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Cores Á, Carmona-Zafra N, Clerigué J, Villacampa M, Menéndez JC. Quinones as Neuroprotective Agents. Antioxidants (Basel) 2023; 12:1464. [PMID: 37508002 PMCID: PMC10376830 DOI: 10.3390/antiox12071464] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/12/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Quinones can in principle be viewed as a double-edged sword in the treatment of neurodegenerative diseases, since they are often cytoprotective but can also be cytotoxic due to covalent and redox modification of biomolecules. Nevertheless, low doses of moderately electrophilic quinones are generally cytoprotective, mainly due to their ability to activate the Keap1/Nrf2 pathway and thus induce the expression of detoxifying enzymes. Some natural quinones have relevant roles in important physiological processes. One of them is coenzyme Q10, which takes part in the oxidative phosphorylation processes involved in cell energy production, as a proton and electron carrier in the mitochondrial respiratory chain, and shows neuroprotective effects relevant to Alzheimer's and Parkinson's diseases. Additional neuroprotective quinones that can be regarded as coenzyme Q10 analogues are idobenone, mitoquinone and plastoquinone. Other endogenous quinones with neuroprotective activities include tocopherol-derived quinones, most notably vatiquinone, and vitamin K. A final group of non-endogenous quinones with neuroprotective activity is discussed, comprising embelin, APX-3330, cannabinoid-derived quinones, asterriquinones and other indolylquinones, pyrroloquinolinequinone and its analogues, geldanamycin and its analogues, rifampicin quinone, memoquin and a number of hybrid structures combining quinones with amino acids, cholinesterase inhibitors and non-steroidal anti-inflammatory drugs.
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Affiliation(s)
- Ángel Cores
- Unidad de Química Orgánica y Farmacéutica, Departamento de Química en Ciencias Farmacéuticas, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain
| | - Noelia Carmona-Zafra
- Unidad de Química Orgánica y Farmacéutica, Departamento de Química en Ciencias Farmacéuticas, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain
| | - José Clerigué
- Unidad de Química Orgánica y Farmacéutica, Departamento de Química en Ciencias Farmacéuticas, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain
| | - Mercedes Villacampa
- Unidad de Química Orgánica y Farmacéutica, Departamento de Química en Ciencias Farmacéuticas, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain
| | - J Carlos Menéndez
- Unidad de Química Orgánica y Farmacéutica, Departamento de Química en Ciencias Farmacéuticas, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal sn, 28040 Madrid, Spain
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2
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Morelli L, García Romañach L, Glauser G, Shanmugabalaji V, Kessler F, Rodriguez-Concepcion M. Nutritional Enrichment of Plant Leaves by Combining Genes Promoting Tocopherol Biosynthesis and Storage. Metabolites 2023; 13:metabo13020193. [PMID: 36837812 PMCID: PMC9965820 DOI: 10.3390/metabo13020193] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/18/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
The enrichment of plant tissues in tocochromanols (tocopherols and tocotrienols) is an important biotechnological goal due to their vitamin E and antioxidant properties. Improvements based on stimulating tocochromanol biosynthesis have repeatedly been achieved, however, enhancing sequestering and storage in plant plastids remains virtually unexplored. We previously showed that leaf chloroplasts can be converted into artificial chromoplasts with a proliferation of plastoglobules by overexpression of the bacterial crtB gene. Here we combined coexpression of crtB with genes involved in tocopherol biosynthesis to investigate the potential of artificial leaf chromoplasts for vitamin E accumulation in Nicotiana benthamiana leaves. We show that this combination improves tocopherol levels compared to controls without crtB and confirm that VTE1, VTE5, VTE6 and tyrA genes are useful to increase the total tocopherol levels, while VTE4 further leads to enrichment in α-tocopherol (the tocochromanol showing highest vitamin E activity). Additionally, we show that treatments that further promote plastoglobule formation (e.g., exposure to intense light or dark-induced senescence) result in even higher improvements in the tocopherol content of the leaves. An added advantage of our strategy is that it also results in increased levels of other related plastidial isoprenoids such as carotenoids (provitamin A) and phylloquinones (vitamin K1).
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Affiliation(s)
- Luca Morelli
- Institute for Plant Molecular and Cell Biology (IBMCP), CSIC-Universitat Politècnica de València, 46022 Valencia, Spain
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
- Correspondence: (L.M.); (M.R.-C.)
| | - Laura García Romañach
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain
| | - Gaetan Glauser
- Neuchâtel Platform of Analytical Chemistry, Faculty of Sciences, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | | | - Felix Kessler
- Laboratory of Plant Physiology, Faculty of Sciences, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Manuel Rodriguez-Concepcion
- Institute for Plant Molecular and Cell Biology (IBMCP), CSIC-Universitat Politècnica de València, 46022 Valencia, Spain
- Correspondence: (L.M.); (M.R.-C.)
