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Groeneveld I, Ariese F, Somsen GW, van Bommel MR. Gas-permeable liquid-core waveguide coupled to LC-MS for studying the influence of oxygen on photodegradation processes. J Photochem Photobiol A Chem 2023. [DOI: 10.1016/j.jphotochem.2023.114685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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Tang P, Ji B, Sun G. Stabilization of flavin mononucleotide by capturing its "tail" with porous organic polymers for long-term photocatalytic degradation of micropollutants. JOURNAL OF HAZARDOUS MATERIALS 2022; 435:128982. [PMID: 35472536 PMCID: PMC11045341 DOI: 10.1016/j.jhazmat.2022.128982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/11/2022] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
Flavin mononucleotide (FMN) produces photo-induced reactive oxygen species (ROS), making it a bio-based and sustainable photosensitizer for micropollutant degradation. However, the rapid self-degradation of FMN under light poses challenges in practical applications. We propose for the first time to use porous organic polymer (POP) structures as particles and in situ grown on nanofibrous membranes to capture the ribityl side chain ("tail") of FMN by electrostatic-driven guest-host interaction. By restraining the free bending mode of FMN in POP, its self-degradation is highly inhibited, showing a prolonged half-life (102.7 and 79.7 times to that in solution and in β-cyclodextrin, respectively) without any impact on the ROS production even after 16 h of UVA irradiation. As a proof-of-concept, the photocatalytic degradation efficiency of FMN-POP complexes can be achieved at 58-93% against micropollutants under UVA. The stabilization of FMN by the "tail" capture in the POP allows its photocatalytic degradation function to be continuously online.
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Affiliation(s)
- Peixin Tang
- Department of Biological and Agricultural Engineering, University of California Davis, CA 95616, USA
| | - Bolin Ji
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China
| | - Gang Sun
- Department of Biological and Agricultural Engineering, University of California Davis, CA 95616, USA.
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Lima AR, da Silva CM, Caires CSA, Chaves H, Pancrácio AS, de Arruda EJ, Caires ARL, Oliveira SL. Photoinactivation of Aedes aegypti larvae using riboflavin as photosensitizer. Photodiagnosis Photodyn Ther 2022; 39:103030. [PMID: 35872352 DOI: 10.1016/j.pdpdt.2022.103030] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/08/2022] [Accepted: 07/20/2022] [Indexed: 10/17/2022]
Abstract
More than half of the global population lives in areas where the Aedes aegypti mosquito is present. Efforts have been made to deal with the population of this mosquito in the larval and adult stages to prevent outbreaks of diseases (Dengue, Zika, Chikungunya, and Yellow Fever). In this scenario, photodynamic inactivation may be an effective alternative method to control this vector population. To evaluate the efficacy of the riboflavin - B2 vitamin - as photosensitizer (PS) in the photodynamic inactivation of Ae. aegypti larvae, different concentrations (0; 0.005; 0.010; 0.025; 0.050; 0.075 and 0.100 mg mL-1) were evaluated under white light from RGB LEDs at a light dose of 495.2 J cm-2. The results reveal that riboflavin can be successfully applied as a PS agent to photoinactivate Ae. aegypti larvae, showing its potential to deal with the larvae population.
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Affiliation(s)
- A R Lima
- Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, Campo Grande, MS 79070-900, Brazil; São Carlos Institute of Physics, University of São Paulo, São Carlos 13566-590, Brazil.
| | - C M da Silva
- Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, Campo Grande, MS 79070-900, Brazil
| | - C S A Caires
- Grupo de Espectroscopia e Bioinformática Aplicados a Biodiversidade e a Saúde, Faculdade de Medicina, CP 549, Campo Grande, MS 79070-900, Brazil
| | - H Chaves
- Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, Campo Grande, MS 79070-900, Brazil
| | - A S Pancrácio
- Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, Campo Grande, MS 79070-900, Brazil
| | - E J de Arruda
- Faculdade de Ciências Exatas e Tecnologia, Universidade Federal da Grande Dourados, CP 533, Dourados, MS 79804-970, Brazil
| | - A R L Caires
- Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, Campo Grande, MS 79070-900, Brazil
| | - S L Oliveira
- Grupo de Óptica e Fotônica, Instituto de Física, Universidade Federal de Mato Grosso do Sul, CP 549, Campo Grande, MS 79070-900, Brazil.
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Beck F, Ilie N. Riboflavin and Its Effect on Dentin Bond Strength: Considerations for Clinical Applicability-An In Vitro Study. BIOENGINEERING (BASEL, SWITZERLAND) 2022; 9:bioengineering9010034. [PMID: 35049743 PMCID: PMC8772893 DOI: 10.3390/bioengineering9010034] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/10/2022] [Accepted: 01/10/2022] [Indexed: 11/30/2022]
Abstract
Bioactive collagen crosslinkers propose to render the dentin hybrid layer less perceptive to hydrolytic challenge. This study aims to evaluate whether bond strength of dental resin composite to dentin benefits from riboflavin (RB)-sensitized crosslinking when used in a clinically applicable protocol. A total of 300 human dentin specimens were prepared consistent with the requirements for a macro-shear bond test. RB was applied on dentin, either incorporated in the primer (RBp) of a two-step self-etch adhesive or as an aqueous solution (RBs) before applying the adhesive, and blue light from a commercial polymerization device was used for RB photoactivation. Bonding protocol executed according to the manufacturer’s information served as control. Groups (n = 20) were tested after 1 week, 1 month, 3 months, 6 months or 1 year immersion times (37 °C, distilled water). The different application methods of RB significantly influenced bond strength (p < 0.001) with a medium impact (η2p = 0.119). After 1 year immersion, post hoc analysis identified a significant advantage for RB groups compared to RBp (p = 0.018), which is attributed to a pH-/solvent-dependent efficiency of RB-sensitized crosslinking, stressing the importance of formulation adjustments. We developed an application protocol for RB-sensitized crosslinking with emphasis on clinical applicability to test its performance against a gold-standard adhesive, and are confident that, with a few adjustments to the application solution, RB-sensitized crosslinking can improve the longevity of adhesive restorations in clinics.
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Bera A, Hasan MN, Chatterjee A, Mukherjee D, Pal SK. Dual Sensitization via Electron and Energy Harvesting in a Nanohybrid for Improvement of Therapeutic Efficacy. ACS PHYSICAL CHEMISTRY AU 2021; 2:171-178. [PMID: 36855571 PMCID: PMC9718314 DOI: 10.1021/acsphyschemau.1c00033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We demonstrate experimental evidence of the effect of surface plasmon resonance of noble metal nanoparticles (NPs) on the activity of a well-known biomedicinal drug in the proximity of a semiconductor having a wide band gap for enhanced photodynamic therapy (PDT) efficacy. We have chosen riboflavin (Rf) (or vitamin B2) as a model photosensitizer, attached with ZnO NPs and further attached with gold (Au) NP-decorated ZnO to increase the efficiency. The synthesized nanohybrids are characterized with the help of different microscopic, optical spectroscopic, and density functional theory (DFT)-based techniques. The DFT and time-dependent DFT-based calculations validate the experimental findings. A detailed ultrafast spectroscopic study has been carried out further to study the excited-state charge dynamics in the interface of the nanohybrids. The occurrence of a Förster resonance energy transfer (FRET) between Rf and Au has been found to be the key reason for the increased efficiency in the Rf-ZnO-Au nanohybrid over the Rf-ZnO one. The dipolar coupling between Au and Rf in the Rf-ZnO-Au nanohybrid further facilitates the generation of reactive oxygen species (ROS) in comparison to Rf-ZnO under blue-light irradiation. The greater efficiency in ROS generation by the Rf-ZnO-Au nanohybrid has been utilized for antimicrobial action against methicillin-resistant S. aureus (MRSA). Overall, the present study highlights the dual sensitization for achieving enhanced electron injection efficiency in the Rf-ZnO-Au nanohybrid in order to use it as an antibacterial agent that could be translated in PDT.
