scholarly journals Erythrocyte vitamin E is oxidized at a lower peroxide concentration in neonates than in adults

Blood ◽  
1985 ◽  
Vol 66 (6) ◽  
pp. 1272-1277
Author(s):  
J Vanderpas ◽  
F Vertongen

Erythrocytes of neonates and adults were incubated with increasing concentrations of H2O2 in the presence of a catalase inhibitor and in the absence of glucose; the pattern of oxidation of vitamin E was analyzed in relationship to that of glutathione, hemoglobin, and polyunsaturated fatty acids (PUFA), and in relationship to hemolysis. The changes of these various parameters were analyzed in function of H2O2 concentration and in relation to incubation time, and were compared in erythrocytes from neonates and adults. In the absence of H2O2, erythrocyte glutathione and tocopherol levels were similar in neonates and adults, despite fourfold lower serum vitamin E level in neonates; alpha-tocopherolquinone, methemoglobin, and malonyldialdehyde (MDA) were not detectable. At 0.375 mmol/L of H2O2, glutathione was completely oxidized. Erythrocyte alpha-tocopherol remained unchanged up to 0.75 mmol/L of H2O2, then decreased linearly, with increasing H2O2 concentrations to 10% of its initial value at 1.5 mmol/L of H2O2 in erythrocytes from neonates, whereas those from adults required 2.0 mmol/L of H2O2 (P less than .05) for the same level of oxidation. The formation of alpha-tocopherolquinone appeared inversely related to the decrease of alpha-tocopherol. The incubation time did not influence the level of vitamin E oxidation. MDA was generated autocatalytically and resulted in hemolysis at 1.5 mmol/L of H2O2 in erythrocytes from neonates and at 3.5 mmol/L of H2O2 in erythrocytes from adults (P less than .001). After four hours of incubation, MDA reached a plateau at a greater level (365 +/- 46 nmol/L) in cells of neonates than in those of adults (208 +/- 37 nmol/L/mL) (P less than .001). Hemoglobin was oxidized in the same pattern in erythrocytes of neonates and adults, and 90% of it was oxidized at 0.625 mmol/L of H2O2. In conclusion, in the experimental conditions used, oxidation of glutathione precedes that of vitamin E, and tocopherol is the last antioxidant to be consumed before the autocatalytic generation of MDA. Differences in the pattern of vitamin E oxidation, MDA generation, and hemolysis in erythrocytes from neonates and adults may be due to a lower erythrocyte vitamin E-PUFA ratio in neonates.

Blood ◽  
1985 ◽  
Vol 66 (6) ◽  
pp. 1272-1277 ◽  
Author(s):  
J Vanderpas ◽  
F Vertongen

Abstract Erythrocytes of neonates and adults were incubated with increasing concentrations of H2O2 in the presence of a catalase inhibitor and in the absence of glucose; the pattern of oxidation of vitamin E was analyzed in relationship to that of glutathione, hemoglobin, and polyunsaturated fatty acids (PUFA), and in relationship to hemolysis. The changes of these various parameters were analyzed in function of H2O2 concentration and in relation to incubation time, and were compared in erythrocytes from neonates and adults. In the absence of H2O2, erythrocyte glutathione and tocopherol levels were similar in neonates and adults, despite fourfold lower serum vitamin E level in neonates; alpha-tocopherolquinone, methemoglobin, and malonyldialdehyde (MDA) were not detectable. At 0.375 mmol/L of H2O2, glutathione was completely oxidized. Erythrocyte alpha-tocopherol remained unchanged up to 0.75 mmol/L of H2O2, then decreased linearly, with increasing H2O2 concentrations to 10% of its initial value at 1.5 mmol/L of H2O2 in erythrocytes from neonates, whereas those from adults required 2.0 mmol/L of H2O2 (P less than .05) for the same level of oxidation. The formation of alpha-tocopherolquinone appeared inversely related to the decrease of alpha-tocopherol. The incubation time did not influence the level of vitamin E oxidation. MDA was generated autocatalytically and resulted in hemolysis at 1.5 mmol/L of H2O2 in erythrocytes from neonates and at 3.5 mmol/L of H2O2 in erythrocytes from adults (P less than .001). After four hours of incubation, MDA reached a plateau at a greater level (365 +/- 46 nmol/L) in cells of neonates than in those of adults (208 +/- 37 nmol/L/mL) (P less than .001). Hemoglobin was oxidized in the same pattern in erythrocytes of neonates and adults, and 90% of it was oxidized at 0.625 mmol/L of H2O2. In conclusion, in the experimental conditions used, oxidation of glutathione precedes that of vitamin E, and tocopherol is the last antioxidant to be consumed before the autocatalytic generation of MDA. Differences in the pattern of vitamin E oxidation, MDA generation, and hemolysis in erythrocytes from neonates and adults may be due to a lower erythrocyte vitamin E-PUFA ratio in neonates.