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3
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Khallouki F, Saber S, Bouddine T, Hajji L, Elbouhali B, Silvente-Poirot S, Poirot M. In vitro and In vivo oxidation and cleavage products of tocols: From chemical tuners to “VitaminEome” therapeutics. A narrative review. FOOD BIOSCI 2022. [DOI: 10.1016/j.fbio.2022.101839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Brain Energy Deficit as a Source of Oxidative Stress in Migraine: A Molecular Basis for Migraine Susceptibility. Neurochem Res 2021; 46:1913-1932. [PMID: 33939061 DOI: 10.1007/s11064-021-03335-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 04/06/2021] [Accepted: 04/22/2021] [Indexed: 02/06/2023]
Abstract
People with migraine are prone to a brain energy deficit between attacks, through increased energy demand (hyperexcitable brain) or decreased supply (mitochondrial impairment). However, it is uncertain how this precipitates an acute attack. Here, the central role of oxidative stress is adduced. Specifically, neurons' antioxidant defenses rest ultimately on internally generated NADPH (reduced nicotinamide adenine dinucleotide phosphate), whose levels are tightly coupled to energy production. Mitochondrial NADPH is produced primarily by enzymes involved in energy generation, including isocitrate dehydrogenase of the Krebs (tricarboxylic acid) cycle; and an enzyme, nicotinamide nucleotide transhydrogenase (NNT), that depends on the Krebs cycle and oxidative phosphorylation to function, and that works in reverse, consuming antioxidants, when energy generation fails. In migraine aura, cortical spreading depression (CSD) causes an initial severe drop in level of NADH (reduced nicotinamide adenine dinucleotide), causing NNT to impair antioxidant defense. This is followed by functional hypoxia and a rebound in NADH, in which the electron transport chain overproduces oxidants. In migraine without aura, a similar biphasic fluctuation in NADH very likely generates oxidants in cortical regions farthest from capillaries and penetrating arterioles. Thus, the perturbations in brain energy demand and/or production seen in migraine are likely sufficient to cause oxidative stress, triggering an attack through oxidant-sensing nociceptive ion channels. Implications are discussed for the development of new classes of migraine preventives, for the current use of C57BL/6J mice (which lack NNT) in preclinical studies of migraine, for how a microembolism initiates CSD, and for how CSD can trigger a migraine.
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Hinman A, Holst CR, Latham JC, Bruegger JJ, Ulas G, McCusker KP, Amagata A, Davis D, Hoff KG, Kahn-Kirby AH, Kim V, Kosaka Y, Lee E, Malone SA, Mei JJ, Richards SJ, Rivera V, Miller G, Trimmer JK, Shrader WD. Vitamin E hydroquinone is an endogenous regulator of ferroptosis via redox control of 15-lipoxygenase. PLoS One 2018; 13:e0201369. [PMID: 30110365 PMCID: PMC6093661 DOI: 10.1371/journal.pone.0201369] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/14/2018] [Indexed: 01/01/2023] Open
Abstract
Ferroptosis is a form of programmed cell death associated with inflammation, neurodegeneration, and ischemia. Vitamin E (alpha-tocopherol) has been reported to prevent ferroptosis, but the mechanism by which this occurs is controversial. To elucidate the biochemical mechanism of vitamin E activity, we systematically investigated the effects of its major vitamers and metabolites on lipid oxidation and ferroptosis in a striatal cell model. We found that a specific endogenous metabolite of vitamin E, alpha-tocopherol hydroquinone, was a dramatically more potent inhibitor of ferroptosis than its parent compound, and inhibits 15-lipoxygenase via reduction of the enzyme's non-heme iron from its active Fe3+ state to an inactive Fe2+ state. Furthermore, a non-metabolizable isosteric analog of vitamin E which retains antioxidant activity neither inhibited 15-lipoxygenase nor prevented ferroptosis. These results call into question the prevailing model that vitamin E acts predominantly as a non-specific lipophilic antioxidant. We propose that, similar to the other lipophilic vitamins A, D and K, vitamin E is instead a pro-vitamin, with its quinone/hydroquinone metabolites responsible for its anti-ferroptotic cytoprotective activity.