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Chalimeswamy A, Thanuja MY, Ranganath SH, Pandya K, Kompella UB, Srinivas SP. Oxidative Stress Induces a Breakdown of the Cytoskeleton and Tight Junctions of the Corneal Endothelial Cells. J Ocul Pharmacol Ther 2021; 38:74-84. [PMID: 34818079 DOI: 10.1089/jop.2021.0037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose: To investigate the impact of oxidative stress, which is a hallmark of Fuchs dystrophy, on the barrier function of the corneal endothelial cells. Methods: Experiments were carried out with cultured bovine and porcine corneal endothelial cells. For oxidative stress, cells were supplemented with riboflavin (Rf) and exposed to UV-A (15-30 min) to induce Type-1 photochemical reactions that release H2O2. The effect of the stress on the barrier function was assayed by transendothelial electrical resistance (TER) measurement. In addition, the associated changes in the organization of the microtubules, perijunctional actomyosin ring (PAMR), and ZO-1 were evaluated by immunocytochemistry, which was also repeated after direct exposure to H2O2 (100 μM, 1 h). Results: Exposure to H2O2 led to the disassembly of microtubules and the destruction of PAMR. In parallel, the contiguous locus of ZO-1 was disrupted, marking a loss of barrier integrity. Accordingly, a sustained loss in TER was induced when cells in the Rf-supplemented medium were exposed to UV-A. However, the addition of catalase (7,000 U/mL) to rapidly decompose H2O2 limited the loss in TER. Furthermore, the adverse effects on microtubules, PAMR, and ZO-1 were suppressed by including catalase, ascorbic acid (1 mM; 30 min), or pretreatment with p38 MAP kinase inhibitor (SB-203580; 10 μM, 1 h). Conclusions: Acute oxidative stress induces microtubule disassembly by a p38 MAP kinase-dependent mechanism, leading to the destruction of PAMR and loss of barrier function. The response to oxidative stress is reminiscent of the (TNF-α)-induced breakdown of barrier failure in the corneal endothelium.
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Affiliation(s)
- Anupama Chalimeswamy
- Department of Biotechnology, Siddaganga Institute of Technology, Tumakuru, India.,Bio-INvENT Lab, Department of Chemical Engineering, Siddaganga Institute of Technology, Tumakuru, India
| | | | - Sudhir H Ranganath
- Bio-INvENT Lab, Department of Chemical Engineering, Siddaganga Institute of Technology, Tumakuru, India
| | - Kaveet Pandya
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Uday B Kompella
- Pharmaceutical Sciences, University of Colorado, Aurora, Colorado, USA
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Ofoedu CE, Iwouno JO, Ofoedu EO, Ogueke CC, Igwe VS, Agunwah IM, Ofoedum AF, Chacha JS, Muobike OP, Agunbiade AO, Njoku NE, Nwakaudu AA, Odimegwu NE, Ndukauba OE, Ogbonna CU, Naibaho J, Korus M, Okpala COR. Revisiting food-sourced vitamins for consumer diet and health needs: a perspective review, from vitamin classification, metabolic functions, absorption, utilization, to balancing nutritional requirements. PeerJ 2021; 9:e11940. [PMID: 34557342 PMCID: PMC8418216 DOI: 10.7717/peerj.11940] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 07/19/2021] [Indexed: 01/22/2023] Open
Abstract
The significant attention gained by food-sourced vitamins has provided insights into numerous current researches; for instance, the potential reversal of epigenetic age using a diet and lifestyle intervention, the balance between food and dietary supplements in the general population, the role of diet and food intake in age-related macular degeneration, and the association of dietary supplement use, nutrient intake and mortality among adults. As relevant literature about food-sourced vitamin increases, continuous synthesis is warranted. To supplement existing information, this perspective review discussed food-sourced vitamins for consumer diet and health needs, scoping from vitamin absorption, metabolic functions, utilization, to balancing nutritional requirements. Relevant literatures were identified through a search of databases like Google Scholar, Web of Science, the Interscience Online Library, ScienceDirect, and PubMed. We demonstrated that vitamins whether from plant- and animal-based sources are prerequisites for the metabolic functions of the human body. The fat- and water-soluble classification of vitamins remains consistent with their respective absorption and dissolution potentials, underpinned by numerous physiological functions. Vitamins, largely absorbed in the small intestine, have their bioavailability dependent on the food composition, its associated interactions, as well as alignment with their metabolic functions, which involves antioxidants, coenzymes, electron acceptor/donor, and hormones. Moreover, vitamin deficiencies, in every form, pose a serious threat to human health. Vitamin toxicities remain rare, but can still occur mainly from supplementation, although it appears much less in water-soluble vitamins of which some excesses get readily removed by the human body, different from the fat-soluble ones that are stored in tissues and organs. Besides discussions of absorption, transport, and cellular uptake of vitamins, this perspective review also included approaches to meeting vitamin requirements and therapeutic strategies against micronutrient deficiency and COVID-19. We have also attempted on how to strike the balance between food-sourced vitamins and dietary supplements.
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Affiliation(s)
- Chigozie E. Ofoedu
- Department of Food Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Jude O. Iwouno
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Ebelechukwu O. Ofoedu
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Chika C. Ogueke
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Victory S. Igwe
- Department of Food Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Ijeoma M. Agunwah
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Arinze F. Ofoedum
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - James S. Chacha
- Department of Food Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China
- Department of Food Technology, Nutrition, and Consumer Sciences, Sokoine University of Agriculture, Chuo Kikuu, Morogoro, Tanzania
| | - Onyinye P. Muobike
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Adedoyin O. Agunbiade
- Department of Food Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China
- Department of Food Science, University of Ibadan, Ibadan, Nigeria
| | - Njideka E. Njoku
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Angela A. Nwakaudu
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Nkiru E. Odimegwu
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Onyekachi E. Ndukauba
- Department of Food Science and Technology, Federal University of Technology, Owerri, Imo State, Nigeria
| | - Chukwuka U. Ogbonna
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Ogun, Nigeria
| | - Joncer Naibaho
- Faculty of Biotechnology and Food Science, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Maciej Korus
- Faculty of Biotechnology and Food Science, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
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Han D, He MN, Zhu Y, Zhang Y, Wei RH. Protective effects of riboflavin-UVA-mediated posterior sclera collagen cross-linking in a guinea pig model of form-deprived myopia. Int J Ophthalmol 2021; 14:333-340. [PMID: 33747806 DOI: 10.18240/ijo.2021.03.01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 12/21/2020] [Indexed: 01/17/2023] Open
Abstract
AIM To evaluate the effect of posterior sclera collagen cross-linking induced by riboflavin-ultraviolet A (UVA) on form-deprived myopia in guinea pigs. METHODES Twenty-five pigmented guinea pigs of 3-week-old were randomly assigned into 4 groups that included normal control (NOR, n=7), form-deprived (FDM, n=7), normal with riboflavin-UVA cross-linking (NOR+CL, n=5) and form-deprived with cross-linking (FDM+CL, n=6). The NOR+CL group and the FDM+CL group received the riboflavin-UVA induced cross-linking at day 0. FDM was induced by monocularly deprived with facemask in the right eyes. The refraction, axial length and corneal curvature were measured by retinoscopy, A-scan and keratometer respectively in scheduled time points (day 0 and 1, 2, 3, 4wk after form-deprivation). At the end of 4 weeks' experiment, stress-strain tests of sclera were measured and morphological changes of sclera and retina were examined. RESULTS After 4wk, the interocular difference of refractive error were -0.11±0.67, -2.93±0.56, 1.10±0.58, and -1.63±0.41 D in the NOR, FDM, NOR+CL, and FDM+CL groups respectively. Mixed-effect linear model revealed significant effect of FDM (P<0.01) and CL (P<0.001). Also, after 4wk, the interocular difference of axial length were 0.01±0.04, 0.29±0.07, -0.13±0.06, and 0.11±0.05 mm in the NOR, FDM, NOR+CL, and FDM+CL group. Mixed-effect linear model revealed significant effect of FDM (P<0.001) and CL (P<0.01). As for corneal curvature, significant interocular difference have not found between any of the two groups. At the end of this experiment, the ultimate stress and elastic modulus were found significantly increased in both CL groups. But no difference was found in the groups without cross-linked. There was no abnormality observed in the retina and RPE cells of the treated eyes. CONCLUSION The posterior sclera collagen cross-linking induced by riboflavin-UVA can slow down the progress of myopia and increase the sclera biomechanical strength in the guinea pig model of form-deprived myopia.
