were not difference in the serum levels of vitamins A, D and E between biliary atresia groups with cholestasis and without cholestasis. It was verified correlation between weight/age, triceps skinfold thickness, subscapular skinfold thickness, midarm circumference, midarm fat area values and vitamin A serum levels, as well as between all anthropometric indicators and vitamin E in patients with autoimmune hepatitis and biliary atresia.

CONCLUSION

The patients with biliary atresia and cholestasis presented the highest nutritional injury. The patients with biliary atresia and autoimmune hepatitis presented lower serum levels of vitamins A, D and E that in control group. There is a directly proportional correlation between vitamin serum levels, mainly vitamin E, and all anthropometric variables of biliary atresia and autoimmune hepatitis groups.

Embryo production and quality of Holstein heifers and cows supplemented with β-carotene and tocopherol

The hypothesis was that the intramuscular injection (i.m.) of beta-carotene associated to tocopherol improves cow (n=86) and heifer (n=91) embryo production and quality. Time of estrus was synchronized in animals with an ear implant with 3 mg of norgestomet associated with an i.m. injection of 6 mg of norgestomet and 10mg of estradiol valerate (CRESTAR, Intervert International B.V., Boxmeer, Holland) and superovulated by 8 i.m. FSH/LHp injections (400 IU-heifers and 500 IU-cows) in decreasing concentrations at 12h intervals. Animals were inseminated 12 and 24h after observed onset of estrus and embryos recovered 7 days later. Animals were randomly allocated to one of three treatments: (1) vegetable oil vehicle (control), (2) 800 mg of beta-carotene and 500 mg of tocopherol (T800) and (3) 1200 mg of beta-carotene and 750 mg of tocopherol (T1200). Supplemental injections were given at the day norgestomet implants were inserted and at first superovulatory injection. An index (Embryo Quality Index or EQI) was proposed to more precisely evaluate embryo quality (excellent*1 + good*2 + regular*3 + poor*4 + degenerate*5 + unfertilized ova*5)/total. There was an interaction between physiological stage (heifer or cow) and treatment on EQI (P=0.01) and on the proportion of viable embryos (P=0.03), where both variables were improved in T1200 cows, but not in heifers. The average EQI for heifers and cows in control, T800 and T1200 were 2.6+/-0.3 and 3.6+/-0.3; 2.5+/-0.3 and 3.6+/-0.3; 2.9+/-0.3 and 2.7+/-0.3, respectively. The average total number of viable embryos was greater (P=0.01) in supplemented cows (3.5+/-1.1; 5.4+/-1.4 and 7.5+/-1.2 in control, T800 and T1200, respectively), but less (P=0.01) in heifers (7.5+/-1.2; 5.6+/-1.2 and 4.0+/-1.1 in control, T800 and T1200, respectively). Supplementation injections of beta-carotene associated to tocopherol improved embryo quality in superovulated Holstein cows, in the present experimental conditions and may be advantageous in similar embryo production systems. However, at dosages applied in the present experiment, this treatment should not be recommended for nulliparous heifers.

The inhibitory effect of vitamin E on cigarette smoke-induced oxidative damage to the rat urothelium: can it prevent transitional cell carcinoma?

INTRODUCTION

We aimed to detect reactive oxygen species (ROS) and assess subsequent carcinogenesis in terms of cellular proliferation in the bladder and kidney epithelial tissues of rats exposed to cigarette smoke (CS), and to investigate the changes following vitamin E treatment.

MATERIALS AND METHODS

Twenty-four male Sprague-Dawley rats were divided into 3 groups: group 1 was kept intact; group 2 was subjected to CS exposure for 8 weeks, and group 3 received intraperitoneal vitamin E injections (200 mg/kg/week) for 8 weeks in addition to CS exposure. Histological examination and Ki67 antigen expression measurements were made from bladder and renal pelvic tissue sections. Luminol-amplified chemiluminescence was used to measure ROS levels. All results were compared using a one-way ANOVA test.

RESULTS

In CS-exposed rats, light microscopy of renal and bladder tissues revealed nonspecific epithelial changes; however, Ki67 expression was significantly increased in bladder tissues compared to other groups (17.5 +/- 4.7, 35 +/- 2.9 and 18.7 +/- 5.1% in groups 1, 2 and 3, respectively, p < 0.05). Chemiluminescence levels in bladder and renal tissues were also significantly higher in the CS-exposed animals (78.1 +/- 11.4, 148 +/- 13.3, 97.8 +/- 6.1 rlu/mg for the bladder, and 99.8 +/- 12.2, 176.1 +/- 27.9, 67.1 +/- 9 rlu/mg, for renal pelvic tissues, respectively, p < 0.05).

CONCLUSIONS

Vitamin E can alleviate CS-induced oxidative damage in rat bladder and kidney epithelium suggesting a potential role for vitamin E in the prevention of CS-mediated carcinogenesis.