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Affiliation(s)
- Andrew Hinman
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Charles R. Holst
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Joey C. Latham
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Joel J. Bruegger
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Gözde Ulas
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Kevin P. McCusker
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Akiko Amagata
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Dana Davis
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Kevin G. Hoff
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Amanda H. Kahn-Kirby
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Virna Kim
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Yuko Kosaka
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Edgar Lee
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Stephanie A. Malone
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Janet J. Mei
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Steve James Richards
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Veronica Rivera
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Guy Miller
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - Jeffrey K. Trimmer
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
| | - William D. Shrader
- BioElectron Technology Corporation, Inc., Mountain View, California, United States of America
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Drotleff AM, Büsing A, Willenberg I, Empl MT, Steinberg P, Ternes W. HPLC Separation of Vitamin E and Its Oxidation Products and Effects of Oxidized Tocotrienols on the Viability of MCF-7 Breast Cancer Cells in Vitro. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:8930-8939. [PMID: 26405759 DOI: 10.1021/acs.jafc.5b04388] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Tocotrienols, a vitamin E subgroup, exert potent anticancer effects, but easily degrade due to oxidation. Eight vitamin E reference compounds, α-, β-, γ-, or δ-tocopherols or -tocotrienols, were thermally oxidized in n-hexane. The corresponding predominantly dimeric oxidation products were separated from the parent compounds by diol-modified normal-phase HPLC-UV and characterized by mass spectroscopy. The composition of test compounds, that is, α-tocotrienol, γ-tocotrienol, or palm tocotrienol-rich fraction (TRF), before and after thermal oxidation was determined by HPLC-DAD, and MCF-7 cells were treated with both nonoxidized and oxidized test compounds for 72 h. Whereas all nonoxidized test compounds (0-100 μM) led to dose-dependent decreases in cell viability, equimolar oxidized α-tocotrienol had a weaker effect, and oxidized TRF had no such effect. However, the IC50 value of oxidized γ-tocotrienol was lower (85 μM) than that of nonoxidized γ-tocotrienol (134 μM), thereby suggesting that γ-tocotrienol oxidation products are able to reduce tumor cell viability in vitro.
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Affiliation(s)
- Astrid M Drotleff
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Anne Büsing
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Ina Willenberg
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Michael T Empl
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Pablo Steinberg
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
| | - Waldemar Ternes
- Department of Analytical Chemistry and ‡Department of Food Toxicology, Center for Food Sciences, Institute for Food Toxicology and Analytical Chemistry, University of Veterinary Medicine Hannover Foundation , Bischofsholer Damm 15, D-30173 Hannover, Germany
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7
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Wang SW, Yang SG, Liu W, Zhang YX, Xu PX, Wang T, Ling TJ, Liu RT. Alpha-tocopherol quinine ameliorates spatial memory deficits by reducing beta-amyloid oligomers, neuroinflammation and oxidative stress in transgenic mice with Alzheimer's disease. Behav Brain Res 2015; 296:109-117. [PMID: 26358659 DOI: 10.1016/j.bbr.2015.09.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/31/2015] [Accepted: 09/02/2015] [Indexed: 11/18/2022]
Abstract
The pathologies of Alzheimer's disease (AD) is associated with soluble beta-amyloid (Aβ) oligomers, neuroinflammation and oxidative stress. Decreasing the levels of Aβ oligomer, glial activation and oxidative stress are potential therapeutic approaches for AD treatment. We previously found alpha-tocopherol quinine (α-TQ) inhibited Aβ aggregation and cytotoxicity, decreased the release of inflammatory cytokines and reactive oxygen species (ROS) in vitro. However, whether α-TQ ameliorates memory deficits and other neuropathologies in mice or patients with AD remains unknown. In this study, we reported that orally administered α-TQ ameliorated memory impairment in APPswe/PS1dE9 transgenic mice, decreased oxidative stress and the levels of Aβ oligomer in the brains of mice, prevented the production of inducible nitric oxide synthase and inflammatory mediators, such as interleukin-6 and interleukin-1β, and inhibited microglial activation by inhibiting NF-κB signaling pathway. These findings suggest that α-TQ has potential therapeutic value for AD treatment.
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Affiliation(s)
- Shao-Wei Wang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Shi-Gao Yang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Wen Liu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Yang-Xin Zhang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Peng-Xin Xu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Life Science, Ningxia University, Yinchuan 750021, China
| | - Teng Wang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Life Science, Anhui Agricultural University, Hefei 230036, China
| | - Tie-Jun Ling
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei 230036, China.