2019 ◽  
Vol 112 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Jiaqi Huang ◽  
Stephanie J Weinstein ◽  
Kai Yu ◽  
Satu Männistö ◽  
Demetrius Albanes

Abstract Background Epidemiologic data are inconsistent regarding the vitamin E-lung cancer association, and no study to our knowledge has examined serologic changes in vitamin E status in relation to subsequent risk. Methods In a cohort of 22 781 male smokers in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, we ascertained 3184 lung cancer cases during up to 28 years of observation. Cox proportional hazards models examined whether higher serum alpha-tocopherol concentrations at baseline, 3 years, or the interval change were associated with lower lung cancer risk. All statistical tests were two-sided. Results After adjustment for age, body mass index, smoking intensity and duration, serum total cholesterol, and trial intervention group, we found lower lung cancer risk in men with high baseline alpha-tocopherol (fifth quintile [Q5] vs Q1, hazard ratio [HR] = 0.76, 95% confidence interval [CI] = 0.66 to 0.87, Ptrend < .001). A similar reduction in risk was seen for serum alpha-tocopherol at 3 years (Q5 vs Q1, HR = 0.78, 95% CI = 0.67 to 0.91, Ptrend = .004). The inverse risk association appeared stronger for younger men and those who had smoked fewer years but was similar across trial intervention groups. We also found reduced risk among men not supplemented with vitamin E who had a lower serum alpha-tocopherol at baseline and greater increases in concentrations at 3 years (third tertile vs first tertile of serum alpha-tocopherol change, HR = 0.74, 95% CI = 0.59 to 0.91, P = .005). Conclusions Higher vitamin E status, as measured by serum alpha-tocopherol concentration, as well as repletion of a low vitamin E state, was related to decreased lung cancer risk during a 28-year period. Our findings provide evidence supporting the importance of adequate physiological vitamin E status for lung cancer risk reduction.


2012 ◽  
Vol 3 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Kusal K. Das ◽  
Jameel G. Jargar ◽  
Shaheenkousar H. Hattiwale ◽  
Saeed M. Yendigeri ◽  
Swastika Das ◽  
...  

2000 ◽  
Vol 58 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Michael Maes ◽  
Nathalie De Vos ◽  
Rosaria Pioli ◽  
Paul Demedts ◽  
Annick Wauters ◽  
...  

2020 ◽  
Vol 10 (3) ◽  
pp. 228-236 ◽  
Author(s):  
Lamia Taouzinet ◽  
Sofiane Fatmi ◽  
Allaeddine Khellouf ◽  
Mohamed Skiba ◽  
Mokrane Iguer-ouada

Background: Alpha-tocopherol is a potent antioxidant involved in sperm protection particularly during cryopreservation. However, its poor solubility limits the optimal protection in aqueous solutions. Objective: The aim of this study was to enhance the solubility of α-tocopherol by the use of liposomes. Methods: The experimental approach consisted to load vitamin E in liposomes prepared by ethanol injection method and the optimization carried out by an experimental design. The optimum solution was characterized by high performance liquid chromatography and scanning electron microscope. Finely, the impact on sperm motility protection was studied by the freezing technic of bovine sperm. Results: The optimum solution was obtained when using 10.9 mg/ml of phospholipids, 1.7 mg/ml of cholesterol and 2 mg/ml of vitamin E. The liposome size was 99.86 nm, providing 78.47% of loaded efficiency. The results showed also a significant positive impact on sperm motility after hours of preservation. Conclusion: In conclusion, the current results showed the interest of liposome preparation as an alternative to enhance vitamin E solubility and to protect spermatozoa during cryopreservation.


