Monthly Archives: August 2021

Systematic review and meta-analyses of vitamin E (alpha-tocopherol) supplementation and blood lipid parameters in patients with diabetes mellitus

Abolfathi Mohammad, Ebrahim Falahi, Mohd Yusof Barakatun-Nisak, Zubaidah Nor Hanipah, S Mohd Redzwan, Loqman Mohamad Yusof, Mohsen Gheitasvand, Farahnaz Rezaie

Diabetes Metab Syndr . Jul-Aug 2021;15(4):102158. doi: 10.1016/j.dsx.2021.05.031. Epub 2021 May 31.

Abstract

Background and aims: The studies have shown that α-tocopherol supplementation could improve lipid profile in diabetes mellitus (DM) patients. Nonetheless, the result remains inconsistent. Therefore, this meta-analysis was performed to evaluate the efficacy of α-tocopherol supplement on lipid parameters in DM patients.

Methods: We conducted an extensive search via Cochrane Library, PubMed, Scopus, and Web of Science databases to acquire the reported RCTs up to October 2020.

Results: The results showed no effects of α-tocopherol supplementation on lipid profile in DM patients except when used ≥12 weeks.

Conclusions: α-tocopherol supplementation in DM patients had no significant effect on lipid profiles.

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Biochemical and Clinical Effects of Vitamin E Supplementation in Hungarian Smith-Lemli-Opitz Syndrome Patients

Katalin Koczok, László Horváth, Zeljka Korade, Zoltán András Mezei, Gabriella P Szabó, Ned A Porter, Eszter Kovács, Károly Mirnics, István Balogh

Biomolecules . 2021 Aug 17;11(8):1228. doi: 10.3390/biom11081228.

Abstract

Smith-Lemli-Opitz syndrome (SLOS) is a severe monogenic disorder resulting in low cholesterol and high 7-dehydrocholesterol (7-DHC) levels. 7-DHC-derived oxysterols likely contribute to disease pathophysiology, and thus antioxidant treatment might be beneficial because of high oxidative stress. In a three-year prospective study, we investigated the effects of vitamin E supplementation in six SLOS patients already receiving dietary cholesterol treatment. Plasma vitamin A and E concentrations were determined by the high-performance liquid chromatography (HPLC) method. At baseline, plasma 7-DHC, 8-dehydrocholesterol (8-DHC) and cholesterol levels were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The clinical effect of the supplementation was assessed by performing structured parental interviews. At baseline, patients were characterized by low or low-normal plasma vitamin E concentrations (7.19-15.68 μmol/L), while vitamin A concentrations were found to be normal or high (1.26-2.68 μmol/L). Vitamin E supplementation resulted in correction or significant elevation of plasma vitamin E concentration in all patients. We observed reduced aggression, self-injury, irritability, hyperactivity, attention deficit, repetitive behavior, sleep disturbance, skin photosensitivity and/or eczema in 3/6 patients, with notable individual variability. Clinical response to therapy was associated with a low baseline 7-DHC + 8-DHC/cholesterol ratio (0.2-0.4). We suggest that determination of vitamin E status is important in SLOS patients. Supplementation of vitamin E should be considered and might be beneficial.

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Fruit tree leaves as valuable new source of tocopherol and tocotrienol compounds

Aneta Wojdyło, Igor Piotr Turkiewicz, Karolina Tkacz, Francisca Hernandez

J Sci Food Agric . 2021 Aug 16. doi: 10.1002/jsfa.11481. Online ahead of print.

Abstract

Background: Nowadays it is highly important to find new, cheap and widely available sources of tocopherol and tocotrienol compounds, and leaves are promising unconventional sources. The main goal of this study was to extend the currently limited knowledge concerning tocopherol and tocotrienol isomers composition determined using ultra-high performance liquid chromatography with fluorescence detection analysis for various fruit tree leaves such as apple, pear, quince, apricot, peach, plum, sour cherry and sweet cherry. The leaves were collected 2 weeks after tree blooming and after fruit collection. Tocopherol and tocotrienol isomers were identified and quantified for the first time in all fruit tree leaves.

Results: The total tocopherol content ranged from 203.34 to 260.86 μg g-1 dry weight for spring leaves and from 23.83 to 235.62 μg g-1 dry weight for autumn leaves and consisted mainly of α-tocopherol. The rest of the isomers of tocopherol and tocotrienols were also found, but in trace amounts. A significantly lower content of tocopherols and tocotrienols was detected in leaves after autumn collection of fruits compared to leaves collected after blooming. Among the analyzed leaves, time collected and species were significantly more important than their cultivars. Regarding quantification analysis, apricot > peach > > plums > apples leaves were identified as the best sources of tocopherols, and sweet and sour cherry leaves exhibited a lower content.

