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Wang S, Dan W, Wang Z, Sun Y, Zhang G. Causal relationships between dietary antioxidant vitamin intake and atopic dermatitis: A two-sample Mendelian randomization study. Skin Res Technol 2024; 30:e13883. [PMID: 39120057 PMCID: PMC11311120 DOI: 10.1111/srt.13883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Accepted: 06/24/2024] [Indexed: 08/10/2024]
Abstract
OBJECTIVE Oxidative stress is strongly associated with atopic dermatitis (AD), and increased antioxidant intake could potentially reduce the risk of or alleviate its symptoms. However, the argument is disputed. Therefore, we conducted a Mendelian randomization (MR) analysis to explore the causal relationship between dietary antioxidant vitamin intake and AD. METHODS We applied MR analysis to examine the causative association between dietary antioxidant vitamin intake (vitamin C, vitamin E, carotene, and retinol) and AD. The genome-wide association study (GWAS) summary data for antioxidant vitamins intake and AD were obtained from the IEU OpenGWAS database and the UK biobank. Our study consisted of two major parts, MR analysis to detect the causal relationship between exposure and outcome, and sensitivity analysis as supplemental evidence to verify the robustness of the results. RESULT The results revealed a suggestive causal relationship between vitamin E intake and AD (p = 0.038, OR 95% CI = 0.745-0.992). However, there was no causal relationship between the other three vitamins (vitamin C, carotene, and retinol) and AD (p = 0.507, OR 95% CI = 0.826-1.099) (p = 0.890, OR 95% CI = 0.864-1.184) (p = 0.492, OR 95% CI = 0.893-1.264). None of the single nucleotide polymorphisms (SNPs) were detected as heterogeneous and pleiotropy in the sensitivity analysis (p > 0.05). CONCLUSION The analysis suggested that dietary intake of vitamin E may potentially lower the risk of AD. Conversely, intake of vitamin C, retinol, and carotene is not causally related to AD. Although vitamin E intake could be protective against AD, intake of dietary antioxidant vitamins to prevent or treat AD is not necessary.
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Affiliation(s)
- Siqing Wang
- Graduate SchoolBeijing University of Chinese Medicine, 11 North Third Ring East Road, Beijing, 100029, China
- Dermatological DepartmentBeijing Hospital of Traditional Chinese MedicineCapital Medical University, 23 Behind the Art Museum, Beijing, 100010, China
- Inner Mongolia Hospital of Beijing Chinese Medicine Hospital, 5 Guangming West Street, Inner Mongolia, 014400, China
| | - Wenchao Dan
- Dermatological DepartmentBeijing Hospital of Traditional Chinese MedicineCapital Medical University, 23 Behind the Art Museum, Beijing, 100010, China
- Inner Mongolia Hospital of Beijing Chinese Medicine Hospital, 5 Guangming West Street, Inner Mongolia, 014400, China
| | - Zixuan Wang
- Dermatological DepartmentBeijing Hospital of Traditional Chinese MedicineCapital Medical University, 23 Behind the Art Museum, Beijing, 100010, China
| | - Yujie Sun
- Graduate SchoolBeijing University of Chinese Medicine, 11 North Third Ring East Road, Beijing, 100029, China
- Dermatological DepartmentBeijing Hospital of Traditional Chinese MedicineCapital Medical University, 23 Behind the Art Museum, Beijing, 100010, China
| | - Guangzhong Zhang
- Dermatological DepartmentBeijing Hospital of Traditional Chinese MedicineCapital Medical University, 23 Behind the Art Museum, Beijing, 100010, China
- Inner Mongolia Hospital of Beijing Chinese Medicine Hospital, 5 Guangming West Street, Inner Mongolia, 014400, China
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Liu D, Hu Z, Lu J, Yi C. Redox-Regulated Iron Metabolism and Ferroptosis in Ovarian Cancer: Molecular Insights and Therapeutic Opportunities. Antioxidants (Basel) 2024; 13:791. [PMID: 39061859 PMCID: PMC11274267 DOI: 10.3390/antiox13070791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024] Open
Abstract
Ovarian cancer (OC), known for its lethality and resistance to chemotherapy, is closely associated with iron metabolism and ferroptosis-an iron-dependent cell death process, distinct from both autophagy and apoptosis. Emerging evidence suggests that dysregulation of iron metabolism could play a crucial role in OC by inducing an imbalance in the redox system, which leads to ferroptosis, offering a novel therapeutic approach. This review examines how disruptions in iron metabolism, which affect redox balance, impact OC progression, focusing on its essential cellular functions and potential as a therapeutic target. It highlights the molecular interplay, including the role of non-coding RNAs (ncRNAs), between iron metabolism and ferroptosis, and explores their interactions with key immune cells such as macrophages and T cells, as well as inflammation within the tumor microenvironment. The review also discusses how glycolysis-related iron metabolism influences ferroptosis via reactive oxygen species. Targeting these pathways, especially through agents that modulate iron metabolism and ferroptosis, presents promising therapeutic prospects. The review emphasizes the need for deeper insights into iron metabolism and ferroptosis within the redox-regulated system to enhance OC therapy and advocates for continued research into these mechanisms as potential strategies to combat OC.