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1088
Author(s):  
Satoshi Haga ◽  
Hiroshi Ishizaki ◽  
Sanggun Roh

Levels of alpha-tocopherol (α-Toc) decline gradually in blood throughout prepartum, reaching lowest levels (hypovitaminosis E) around calving. Despite numerous reports about the disease risk in hypovitaminosis E and the effect of α-Toc supplementation on the health of transition dairy cows, its risk and supplemental effects are controversial. Here, we present some novel data about the disease risk of hypovitaminosis E and the effects of α-Toc supplementation in transition dairy cows. These data strongly demonstrate that hypovitaminosis E is a risk factor for the occurrence of peripartum disease. Furthermore, a study on the effectiveness of using serum vitamin levels as biomarkers to predict disease in dairy cows was reported, and a rapid field test for measuring vitamin levels was developed. By contrast, evidence for how hypovitaminosis E occurred during the transition period was scarce until the 2010s. Pioneering studies conducted with humans and rodents have identified and characterised some α-Toc-related proteins, molecular players involved in α-Toc regulation followed by a study in ruminants from the 2010s. Based on recent literature, the six physiological factors: (1) the decline in α-Toc intake from the close-up period; (2) changes in the digestive and absorptive functions of α-Toc; (3) the decline in plasma high-density lipoprotein as an α-Toc carrier; (4) increasing oxidative stress and consumption of α-Toc; (5) decreasing hepatic α-Toc transfer to circulation; and (6) increasing mammary α-Toc transfer from blood to colostrum, may be involved in α-Toc deficiency during the transition period. However, the mechanisms and pathways are poorly understood, and further studies are needed to understand the physiological role of α-Toc-related molecules in cattle. Understanding the molecular mechanisms underlying hypovitaminosis E will contribute to the prevention of peripartum disease and high performance in dairy cows.


Heliyon ◽  
2021 ◽  
pp. e07339
Author(s):  
Daniel Edem Kpewou ◽  
Faustina O. Mensah ◽  
Collins A. Appiah ◽  
Huseini Wiisibie Alidu ◽  
Vitus Sambo Badii

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 173
Author(s):  
Desirée Bartolini ◽  
Rita Marinelli ◽  
Danilo Giusepponi ◽  
Roberta Galarini ◽  
Carolina Barola ◽  
...  

The metabolism of α-tocopherol (α-TOH, vitamin E) shows marked interindividual variability, which may influence the response to nutritional and therapeutic interventions with this vitamin. Recently, new metabolomics protocols have fostered the possibility to explore such variability for the different metabolites of α-TOH so far identified in human blood, i.e., the “vitamin E metabolome”, some of which have been reported to promote important biological functions. Such advances prompt the definition of reference values and degree of interindividual variability for these metabolites at different levels of α-TOH intake. To this end, a one-week oral administration protocol with 800 U RRR-α-TOH/day was performed in 17 healthy volunteers, and α-TOH metabolites were measured in plasma before and at the end of the intervention utilizing a recently validated LC-MS/MS procedure; the expression of two target genes of α-TOH with possible a role in the metabolism and function of this vitamin, namely pregnane X receptor (PXR) and the isoform 4F2 of cytochrome P450 (CYP4F2) was assessed by immunoblot in peripheral blood leukocytes. The levels of enzymatic metabolites showed marked interindividual variability that characteristically increased upon supplementation. With the exception of α-CEHC (carboxy-ethyl-hydroxychroman) and the long-chain metabolites M1 and α-13′OH, such variability was found to interfere with the possibility to utilize them as sensitive indicators of α-TOH intake. On the contrary, the free radical-derived metabolite α-tocopheryl quinone significantly correlated with the post-supplementation levels of α-TOH. The supplementation stimulated PXR, but not CYP4F2, expression of leucocytes, and significant correlations were observed between the baseline levels of α-TOH and both the baseline and post-supplementation levels of PXR. These findings provide original analytical and molecular information regarding the human metabolism of α-TOH and its intrinsic variability, which is worth considering in future nutrigenomics and interventions studies.


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