| | - Rui-Tian Liu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
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8
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Li Q, Cheng Y, Bi M, Lin H, Chen Y, Zou Y, Liu Y, Kang H, Guo Y. Effects of N-butylphthalide on the activation of Keap1/Nrf-2 signal pathway in rats after carbon monoxide poisoning. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2015; 40:22-9. [PMID: 26056974 DOI: 10.1016/j.etap.2015.05.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 05/13/2015] [Accepted: 05/16/2015] [Indexed: 05/16/2023]
Abstract
UNLABELLED Carbon monoxide (CO) is the leading cause of death by poisoning all over the world and may result in neuropathologic changes and cognitive and neurologic sequelae, yet little is known regarding its outcomes. The present study aimed to evaluate the neuroprotective effects of N-butylphthalide (NBP) against brain damage after acute CO poisoning. The animal model of CO poisoning was established by exposed to 1000 ppm CO in air for 40 min and then to 3000 ppm for another 20 min. RT-PCR was used to assess the expressions of apoptosis-associated genes Bcl-2 mRNA and Bax mRNA. Mitochondrial membrane potential (MMP) was detected by fluorescent probe JC-1. Immunohistochemistry stain and Western blot assay were used to evaluate the expression levels of Kelch-like ECH-associated protein 1 (Keapl), nuclear factor erythroid 2-related factor 2 (Nrf-2) and NAD(P)H quinone oxidoreductase 1(NQO-1). CO poisoning could increase the levels of Bcl-2 mRNA and Bax mRNA expressions, and obviously decrease the MMP of cells. NBP treatment could maintain the high MMP, significantly up-regulate Bcl-2 mRNA and down-regulate Bax mRNA expression, and the ratio of Bcl-2 mRNA/Bax mRNA expressions was higher than that in the CO poisoning group (P<0.05). CO poisoning could start oxidative stress response. The expressions of Keap1, Nrf-2 and NQO-1 proteins significantly increased at 1, 3 and 7 day after NBP administration as compared with the CO poisoning group (P<0.01). These findings suggest that N-butylphthalide may protect mitochondrial function, balance the expressions of anti-apoptosis genes and pro-apoptosis genes, be in part associated with activation of Keap1-Nrf-2/antioxidant response element (ARE) signaling pathway, and play a neuroprotective role in brain damage after acute CO poisoning.
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Affiliation(s)
- Qin Li
- Emergency Centre, Yantai Yuhuangding Hospital Affiliated Hospital of Qingdao University Medical College, Yantai Yudong 20 Road, PR China
| | - Yongmei Cheng
- Emergency Centre, Yantai Yuhuangding Hospital Affiliated Hospital of Qingdao University Medical College, Yantai Yudong 20 Road, PR China.
| | - MingJun Bi
- Emergency Centre, Yantai Yuhuangding Hospital Affiliated Hospital of Qingdao University Medical College, Yantai Yudong 20 Road, PR China.
| | - Hongyang Lin
- Emergency Centre, Yantai Yuhuangding Hospital Affiliated Hospital of Qingdao University Medical College, Yantai Yudong 20 Road, PR China
| | - Yufei Chen
- Emergency Centre, Yantai Yuhuangding Hospital Affiliated Hospital of Qingdao University Medical College, Yantai Yudong 20 Road, PR China
| | - Yong Zou
- Department of Clinical Medicine, Yantai Yuhuangding Hospital Affiliated Hospital of Qingdao University Medical College, Yantai Yudong 20 Road, PR China
| | - Yuanyuan Liu
- Emergency Centre, Yantai Yuhuangding Hospital Affiliated Hospital of Qingdao University Medical College, Yantai Yudong 20 Road, PR China
| | - Hai Kang
- Emergency Centre, Yantai Yuhuangding Hospital Affiliated Hospital of Qingdao University Medical College, Yantai Yudong 20 Road, PR China
| | - Yunliang Guo
- Institute of Cerebrovascular Diseases, Affiliated Hospital of Qingdao University Medical College, Qingdao Jiangsu 16 Road, PR China
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Abstract
Vitamin E was identified almost a century ago as a botanical compound necessary for rodent reproduction. Decades of research since then established that of all members of the vitamin E family, α-tocopherol is selectively enriched in human tissues, and it is essential for human health. The major function of α-tocopherol is thought to be that of a lipid-soluble antioxidant that prevents oxidative damage to biological components. As such, α-tocopherol is necessary for numerous physiological processes such as permeability of lipid bilayers, cell adhesion, and gene expression. Inadequate levels of α-tocopherol interfere with cellular function and precipitate diseases, notably ones that affect the central nervous system. The extreme hydrophobicity of α-tocopherol poses a serious thermodynamic barrier for proper distribution of the vitamin to target tissues and cells. Although transport of the vitamin shares some steps with that of other lipids, selected tissues evolved dedicated transport mechanisms involving the α-tocopherol transfer protein (αTTP). The critical roles of this protein and its ligand are underscored by the debilitating pathologies that characterize human carriers of mutations in the TTPA gene.
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Affiliation(s)
- Lynn Ulatowski
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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