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Natural Product Research 2014The oleic acid content of seed oils varied between 21.4% (ATAEM7) and 26.6% (Türksoy). The proportion of linoleic acid of soybean oil ranged from 49.0% (Türksoy) to...
The oleic acid content of seed oils varied between 21.4% (ATAEM7) and 26.6% (Türksoy). The proportion of linoleic acid of soybean oil ranged from 49.0% (Türksoy) to 53.5% (ATAEM7), while the palmitic acid of oils varied between 9.2% (Adasoy) and 11.2% (Noya). The major tocopherols were ¥-tocopherol, α-tocopherol and δ-tocopherol in all the varieties of soybean oil. As a result, this study showed that the seeds are to be a potential source of valuable oil which might be used for edible and other industrial applications.
Topics: Fatty Acids; Linoleic Acid; Oleic Acid; Palmitic Acid; Soybean Oil; Tocopherols; Turkey; alpha-Tocopherol
PubMed: 24499198
DOI: 10.1080/14786419.2014.883396 -
Journal of Neuroscience Research Dec 2008Tocopherols (vitamin E) are potent antioxidants as well as modulators of enzymes involved in signal transduction, like nitric oxide synthase (NOS). In primary murine...
Tocopherols (vitamin E) are potent antioxidants as well as modulators of enzymes involved in signal transduction, like nitric oxide synthase (NOS). In primary murine microglial cells and in the microglial cell line BV-2, alpha-, gamma-, and delta-tocopherol and alpha-tocopherol acid succinate, respectively, promote nitric oxide (NO) release. The NOS inhibitors aminoguanidine and N(G)-methyl-L-arginine (L-NMMA) suppressed alpha- and gamma-tocopherol-induced NO release, but had no significant effect on delta-tocopherol- and alpha-tocopherol acid succinate-induced NO release. In BV-2 cells, but not in primary microglial cells, gamma- and delta-tocopherol and alpha-tocopherol acid succinate, respectively, led to cell death, characterized by exposition of phosphatidylserine on the cell surface, chromatin condensation, changes in cell volume, and formation of blebs on the cell surface. Aminoguanidine, L-NMMA, and the NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) enhanced apoptosis in gamma-tocopherol-exposed cells and suppressed apoptosis in delta-tocopherol-treated cells, but had no effect on cells supplemented with alpha-tocopherol acid succinate. The NO donors sodium nitroprusside and 2-(N,N-diethylamino)-diazenolate 2-oxide enhanced apoptosis in gamma- or delta-tocopherol-treated cells, but rescued cells from alpha-tocopherol acid succinate-induced cell death.
Topics: Animals; Animals, Newborn; Antioxidants; Cell Death; Cell Line; Cell Membrane; Cell Size; Cells, Cultured; Chromosome Aberrations; Coculture Techniques; Enzyme Inhibitors; Gliosis; Mice; Mice, Inbred C57BL; Microglia; Neurodegenerative Diseases; Nitric Oxide; Nitric Oxide Synthase; Oxidative Stress; Tocopherols; alpha-Tocopherol; gamma-Tocopherol
PubMed: 18709655
DOI: 10.1002/jnr.21811 -
Antioxidants (Basel, Switzerland) Feb 2020Most of the biological impacts of Vitamin E, including the redox effects, have been raised from studies with α-tocopherol only, despite the fact that...
Most of the biological impacts of Vitamin E, including the redox effects, have been raised from studies with α-tocopherol only, despite the fact that tocopherol-containing foods carry mixed tocopherol isomers. Here, we investigated the cellular mechanisms involved in the immediate antioxidant responses evoked by α-, γ- and δ-tocopherol in Caco-2 cells. In order to track the cytosolic redox impact, we performed imaging on cells expressing HyPer, a fluorescent redox biosensor, while cytosolic calcium fluctuations were monitored by means of Fura-2 dye and imaging. With this approach, we could observe fast cellular responses evoked by the addition of α-, γ- and δ-tocopherol at concentrations as low as 2.5 μM. Each isomer induced rapid and consistent increases in cytosolic calcium with fast kinetics, which were affected by chelation of extracellular Ca, suggesting that tocopherols promoted a calcium entry upon the contact with the plasma membrane. In terms of redox effects, δ-tocopherol was the only isomer that evoked a significant change in the HyPer signal at 5 μM. By mimicking Ca entry with ionomycin and monensin, a decline in the HyPer signal was induced as well. Finally, by silencing calcium with 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), an intracellular Ca chelator, none of the isomers were able to induce redox changes. Altogether, our data indicate that an elevation in cytoplasmic Ca is necessary for the development of a tocopherol-induced antioxidant impact on the cytoplasm of Caco-2 cells reported by HyPer biosensor.
