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Antioxidative Effect of Dihydrosphingosine (d18:0) and α-Tocopherol on Tridocosahexaenoin (DHA-TAG).Journal of Agricultural and Food... Oct 2023Sphingoid bases have shown promise as effective antioxidants in fish oils together with α-tocopherol, and the effect has been attributed to products resulting from...
Sphingoid bases have shown promise as effective antioxidants in fish oils together with α-tocopherol, and the effect has been attributed to products resulting from amino-carbonyl reactions (lipation products) between the sphingoid base amine group and carbonyl compounds from lipid oxidation. In this study, the synergistic effect of dihydrosphingosine (d18:0) and α-tocopherol was studied on pure docosahexaenoic acid (DHA) triacylglycerols with an omics-type liquid- and gas-chromatographic mass spectrometric approach to verify the synergistic effect, to get a comprehensive view on the effect of d18:0 on the oxidation pattern, and to identify the lipation products. The results confirmed that d18:0 rapidly reacts further in the presence of lipid oxidation products and α-tocopherol. α-Tocopherol and d18:0 showed an improved antioxidative effect after 12 h of oxidation, indicating the formation of antioxidants through carbonyl-amine reactions. Imines formed from the carbonyls and d18:0 could be tentatively identified.
Topics: Antioxidants; alpha-Tocopherol; Docosahexaenoic Acids; Sphingosine; Oxidation-Reduction
PubMed: 37751317
DOI: 10.1021/acs.jafc.3c02668 -
ACS Omega Jul 2023Soil salinity negatively impacts agricultural productivity. Consequently, strategies should be developed to inculcate a salinity tolerance in crops for sustainable food...
Soil salinity negatively impacts agricultural productivity. Consequently, strategies should be developed to inculcate a salinity tolerance in crops for sustainable food production. Growth regulators play a vital role in regulating salinity stress tolerance. Thus, we examined the effect of exogenous salicylic acid (SA) and alpha-tocopherol (TP) (100 mg/L) on the morphophysio-biochemical responses of two wheat cultivars (Pirsabak-15 and Shankar) to salinity stress (0 and 40 mM). Both Pirsabak-15 and Shankar cultivars were negatively affected by salinity stress. For instance, salinity reduced growth attributes (i.e., leaf fresh and dry weight, leaf moisture content, leaf area ratio, shoot and root dry weight, shoot and root length, as well as root-shoot ratio), pigments (chlorophyll a, chlorophyll a, and carotenoids) but increased hydrogen peroxide (HO), malondialdehyde (MDA), and endogenous TP in both cultivars. Among the antioxidant enzymes, salinity enhanced the activity of peroxidase (POD) and polyphenol oxidase (PPO) in Pirsabak-15; glutathione reductase (GR) and PPO in Shankar, while ascorbate peroxidase (APOX) was present in both cultivars. SA and TP could improve the salinity tolerance by improving growth and photosynthetic pigments and reducing MDA and HO. In general, the exogenous application did not have a positive effect on antioxidant enzymes; however, it increased PPO in Pirsabak-15 and SOD in the Shankar cultivar. Consequently, we suggest that SA and TP could have enhanced the salinity tolerance of our selected wheat cultivars by modulating their physiological mechanisms in a manner that resulted in improved growth. Future molecular studies can contribute to a better understanding of the mechanisms by which SA and TP regulate the selected wheat cultivars underlying salinity tolerance mechanisms.
PubMed: 37521660
DOI: 10.1021/acsomega.3c02166 -
Free Radical Biology & Medicine Aug 2024It has generally been accepted that vitamin E refers to a group of tocochromanols, α-, β-, γ-, and δ-tocopherols and the corresponding four tocotrienols. Recently,... (Review)
Review
It has generally been accepted that vitamin E refers to a group of tocochromanols, α-, β-, γ-, and δ-tocopherols and the corresponding four tocotrienols. Recently, Azzi and colleagues proposed to restrict the term vitamin E only to RRR-α-tocopherol, not to other tocopherols and tocotrienols (Azzi A et al. Free Radic Biol Med. 2023; 207:178-180. doi: 10.1016/j.freeradbiomed.2023.06.029). The aim of this paper is to express our opinion on the nomenclature of vitamin E based on available scientific data. In our opinion, it would be inappropriate to exclude all the tocochromanols other than RRR-α-tocopherol from the vitamin E group at this stage when the molecular mechanisms showing how vitamin E deficiency causes diseases such as ataxia and how vitamin E prevents/reverses such diseases are not elucidated. Understanding of whole functions of tocochromanols including underlying mechanisms and dynamics is essential before revision of currently accepted definition of vitamin E. The potential roles of γ-tocopherol and tocotrienols are discussed despite whether they are vitamin function should be clarified in the future studies.