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Affiliation(s)
- Ding Han
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
| | - Mei-Nan He
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
| | - Ying Zhu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
| | - Yan Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
| | - Rui-Hua Wei
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 300384, China
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Karakurt I, Aydoğdu A, Çıkrıkcı S, Orozco J, Lin L. Stereolithography (SLA) 3D printing of ascorbic acid loaded hydrogels: A controlled release study. Int J Pharm 2020; 584:119428. [DOI: 10.1016/j.ijpharm.2020.119428] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/04/2020] [Accepted: 05/09/2020] [Indexed: 12/28/2022]
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Bergwik J, Åkerström B. α 1-Microglobulin Binds Illuminated Flavins and Has a Protective Effect Against Sublethal Riboflavin-Induced Damage in Retinal Epithelial Cells. Front Physiol 2020; 11:295. [PMID: 32300309 PMCID: PMC7142231 DOI: 10.3389/fphys.2020.00295] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/16/2020] [Indexed: 12/28/2022] Open
Abstract
Riboflavin (vitamin B2) is an important constituent of the prosthetic groups flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), which are utilized as electron-carriers in energy metabolism. Excitation by UV-light leads to the generation of riboflavin radicals and reactive oxygen species (ROS), which can oxidize a wide range of biomolecules. The human protein α1-microglobulin (A1M) is a reductase and a radical scavenger, which can protect cells and matrix against oxidative damage. Here, we provide evidence of a molecular interaction between illuminated riboflavin and A1M, similar to the radical scavenging reactions previously seen between A1M and other organic radicals. Binding between riboflavin and A1M was demonstrated by gel migration shift, UV-absorbance and fluorescence spectrum analysis. The reaction between A1M and UV-light illuminated riboflavin involved covalent modification of A1M and proteolytic release of an N-terminal part of the protein. Furthermore, A1M also inhibited the ROS-induced photoreduction reaction of riboflavin, in a reaction involving the free thiol group in position C34. Finally, the results show a protective effect of A1M, analyzed by gene expression rates of stress genes, against sublethal damage in retinal epithelial cells in culture. Together, our results suggest a new role of A1M as a scavenger of riboflavin radicals and ROS produced during illumination of riboflavin.
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Affiliation(s)
- Jesper Bergwik
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Bo Åkerström
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
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Anbaraki A, Ghahramani M, Muranov KO, Kurganov BI, Yousefi R. Structural and functional alteration of human αA-crystallin after exposure to full spectrum solar radiation and preventive role of lens antioxidants. Int J Biol Macromol 2018; 118:1120-1130. [PMID: 29964111 DOI: 10.1016/j.ijbiomac.2018.06.136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/06/2018] [Accepted: 06/26/2018] [Indexed: 12/31/2022]
Abstract
The chronically exposure of eye lenses to ultra violet and visible light of the solar radiation is an important risk factor for development of the senile cataract diseases. Various photosensitizer molecules including riboflavin (RF) play a significant role in photo-oxidative damages of lens proteins underlying development of opacity in the lenticular tissues. In the current study, RF-mediated photo-oxidation of human αA-crystallin (αA-Cry) was assessed using SDS-PAGE analysis, dynamic light scattering and other spectroscopic assessments. The RF-photosensitized reactions led to non-disulfide covalent cross-linking, oligomerization and significant structural changes in αA-Cry. The photo-damaging of αA-Cry under solar radiation was also accompanied by the reduction in both Trp and Tyr fluorescence intensities which followed by the formation of new photosensitizer chromophores. The solvent exposed hydrophobic patches, secondary structures and chaperone-like activity of αA-Cry were significantly altered after exposure to the solar radiation in the presence of RF. Although glutathione and ascorbate were capable to partially protect the photo-induced structural damages of human αA-Cry, they also disrupted its chaperone function when co-exposed with this protein to the solar radiation. Also, the most promising data were obtained with cysteine which its availability in the lenticular tissues is a rate limiting factor for the biosynthesis of glutathione. Overall our results suggest that glutathione and ascorbate, as the major anti-oxidant compounds within lenticular tissues, demonstrate controversial effect on structure and chaperone-like activity of human αA-Cry. Elucidation of this effect may demand further experiments.
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Affiliation(s)
- Afrooz Anbaraki
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Maryam Ghahramani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Konstantin O Muranov
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin str. 4, Moscow 119991, Russia
| | - Boris I Kurganov
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., Moscow 119071, Russia
| | - Reza Yousefi
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran.
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Cáceres J, Robinson-Duggon J, Tapia A, Paiva C, Gómez M, Bohne C, Fuentealba D. Photochemical behavior of biosupramolecular assemblies of photosensitizers, cucurbit[n]urils and albumins. Phys Chem Chem Phys 2018; 19:2574-2582. [PMID: 28059428 DOI: 10.1039/c6cp07749h] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biosupramolecular assemblies combining cucurbit[n]urils (CB[n]s) and proteins for the targeted delivery of drugs have the potential to improve the photoactivity of photosensitizers used in the photodynamic therapy of cancer. Understanding the complexity of these systems and how it affects the properties of photosensitizers is the focus of this work. We used acridine orange (AO+) as a model photosensitizer and compared it with methylene blue (MB+) and a cationic porphyrin (TMPyP4+). Encapsulation of the photosensitizers into CB[n]s (n = 7, 8) modified their photoactivity. In particular, for AO+, the photo-oxidation of HSA was enhanced in the presence of CB[7]; meanwhile it was decreased when included into CB[8]. Accordingly, peroxide generation and protein fragmentation were also increased when AO+ was encapsulated into CB[7]. The triplet excited state lifetimes of all the photosensitizers were lengthened by their encapsulation into CB[n]s, while the singlet oxygen quantum yield was enhanced only for AO+ and TMPyP4+, but it decreased for MB+. The results obtained in this work prompt the necessity of further investigating these kinds of hybrid assemblies as drug delivery systems because of their possible applications in biomedicine.
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Affiliation(s)
- Javiera Cáceres
- Laboratorio de Estructuras Biosupramoleculares, Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - José Robinson-Duggon
- Laboratorio de Estructuras Biosupramoleculares, Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Anita Tapia
- Laboratorio de Estructuras Biosupramoleculares, Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Constanza Paiva
- Laboratorio de Estructuras Biosupramoleculares, Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Matías Gómez
- Laboratorio de Estructuras Biosupramoleculares, Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Cornelia Bohne
- Department of Chemistry, University of Victoria, P.O. Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada
| | - Denis Fuentealba
- Laboratorio de Estructuras Biosupramoleculares, Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile.
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13
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Daidone I, Amadei A, Aschi M, Zanetti-Polzi L. On the nature of solvatochromic effect: The riboflavin absorption spectrum as a case study. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 192:451-457. [PMID: 29212059 DOI: 10.1016/j.saa.2017.11.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/27/2017] [Accepted: 11/14/2017] [Indexed: 06/07/2023]
Abstract
We present here the calculation of the absorption spectrum of riboflavin in acetonitrile and dimethyl sulfoxide using a hybrid quantum/classical approach, namely the perturbed matrix method, based on quantum mechanical calculations and molecular dynamics simulations. The calculated spectra are compared to the absorption spectrum of riboflavin previously calculated in water and to the experimental spectra obtained in all three solvents. The experimentally observed variations in the absorption spectra upon change of the solvent environment are well reproduced by the calculated spectra. In addition, the nature of the excited states of riboflavin interacting with different solvents is investigated, showing that environment effects determine a recombination of the gas-phase electronic states and that such a recombination is strongly affected by the polarity of the solvent inducing significant changes in the absorption spectra.
