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Sadowska-Bartosz I, Bartosz G. The Cellular and Organismal Effects of Nitroxides and Nitroxide-Containing Nanoparticles. Int J Mol Sci 2024; 25:1446. [PMID: 38338725 PMCID: PMC10855878 DOI: 10.3390/ijms25031446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/21/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Nitroxides are stable free radicals that have antioxidant properties. They react with many types of radicals, including alkyl and peroxyl radicals. They act as mimics of superoxide dismutase and stimulate the catalase activity of hemoproteins. In some situations, they may exhibit pro-oxidant activity, mainly due to the formation of oxoammonium cations as products of their oxidation. In this review, the cellular effects of nitroxides and their effects in animal experiments and clinical trials are discussed, including the beneficial effects in various pathological situations involving oxidative stress, protective effects against UV and ionizing radiation, and prolongation of the life span of cancer-prone mice. Nitroxides were used as active components of various types of nanoparticles. The application of these nanoparticles in cellular and animal experiments is also discussed.
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Affiliation(s)
- Izabela Sadowska-Bartosz
- Laboratory of Analytical Biochemistry, Institute of Food Technology and Nutrition, College of Natural Sciences, University of Rzeszow, 4 Zelwerowicza Street, 35-601 Rzeszow, Poland;
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Bartosz G, Pieńkowska N, Kut K, Cieniek B, Stefaniuk I, Sadowska-Bartosz I. Effect of Low Concentration of Nitroxides on SH-SY5Y Cells Transfected with the Tau Protein. Int J Mol Sci 2023; 24:16675. [PMID: 38069000 PMCID: PMC10706669 DOI: 10.3390/ijms242316675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 11/17/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023] Open
Abstract
Nitroxides, stable synthetic free radicals, are promising antioxidants, showing many beneficial effects both at the cellular level and in animal studies. However, the cells are usually treated with high millimolar concentrations of nitroxides which are not relevant to the concentrations that could be attained in vivo. This paper aimed to examine the effects of low (≤10 μM) concentrations of three nitroxides, 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO), 4-hydroxy-TEMPO (TEMPOL) and 4-amino-TEMPO (TEMPAMINE), in pure chemical systems and on SH-SY5Y cells transfected with the human tau protein (TAU cells), a model of chronic cellular oxidative stress, and transfected with the empty plasmid (EP cells). All nitroxides were active in antioxidant-activity tests except for the 2,2'-azinobis-(3-ethylbenzthiazolin-6-sulfonate) radical (ABTS•) decolorization assay and reduced Fe3+, inhibited autoxidation of adrenalin and pyrogallol and oxidation of dihydrorhodamine123 by 3-morpholino-sydnonimine SIN-1. TEMPO protected against fluorescein bleaching from hypochlorite, but TEMPAMINE enhanced the bleaching. Nitroxides showed no cytotoxicity and were reduced by the cells to non-paramagnetic derivatives. They decreased the level of reactive oxygen species, depleted glutathione, and increased mitochondrial-membrane potential in both types of cells, and increased lipid peroxidation in TAU cells. These results demonstrate that even at low micromolar concentrations nitroxides can affect the cellular redox equilibrium and other biochemical parameters.
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Affiliation(s)
- Grzegorz Bartosz
- Laboratory of Analytical Biochemistry, Institute of Food Technology and Nutrition, College of Natural Sciences, Rzeszow University, 4 Zelwerowicza Street, 35-601 Rzeszow, Poland; (G.B.); (N.P.); (K.K.)
| | - Natalia Pieńkowska
- Laboratory of Analytical Biochemistry, Institute of Food Technology and Nutrition, College of Natural Sciences, Rzeszow University, 4 Zelwerowicza Street, 35-601 Rzeszow, Poland; (G.B.); (N.P.); (K.K.)
| | - Kacper Kut
- Laboratory of Analytical Biochemistry, Institute of Food Technology and Nutrition, College of Natural Sciences, Rzeszow University, 4 Zelwerowicza Street, 35-601 Rzeszow, Poland; (G.B.); (N.P.); (K.K.)
| | - Bogumił Cieniek
- Institute of Materials Engineering, College of Natural Sciences, University of Rzeszów, 35-310 Rzeszów, Poland; (B.C.); (I.S.)
| | - Ireneusz Stefaniuk
- Institute of Materials Engineering, College of Natural Sciences, University of Rzeszów, 35-310 Rzeszów, Poland; (B.C.); (I.S.)
| | - Izabela Sadowska-Bartosz
- Laboratory of Analytical Biochemistry, Institute of Food Technology and Nutrition, College of Natural Sciences, Rzeszow University, 4 Zelwerowicza Street, 35-601 Rzeszow, Poland; (G.B.); (N.P.); (K.K.)