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Affiliation(s)
- Dan Liu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital, Yangtze University, Jingzhou 434000, China; (D.L.); (Z.H.)
- Hubei Provincial Clinical Research Center for Personalized Diagnosis and Treatment of Cancer, Jingzhou 434000, China
| | - Zewen Hu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital, Yangtze University, Jingzhou 434000, China; (D.L.); (Z.H.)
- Hubei Provincial Clinical Research Center for Personalized Diagnosis and Treatment of Cancer, Jingzhou 434000, China
| | - Jinzhi Lu
- Hubei Provincial Clinical Research Center for Personalized Diagnosis and Treatment of Cancer, Jingzhou 434000, China
- Department of Laboratory Medicine, The First Affiliated Hospital, Yangtze University, Jingzhou 434000, China
| | - Cunjian Yi
- Department of Obstetrics and Gynecology, The First Affiliated Hospital, Yangtze University, Jingzhou 434000, China; (D.L.); (Z.H.)
- Hubei Provincial Clinical Research Center for Personalized Diagnosis and Treatment of Cancer, Jingzhou 434000, China
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Rahimi H, Mirnezami M, Yazdabadi A, Hajihashemi A. Evaluation of systemic oxidative stress in patients with melasma. J Cosmet Dermatol 2024; 23:284-288. [PMID: 37461812 DOI: 10.1111/jocd.15924] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/13/2023] [Accepted: 06/28/2023] [Indexed: 01/02/2024]
Abstract
BACKGROUND The significance of oxidative stress has been assessed and proven in the etiopathogenesis of many cutaneous disorders, but there are few studies that evaluated the role of only some factors involved in oxidative stress in patients with melasma. OBJECTIVE This study aimed to examine the role of oxidative stress in melasma and assess the relationship between systemic oxidative stress and the severity and extension of this disease. METHODS In this study, the serum levels of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), malondialdehyde (MDA), protein carbonyl (PC), selenium (Se), vitamin E (vit E), and vitamin C (vit C) of fifty patients with melasma were compared with those of fifty controls. RESULTS The serum level of MDA was significantly higher in the melasma group (3.08 vs. 2.35 U/mL; p < 0.05), and it was positively correlated with the severity (r = 0.4; p < 0.001) and extension (r = 0.3; p < 0.05) of the disease. Furthermore, the serum level of vit C was significantly lower in melasma patients (2.16 vs. 2.57 μg/mL; p < 0.001). CONCLUSION Systemic oxidative stress has a key role in the etiopathogenesis of melasma. Serum concentrations of MDA and vitamin C are indicators of this impairment.