Topics: Vitamin E; Humans; Vitamin E Deficiency; Terminology as Topic; alpha-Tocopherol; Ataxia; Tocotrienols; Antioxidants; Animals
PubMed: 38754742
DOI: 10.1016/j.freeradbiomed.2024.05.027 -
Brain Sciences Jul 2023Dietary constituents may affect the progression of Parkinson's disease (PD). This study aimed to assess the contribution of dietary intake of vitamins and minerals to...
BACKGROUND AND OBJECTIVE
Dietary constituents may affect the progression of Parkinson's disease (PD). This study aimed to assess the contribution of dietary intake of vitamins and minerals to the severity, motor and non-motor symptoms, and risk of PD.
METHODS
In this case-control study, 120 patients with PD and 50 healthy participants participated. Dietary intake of vitamins and minerals was determined using a 147-item food frequency questionnaire. The severity of PD was determined by the Unified Parkinson's Disease Rating Scale (UPDRS).
RESULTS
Patients with PD had lower intake of several vitamins and minerals including lycopene, thiamine, vitamin B6, vitamin B12, pantothenic acid, magnesium, zinc, manganese, selenium, chromium, and phosphorus, but had higher intake of α-tocopherol. High dietary intake of vitamin A, α-carotene, β-cryptoxanthin, vitamin C, and α-tocopherol were correlated with increased odds of PD. High intake of lycopene, thiamin, vitamin B6, pantothenic acid, magnesium, zinc, manganese, chromium, and phosphorous correlated with reduced odds of PD. The predictive power of α-tocopherol concerning the risk of PD was stronger relative to other vitamins. Dietary intake of pantothenic acid was negatively correlated with PD severity and symptoms of motor examination and complication. The severity and motor symptoms of PD were also negatively correlated with β-carotene, vitamin C, riboflavin, vitamin B6, and biotin intake. The UPDRS total score and motor symptoms in PD patients were negatively correlated with phosphorus, magnesium, zinc, manganese, and chromium, and strongly with potassium intake.
CONCLUSION
The findings indicate that adequate dietary intake of vitamins and minerals may have a preventive effect on developing PD and progression of motor decline.
PubMed: 37509049
DOI: 10.3390/brainsci13071119 -
Animal Nutrition (Zhongguo Xu Mu Shou... Dec 2023Tocopherol sources in diets are often a combination of -α-tocopheryl acetate (synthetic α-tocopherol) from vitamin supplements and natural tocopherols and 2R-(4'R,...
Tocopherol sources in diets are often a combination of -α-tocopheryl acetate (synthetic α-tocopherol) from vitamin supplements and natural tocopherols and 2R-(4'R, 8'R)-5,7,8-trimethyltocotrienol (α-tocotrienols) from the feed sources. Synthetic α-tocopherol consists of 8 different stereoisomers including 2R-(4'R, 8'R)-5,7,8-trimethyltocol (-α-tocopherol), 2R-(4'S, 8'R)-5,7,8-trimethyltocol (-α-tocopherol), 2R-(4'R, 8'S)-5,7,8-trimethyltocol (-α-tocopherol), 2R-(4'S, 8'S)-5,7,8-trimethyltocol (-α-tocopherol), 2S-(4'S, 8'S)-5,7,8-trimethyltocol (-α-tocopherol), 2S-(4'R, 8'S)-5,7,8-trimethyltocol (-α-tocopherol), 2S-(4'S, 8'R)-5,7,8-trimethyltocol (-α-tocopherol), and 2S-(4'R, 8'R)-5,7,8-trimethyltocol (-α-tocopherol). The pre-absorption metabolism of tocopherols and tocotrienols in ruminants differs from monogastric animals due to the extensive microbial fermentation in the anaerobic rumen. The current study investigated the impact of toasting and decortication of oats on metabolism in the digestive tract (synthesis, digestion), and intestinal digestibility of tocopherols in dairy cows by using 4 ruminal and intestinal cannulated Danish Holstein cows in a 4 × 4 Latin square design for 4 periods. Cows were fed a total mixed ration ad libitum containing different forms of oats: whole oat, decorticated oat, toasted