Conclusion: Fruit tree leaves are a novel significant source and good material for isolation of α-tocopherol for application in cosmetics, pharmaceuticals or in the food industry – for example, production of beverages or other functional foods.

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Vitamins E and C do not effectively inhibit low density lipoprotein oxidation by ferritin at lysosomal pH

Oluwatosin O Ojo, David S Leake

Free Radic Res . 2021 Aug 16;1-10. doi: 10.1080/10715762.2021.1964494. Online ahead of print.

Abstract

Low density lipoprotein (LDL) might be oxidized by iron in the lysosomes of macrophages in atherosclerotic lesions. We have shown previously that the iron-storage proteinferritin can oxidize LDL at lysosomal pH. We have now investigated the roles of the most important antioxidant contained in LDL, α-tocopherol (the main form of vitamin E) and of ascorbate (vitamin C), a major water-soluble antioxidant, on LDL oxidation by ferritin at lysosomal pH (pH 4.5). We incubated LDL with ferritin at pH 4.5 and 37 °C and measured its oxidation by monitoring the formation of conjugated dienes at 234 n min a spectrophotometer. α-Tocopherol is well known to inhibit LDL oxidation at pH 7.4, but enrichment of LDL with α-tocopherol was unable to inhibit LDL oxidation by ferritin at pH 4.5. Ascorbate had a complex effect on LDL oxidation by ferritin at lysosomal pH and exhibited both antioxidant and pro-oxidant effects. It had no antioxidant effect on partially oxidized LDL, only a pro-oxidant effect. Ascorbate completely inhibited LDL oxidation by copper at pH 7.4 for a long period, but in marked contrast did not inhibit LDL oxidation by copper at lysosomal pH. Dehydroascorbate, the oxidation product of ascorbate, had a pronounced pro-oxidant effect on LDL incubated with ferritin at pH 4.5. The inability of α-tocopherol and ascorbate to effectively inhibit LDL oxidation by ferritin at lysosomal pH might help to explain why the large clinical trials with these vitamins failed to show protection against cardiovascular diseases.

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Dietary intake of tocopherols and risk of incident disabling dementia

Shoko Aoki, Kazumasa Yamagishi, Koutatsu Maruyama, Rie Kishida, Ai Ikeda, Mitsumasa Umesawa, Cui Renzhe, Yasuhiko Kubota, Mina Hayama-Terada, Yuji Shimizu, Isao Muraki, Hironori Imano, Tomoko Sankai, Takeo Okada, Akihiko Kitamura, Masahiko Kiyama, Hiroyasu Iso

Sci Rep . 2021 Aug 12;11(1):16429. doi: 10.1038/s41598-021-95671-7.

Abstract

Tocopherols, strong antioxidants, may be useful in preventing dementia, but the epidemiological evidence is insufficient. We performed a community-based follow-up study of Japanese, the Circulatory Risk in Community Study, involving 3739 people aged 40-64 years at baseline (1985-1999). Incident disabling dementia was followed up from 1999 through 2020. For subtype analysis, we classified disabling dementia into that with and that without a history of stroke. Dietary intake of tocopherols (total, α, β, γ, and δ) were estimated using 24-h recall surveys. During a median follow-up of 19.7 years, 670 cases of disabling dementia developed. Total tocopherol intake was inversely associated with risk of disabling dementia with multivariable hazard ratios (95% confidence intervals) of 0.79 (0.63-1.00) for the highest versus lowest quartiles of total tocopherol intake (P for trend = 0.05). However, the association was strengthened when further adjusted for α-linolenic acid intake (Spearman correlation with total tocopherol intake = 0.93), with multivariable hazard ratios of 0.50 (0.34-0.74) (P for trend = 0.001) but was weakened and nonsignificant when further adjusted for linoleic acid intake (Spearman correlation with total tocopherol intake = 0.92), with multivariable hazard ratios of 0.69 (0.47-1.01) (P for trend = 0.05). Similar but nonsignificant inverse associations were observed for α-, γ-, and δ-tocopherols but not for β-tocopherol. These results were similar regardless of the presence of a history of stroke. Dietary tocopherol intake was inversely associated with risk of disabling dementia, but its independent effect was uncertain owing to a high intercorrelation of α-linolenic linoleic acids with total tocopherol intake. Even with such confounding, a diet high in tocopherols may help prevent the onset of dementia.