PubMed: 32075011
DOI: 10.3390/antiox9020155 -
Journal of Chromatography. A Mar 2006Different forms of tocopherols, together with tocotrienols, are collectively named as vitamin E, and each possesses different degree of medical, biological and...
Different forms of tocopherols, together with tocotrienols, are collectively named as vitamin E, and each possesses different degree of medical, biological and physiochemical significance. The main difficulty of separating different forms of tocopherols lay in their highly structural similarities and hydrophobicities. Microemulsion electrokinetic chromatography (MEEKC), claimed to attain high peak efficiency with great solubilization power, has not previously been applied to the separation of tocopherols. The effects that various parameters, such as buffer system, type and concentration of cyclodextrins, temperature, and sample matrix, have on the separation of tocopherols by MEEKC have been investigated. By using a buffer mixture of 4% (w/w) sodium dodecyl sulfate (SDS), 6.6% (w/w) 1-butanol, 0.8% (w/w) n-octane, 20% (w/w) 2-propanol, 68.6% (w/w) phosphate (25mM, pH 2.5), and 25mM heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CD), the separation of alpha-, gamma-, and delta-tocopherol, alpha-tocopherol acetate, as well as the antioxidant butylated hydroxytoluene (BHT) at -26kV, 25 degrees C was completed within 35min. The practical potential of the present approach has been further validated by the determination of tocopherols in a vitamin E preparation, with the result of 132.63 (RSD 1.25%), 176.51 (RSD 0.29%), and 64.32mg (RSD 3.34%) per 500mg capsule for alpha-, gamma- and delta-tocopherol, respectively.
Topics: Antioxidants; Buffers; Butylated Hydroxytoluene; Chromatography, Micellar Electrokinetic Capillary; Cyclodextrins; Pharmaceutical Preparations; Time Factors; Tocopherols; Vitamin E; alpha-Tocopherol; gamma-Tocopherol
PubMed: 16457832
DOI: 10.1016/j.chroma.2006.01.048 -
International Journal of Cosmetic... Aug 2021We investigated the dermal bioavailability and antioxidative properties of a sunscreen formulation containing two antioxidants, oxothiazolidine (OTZ) and δ-tocopheryl...
Sustained effect of two antioxidants (oxothiazolidine and δ-tocopheryl glucoside) for immediate and long-term sun protection in a sunscreen emulsion based on their different penetrating properties.
OBJECTIVE
We investigated the dermal bioavailability and antioxidative properties of a sunscreen formulation containing two antioxidants, oxothiazolidine (OTZ) and δ-tocopheryl glucoside (DTG). OTZ reacts directly with reactive oxygen species to form taurine, while DTG is metabolized in δ-tocopherol to achieve antioxidative activities.
METHODS
After topical application to a hair follicle-derived reconstructed human epidermis (RHE) model, followed by solar-simulated radiation, kinetics of bioavailability and antioxidative responses were measured over 24 h. Markers for oxidative stress were malondialdehyde (MDA), superoxide dismutase (SOD) and catalase activities.
RESULTS
The two antioxidants had different bioavailability profiles: OTZ was rapidly and extensively absorbed, whereas DTG was slowly absorbed and converted to δ-tocopherol. Compared to OTZ alone, the protection against effects on MDA levels and SOD and catalase activities was higher when DTG was used alone or in combination with OTZ. When used in combination, the degree of protection increased over time and remained constant over 24 h with maximal protection 2 h post-irradiation. DTG slowly penetrated into the skin and was present in the skin at all post-irradiation timepoints, thus allowing a slow but constant supply of δ-tocopherol over at least 24 h. By contrast, the oxidative protection by OTZ was immediate but short-lived due to its rapid penetration through the RHE and into the receptor fluid.
CONCLUSION
These results indicate a complementary sunlight protective action of OTZ and DTG with an immediate delivery of OTZ just after topical application of the formulation, and a prolonged skin delivery of δ-tocopherol from the slower penetration and metabolism of DTG.
Topics: Administration, Topical; Antioxidants; Biological Availability; Catalase; Emulsions; Humans; Malondialdehyde; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species; Skin; Sunscreening Agents; Superoxide Dismutase; Thiazolidines; alpha-Tocopherol
PubMed: 33848378
DOI: 10.1111/ics.12705 -
Physiologia Plantarum Dec 2011γ-Tocopherol methyltransferase (γ-TMT) (EC 2.1.1.95) is a very important enzyme in tocopherol biosynthesis in all photosynthetic organisms. In this paper, we present...