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Affiliation(s)
- Isabella Daidone
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio (Coppito 1), L'Aquila 67010, Italy
| | - Andrea Amadei
- Department of Chemical and Technological Sciences, University of Rome "Tor Vergata", Via della Ricerca Scientifica, 00185 Rome, Italy
| | - Massimiliano Aschi
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio (Coppito 1), L'Aquila 67010, Italy
| | - Laura Zanetti-Polzi
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio (Coppito 1), L'Aquila 67010, Italy.
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14
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15
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Qiu TA, Meyer BM, Christenson KG, Klaper RD, Haynes CL. A mechanistic study of TiO 2 nanoparticle toxicity on Shewanella oneidensis MR-1 with UV-containing simulated solar irradiation: Bacterial growth, riboflavin secretion, and gene expression. CHEMOSPHERE 2017; 168:1158-1168. [PMID: 27823777 DOI: 10.1016/j.chemosphere.2016.10.085] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 10/14/2016] [Accepted: 10/22/2016] [Indexed: 06/06/2023]
Abstract
Toxicity of nanomaterials to ecological systems has recently emerged as an important field of research, and thus, many researchers are exploring the mechanisms of how nanoparticles impact organisms. Herein, we probe the mechanisms of bacteria-nanoparticle interaction by investigating how TiO2 nanoparticles impact a model organism, the metal-reducing bacterium Shewanella oneidensis MR-1. In addition to examining the effect of TiO2 exposure, the effect of synergistic simulated solar irradiation containing UV was explored in this study, as TiO2 nanoparticles are known photocatalysts. The data reveal that TiO2 nanoparticles cause an inhibition of S. oneidensis growth at high dosage without compromising cell viability, yet co-exposure of nanoparticles and illumination does not increase the adverse effects on bacterial growth relative to TiO2 alone. Measurements of intracellular reactive oxygen species and riboflavin secretion, on the same nanoparticle-exposed bacteria, reveal that TiO2 nanoparticles have no effect on these cell functions, but application of UV-containing illumination with TiO2 nanoparticles has an impact on the level of riboflavin outside bacterial cells. Finally, gene expression studies were employed to explore how cells respond to TiO2 nanoparticles and illumination, and these results were correlated with cell growth and cell function assessment. Together these data suggest a minimal impact of TiO2 NPs and simulated solar irradiation containing UV on S. oneidensis MR-1, and the minimal impact could be accounted for by the nutrient-rich medium used in this work. These measurements demonstrate a comprehensive scheme combining various analytical tools to enable a mechanistic understanding of nanoparticle-cell interactions and to evaluate the potential adverse effects of nanoparticles beyond viability/growth considerations.
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Affiliation(s)
- Tian A Qiu
- Department of Chemistry, University of Minnesota, 207 Pleasant St SE, Minneapolis, MN 55455, United States
| | - Ben M Meyer
- Department of Chemistry, University of Minnesota, 207 Pleasant St SE, Minneapolis, MN 55455, United States
| | - Ky G Christenson
- Department of Chemistry, University of Minnesota, 207 Pleasant St SE, Minneapolis, MN 55455, United States
| | - Rebecca D Klaper
- School of Freshwater Sciences, University of Wisconsin Milwaukee, 600 E. Greenfield Ave, Milwaukee, WI 53204, United States
| | - Christy L Haynes
- Department of Chemistry, University of Minnesota, 207 Pleasant St SE, Minneapolis, MN 55455, United States.
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16
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Anbaraki A, Khoshaman K, Ghasemi Y, Yousefi R. Preventive role of lens antioxidant defense mechanism against riboflavin-mediated sunlight damaging of lens crystallins. Int J Biol Macromol 2016; 91:895-904. [DOI: 10.1016/j.ijbiomac.2016.06.047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/11/2016] [Accepted: 06/14/2016] [Indexed: 10/21/2022]
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17
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Metternich JB, Gilmour R. One Photocatalyst, n Activation Modes Strategy for Cascade Catalysis: Emulating Coumarin Biosynthesis with (-)-Riboflavin. J Am Chem Soc 2016; 138:1040-5. [PMID: 26714650 DOI: 10.1021/jacs.5b12081] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Generating molecular complexity using a single catalyst, where the requisite activation modes are sequentially exploited as the reaction proceeds, is an attractive guiding principle in synthesis. This requires that each substrate transposition exposes a catalyst activation mode (AM) to which all preceding or future intermediates are resistant. While this concept is exemplified by MacMillan's beautiful merger of enamine and iminium ion activation, examples in other fields of contemporary catalysis remain elusive. Herein, we extend this tactic to organic photochemistry. By harnessing the two discrete photochemical activation modes of (-)-riboflavin, it is possible to sequentially induce isomerization and cyclization by energy transfer (ET) and single-electron transfer (SET) activation pathways, respectively. This catalytic approach has been utilized to emulate the coumarin biosynthesis pathway, which features a key photochemical E → Z isomerization step. Since the ensuing SET-based cyclization eliminates the need for a prefunctionalized aryl ring, this constitutes a novel disconnection of a pharmaceutically important scaffold.
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Affiliation(s)
- Jan B Metternich
- Institute for Organic Chemistry, Westfälische Wilhelms-Universität Münster , Corrensstrasse 40, 48149 Münster, Germany
| | - Ryan Gilmour
- Institute for Organic Chemistry, Westfälische Wilhelms-Universität Münster , Corrensstrasse 40, 48149 Münster, Germany
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Riboflavin degradation in the presence of quercetin in methanol under continuous UV-B irradiation: the ESI–MS–UHPLC analysis. MONATSHEFTE FUR CHEMIE 2015. [DOI: 10.1007/s00706-015-1561-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Chaudhuri S, Sardar S, Bagchi D, Singha SS, Lemmens P, Pal SK. Sensitization of an Endogenous Photosensitizer: Electronic Spectroscopy of Riboflavin in the Proximity of Semiconductor, Insulator, and Metal Nanoparticles. J Phys Chem A 2015; 119:4162-9. [DOI: 10.1021/acs.jpca.5b03021] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Siddhi Chaudhuri
- Department
of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
| | - Samim Sardar
- Department
of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
| | - Damayanti Bagchi
- Department
of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
| | - Shib Shankar Singha
- Department
of Physics, Bose Institute, 93/1, Acharya Prafulla Chandra Road, Kolkata 700 009, India
| | | | - Samir Kumar Pal
- Department
of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
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Natera J, Gatica E, Challier C, Possetto D, Massad W, Miskoski S, Pajares A, García NA. On the photooxidation of the multifunctional drug niclosamide. A kinetic study in the presence of vitamin B2 and visible light. Redox Rep 2015; 20:259-66. [PMID: 25897629 DOI: 10.1179/1351000215y.0000000010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
OBJECTIVES The multifunctional drug niclosamide (NSD), extensively employed therapeutically, is a frequent pollutant of surface waters. Considering the environmental importance of photodegradative processes for this type of contaminant, the kinetic and mechanistic aspects of the possible visible-light-mediated photooxidation of NSD were studied under naturalistic conditions. METHODS The visible-light absorber riboflavin (vitamin B2) was employed as a photosensitizer. The vitamin can usually be found in natural waters and is the most common endogenous photosensitizer in mammals. The interaction of NSD with electronically excited states of Rf and with photogenerated reactive oxygen species (ROS) was evaluated through conventional UV spectroscopy, laser flash photolysis, time-resolved phosphorescence detection of singlet molecular oxygen (O2((1)Δg)), and polarographic dosage of dissolved oxygen. RESULTS Ground state NSD quenched the long-lived triplet excited state of Rf ((3)Rf*) and the photogenerated ROS (O2((1)Δg)) and superoxide radical anion (O2•−). As a result, NSD was photooxidized. The rate constants for the interaction NSD-O2((1)Δg) are particularly low, in the order of 10(6)/M/s, although the whole interaction is attributable to a pure reactive process. The O2((1)Δg) quenching was faster in alkaline medium, favored by the ionization of the NSD phenolic group. Under Rf-photosensitization, NSD was degraded very much more rapidly than phenol, the latter being considered a paradigmatic water-contaminant model compound. NSD may behave as an antioxidant in bio-environments, as demonstrated employing the photooxidizable amino acid tryptophan as a relevant biological target. DISCUSSION The results indicate that a O2•−-mediated process is the main route for the Rf-sensitized photooxidation of NSD. Photodegradation of the biocide in the presence and absence of phenol and tryptophan was quantitatively evaluated, discussed, and interpreted in terms of competitive quenching processes of (3)Rf*, O2((1)Δg), and O2•− by the substrates.
