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Getoff N. Vitamin-induced intracellular electrons are the mechanism for their well-known beneficial effects: a review. Nutrition 2013; 29:597-604. [PMID: 23306138 DOI: 10.1016/j.nut.2012.09.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 08/27/2012] [Accepted: 09/10/2012] [Indexed: 10/27/2022]
Abstract
A new conception of the action mechanisms of vitamins and some other compounds without a vitamin status is briefly presented. It is based on results obtained through pulse radiolysis, molecular radiation biological investigations, and in vitro studies. The data clearly show that antioxidant vitamins (C, E, β-carotene) and B vitamins and related compounds possess the capability to emit "solvated electrons" in aqueous solutions or polar media. In consequence, the well-known vitamin effects are attributed to the action of the emitted solvated electrons and the resulting vitamin free radicals rather than the vitamin molecules per se, as generally accepted.
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Affiliation(s)
- Nikola Getoff
- Section of Radiation Biology, Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria.
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Getoff N, Hartmann J, Huber JC, Quint RM. Photo-induced electron emission from 17beta-estradiol and progesterone and possible biological consequences. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2008; 92:38-41. [PMID: 18499468 DOI: 10.1016/j.jphotobiol.2008.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 03/31/2008] [Accepted: 04/07/2008] [Indexed: 12/23/2022]
Abstract
It was established for the first time, that the sexual hormones 17beta-estradiol (17betaE2) and progesterone (PRG) are able to emit electrons from their excited single state in water-ethanol mixtures. The yield of the "solvated electrons" (e(s)(-)) depends on the substrate concentration, the ratio of water-alcohol-mixtures and the temperature. The e(s)(-) yield obtained from 17betaE2 is by two orders of magnitude higher than this of PRG. The possible relationship of the resulting hormone transients from 17betaE2 leading via specific metabolites to breast cancer is discussed.
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Affiliation(s)
- Nikola Getoff
- Department of Nutritional Sciences, Section Radiation Biology, The University of Vienna, A-1090 Vienna, Althanstrasse 14, UZAII, Austria.
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Hughes JL, Smith P, Pace R, Krausz E. Charge separation in photosystem II core complexes induced by 690-730 nm excitation at 1.7 K. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:841-51. [PMID: 16859635 DOI: 10.1016/j.bbabio.2006.05.035] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 05/01/2006] [Accepted: 05/22/2006] [Indexed: 11/24/2022]
Abstract
The illumination of oxygen-evolving PSII core complexes at very low temperatures in spectral regions not expected to excite P680 leads to charge separation in a majority of centers. The fraction of centers photoconverted as a function of the number of absorbed photons per PSII core is determined by quantification of electrochromic shifts on Pheo(D1). These shifts arise from the formation of metastable plastoquinone anion (Q(A)(-)) configurations. Spectra of concentrated samples identify absorption in the 700-730 nm range. This is well beyond absorption attributable to CP47. Spectra in the 690-730 nm region can be described by the 'trap' CP47 absorption at 689 nm, with dipole strength of approximately 1 chlorophyll a (chl a), partially overlapping a broader feature near 705 nm with a dipole strength of approximately 0.15 chl a. This absorption strength in the 700-730 nm region falls by 40% in the photoconverted configuration. Quantum efficiencies of photoconversion following illumination in the 690-700 nm region are similar to those obtained with green illumination but fall significantly in the 700-730 nm range. Two possible assignments of the long-wavelength absorption are considered. Firstly, as a low intensity component of strongly exciton-coupled reaction center chlorin excitations and secondly as a nominally 'dark' charge-transfer excitation of the 'special pair' P(D1)-P(D2). The opportunities offered by these observations towards the understanding of the nature of P680 and PSII fluorescence are discussed.