oat, and decorticated toasted oat, all rolled before mixed ration. Overall means across 4 treatments were statistically analyzed, testing whether overall means were different from zero. Decortication or toasting did not affect the balance or digestibility of α-tocopherols in rumen. Average across treatments showed the ruminal degradation of synthetic α-tocopherol (279 mg/d, = 0.02; -value shows that average across treatments is different from zero), synthetic 2R-α-tocopherol (133 mg/d, < 0.01; summation of -, - and -α-tocopherol), and 2S-α-tocopherol (190 mg/d; < 0.01, summation of -, -, , and -α-tocopherol), while -α-tocopherol was formed in the rumen (221 mg/d, = 0.10). The average across treatments showed that small intestinal digestibility of tocopherols ranked in the following order: α-tocotrienol > natural α-tocopherol > synthetic α-tocopherols > 2R-(4'R, 8'R)-,7,8-dimethyltocol (γ-tocopherol). The average across treatments for small intestinal and feed-ileum digestibility ranked in the following order: -α-tocopherol > synthetic 2R-α-tocopherol > 2S-α-tocopherol. Results showed the first evidence for -α-tocopherol formation under anaerobic conditions in the rumen. In addition, synthetic α-tocopherol stereoisomers, γ-tocopherol and α-tocotrienol were degraded in the rumen. There was a discrimination against absorption of synthetic 2R- and 2S-α-tocopherol in the small intestine.
PubMed: 38058569
DOI: 10.1016/j.aninu.2023.07.007 -
Biomedicine & Pharmacotherapy =... Jun 2024Spinal cord injury (SCI) is a type of central nervous system (CNS) injury in which ferroptosis is becoming a promising target for treatment. Alpha-tocopherol (Vitamin E,...
Spinal cord injury (SCI) is a type of central nervous system (CNS) injury in which ferroptosis is becoming a promising target for treatment. Alpha-tocopherol (Vitamin E, Vit E) is a compound with anti-ferroptosis activity. The mechanism of alpha-tocopherol in regulating ferroptosis after SCI has not been deeply studied. In this study, rats with SCI were treated by Alpha-tocopherol based on bioinformatic analysis and molecular docking prediction. Behavioral tests and histological findings showed that Alpha-tocopherol promoted neural function recovery and tissue repairment in rats with SCI. Subsequently, regulatory effects of Alpha-tocopherol on Alox15 and ferroptosis were detected and then localized by immunofluorescence. In vitro, alpha-tocopherol improved the ROS accumulation, iron overload, lipid peroxidation and mitochondrial dysfunction. The effects of Alpha-tocopherol on the expression of Alox15, Ptgs2 and 4Hne were validated in vitro. Finally, the inhibitory effects of Alpha-tocopherol on Alox15 and ferroptosis were weakened by the mutation of 87th residue of Alox15. In summary, alpha-tocopherol could alleviate SCI-induced ferroptosis by downregulating Alox15 to promote neural function recovery in rats with SCI. Findings in this study could help further our understanding on SCI-induced ferroptosis and provide a novel insight for treating SCI.
Topics: Animals; Ferroptosis; alpha-Tocopherol; Spinal Cord Injuries; Recovery of Function; Down-Regulation; Rats; Arachidonate 15-Lipoxygenase; Rats, Sprague-Dawley; Lipid Peroxidation; Male; Reactive Oxygen Species; Arachidonate 12-Lipoxygenase; Disease Models, Animal; Molecular Docking Simulation
PubMed: 38754264
DOI: 10.1016/j.biopha.2024.116734 -
Archives of Toxicology May 2024Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are well recognized for playing a dual role, since they can be either deleterious or beneficial to... (Review)
Review
Several lines of antioxidant defense against oxidative stress: antioxidant enzymes, nanomaterials with multiple enzyme-mimicking activities, and low-molecular-weight antioxidants.