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Avila F, Friguet B, Silva E. Photosensitizing Activity of Endogenous Eye Lens Chromophores: An Attempt to Unravel Their Contributions to Photo-Aging and Cataract Disease. Photochem Photobiol 2015; 91:767-79. [DOI: 10.1111/php.12443] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/20/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Felipe Avila
- Escuela de Nutrición y Dietética; Facultad de Ciencias de la Salud; Universidad de Talca; Talca Chile
- Programa de Investigación de Excelencia Interdisciplinario en Envejecimiento Saludable (PIEI-ES); Universidad de Talca; Talca Chile
| | - Bertrand Friguet
- UPMC Univ. Paris 06; CNRS UMR 8256; INSERM U1164; Adaptation Biologique et Vieillissement; Institute of Biology Paris-Seine; Paris France
| | - Eduardo Silva
- Departamento de Química Física; Facultad de Química; Pontifícia Universidad Católica de Chile; Santiago Chile
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22
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Chaudhuri S, Batabyal S, Polley N, Pal SK. Vitamin B2 in Nanoscopic Environments under Visible Light: Photosensitized Antioxidant or Phototoxic Drug? J Phys Chem A 2014; 118:3934-43. [DOI: 10.1021/jp502904r] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Siddhi Chaudhuri
- Department
of Chemical, Biological
and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
| | - Subrata Batabyal
- Department
of Chemical, Biological
and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
| | - Nabarun Polley
- Department
of Chemical, Biological
and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
| | - Samir Kumar Pal
- Department
of Chemical, Biological
and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
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Grippa JM, de Zawadzki A, Grossi AB, Skibsted LH, Cardoso DR. Riboflavin photosensitized oxidation of myoglobin. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:1153-1158. [PMID: 24456528 DOI: 10.1021/jf405182f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The reaction of the fresh meat pigment oxymyoglobin, MbFe(II)O₂, and its oxidized form metmyoglobin, MbFe(III), with triplet-state riboflavin involves the pigment protein, which is oxidatively cleaved or dimerized as shown by SDS-PAGE and Western blotting. The overall rate constant for oxidation of MbFe(II)O₂ by ³Rib is (3.0 ± 0.5) × 10⁹ L·mol⁻¹·s⁻¹ and (3.1 ± 0.4) × 10⁹ L·mol⁻¹·s⁻¹ for MbFe(III) in phosphate buffer of pH 7.4 at 25 °C as determined by laser flash photolysis. The high rates are rationalized by ground state hydrophobic interactions as detected as static quenching of fluorescence from singlet-excited state riboflavin by myoglobins using time-resolved fluorescence spectroscopy and a Stern-Volmer approach. Binding of riboflavin to MbFe(III) has K(a) = (1.2 ± 0.2) × 10⁴ mol·L⁻¹ with ΔH° = -112 ± 22 kJ·mol⁻¹ and ΔS° = -296 ± 75 J·mol⁻¹·K⁻¹. For meat, riboflavin is concluded to be a photosensitizer for protein oxidation but not for discoloration.
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Affiliation(s)
- Juliana M Grippa
- Instituto de Química de São Carlos, Universidade de São Paulo , Av. Trabalhador São Carlense 400, CP 780, CEP 13560-970, São Carlos, SP, Brazil
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Montaña MP, Ferrari G, Gatica E, Natera J, Massad W, García NA. Mutual effects between aromatic amino acids and guanosine upon vitamin B2 photosensitization in the presence of visible light. CAN J CHEM 2013. [DOI: 10.1139/cjc-2012-0251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Considering the importance of the visible-light-induced photodynamic effect in complex bioenvironments, mutual effects between the individual aromatic amino acids (AAs) tyrosine (Tyr), tryptophan (Trp), and histidine (His) and the nucleoside guanosine (GUO) were investigated in pH 7 aqueous solution with vitamin B2 (riboflavin (Rf)) as a dye sensitizer. The quantum yields of oxygen uptake (Φ–O2) for most of the AA−GUO mixtures studied, taken as a measure of overall photooxidation susceptibility, are not straightforwardly predictable from the individual behaviour of the components of the mixture. The final result depends on several connected factors, such as the respective abilities of the substrates as quenchers of the long-lived Rf triplet excited state and the generated reactive oxygen species singlet molecular oxygen (O2(1Δg)) and superoxide radical anion ([Formula: see text]). A mechanistic interpretation of the Rf-sensitized results can be roughly resumed as follows: Tyr at pH 7 exerts a protective effect on the photooxidation of the mixture Tyr−GUO due to the O2(1Δg) physical quenching by the AA. The same effect was observed for Trp−GUO and His−GUO at pH 7. In these cases, it is attributed to the quenching of3Rf* by GUO in detriment of the Type II route. For the system Tyr−GUO at pH 9, a marked decrease in the Φ–O2occurred for the mixture as compared with the respective Φ–O2for the individual components. It was ascribed to the participation of a radical-mediated mechanism without oxygen consumption in a competitive pathway with the [Formula: see text]-mediated route.
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Affiliation(s)
- M. Paulina Montaña
- Area de Química Física-INQUISAL (CONICET-Universidad Nacional de San Luis), 5700 San Luis, Argentina
| | - Gabriela Ferrari
- Area de Química Física-INQUISAL (CONICET-Universidad Nacional de San Luis), 5700 San Luis, Argentina
| | - Eduardo Gatica
- Facultad de Agronomía y Veterinaria, Universidad Nacional de Río Cuarto, 5800 Río Cuarto, Argentina
| | - José Natera
- Facultad de Agronomía y Veterinaria, Universidad Nacional de Río Cuarto, 5800 Río Cuarto, Argentina
| | - Walter Massad
- Departamento de Química, Universidad Nacional de Río Cuarto, 5800 Río Cuarto, Argentina
| | - Norman A. García
- Departamento de Química, Universidad Nacional de Río Cuarto, 5800 Río Cuarto, Argentina
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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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OLIVEIRA LUCIANASIQUEIRA, MOURA CARLOSFARLEYHERBSTER, BRITO EDYSOUSA, FERNANDES FABIANOANDRENARCISO, MIRANDA MARIARAQUELALCANTARA. QUALITY CHANGES AND ANTHOCYANIN AND VITAMIN C DECAY RATES OF FROZEN ACEROLA PURÉE DURING LONG-TERM STORAGE. J FOOD PROCESS PRES 2012. [DOI: 10.1111/j.1745-4549.2011.00610.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Cardoso DR, Libardi SH, Skibsted LH. Riboflavin as a photosensitizer. Effects on human health and food quality. Food Funct 2012; 3:487-502. [DOI: 10.1039/c2fo10246c] [Citation(s) in RCA: 173] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Ahmad I, Sheraz MA, Ahmed S, Bano R, Vaid FHM. Photochemical interaction of ascorbic acid with riboflavin, nicotinamide and alpha-tocopherol in cream formulations. Int J Cosmet Sci 2011; 34:123-31. [DOI: 10.1111/j.1468-2494.2011.00690.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Shapira N. Nutritional approach to sun protection: a suggested complement to external strategies. Nutr Rev 2010; 68:75-86. [PMID: 20137053 DOI: 10.1111/j.1753-4887.2009.00264.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The increasing incidence of skin cancer despite the use of externally applied sun protection strategies, alongside research showing that nutrients reduce photo-oxidative damage, suggest nutritional approaches could play a beneficial role in skin cancer prevention. Penetrating photo-oxidative ultraviolet A radiation reduces skin and blood antioxidants and damages cell components, including DNA. Dietary antioxidant vitamins, minerals, and phytochemicals in addition to n-3 polyunsaturated fatty acids, n-9 monounsaturated fatty acids, and low pro-inflammatory n-6 polyunsaturated fatty acids, have demonstrated protective properties. The presence of these elements in the traditional Greek-style Mediterranean diet may have contributed to the low rates of melanoma in the Mediterranean region despite high levels of solar radiation. This suggests a potentially relevant model for studying dietary/nutritional supplementation for lifelong internal support of sun-protection mechanisms, which could complement external strategies.