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Affiliation(s)
- Hoda Rahimi
- Skin Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mina Mirnezami
- Department of Dermatology, Arak University of Medical Sciences, Arak, Iran
| | - Anousha Yazdabadi
- Department of Dermatology, Eastern Health, Box Hill, Victoria, Australia
- Monash University, Eastern Health, Box Hill, Victoria, Australia
- Department of Medical Education, University of Melbourne, Melbourne, Victoria, Australia
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Zhang X, Hou L, Guo Z, Wang G, Xu J, Zheng Z, Sun K, Guo F. Lipid peroxidation in osteoarthritis: focusing on 4-hydroxynonenal, malondialdehyde, and ferroptosis. Cell Death Discov 2023; 9:320. [PMID: 37644030 PMCID: PMC10465515 DOI: 10.1038/s41420-023-01613-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 08/11/2023] [Accepted: 08/16/2023] [Indexed: 08/31/2023] Open
Abstract
Osteoarthritis (OA) is a multifactorial and increasingly prevalent degenerative disease that affects the whole joint. The pathogenesis of OA is poorly understood and there is a lack of therapeutic interventions to reverse the pathological process of this disease. Accumulating studies have shown that the overproduction of reactive oxygen species (ROS) and ROS-induced lipid peroxidation are involved in the pathogenesis of OA. 4-Hydroxy-2-nonenal (4-HNE) and malondialdehyde (MDA) have received considerable attention for their role in cartilage degeneration and subchondral bone remodeling during OA development. Ferroptosis is a form of cell death characterized by a lack of control of membrane lipid peroxidation and recent studies have suggested that chondrocyte ferroptosis contributes to OA progression. In this review, we aim to discuss lipid peroxidation-derived 4-HNE and MDA in the progression of OA. In addition, the therapeutic potential for OA by controlling the accumulation of lipid peroxidation and inhibiting chondrocyte ferroptosis are discussed.
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Affiliation(s)
- Xiong Zhang
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Liangcai Hou
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Zhou Guo
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Genchun Wang
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Jingting Xu
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Zehang Zheng
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Kai Sun
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
| | - Fengjing Guo
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
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5
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Progress in HNE Biology. Arch Biochem Biophys 2023; 735:109513. [PMID: 36646268 DOI: 10.1016/j.abb.2023.109513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Liao S, Omage SO, Börmel L, Kluge S, Schubert M, Wallert M, Lorkowski S. Vitamin E and Metabolic Health: Relevance of Interactions with Other Micronutrients. Antioxidants (Basel) 2022; 11:antiox11091785. [PMID: 36139859 PMCID: PMC9495493 DOI: 10.3390/antiox11091785] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/31/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
A hundred years have passed since vitamin E was identified as an essential micronutrient for mammals. Since then, many biological functions of vitamin E have been unraveled in both cell and animal models, including antioxidant and anti-inflammatory properties, as well as regulatory activities on cell signaling and gene expression. However, the bioavailability and physiological functions of vitamin E have been considerably shown to depend on lifestyle, genetic factors, and individual health conditions. Another important facet that has been considered less so far is the endogenous interaction with other nutrients. Accumulating evidence indicates that the interaction between vitamin E and other nutrients, especially those that are enriched by supplementation in humans, may explain at least some of the discrepancies observed in clinical trials. Meanwhile, increasing evidence suggests that the different forms of vitamin E metabolites and derivates also exhibit physiological activities, which are more potent and mediated via different pathways compared to the respective vitamin E precursors. In this review, possible molecular mechanisms between vitamin E and other nutritional factors are discussed and their potential impact on physiological and pathophysiological processes is evaluated using published co-supplementation studies.
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Affiliation(s)
- Sijia Liao
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
- Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD) Halle-Jena-Leipzig, 07743 Jena, Germany
| | - Sylvia Oghogho Omage
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
- Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD) Halle-Jena-Leipzig, 07743 Jena, Germany
| | - Lisa Börmel
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
- Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD) Halle-Jena-Leipzig, 07743 Jena, Germany
| | - Stefan Kluge
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
- Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD) Halle-Jena-Leipzig, 07743 Jena, Germany
| | - Martin Schubert
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
- Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD) Halle-Jena-Leipzig, 07743 Jena, Germany
| | - Maria Wallert
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
- Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD) Halle-Jena-Leipzig, 07743 Jena, Germany
| | - Stefan Lorkowski
- Institute of Nutritional Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
- Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD) Halle-Jena-Leipzig, 07743 Jena, Germany
- Correspondence:
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Zhang C, Liu N. Ferroptosis, necroptosis, and pyroptosis in the occurrence and development of ovarian cancer. Front Immunol 2022; 13:920059. [PMID: 35958626 PMCID: PMC9361070 DOI: 10.3389/fimmu.2022.920059] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/27/2022] [Indexed: 12/13/2022] Open
Abstract
Ovarian cancer (OC) is one of the most common malignancies that causes death in women and is a heterogeneous disease with complex molecular and genetic changes. Because of the relatively high recurrence rate of OC, it is crucial to understand the associated mechanisms of drug resistance and to discover potential target for rational targeted therapy. Cell death is a genetically determined process. Active and orderly cell death is prevalent during the development of living organisms and plays a critical role in regulating life homeostasis. Ferroptosis, a novel type of cell death discovered in recent years, is distinct from apoptosis and necrosis and is mainly caused by the imbalance between the production and degradation of intracellular lipid reactive oxygen species triggered by increased iron content. Necroptosis is a regulated non-cysteine protease–dependent programmed cell necrosis, morphologically exhibiting the same features as necrosis and occurring via a unique mechanism of programmed cell death different from the apoptotic signaling pathway. Pyroptosis is a form of programmed cell death that is characterized by the formation of membrane pores and subsequent cell lysis as well as release of pro-inflammatory cell contents mediated by the abscisin family. Studies have shown that ferroptosis, necroptosis, and pyroptosis are involved in the development and progression of a variety of diseases, including tumors. In this review, we summarized the recent advances in ferroptosis, necroptosis, and pyroptosis in the occurrence, development, and therapeutic potential of OC.