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are well recognized for playing a dual role, since they can be either deleterious or beneficial to biological systems. An imbalance between ROS production and elimination is termed oxidative stress, a critical factor and common denominator of many chronic diseases such as cancer, cardiovascular diseases, metabolic diseases, neurological disorders (Alzheimer's and Parkinson's diseases), and other disorders. To counteract the harmful effects of ROS, organisms have evolved a complex, three-line antioxidant defense system. The first-line defense mechanism is the most efficient and involves antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This line of defense plays an irreplaceable role in the dismutation of superoxide radicals (O) and hydrogen peroxide (HO). The removal of superoxide radicals by SOD prevents the formation of the much more damaging peroxynitrite ONOO (O + NO → ONOO) and maintains the physiologically relevant level of nitric oxide (NO), an important molecule in neurotransmission, inflammation, and vasodilation. The second-line antioxidant defense pathway involves exogenous diet-derived small-molecule antioxidants. The third-line antioxidant defense is ensured by the repair or removal of oxidized proteins and other biomolecules by a variety of enzyme systems. This review briefly discusses the endogenous (mitochondria, NADPH, xanthine oxidase (XO), Fenton reaction) and exogenous (e.g., smoking, radiation, drugs, pollution) sources of ROS (superoxide radical, hydrogen peroxide, hydroxyl radical, peroxyl radical, hypochlorous acid, peroxynitrite). Attention has been given to the first-line antioxidant defense system provided by SOD, CAT, and GPx. The chemical and molecular mechanisms of antioxidant enzymes, enzyme-related diseases (cancer, cardiovascular, lung, metabolic, and neurological diseases), and the role of enzymes (e.g., GPx4) in cellular processes such as ferroptosis are discussed. Potential therapeutic applications of enzyme mimics and recent progress in metal-based (copper, iron, cobalt, molybdenum, cerium) and nonmetal (carbon)-based nanomaterials with enzyme-like activities (nanozymes) are also discussed. Moreover, attention has been given to the mechanisms of action of low-molecular-weight antioxidants (vitamin C (ascorbate), vitamin E (alpha-tocopherol), carotenoids (e.g., β-carotene, lycopene, lutein), flavonoids (e.g., quercetin, anthocyanins, epicatechin), and glutathione (GSH)), the activation of transcription factors such as Nrf2, and the protection against chronic diseases. Given that there is a discrepancy between preclinical and clinical studies, approaches that may result in greater pharmacological and clinical success of low-molecular-weight antioxidant therapies are also subject to discussion.
Topics: Humans; Antioxidants; Reactive Oxygen Species; Hydrogen Peroxide; Superoxides; Peroxynitrous Acid; Anthocyanins; Oxidative Stress; Neoplasms; Nitric Oxide; Superoxide Dismutase; Chronic Disease
PubMed: 38483584
DOI: 10.1007/s00204-024-03696-4 -
Free Radical Biology & Medicine Mar 2024The recent publication by Azzi and colleagues puts forth the argument that only RRR-α-tocopherol should be considered as vitamin E from a physiological point of view.... (Review)
Review
The recent publication by Azzi and colleagues puts forth the argument that only RRR-α-tocopherol should be considered as vitamin E from a physiological point of view. They base their argument primarily on the assertion that only this form has been used to treat stark vitamin E deficiency in humans (known as AVED, or Ataxia with Vitamin E Deficiency). Azzi et al. also argue that other chemically similar molecules, such as tocopherols other than α-tocopherol and tocotrienols do not provide vitamin E activity. Azzi and colleagues are correct on this second point. An investigation into the biological activities of vitamin E, and the mechanisms behind these activities, confirms that physiological vitamin E activity is limited to certain α-tocopherol forms. However, it is also clear that these activities are not restricted only to the RRR-form but include other 2R-forms as well. Indeed, the α-tocopherol transfer protein (α-TTP), which is critical to mediate vitamin E trafficking and biological activity, and genetic defects of which lead to vitamin E deficiency, binds well to all 2R-forms of α-tocopherol. Furthermore, both RRR-α-tocopherol and the other 2R-forms are maintained in human plasma and distributed to tissues and organs, whereas the 2S-stereoisomers are excreted quickly. As such, in recent years the definition of vitamin E including both 2R- and RRR-α-tocopherol has gained both broad scientific and regulatory acceptance. Consistent with this understanding, we provide evidence that AVED has indeed been treated successfully with forms in addition to RRR-α-tocopherol, again arguing against the restriction of the definition to RRR-α-tocopherol only. Finally, we provide evidence against any safety concerns utilizing the currently accepted definition of vitamin E.