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Affiliation(s)
- Niva Shapira
- Stanley Steyer School of Health Professions, Tel Aviv University, Tel Aviv, Israel.
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30
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Yettella RR, Min DB. Effects of Trolox and ascorbic acid on the riboflavin photosensitised oxidation of aromatic amino acids. Food Chem 2010. [DOI: 10.1016/j.foodchem.2009.04.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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31
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Huvaere K, Skibsted LH. Light-Induced Oxidation of Tryptophan and Histidine. Reactivity of Aromatic N-Heterocycles toward Triplet-Excited Flavins. J Am Chem Soc 2009; 131:8049-60. [DOI: 10.1021/ja809039u] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kevin Huvaere
- Food Chemistry, Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
| | - Leif H. Skibsted
- Food Chemistry, Department of Food Science, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
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Wollensak G, Iomdina E. Long-term biomechanical properties of rabbit sclera after collagen crosslinking using riboflavin and ultraviolet A (UVA). Acta Ophthalmol 2009; 87:193-8. [PMID: 18803623 DOI: 10.1111/j.1755-3768.2008.01229.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE Scleral crosslinking by the photosensitizer riboflavin and ultraviolet A (UVA) has been shown to increase significantly the scleral biomechanical rigidity and might therefore become a possible sclera-based treatment modality for progressive myopia. In the present study, the long-term effect of the new crosslinking method on biomechanical properties was investigated in the rabbit sclera. METHODS A 10 x 10 mm sector of the equatorial sclera of nine Chinchilla rabbit eyes was treated in vivo using a UVA double diode of 370 nm with a surface irradiance of 3 mW/cm(2) and application of 0.1% riboflavin-5-phosphate drops as photosensitizer for 30 min. Three days, 4 months and 8 months postoperatively, biomechanical stress-strain measurements of the treated scleral strips were performed and compared to contralateral control sclera using a microcomputer-controlled biomaterial tester. In addition, routine histological controls were performed. RESULTS Following the crosslinking treatment, Young's modulus was increased by 320% after 3 days, 277% after 4 months and 502% after 8 months, and ultimate stress by 341% after 3 days, 131% after 4 months and 213.8% after 8 months versus the controls. The decrease in ultimate strain was between 24% and 44.8%. On histology, no tissue damage was detected. CONCLUSION Our new method of scleral collagen crosslinking proved very effective and constant over a time interval of up to 8 months in increasing the scleral biomechanical strength. Therefore, the new treatment might become an option for strengthening scleral tissue in progressive myopia and other conditions associated with weakened sclera. There were no side-effects on the retina or retinal pigment epithelium. The new crosslinking treatment could now be tested in a suitable myopia model (like the tree shrew) and finally in human eyes.
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Affiliation(s)
- Gregor Wollensak
- Department of Ophthalmology, Martin-Luther-University, Halle, Germany.
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Zhu H, Chen S, Yao S, Wang W. Protective effect of melatonin on photo-damage to lysozyme. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2009; 94:125-30. [DOI: 10.1016/j.jphotobiol.2008.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 11/18/2008] [Accepted: 11/18/2008] [Indexed: 11/29/2022]
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Yettella RR, Min DB. Quenching mechanisms and kinetics of Trolox and ascorbic acid on the riboflavin-photosensitized oxidation of tryptophan and tyrosine. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:10887-10892. [PMID: 18975971 DOI: 10.1021/jf8006739] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The effects of 0, 0.3, 0.6, and 0.9 mM Trolox and ascorbic acid on the singlet oxygen oxidation of tryptophan and tyrosine containing 25 ppm of riboflavin were determined by measuring tryptophan and tyrosine concentration by high-performance liquid chromatography analysis. The samples were stored in the a 1000 lx light storage box for 4 h at 30 degrees C. As the concentration of Trolox and ascorbic acid increased, the degradation of tryptophan and tyrosine decreased significantly at p < 0.05. Trolox reduced tryptophan and tyrosine degradation by quenching both singlet oxygen and excited triplet riboflavin, whereas ascorbic acid quenched singlet oxygen only. The total singlet oxygen quenchings of Trolox in the presence of tryptophan and tyrosine were 1.55 x 10(7) and 1.32 x 10(7) M(-1) s(-1), respectively. The total singlet oxygen quenchings of ascorbic acid in the presence of tryptophan and tyrosine were 1.16 x 10(7) and 1.10 x 10(7) M(-1) s(-1), respectively. Trolox was more effective than ascorbic acid in preventing the degradation of tryptophan and tyrosine.
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Affiliation(s)
- Ramesh R Yettella
- Department of Food Science and Technology, The Ohio State University, Columbus, Ohio 43210, USA
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35
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Chignell CF, Sik RH, Bilski PJ. The Photosensitizing Potential of Compact FluorescentvsIncandescent Light Bulbs. Photochem Photobiol 2008; 84:1291-3. [DOI: 10.1111/j.1751-1097.2008.00366.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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36
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Quenching Reactions of Triplet State Riboflavin by Vitamin C: A Theoretical Investigation. J AM OIL CHEM SOC 2008. [DOI: 10.1007/s11746-008-1270-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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37
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Steindal AH, Tam TTT, Lu XY, Juzeniene A, Moan J. 5-Methyltetrahydrofolate is photosensitive in the presence of riboflavin. Photochem Photobiol Sci 2008; 7:814-8. [PMID: 18597029 DOI: 10.1039/b718907a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
5-Methyltetrahydrofolate (5MTHF) is the main form of folate in human plasma, and an important vitamin for human health. Photodegradation of folates may have played a role in the development of different human skin colours. 5MTHF can be degraded directly by exposure to ultraviolet radiation or by exposure to visible light in the presence of endogenous sensitizers like riboflavin (RF). These photochemical reactions were studied by absorption spectroscopy. While 5MTHF is stable under UV and visible light exposure in pure aqueous media, it is quickly degraded in the presence of RF during UVA and blue light exposure. The degradation of 5MTHF is dependent on the concentration of RF, but not on the concentration of 5MTHF itself. UVA and blue light gave similar reactions. Further investigations are necessary to evaluate the consequences of large light exposures in vivo in humans. Our findings should be taken into the ongoing discussion about the development of human skin colours. Due to the presence of RF in human blood, folate can be significantly degraded during prolonged or intense blue light exposure. Thus, a dark skin colour may be favourable for prevention of folate degradation under high solar fluence rates, such as in equatorial areas.