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Kitabayashi N, Nakao S, Mita Y, Arisawa K, Hoshi T, Toyama T, Ishii KA, Takamura T, Noguchi N, Saito Y. Role of selenoprotein P expression in the function of pancreatic β cells: Prevention of ferroptosis-like cell death and stress-induced nascent granule degradation. Free Radic Biol Med 2022; 183:89-103. [PMID: 35318102 DOI: 10.1016/j.freeradbiomed.2022.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/07/2022] [Accepted: 03/11/2022] [Indexed: 02/05/2023]
Abstract
Selenoprotein P (SELENOP) is a major selenium (Se)-containing protein (selenoprotein) in human plasma that is mainly synthesized in the liver. SELENOP transports Se to the cells, while SELENOP synthesized in peripheral tissues is incorporated in a paracrine/autocrine manner to maintain the levels of cellular selenoproteins, called the SELENOP cycle. Pancreatic β cells, responsible for the synthesis and secretion of insulin, are known to express SELENOP. Here, using MIN6 cells as a mouse model for pancreatic β cells and Selenop small interfering (si)RNA, we found that Selenop gene knockdown (KD) resulted in decreased cell viability, cellular pro/insulin levels, insulin secretion, and levels of several cellular selenoproteins, including glutathione peroxidase 4 (Gpx4) and selenoprotein K (Selenok). These dysfunctions induced by Selenop siRNA were recovered by the addition of Se. Ferroptosis-like cell death, regulated by Gpx4, was involved in the decrease of cell viability by Selenop KD, while stress-induced nascent granule degradation (SINGD), regulated by Selenok, was responsible for the decrease in proinsulin. SINGD was also observed in the pancreatic β cells of Selenop knockout mice. These findings indicate a significant role of SELENOP expression for the function of pancreatic β cells by maintaining the levels of cellular selenoproteins such as GPX4 and SELENOK.
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Affiliation(s)
- Nanako Kitabayashi
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, 610-0394, Japan
| | - Shohei Nakao
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, 610-0394, Japan
| | - Yuichiro Mita
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, 610-0394, Japan
| | - Kotoko Arisawa
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Takayuki Hoshi
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Takashi Toyama
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Kiyo-Aki Ishii
- Department of Endocrinology and Metabolism, Kanazawa University Graduate School of Medical Sciences, Kanazawa, 920-8640, Japan
| | - Toshinari Takamura
- Department of Endocrinology and Metabolism, Kanazawa University Graduate School of Medical Sciences, Kanazawa, 920-8640, Japan
| | - Noriko Noguchi
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, 610-0394, Japan
| | - Yoshiro Saito
- The Systems Life Sciences Laboratory, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, 610-0394, Japan; Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, 980-8578, Japan.
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Traber MG, Head B. Vitamin E: How much is enough, too much and why! Free Radic Biol Med 2021; 177:212-225. [PMID: 34699937 DOI: 10.1016/j.freeradbiomed.2021.10.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/08/2021] [Accepted: 10/11/2021] [Indexed: 12/12/2022]
Abstract
α-Tocopherol (α-T) is a required dietary nutrient for humans and thus is a vitamin. This narrative review focuses on vitamin E structures, functions, biological determinants and its deficiency symptoms in humans. The mechanisms for the preferential α-T tissue enrichment in the human body include the α-T transfer protein (TTPA) and the preferential metabolism of non-α-T forms. Potential new α-T biomarkers, pharmacokinetic data, and whether there are better approaches to evaluate and set the α-T dietary requirement are discussed. Finally, the possible role of α-T supplements in delay of chronic diseases and the evaluation of vitamin E safety are considered.