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Bujak-Pietrek S, Pieniazek A, Gwozdzinski K, Gwozdzinski L. The Effect of Piperidine Nitroxides on the Properties of Metalloproteins in Human Red Blood Cells. Molecules 2023; 28:6174. [PMID: 37630426 PMCID: PMC10459006 DOI: 10.3390/molecules28166174] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Nitroxides are stable, low molecular-weight radicals containing a nitroxide group that has an unpaired electron. The presence of a nitroxide group determines their redox properties. The effect of the piperidine nitroxides, Tempo, Tempol, and Tempamine, on metalloproteins (hemoglobin, superoxide dismutase, catalase) and lactate dehydrogenase in red blood cells was investigated in this research. In addition, the level of lipid peroxidation and the level of protein carbonyl groups were examined as indicators of the effect of oxidative stress. Nitroxides increased superoxide dismutase activity and oxidized hemoglobin to methemoglobin, and also slightly decreased the catalase activity of red blood cells treated with nitroxides. Tempol significantly decreased lactate dehydrogenase activity. All three nitroxides had no effect on membrane lipid peroxidation and protein oxidation. Our results confirm that nitroxides have both antioxidant and prooxidative effects in human red blood cells. The piperidine nitroxides do not initiate the oxidation of proteins and lipids in the membranes of human red blood cells.
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Affiliation(s)
- Stella Bujak-Pietrek
- Department of Physical Hazards, Nofer Institute of Occupational Medicine, 91-348 Lodz, Poland;
| | - Anna Pieniazek
- Department of Oncobiology and Epigenetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland; (A.P.); (K.G.)
| | - Krzysztof Gwozdzinski
- Department of Oncobiology and Epigenetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland; (A.P.); (K.G.)
| | - Lukasz Gwozdzinski
- Department of Pharmacology and Toxicology, Medical University of Lodz, 90-752 Lodz, Poland
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Park WH. Tempol Inhibits the Growth of Lung Cancer and Normal Cells through Apoptosis Accompanied by Increased O 2•- Levels and Glutathione Depletion. Molecules 2022; 27:7341. [PMID: 36364165 PMCID: PMC9658942 DOI: 10.3390/molecules27217341] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 03/27/2024] Open
Abstract
Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) is a stable, cell-permeable redox-cycling nitroxide water-soluble superoxide dismutase (SOD) mimetic agent. However, little is known about its cytotoxic effects on lung-related cells. Thus, the present study investigated the effects of Tempol on cell growth and death as well as changes in reactive oxygen species (ROS) and glutathione (GSH) levels in Calu-6 and A549 lung cancer cells, normal lung WI-38 VA-13 cells, and primary pulmonary fibroblast cells. Results showed that Tempol (0.5~4 mM) dose-dependently inhibited the growth of lung cancer and normal cells with an IC50 of approximately 1~2 mM at 48 h. Tempol induced apoptosis in lung cells with loss of mitochondrial membrane potential (MMP; ∆Ψm) and activation of caspase-3. There was no significant difference in susceptibility to Tempol between lung cancer and normal cells. Z-VAD, a pan-caspase inhibitor, significantly decreased the number of annexin V-positive cells in Tempol-treated Calu-6, A549, and WI-38 VA-13 cells. A 2 mM concentration of Tempol increased ROS levels, including O2•- in A549 and WI-38 VA-13 cells after 48 h, and specifically increased O2•- levels in Calu-6 cells. In addition, Tempol increased the number of GSH-depleted cells in Calu-6, A549, and WI-38 VA-13 cells at 48 h. Z-VAD partially downregulated O2•- levels and GSH depletion in Tempol-treated these cells. In conclusion, treatment with Tempol inhibited the growth of both lung cancer and normal cells via apoptosis and/or necrosis, which was correlated with increased O2•- levels and GSH depletion.
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Affiliation(s)
- Woo Hyun Park
- Department of Physiology, Medical School, Jeonbuk National University, 20 Geonji-ro, Deokjin, Jeonju 54907, Korea
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G JM, P P, Dharmarajan A, Warrier S, Gandhirajan RK. Modulation of Reactive Oxygen Species in Cancers: Recent Advances. Free Radic Res 2022; 56:447-470. [PMID: 36214686 DOI: 10.1080/10715762.2022.2133704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Oxidation-reduction reactions played a significant role in the chemical evolution of life forms on oxygenated earth. Cellular respiration is dependent on such redox reactions, and any imbalance leads to the accumulation of reactive oxygen species (ROS), resulting in both chronic and acute illnesses. According to the International Agency for Research on Cancer (IARC), by 2040, the global burden of new cancer cases is expected to be around 27.5 million, with 16.3 million cancer deaths due to an increase in risk factors such as unhealthy lifestyle, environmental factors, aberrant gene mutations, and resistance to therapies. ROS play an important role in cellular signalling, but they can cause severe damage to tissues when present at higher levels. Elevated and chronic levels of ROS are pertinent in carcinogenesis, while several therapeutic strategies rely on altering cellular ROS to eliminate tumour cells as they are more susceptible to ROS-induced damage than normal cells. Given this selective targeting potential, therapies that can effectively modulate ROS levels have been the focus of intense research in recent years. The current review describes biologically relevant ROS, its origins in solid and haematological cancers, and the current status of evolving antioxidant and pro-oxidant therapies in cancers.