Topics: Humans; Vitamin E; alpha-Tocopherol; Stereoisomerism; Antioxidants; Vitamin E Deficiency
PubMed: 38401827
DOI: 10.1016/j.freeradbiomed.2024.02.013 -
Current Opinion in Chemical Biology Aug 2023Selenium is connected to three small molecule antioxidant compounds, ascorbate, α-tocopherol, and ergothioneine. Ascorbate and α-tocopherol are true vitamins, while... (Review)
Review
Selenium is connected to three small molecule antioxidant compounds, ascorbate, α-tocopherol, and ergothioneine. Ascorbate and α-tocopherol are true vitamins, while ergothioneine is a "vitamin-like" compound. Here we review how selenium is connected to all three. Selenium and vitamin E work together as a team to prevent lipid peroxidation. Vitamin E quenches lipid hydroperoxyl radicals and the resulting lipid hydroperoxide is then converted to the lipid alcohol by selenocysteine-containing glutathione peroxidase. Ascorbate reduces the resulting α-tocopheroxyl radical in this reaction back to α-tocopherol with concomitant production of the ascorbyl radical. The ascorbyl radical can be reduced back to ascorbate by selenocysteine-containing thioredoxin reductase. Ergothioneine and ascorbate are both water soluble, small molecule reductants that can reduce free radicals and redox-active metals. Thioredoxin reductase can reduce oxidized forms of ergothioneine. While the biological significance of this is not yet realized, this discovery underscores the centrality of selenium to all three antioxidants.
Topics: Ascorbic Acid; Selenium; Ergothioneine; alpha-Tocopherol; Selenocysteine; Thioredoxin-Disulfide Reductase; Vitamin E; Antioxidants; Vitamins; Oxidation-Reduction; Free Radicals; Lipid Peroxides
PubMed: 37236134
DOI: 10.1016/j.cbpa.2023.102328 -
Pharmaceutics Jul 2023A novel co-encapsulation system called bicosomes (bicelles within liposomes) has been developed to overcome the limitations associated with the topical application of...
A novel co-encapsulation system called bicosomes (bicelles within liposomes) has been developed to overcome the limitations associated with the topical application of curcumin (cur) and α-tocopherol (α-toc). The physicochemical properties and biological activity in vitro of bicosome systems were evaluated. Bicelles were prepared with DPPC, DHPC, cur, and α-toc (cur/α-toc-bicelles). Liposomal vesicles loading cur/α-toc-bicelles were prepared with Lipoid P-100 and cholesterol-forming cur/α-toc-bicosomes. Three cur/α-toc-bicosomes were evaluated using different total lipid percentages (12, 16, and 20% /). The results indicated that formulations manage to solubilize cur and α-toc in homogeneous bicelles < 20 nm, while the bicosomes reaches 303-420 nm depending on the total lipid percentage in the systems. Bicosomes demonstrated high-encapsulation efficiency (EE) for cur (56-77%) and α-toc (51-65%). The loading capacity (LC) for both antioxidant compounds was 52-67%. In addition, cur/α-toc-bicosomes decreased the lipid oxidation by 52% and increased the antioxidant activity by 60% compared to unloaded bicosomes. The cell viability of these cur/α-toc-bicosomes was >85% in fibroblasts (3T3L1/CL-173™) and ≥65% in keratinocytes (Ha-CaT) and proved to be hematologically compatible. The cur/α-toc-bicelles and cur/α-toc-bicosomes inhibited the growth of in a range between 33 and 76%. Our results propose bicosome systems as a novel carrier able to co-encapsulate, solubilize, protect, and improve the delivery performance of antioxidant molecules. The relevance of these findings is based on the synergistic antioxidant effect of its components, its biocompatibility, and its efficacy for dermal tissue treatment damaged by oxidative stress or by the presence of . However, further studies are needed to assess the efficacy and safety of cur/α-toc bicosomes in vitro and in vivo.
PubMed: 37514098
DOI: 10.3390/pharmaceutics15071912