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Affiliation(s)
- Arnfinn Hykkerud Steindal
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, N-0310, Oslo, Norway
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38
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Transcranial photo-inactivation of neural activities in the mouse auditory cortex. Neurosci Res 2008; 60:422-30. [DOI: 10.1016/j.neures.2007.12.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Revised: 12/11/2007] [Accepted: 12/25/2007] [Indexed: 11/19/2022]
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39
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40
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Fuentealba D, Galvez M, Alarcón E, Lissi E, Silva E. Photosensitizing Activity of Advanced Glycation Endproducts on Tryptophan, Glucose 6-phosphate Dehydrogenase, Human Serum Albumin and Ascorbic Acid Evaluated at Low Oxygen Pressure†. Photochem Photobiol 2007; 83:563-9. [PMID: 17007563 DOI: 10.1562/2006-08-01-ra-990] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A comparative study of the photosensitizing activity of advanced glycation endproducts (AGEs) prepared by incubating glucose (Glc), threose (Threo) and ascorbate (AH-) in the presence of lysine (Lys) was performed. Photochemical activity was evaluated under low oxygen pressure with the aim to simulate the conditions of the eye lens. AGE-sensitized tryptophan and AH- photodecomposition and glucose 6-phosphate dehydrogenase inactivation were studied. In all systems, glucose-derived AGEs showed the highest photosensitizing efficiency, followed by ascorbate and threose. The presence of different sensitizers in glycation products mixtures was investigated. For this purpose, Trp decomposition quantum yields were determined at 344 and 367 nm. The values obtained at 344 nm are between three and six times higher than those observed at 367 nm, confirming the presence of at least two compounds with different photosensitizing activities in the mixtures. The chemiluminescence associated with the AGE-mediated oxidation of free Trp and Trp residues in human serum albumin was also studied, and a good correlation between the emission of light and the extent of Trp decomposition was found. In conclusion, it is demonstrated that glucose derived AGEs, which can be formed in vivo in the eye lens of diabetic patients and are accumulated in elderly lenses, have a higher photosensitizing efficiency, at low oxygen pressure, than those arising from ascorbate and threose. This high efficiency is especially significant when proteins are employed as photochemical targets, indicating that protein-sensitizer interaction and the local environment around the sensitizers play an important role.
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Affiliation(s)
- Denis Fuentealba
- Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile
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41
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Görner H. Oxygen uptake after electron transfer from amines, amino acids and ascorbic acid to triplet flavins in air-saturated aqueous solution. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2007; 87:73-80. [DOI: 10.1016/j.jphotobiol.2007.02.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 02/05/2007] [Accepted: 02/20/2007] [Indexed: 11/29/2022]
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42
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Silva E, Jopia M, Edwards AM, Lemp E, Fuente JR, Lissi E. Protective Effect of Boldo and Tea Infusions on the Visible Light-mediated Pro-oxidant Effects of Vitamin B2, Riboflavin¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2002)0750585peobat2.0.co2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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43
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Xu Y, Hixon MS, Yamamoto N, McAllister LA, Wentworth AD, Wentworth P, Janda KD. Antibody-catalyzed anaerobic destruction of methamphetamine. Proc Natl Acad Sci U S A 2007; 104:3681-6. [PMID: 17360412 PMCID: PMC1820643 DOI: 10.1073/pnas.0611094104] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Methamphetamine [(+)-2] abuse has emerged as a fast-rising global epidemic, with immunopharmacotherapeutic approaches being sought for its treatment. Herein, we report the generation and characterization of a monoclonal antibody, YX1-40H10, that catalyzes the photooxidation of (+)-2 into the nonpsychoactive compound benzaldehyde (14) under anaerobic conditions in the presence of riboflavin (6). Studies have revealed that the antibody facilitates the conversion of (+)-2 into 14 by binding the triplet photoexcited state of 6 in proximity to (+)-2. The antibody binds riboflavin (K(d) = 180 muM), although this was not programmed into hapten design, and the YX1-40H10-catalyzed reaction is inhibited by molecular oxygen via the presumed quenching of the photoexcited triplet state of 6. Given that this reaction is another highlight in the processing of reactive intermediates by antibodies, we speculate that this process may have future significance in vivo with programmed immunoglobulins that use flavins as cofactors to destroy selectable molecular targets under hypoxic or even anoxic conditions.
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Affiliation(s)
- Yang Xu
- Departments of Chemistry and
- The Skaggs Institute for Chemical Biology, and
| | - Mark S. Hixon
- Departments of Chemistry and
- The Skaggs Institute for Chemical Biology, and
| | - Noboru Yamamoto
- Departments of Chemistry and
- The Skaggs Institute for Chemical Biology, and
- The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037; and
| | | | | | - Paul Wentworth
- Departments of Chemistry and
- The Skaggs Institute for Chemical Biology, and
- The Scripps–Oxford Laboratory, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
- To whom correspondence may be addressed. E-mail:
or
| | - Kim D. Janda
- Departments of Chemistry and
- Immunology
- The Skaggs Institute for Chemical Biology, and
- The Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037; and
- To whom correspondence may be addressed. E-mail:
or
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44
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Nieva J, Kerwin L, Wentworth AD, Lerner RA, Wentworth P. Immunoglobulins can utilize riboflavin (Vitamin B2) to activate the antibody-catalyzed water oxidation pathway. Immunol Lett 2005; 103:33-8. [PMID: 16386801 DOI: 10.1016/j.imlet.2005.11.020] [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] [Received: 11/19/2005] [Revised: 11/20/2005] [Accepted: 11/21/2005] [Indexed: 10/25/2022]
Abstract
We have recently discovered a reaction that all antibodies, regardless of source or antigenic specificity can catalyze, that is the reaction between singlet dioxygen ((1)O(2)(*)) and H(2)O to generate H(2)O(2). We have named this process the antibody-catalyzed water oxidation pathway (ACWOP). As part of our ongoing investigations into the possible biological role of this pathway, we have studied whether isoalloxazine-containing cofactors, that are known to be endogenous photosensitizers via Type-II pathways to generate (1)O(2)(*), such as riboflavin (RF, Vitamin B2) can trigger the ACWOP. Herein we show that regardless of the antigenic specificity or heavy and light chain composition, all antibodies and their fragments are able to intercept the (1)O(2)(*) generated by photo-oxidation of RF in the presence of oxygen (ambient aerobic conditions) to activate the ACWOP. The initial rate of HOOH generation by a panel of murine antibodies ranges from 0.218 to 0.998 microM/min. The initial rate of antibody-catalyzed HOOH production is accelerated in D(2)O and is quenched in NaN(3), highlighting the key intermediacy of (1)O(2)(*) in the process. Critically, the ACWOP is photo-activated at physiologically relevant concentrations of RF (<50 nM) suggesting that this pathway may be relevant in an in vivo setting. Finally, when activated by RF the ACWOP generates oxidants that accelerate the hemolysis of sheep RBCs hinting at a pathophysiological effect of this RF-induced photo-oxidation pathway.
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Affiliation(s)
- Jorge Nieva
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA
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46
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Massad W, Criado S, Bertolotti S, Pajares A, Gianotti J, Escalada JP, Amat-Guerri F, García NA. Photodegradation of the herbicide Norflurazon sensitised by Riboflavin. A kinetic and mechanistic study. CHEMOSPHERE 2004; 57:455-461. [PMID: 15350407 DOI: 10.1016/j.chemosphere.2004.06.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2003] [Revised: 03/23/2004] [Accepted: 06/03/2004] [Indexed: 05/24/2023]
Abstract
The kinetics and mechanism of the Riboflavin (Rf)-promoted photochemical degradation with visible light of the herbicide Norflurazon (NF) has been studied by time-resolved and stationary techniques. Using light of wavelength higher than 400 nm--a region where NF is totally transparent--and with concentrations of Rf and NF of ca. 0.02 and 1 mM, respectively, only the excited triplet state of Rf ((3)Rf*) is quenched by NF, in competition with dissolved ground state triplet oxygen, O(2)((3)Sigma(g)(-)). NF degradation mainly occurs by reaction with superoxide radical anion O(2)(-) formed through two electron transfer steps: from NF to (3)Rf*, yielding Rf radical anion, and from this anion to O(2)((3)Sigma(g)(-)), regenerating ground state Rf. Although singlet molecular oxygen is also produced, NF only quenches this oxidative species in a physical mode. The global result is the photoprotection of the sensitiser and the photodegradation of NF.