γ-Tocopherol methyltransferase (γ-TMT) (EC 2.1.1.95) is a very important enzyme in tocopherol biosynthesis in all photosynthetic organisms. In this paper, we present the functional characterization and expression analysis of γ-TMT from the unicellular green alga Chlamydomonas reinhardtii. Recombinant TMT1 enzyme was purified and characterized. The size of TMT1 subunit was estimated as 37 kDa by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE), in accordance with the predicted molecular size after TMT1 cDNA sequence. Recombinant TMT1 also showed an apparent molecular mass of 37 kDa in its native conformation, suggesting that native TMT1 has a monomeric structure similar to the plant TMTs already characterized. pH and temperature dependence of TMT1 activity were also similar to plant TMTs. Substrate specificity studies showed that Chlamydomonas TMT1 is responsible for the conversion of γ- and δ-tocopherol to α- and β-tocopherol, respectively. The kinetic properties of Chlamydomonas recombinant γ-TMT activity were studied and γ-TMT1 has a similar affinity for γ- and δ-tocopherol. Promoter sequence analysis and expression analysis by northern blot revealed that tmt1 expression is strongly upregulated by high light and downregulated by low temperature. This regulatory pattern of tmt1 expression supports the idea that γ- and α-tocopherol play specific roles in the adaptation to growth under low temperature and high light stress conditions.
Topics: Base Sequence; Chlamydomonas reinhardtii; Enzyme Stability; Escherichia coli; Gene Expression Regulation, Plant; Hydrogen-Ion Concentration; Methyltransferases; Molecular Sequence Data; Plant Proteins; Promoter Regions, Genetic; RNA, Plant; Sequence Analysis, DNA; Temperature; Tocopherols
PubMed: 21883249
DOI: 10.1111/j.1399-3054.2011.01507.x -
International Journal of Cancer Sep 2008Studies of vitamin E and cancer have focused on the alpha-tocopherol form of the vitamin. However, other forms of vitamin E, in particular gamma-tocopherol may have...
Studies of vitamin E and cancer have focused on the alpha-tocopherol form of the vitamin. However, other forms of vitamin E, in particular gamma-tocopherol may have unique mechanistic characteristics relevant to lung cancer prevention. In an ongoing study of 1,088 incident lung cancer cases and 1,414 healthy matched controls, we studied the associations between 4 tocopherols (alpha-, beta-, gamma-, and delta-tocopherol) in the diet and lung cancer risk. Using multiple logistic regression analysis, the adjusted odds ratios (OR) and 95% confidence intervals (CI) of lung cancer for increasing quartiles of dietary alpha-tocopherol intake were 1.0, 0.63 (0.50-0.79), 0.58 (0.44-0.76) and 0.39 (0.28-0.53), respectively (p-trend < 0.0001). For dietary intake of beta-tocopherol, the OR and 95% CI for all subjects were: 1.0, 0.79 (0.63-0.98), 0.59 (0.45-0.78) and 0.56 (0.42-0.74), respectively (p-trend < 0.0001). Similar results for dietary gamma-tocopherol intake were observed: 1.0, 0.84 (0.67-1.06), 0.76 (0.59-0.97) and 0.56 (0.42-0.75), respectively (p- trend = 0.0002). No significant association between delta-tocopherol intake and lung cancer risk was detected. When the 4 tocopherols were summed as total tocopherol intake, a monotonic risk reduction was also observed. When we entered the other tocopherols in our model, only the association with dietary alpha-tocopherol intake remained significant; i.e., increasing intake of dietary alpha-tocopherol accounted for 34-53% reductions in lung cancer risk. To the best of our knowledge, this is the first report of the independent associations of the 4 forms of dietary tocopherol (alpha-, beta-, gamma- and delta-tocohperol) on lung cancer risk. Given the limitations with case-control studies, these findings need to be confirmed in further investigations.
Topics: Adenocarcinoma; Adult; Aged; Antioxidants; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Case-Control Studies; Dietary Supplements; Female; Humans; Logistic Models; Lung Neoplasms; Male; Middle Aged; Odds Ratio; Risk Assessment; Risk Factors; Tocopherols; United States; alpha-Tocopherol; beta-Tocopherol; gamma-Tocopherol
PubMed: 18546288
DOI: 10.1002/ijc.23649 -
In Vivo (Athens, Greece) 2006Despite a large number of previous studies, the mechanism of free radical interaction between vitamin E (VE) (alpha-, beta-, gamma- and delta-tocopherol) and ascorbate...