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Affiliation(s)
- Joseph L Hughes
- Research School of Chemistry, Australian National University, Canberra
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Wohlleben W, Buckup T, Hashimoto H, Cogdell RJ, Herek JL, Motzkus M. Pump−Deplete−Probe Spectroscopy and the Puzzle of Carotenoid Dark States. J Phys Chem B 2004. [DOI: 10.1021/jp036145k] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wendel Wohlleben
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany, Department of Physics, Osaka City University, Osaka 558-8585, Japan, Institute of Biomedical and Life Sciences (IBLS), University of Glasgow, Glasgow G12 8QQ, United Kingdom, and FOMInstitute for Atomic and Molecular Physics, 1098 SJ Amsterdam, The Netherlands
| | - Tiago Buckup
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany, Department of Physics, Osaka City University, Osaka 558-8585, Japan, Institute of Biomedical and Life Sciences (IBLS), University of Glasgow, Glasgow G12 8QQ, United Kingdom, and FOMInstitute for Atomic and Molecular Physics, 1098 SJ Amsterdam, The Netherlands
| | - Hideki Hashimoto
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany, Department of Physics, Osaka City University, Osaka 558-8585, Japan, Institute of Biomedical and Life Sciences (IBLS), University of Glasgow, Glasgow G12 8QQ, United Kingdom, and FOMInstitute for Atomic and Molecular Physics, 1098 SJ Amsterdam, The Netherlands
| | - Richard J. Cogdell
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany, Department of Physics, Osaka City University, Osaka 558-8585, Japan, Institute of Biomedical and Life Sciences (IBLS), University of Glasgow, Glasgow G12 8QQ, United Kingdom, and FOMInstitute for Atomic and Molecular Physics, 1098 SJ Amsterdam, The Netherlands
| | - Jennifer L. Herek
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany, Department of Physics, Osaka City University, Osaka 558-8585, Japan, Institute of Biomedical and Life Sciences (IBLS), University of Glasgow, Glasgow G12 8QQ, United Kingdom, and FOMInstitute for Atomic and Molecular Physics, 1098 SJ Amsterdam, The Netherlands
| | - Marcus Motzkus
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany, Department of Physics, Osaka City University, Osaka 558-8585, Japan, Institute of Biomedical and Life Sciences (IBLS), University of Glasgow, Glasgow G12 8QQ, United Kingdom, and FOMInstitute for Atomic and Molecular Physics, 1098 SJ Amsterdam, The Netherlands
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Ortmann EK, Mayerhofer T, Getoff N, Kodym R. Effect of Antioxidant Vitamins on Radiation-Induced Apoptosis in Cells of a Human Lymphoblastic Cell Line. Radiat Res 2004; 161:48-55. [PMID: 14680397 DOI: 10.1667/rr3102] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Modulating the amount of radiation-induced apoptosis by administering antioxidant vitamins offers a possible way to influence radiation-induced side effects in normal tissues. Therefore, we investigated the effect of beta-carotene, vitamin C and alpha-tocopherol on radiation-induced apoptosis in cells in culture. Human T-lymphoblastic MOLT-3 cells were irradiated with a dose of 3 Gy 1 h after or immediately prior to the addition of vitamins in three concentrations (0.01 microM, 1 microM and 100 microM). Eight hours later, apoptosis was scored morphologically by staining the nuclear DNA with Hoechst 33342. When given prior to irradiation, beta-carotene and vitamin E reduced the amount of radiation-induced apoptosis significantly at concentrations of 0.01 microM and 1 microM. In contrast, vitamin C did not show any protective effect when given at these two concentrations and caused a slight but significant radiosensitization at 100 microM. At 0.01 microM, all combinations of two vitamins showed a protective effect. This was also observed for the combination of all three vitamins at concentrations of 0.01 and 1 microM. When given immediately after irradiation, each of the three vitamins showed a protective effect at 0.01 microM. In addition, the combination of alpha-tocopherol and vitamin C reduced radiation-induced apoptosis slightly when given at 1 microM. In all other cases, no statistically significant modulation of radiation-induced apoptosis was observed. In our experimental system, the protective effect of beta-carotene and vitamin E was dependent on concentration and occurred only in the micromolar and sub-micromolar concentration range, while vitamin C alone, but not in combinations, had a sensitizing effect, thus arguing for a careful consideration of vitamin concentrations in clinical settings.
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Affiliation(s)
- Elisabeth K Ortmann
- Department of Radiobiology, Clinic for Radiotherapy and Radiobiology General Hospital Vienna, The University of Vienna, Austria
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Naqvi KR, Melø TB, Sliwka HR, Mohamad SBB, Partali V. Photochemical and photophysical behaviour of vitamin E: interaction of its long-lived transient photoproducts with carotenoids. Photochem Photobiol Sci 2003; 2:381-5. [PMID: 12760534 DOI: 10.1039/b210972g] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multi-channel, flash kinetic spectroscopy with microsecond time resolution has been used for investigating the interactions between carotenoids and the following photoproducts of alpha-tocopherol (EH) in hexane, methanol, acetonitrile, and dimethyl sulfoxide: (a) the lowest triplet, (b) the tocopherol radical cation, which could be seen only in the polar aprotic solvents acetonitrile and dimethyl sulfoxide, and (c) the neutral tocopheroxyl radical. The first two species reconvert to EH by transferring triplet excitation and positive charge (respectively) to the carotenoid; the third is unreactive. The relevance of these observations to photoprotection and the photoionisation of sterically hindered phenols is pointed out.
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Affiliation(s)
- K Razi Naqvi
- Department of Physics, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway.
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