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Affiliation(s)
- Maret G Traber
- Linus Pauling Institute, USA; School of Biological and Population Health Sciences, College of Public Health and Human Sciences, USA.
| | - Brian Head
- Linus Pauling Institute, USA; Molecular and Cell Biology Program, Oregon State University, Corvallis, OR, USA
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10
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Niki E. Lipid oxidation that is, and is not, inhibited by vitamin E: Consideration about physiological functions of vitamin E. Free Radic Biol Med 2021; 176:1-15. [PMID: 34481937 DOI: 10.1016/j.freeradbiomed.2021.09.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 12/12/2022]
Abstract
Lipids are oxidized in vivo by multiple oxidizing species with different properties, some by regulated manner to produce physiological mediators, while others by random mechanisms to give detrimental products. Vitamin E plays an important role as a physiologically essential antioxidant to inhibit unregulated lipid peroxidation by scavenging lipid peroxyl radicals to break chain propagation independent of the type of free radicals which induce chain initiation. Kinetic data suggest that vitamin E does not act as an efficient scavenger of nitrogen dioxide radical, carbonate anion radical, and hypochlorite. The analysis of regio- and stereo-isomer distribution of the lipid oxidation products shows that, apart from lipid oxidation by CYP enzymes, the free radical-mediated lipid peroxidation is the major pathway of lipid oxidation taking place in humans. Compared with healthy subjects, the levels of racemic and trans,trans-hydro (pero)xyoctadecadienoates, specific biomarker of free radical lipid oxidation, are elevated in the plasma of patients including atherosclerosis and non-alcoholic fatty liver diseases. α-Tocopherol acts as a major antioxidant, while γ-tocopherol scavenges nitrogen dioxide radical, which induces lipid peroxidation, nitration of aromatic compounds and unsaturated fatty acids, and isomerization of cis-fatty acids to trans-fatty acids. It is essential to appreciate that the antioxidant effects of vitamin E depend on the nature of both oxidants and substrates being oxidized. Vitamin E, together with other antioxidants such as vitamin C, contributes to the inhibition of detrimental oxidation of biological molecules and thereby to the maintenance of human health and prevention of diseases.
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Affiliation(s)
- Etsuo Niki
- Research Center for Advanced Science and Technology, The University of Tokyo, Komaba, Tokyo, 153-8904, Japan.
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Saito Y. Diverse cytoprotective actions of vitamin E isoforms- role as peroxyl radical scavengers and complementary functions with selenoproteins. Free Radic Biol Med 2021; 175:121-129. [PMID: 34481936 DOI: 10.1016/j.freeradbiomed.2021.08.234] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 02/05/2023]
Abstract
Vitamin E, a generic term for tocopherol (T) and tocotrienol (T3), is one of the most potent lipid-soluble antioxidants in the body. It is classified into T and T3 based on the difference in the side chain structure. T and T3 have four isoforms: α-, β-, γ-, and δ, which have different chroman rings. Both T and T3 exhibit a similar ability to scavenge free radicals, and the extent of this ability depends on the difference in the chroman structure. However, they display unique cytoprotective activities in cultured cells depending on the difference in the side chain structure. The cytoprotective effects of vitamin E have received much attention in the prevention of ferroptosis, which is a distinct form of cell death involving iron-dependent lipid peroxidation. This review focuses on the cytoprotective actions of vitamin E isoforms against oxidative stress, particularly the difference between T and T3 and its relation to cellular uptake and distribution. Moreover, the molecular mechanism for cytoprotection of vitamin E oxidation products is explained, and the complementary role of vitamin E and selenoproteins to prevent lipid peroxidation and ferroptosis is described. Furthermore, the evaluation of vitamin E's radical scavenging activity in vivo using oxidative stress markers is discussed, particularly based on kinetic data and the physiological molar ratio of vitamin E to substrates, and the limited role of vitamin E as a peroxyl radical scavenger is described. The future directions and unresolved issues related to vitamin E and lipid peroxidation are also discussed.
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Affiliation(s)
- Yoshiro Saito
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University C301, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
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