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Affiliation(s)
- W Massad
- Departamento de Quimica y Fisica, Universidad Nacional de Rio Cuarto, Agencia Postal Nro. 3, 5800 Río Cuarto, Argentina
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47
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Ahmad I, Fasihullah Q, Noor A, Ansari IA, Ali QNM. Photolysis of riboflavin in aqueous solution: a kinetic study. Int J Pharm 2004; 280:199-208. [PMID: 15265559 DOI: 10.1016/j.ijpharm.2004.05.020] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2004] [Revised: 05/12/2004] [Accepted: 05/20/2004] [Indexed: 11/20/2022]
Abstract
The kinetics of photolysis of aqueous riboflavin solutions on UV and visible irradiation has been studied in the pH range 1-12 using a specific multicomponent spectrophotometric method for the simultaneous determination of riboflavin and its major photoproducts (formylmethylflavin, lumichrome and lumiflavin). The apparent first-order rate constants for the photodegradation reactions in the pH range have been determined. The log k-pH profiles indicate that riboflavin has maximum photostability around pH 5-6, at which the rate of oxidation-reduction of the molecule is lowest. The cationic and anionic forms of riboflavin are non-fluorescent and less susceptible to photolysis than the non-ionised molecule as indicated by the relatively slow rates below pH 3.0 and above pH 10.0. The rate of photolysis is increased up to 80-fold at pH 10.0, compared to that at pH 5.0, due to increase in redox potentials with an increase in pH and consequently the ease with which the molecule is oxidised. The increase in rate at pH 3.0, compared to that at pH 5.0, appears to be due to the involvement of the excited singlet state as well as the triplet state in riboflavin degradation. The apparent first-order rate constants for the photolysis of riboflavin at pH 5.0-10.0 with UV and visible radiation are 0.185 x 10(-2) to 13.182 x 10(-2)min(-1) and 0.098 x 10(-2) to 7.762 x 10(-2)min(-1), respectively.
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Affiliation(s)
- Iqbal Ahmad
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Karachi, Karachi 75270, Pakistan.
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48
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de La Rochette A, Birlouez-Aragon I, Silva E, Morlière P. Advanced glycation endproducts as UVA photosensitizers of tryptophan and ascorbic acid: consequences for the lens. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1621:235-41. [PMID: 12787919 DOI: 10.1016/s0304-4165(03)00072-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Upon aging, the lens accumulates brown fluorophores, mainly derived from the Maillard reaction between vitamin C oxidation products and crystallins lysine residues. At the same time, the concentration of UVA filters decreases, allowing some radiation to be absorbed by lenticular advanced glycation endproducts (AGEs). This paper quantifies the photosensitizing activity of AGEs at various oxygen pressures, and compares it to that of lenticular riboflavin (RF). Solutions containing the sensitizer and the substrates tryptophan (Trp) and ascorbate (AH(-)) were irradiated at 365 nm. We show that the AGEs-photosensitized Trp oxidation rate increases with AGEs concentration and is optimal at 5% oxygen, the pressure in the lens. By contrast, for AH(-), the photooxidation rate increases with oxygen concentration. Despite the higher quantum yield of RF-depending reactions, its low concentration as compared to that of AGEs in aging lenses induces significantly higher Trp and AH(-) photodegradation rates with AGEs than with RF. As ascorbate is more rapidly photodegraded than Trp, the antioxidant competitively protects Trp from oxidation up to 1 mM, although not absolutely. We conclude that in the aging lens, AH(-) exerts a strong UVA protecting activity, but does not impede some Trp residue to be photodegraded proportionally to the AGEs concentration.
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Affiliation(s)
- Arnauld de La Rochette
- Laboratoire de Chimie Analytique, Institut National Agronomique Paris-Grignon, 16 rue Claude Bernard, 75231 Paris Cedex 05, France
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Lyons NM, O'Brien NM. Modulatory effects of an algal extract containing astaxanthin on UVA-irradiated cells in culture. J Dermatol Sci 2002; 30:73-84. [PMID: 12354422 DOI: 10.1016/s0923-1811(02)00063-4] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
UV radiation from sunlight is the most potent environmental risk factor in skin cancer pathogenesis. In the present study the ability of an algal extract to protect against UVA-induced DNA alterations was examined in human skin fibroblasts (1BR-3), human melanocytes (HEMAc) and human intestinal CaCo-2 cells. The protective effects of the proprietary algal extract, which contained a high level of the carotenoid astaxanthin, were compared with synthetic astaxanthin. DNA damage was assessed using the single cell gel electrophoresis or comet assay. In 1BR-3 cells, synthetic astaxanthin prevented UVA-induced DNA damage at all concentrations (10 nM, 100 nM, 10 microM) tested. In addition, the synthetic carotenoid also prevented DNA damage in both the HEMAc and CaCo-2 cells. The algal extract displayed protection against UVA-induced DNA damage when the equivalent of 10 microM astaxanthin was added to all three-cell types, however, at the lower concentrations (10 and 100 nM) no significant protection was evident. There was a 4.6-fold increase in astaxanthin content of CaCo-2 cells exposed to the synthetic compound and a 2.5-fold increase in cells exposed to algal extract. In 1BR-3 cells, exposure to UVA for 2 h resulted in a significant induction of cellular superoxide dismutase (SOD) activity, coupled with a marked decrease in cellular glutathione (GSH) content. However pre-incubation (18 h) with 10 microM of the either the synthetic astaxanthin or the algal extract prevented UVA-induced alterations in SOD activity and GSH content. Similarly, in CaCo-2 cells a significant depletion of GSH was observed following UVA-irradiation which was prevented by simultaneously incubating with 10 microM of either synthetic astaxanthin or the algal extract. SOD activity was unchanged following UVA exposure in the intestinal cell line. This work suggests a role for the algal extract as a potentially beneficial antioxidant.
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Affiliation(s)
- Nicole M Lyons
- Department of Food Science, Food Technology and Nutrition, University College Cork, Cork, Ireland.
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50
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Silva E, Jopia M, Edwards AM, Lemp E, De la Fuente JR, Lissi E. Protective effect of Boldo and tea infusions on the visible light-mediated pro-oxidant effects of vitamin B2, riboflavin. Photochem Photobiol 2002; 75:585-90. [PMID: 12081319 DOI: 10.1562/0031-8655(2002)075<0585:peobat>2.0.co;2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effect of Boldo and black tea infusions on the pro-oxidant effects of vitamin B2, riboflavin (RF), when exposed to the action of visible light was studied. The amounts of antioxidants present in Boldo and tea infusions were evaluated by a procedure based on the bleaching of preformed 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cations and were expressed as 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid equivalent concentrations. The quenching rate constants of singlet oxygen (1O2; [kq]Boldo = 6.0 x 10(7) M(-1) s(-1) and [kq]Tea = 3.2 x 10(7) M(-1) s(-1)) and triplet RF (3RF; [3RFkq]Boldo = 10 x 10(8) M(-1) s(-1) and [3RFkq]TEA = 3.2 x 10(8) M(-1) s(-1)) with Boldo and tea were determined by flash photolysis. These data allow a quantitative interpretation of the results obtained. Our data suggest that most of the oxygen consumption observed in the photolysis of RF in the presence of tea and Boldo infusions is caused by 1O2 reactions. The oxygen consumption quantum yield is considerably smaller than the fraction of RF triplets trapped by the additives (AH) present in the infusion, indicating that their interaction with 3RF does not lead to chemical reactions or that the AH*+ radical ions initially formed participate in secondary processes that do not consume oxygen. Boldo and tea infusions have a significant protective effect when a system containing RF and tryptophan (Trp) is exposed to visible light, not only by quenching the 1O2 and interfering with the Type-I mechanism but also by repairing the damage to Trp molecules associated with the latter mechanism.
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Affiliation(s)
- E Silva
- Facultad de Química, Pontificia Universidad Católica de Chile, Santiago.
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