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Exploration of Long-Chain Vitamin E Metabolites for the Discovery of a Highly Potent, Orally Effective, and Metabolically Stable 5-LOX Inhibitor that Limits Inflammation

Konstantin Neukirch, Khaled Alsabil, Chau-Phi Dinh, Rossella Bilancia, Martin Raasch, Alexia Ville, Ida Cerqua, Guillaume Viault, Dimitri Bréard, Simona Pace, Veronika Temml, Elena Brunner, Paul M Jordan, Marta C Marques, Konstantin Loeser, André Gollowitzer 1 2, Stephan Permann, Jana Gerstmeier, Stefan Lorkowski, Hermann Stuppner, Ulrike Garscha, Tiago Rodrigues, Gonçalo J L Bernardes, Daniela Schuster, Denis Séraphin, Pascal Richomme, Antonietta Rossi, Alexander S Mosig, Fiorentina Roviezzo, Oliver Werz, Jean-Jacques Helesbeux, Andreas Koeberle

J Med Chem . 2021 Aug 12;64(15):11496-11526. doi: 10.1021/acs.jmedchem.1c00806. Epub 2021 Jul 19.

Abstract

Endogenous long-chain metabolites of vitamin E (LCMs) mediate immune functions by targeting 5-lipoxygenase (5-LOX) and increasing the systemic concentrations of resolvin E3, a specialized proresolving lipid mediator. SAR studies on semisynthesized analogues highlight α-amplexichromanol (27a), which allosterically inhibits 5-LOX, being considerably more potent than endogenous LCMs in human primary immune cells and blood. Other enzymes within lipid mediator biosynthesis were not substantially inhibited, except for microsomal prostaglandin E2 synthase-1. Compound 27a is metabolized by sulfation and β-oxidation in human liver-on-chips and exhibits superior metabolic stability in mice over LCMs. Pharmacokinetic studies show distribution of 27a from plasma to the inflamed peritoneal cavity and lung. In parallel, 5-LOX-derived leukotriene levels decrease, and the inflammatory reaction is suppressed in reconstructed human epidermis, murine peritonitis, and experimental asthma in mice. Our study highlights 27a as an orally active, LCM-inspired drug candidate that limits inflammation with superior potency and metabolic stability to the endogenous lead.

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Effect of δ-Tocopherol on Mice Adipose Tissues and Mice Adipocytes Induced Inflammation

Chikako Kiyose, Haruka Takeuchi, Yoshimi Yabe, Tomoki Nojima, Mana Nagase, Chie Takahashi-Muto, Rieko Tanaka-Yachi

J Oleo Sci . 2021 Aug 6. doi: 10.5650/jos.ess21124. Online ahead of print.

Abstract

The study aim was to evaluate the potential anti-inflammatory effects of vitamin E analogs, especially α-tocopherol and δ-tocopherol. We used male C57BL/6JJcl mice, which were divided into four groups: the control (C), high-fat and high-sucrose diet (H), high-fat and high-sucrose diet+α-tocopherol (Ha) and high-fat and high-sucrose diet+δ-tocopherol (Hd) groups. The mice were fed for 16 weeks. To the high-fat and high-sucrose diet, 800 mg/kg of α-tocopherol or δ-tocopherol was added more. The final body weight was significantly higher in the H group than in the C group. On the other hand, the final body weight was drastically lower in the Ha group and Hd group than in the H group. However, the energy intake was not significantly different among all groups. Therefore, we assumed that α-tocopherol and δ-tocopherol have potential anti-obesity effect. Besides, inflammatory cytokine gene expression was significantly higher in the epididymal fat of the H group than in the C group. These results showed that inflammation was induced by epididymal fat of mice fed a high-fat and high-sucrose diet for 16 weeks. Unfortunately, addition of α-tocopherol or δ-tocopherol to the diet did not restrain inflammation of epididymal fat. Investigation of the anti-inflammatory effects of α-tocopherol or δ-tocopherol in co-cultured 3T3-L1 cells and RAW264.7 cells showed that δ-tocopherol inhibited increased gene expression of the inflammatory cytokines, IL-1β, IL-6, and iNOS. These results suggest that an anti-inflammatory effect in the δ-tocopherol is stronger than that in the α-tocopherol in vitro. We intend to perform an experiment by in vivo sequentially in the future.