Adverse effects of T-2 toxin on chicken lymphocytes blastogenesis and its protection with Vitamin E

T-2 toxin, a trichothecene mycotoxin that is produced by fusarium species, is prevalent mainly in cereal crops and poultry feed. One of the major effects of this toxin is immunomodulation. The effect of T-2 toxin on chicken lymphocyte proliferation in the presence of mitogens and the subsequent protection with Vitamin E in both fat and water soluble forms was studied using an MTT colorimetric assay. T-2 toxin was administered in concentrations ranging from 0 to 10ng/mL of lymphocytes in the presence of either concanavalin A (ConA) or phytohemagglutinine (PHA-M) at optimum concentration of 333ng/mL and a dilution of 1:160 for ConA and PHA-M, respectively. Lymphocyte proliferation in response to ConA and PHA-M mitogens was depressed at T-2 doses of 1ng/mL or higher (p<0.05). The proliferation was completely abolished at 10ng/mL when the toxin was added at 0 time, while it was decreased by 80% when the toxin was added to the lymphocytes after 24h. The addition of Vitamin E in the fat soluble form (alpha-tocopheryl acetate) did not exert any protection effect against the toxin when it was added at either 25 or 100microg. However, when the water soluble form (Trolox) was added at a concentration of (200microg) (equivalent to 100microM of alpha-tocopherol), it provided considerable protection (p<0.05) against T-2 toxin inhibition of lymphocyte proliferation. The difference in the effect between the two forms of Vitamin E might be related to their relative solubility in the culture media which in turn may affect their availability for protection.

The effects of tobacco smoke on plasma alpha- and gamma-tocopherol levels in passive and active cigarette smokers

Tobacco smoke is one of the causes of oxidative stress that is leading to attenuation of the antioxidative body protective barrier by means of decreasing the levels of intra- and extracellular antioxidants. The effect of tobacco smoke on plasma levels of two main forms of Vitamin E, alpha- and gamma-tocopherol, in passive smokers (urinary cotinine concentration 50-500 microg/L) and active smokers (urinary cotinine concentration >500 microg/L) were studied. Slight, but statistically significant decreases in plasma alpha-tocopherol level in passive and active smokers in comparison with non-smokers (by 5.7% and 9.2%, respectively) were found. The plasma gamma-tocopherol levels remained unchanged. The Pearson's correlation coefficient for the plasma alpha-tocopherol level and the urinary cotinine concentration in passive and active smokers was -0.431, P = 0.004 and -0.534, P < 0.001, respectively, and for gamma-tocopherol in similar conditions -0.190, P = 0.217 and 0.346, P = 0.027, respectively. The obtained results indicate the secondary role that alpha- and gamma-tocopherol play in the process of tobacco smoke free radical scavenge, or they may also reflect the body increased anti-oxidative mobilization in response to oxidative stress evoked by tobacco smoke.

Photochemical and photophysical behaviour of vitamin E: interaction of its long-lived transient photoproducts with carotenoids

Multi-channel, flash kinetic spectroscopy with microsecond time resolution has been used for investigating the interactions between carotenoids and the following photoproducts of alpha-tocopherol (EH) in hexane, methanol, acetonitrile, and dimethyl sulfoxide: (a) the lowest triplet, (b) the tocopherol radical cation, which could be seen only in the polar aprotic solvents acetonitrile and dimethyl sulfoxide, and (c) the neutral tocopheroxyl radical. The first two species reconvert to EH by transferring triplet excitation and positive charge (respectively) to the carotenoid; the third is unreactive. The relevance of these observations to photoprotection and the photoionisation of sterically hindered phenols is pointed out.

Divergence in plasmatic and urinary isoprostane levels in type 2 diabetes

BACKGROUND

Oxidative stress is currently suggested as a mechanism underlying diabetes. The present study was designed to evaluate isoprostane levels in plasma and in urine in type 2 diabetic patients, and to compare them to other currently used biomarkers of oxidative stress.

METHODS

The work was performed in a control group (n = 10) and in a type 2 diabetic group (n = 10). Besides the traditional biochemical parameters, we evaluated the plasma and urine levels of isoprostanes and malondialdehyde (MDA) as markers of oxidative stress.

RESULTS

We found increased plasma and urine MDA in the diabetic patients and almost significantly decreased plasma vitamin E. Urinary isoprostane levels in diabetic patients were increased but they presented a strong tendency to a decrease in plasma isoprostanes. It is therefore suggested that, in the studied diabetic patients, although the production of isoprostanes in the body was increased (as other plasma oxidative stress biomarkers were altered) it did not lead to an increase in plasma isoprostane levels. It could be hypothesised that this results from an increased elimination of this metabolite and therefore an increased excretion in urine.

CONCLUSION

Our results showed that the measurement of same oxidative stress biomarker, isoprostane, in two different biologic fluids, plasma and urine, led to divergent results and emphasised the importance to measure a biomarker both in the circulation fluid (plasma) and in the elimination fluid (urine), to have a general idea of what is occurring in the organism.

NIST micronutrients measurement quality assurance program: characterizing the measurement community's performance over time

The Micronutrients Measurement Quality Assurance Program (M2QAP) at the National Institute of Standards and Technology was created in 1984 with the goal of improving among-participant measurement comparability for fat-soluble vitamin-related compounds in human serum. We recently described improved tools for evaluating comparison exercise data; we here extend and apply these tools to the evaluation of the measurement community's performance over the entire 15-year history of the M2QAP. We here display measurement performance characteristics for the 14 measurands most commonly reported by the M2QAP community. We confirm that among-participant comparability for total beta-carotene cannot be much improved without improving average long-term within-participant measurement stability. We demonstrate that improved measurand definition and/or identification of interferences may help participants improve comparability for many of the M2QAP's other commonly reported measurands. The reported measurement performance characteristics may be of interest to clinical, nutritional, and epidemiological studies involving any of these measurands. The data analysis techniques utilized may be applicable to other programs.