Despite a large number of previous studies, the mechanism of free radical interaction between vitamin E (VE) (alpha-, beta-, gamma- and delta-tocopherol) and ascorbate or flavonoids as coantioxidants remains unclear. VE, particularly alpha-tocopherol, shows less antioxidant activity against peroxyl radicals, suggesting that VE possesses functions that are independent of its antioxidant/radical-scavenging activity. The synergistic antioxidant effect of VE or L-ascorbyl 2,6-dibutyrate (ASDB, an ascorbate derivative) with the flavonoids (-)-epicatechin (EC) and (-)-epigallocatechin gallate (EGCG) was investigated using the induction period method in the polymerization of methyl methacrylate initiated by thermal decomposition of benzoyl peroxide (an oxygen-centered radical, PhCOO*) under nearly anaerobic conditions. For delta-tocopherol, a synergistic antioxidant effect was observed in the presence of both EC and EGCG, whereas antioxidant activity for alpha-, beta- and gamma-tocopherol was decreased by addition of EC and EGCG. This suggested that the partial regeneration between VE and flavonoids may depend on the chemical structure of VE, i.e., monomethyl, dimethyl, or trimethyl tocol. The regeneration of delta-tocopherol, a monomethyl tocol, by flavonoids may be due to the lower steric effect of tocol. For ASDB, regeneration of vitamin E, which is well-known for a VE/ascorbate mixture, was not observed, possibly due to the anaerobic experimental conditions. The radical interaction between VE and EC, EGCG or ASDB suggests reactivity of VE with biological systems.
Topics: Anaerobiosis; Antioxidants; Ascorbic Acid; Benzoyl Peroxide; Calorimetry, Differential Scanning; Catechin; Flavonoids; Free Radical Scavengers; Free Radicals; Kinetics; Methylmethacrylate; Molecular Structure; Polymers; Tocopherols; Vitamin E
PubMed: 17203774
DOI: No ID Found -
Journal of Cardiovascular Pharmacology May 2002Intake of vitamin E with food (mixed tocopherols) has been found to counteract the development of atherosclerotic cardiovascular disease, whereas intake of large amounts... (Comparative Study)
Comparative Study
Intake of vitamin E with food (mixed tocopherols) has been found to counteract the development of atherosclerotic cardiovascular disease, whereas intake of large amounts of pure alpha-tocopherol has shown only a slight or no effect in clinical studies. This study was designed to investigate the effects of alpha-tocopherol alone and a mixed tocopherol preparation (gamma-, delta-, and alpha-tocopherol) on hydrogen peroxide-induced lipid peroxidation in human erythrocytes. Erythrocytes were incubated with different concentrations of alpha-tocopherol or mixed tocopherols and then exposed to hydrogen peroxide. Tocopherol levels and malondialdehyde-thiobarbituric acid-reactive substances were determined by high-performance liquid chromatography and fatty acids by gas chromatography. Incubation of erythrocytes with tocopherols (30-120 microM) increased the tocopherol level in a concentration-dependent manner. The uptake of gamma- and delta-tocopherols was much higher than that of alpha-tocopherol. Hydrogen peroxide strongly increased lipid peroxidation and decreased polyunsaturated fatty acids in erythrocytes. Both alpha-tocopherol and the tocopherol mixture protected the cells from lipid peroxidation, the mixture being much more potent than alpha-tocopherol alone. This study indicates that a mixture of tocopherols has a stronger inhibitory effect on lipid peroxidation induced in human erythrocytes than alpha-tocopherol alone, due to higher uptake of gamma- and delta-tocopherol in the cells.
Topics: Adult; Analysis of Variance; Antioxidants; Dose-Response Relationship, Drug; Erythrocytes; Humans; Lipid Peroxidation; Middle Aged; Pharmaceutical Solutions; Tocopherols; alpha-Tocopherol
PubMed: 11973415
DOI: 10.1097/00005344-200205000-00012 -
Evidence-based Complementary and... 2022Uremic pruritus is a frequent and prominent symptom in patients with advanced or end-stage renal disease. Lack of an effective treatment for kidney disease-associated... (Review)
Review
Uremic pruritus is a frequent and prominent symptom in patients with advanced or end-stage renal disease. Lack of an effective treatment for kidney disease-associated pruritus often leads to many problems for these patients and makes it difficult to choose an appropriate treatment. The purpose of this evidence-based hypothesis is to share the scientific reasons and related mechanisms in order to claim that lettuce could be useful in the treatment of uremic pruritus. This hypothesis is based on studies related to lettuce and its anti-inflammatory, antioxidant, antidiabetic, sedative, hypnotic, nephroprotective, potassium balancing, and blood purification properties. As a result, we suggest that lettuce could be a good choice for improving and reducing uremic pruritus due to its certain characteristics. Although proof of this hypothesis requires further clinical trial studies, this hypothesis can nevertheless lead to formulating an appropriate therapy for uremic-induced pruritus. By conducting a molecular docking study, we investigated the interactions between nineteen natural bioactive components of lettuce () and human kappa opioid receptors. The docking studies revealed that most of the ligands showed better antipruritic efficacy than gabapentin. Gamma-tocopherol, delta-tocopherol, and campesterol demonstrated the highest binding affinities toward the target protein.
PubMed: 35392648
DOI: 10.1155/2022/4231854