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PEGylated phospholipid micelles containing D-α-tocopheryl succinate as multifunctional nanocarriers for enhancing the antitumor efficacy of doxorubicin

Weiwei Jiang, Qing Fan, Jing Wang, Bingning Zhang, Tangna Hao, Qixian Chen, Lei Li, Lixue Chen, Hongxia Cui, Zhen Li

Int J Pharm . 2021 Aug 6;120979. doi: 10.1016/j.ijpharm.2021.120979. Online ahead of print.

Abstract

The aim of this investigation is to clarify the effect of D-α-tocopheryl succinate (vitamin E succinate, VES) and distearoylphosphatidyl ethanolamine-poly(ethylene glycol) (DSPE-PEG) on the encapsulation and controlled release of doxorubicin (DOX) in nano-assemblies and their consequences on the anti-tumor efficacy of DOX. DOX molecules were successfully loaded into the hybrid micelles with VES and DSPE-PEG (VDPM) via thin-film hydration method, exhibiting a small hydrodynamic particle size (∼30 nm) and a weak negative zeta potential of around -5 mv. The obtained DOX-loaded VDPM2 displayed retarded DOX release at pH of 7.4, while substantially accelerated drug release at acidic pH of 5.0. Furthermore, the DOX-loaded VDPM2 exhibited substantially slower drug release rate at pH 7.4 compared with the drug-loaded VDPM1 or DPM preparation, benefiting for decreasing the premature DOX release during blood circulation. In vitro cell experiment indicated that DOX-Loaded micelles (DPM, VDPM1 and VDPM2) improved the cellular uptake of DOX in 4T1 and MDA-MB-231 cells. The existence of VES component in the structure of DOX-loaded micelles had no obvious influence on the subcellular distribution of the encapsulated DOX molecules. However, the DOX-loaded VDPM2 exhibited more pronounced cytotoxicity to 4T1 and MDA-MB-231 cancerous cells compared with DOX-loaded DPM and free DOX solution. The hybrid nanocarriers including VES and DSPE-PEG selectively induced intracellular ROS accumulation and increased level of cytoplasmic calcium ion in cancerous cells by interacting with mitochondria and endoplasmic reticulum, bringing about the improved cytotoxicity of DOX. In vivo antitumor efficacy investigation of DOX-loaded VDPM2 against 4T1 xenograft-bearing mice displayed satisfied therapeutic activity with negligible systemic toxicity, as evidenced by the histological analysis and change of body weight. The proposed DOX-loaded VDPM preparation, as a mulifunctional chemotherapeutic nanomedicine system, holds great potential and bright prospect for clinical tumor therapy.

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Efficacy of water-based vitamin E solution versus placebo in the prevention of retinopathy of prematurity in very low birth weight infants: A randomized clinical trial

Silvia Romero-Maldonado, Araceli Montoya-Estrada, Enrique Reyes-Muñoz, Alberto Martín Guzmán-Grenfell, Yessica Dorin Torres-Ramos, Mario David Sánchez-Mendez, Maricruz Tolentino-Dolores, Manuel Bernardo Salgado-Valladares, Aurora Belmont-Gómez, Nayelli Najéra, Guillermo Ceballos, Jorge Arturo Cardona-Pérez, Juan José Hicks, Javier Mancilla-Ramírez

Medicine (Baltimore) . 2021 Aug 6;100(31):e26765. doi: 10.1097/MD.0000000000026765.

Abstract

Background:: Vitamin E has antioxidant properties, which help in scavenging free radicals, thereby reducing oxidation of lipids and proteins. This study aims to evaluate the efficacy of oral vitamin E supplementation in preventing retinopathy of prematurity (ROP) in very low birth weight (VLBW) infants with respiratory distress syndrome (RDS) and decreasing oxidative stress 15 and 28 days post-intervention.

Methods:: Ninety VLBW infants were randomly assigned to two groups:

 

  1. 1.Treatment (treatment group (T), n = 48) or
  2. 2.Placebo (control group (C), n = 42).

 

Each group received 25 IU of vitamin E (T) or placebo (C).

Results:: The incidence of ROP in groups T and C was 12.5% (n=6) and 31% (n = 13), respectively (RR: 0.40; 95% CI: 0.10–0.96). There were no differences in mortality between groups. As expected, the vitamin E concentration was significantly increased 28 days post-intervention in group T.

Conclusion:: Oral supplementation with vitamin E may effectively prevent ROP development in VLBW infants with RDS. Oxidative damage markers were significantly lower, whereas total antioxidant capacity was increased in group T. However, levels of other antioxidants as vitamin A and C were not measured in two groups.

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