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Affiliation(s)
- Jeyasree M G
- Department of Human Genetics, Faculty of Biomedical Sciences, Technology and Research, Sri Ramachandra University, Porur, Chennai 600116, India
| | - Prerana P
- Department of Human Genetics, Faculty of Biomedical Sciences, Technology and Research, Sri Ramachandra University, Porur, Chennai 600116, India
| | - Arun Dharmarajan
- Department of Biomedical Sciences, Faculty of Biomedical Sciences, Technology and Research, Sri Ramachandra University, Porur, Chennai 600116, India.,Stem Cell and Cancer Biology Laboratory, Curtin University, Perth, WA, Australia.,School of Pharmacy and Biomedical Sciences, Curtin University, Perth, WA 6102, Australia.,Curtin Health and Innovation Research Institute, Curtin University, Perth, WA 6102, Australia
| | - Sudha Warrier
- Division of Cancer Stem Cells and Cardiovascular Regeneration, School of Regenerative Medicine, Manipal Academy of Higher Education (MAHE), Bangalore 560065, India.,Cuor Stem Cellutions Pvt Ltd, Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education (MAHE), Bangalore 560065, India
| | - Rajesh Kumar Gandhirajan
- Department of Human Genetics, Faculty of Biomedical Sciences, Technology and Research, Sri Ramachandra University, Porur, Chennai 600116, India
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Escada-Rebelo S, Cristo MI, Ramalho-Santos J, Amaral S. Mitochondria-Targeted Compounds to Assess and Improve Human Sperm Function. Antioxid Redox Signal 2022; 37:451-480. [PMID: 34847742 DOI: 10.1089/ars.2021.0238] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Significance: Currently 10%-15% of couples in reproductive age face infertility issues. More importantly, male factor contributes to 50% of these cases (either alone or in combination with female causes). Among various reasons, impaired sperm function is the main cause for male infertility. Furthermore, mitochondrial dysfunction and oxidative stress due to increased reactive oxygen species (ROS) production, particularly of mitochondrial origin, are believed to be the main contributors. Recent Advances: Mitochondrial dysfunction, particularly due to increased ROS production, has often been linked to impaired sperm function/quality. For decades, different methods and approaches have been developed to assess mitochondrial features that might correlate with sperm functionality. This connection is now completely accepted, with mitochondrial functionality assessment used more commonly as a readout of sperm functionality. More recently, mitochondria-targeted compounds are on the frontline for both assessment and therapeutic approaches. Critical Issues: In this review, we summarize the current methods for assessing key mitochondrial parameters known to reflect sperm quality as well as therapeutic strategies using mitochondria-targeted antioxidants aiming to improve sperm function in various situations, particularly after sperm cryopreservation. Future Directions: Although more systematic research is needed, mitochondria-targeted compounds definitely represent a promising tool to assess as well as to protect and improve sperm function. Antioxid. Redox Signal. 37, 451-480.
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Affiliation(s)
- Sara Escada-Rebelo
- PhD Programme in Experimental Biology and Biomedicine, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Biology of Reproduction and Stem Cell Group, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,IIIUC - Institute for Interdisciplinary Research, Casa Costa Alemão, University of Coimbra, Coimbra, Portugal
| | - Maria Inês Cristo
- Biology of Reproduction and Stem Cell Group, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - João Ramalho-Santos
- Biology of Reproduction and Stem Cell Group, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Sandra Amaral
- Biology of Reproduction and Stem Cell Group, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,IIIUC - Institute for Interdisciplinary Research, Casa Costa Alemão, University of Coimbra, Coimbra, Portugal
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Tiwari S, Dewry RK, Srivastava R, Nath S, Mohanty TK. Targeted antioxidant delivery modulates mitochondrial functions, ameliorates oxidative stress and preserve sperm quality during cryopreservation. Theriogenology 2021; 179:22-31. [PMID: 34823058 DOI: 10.1016/j.theriogenology.2021.11.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/11/2021] [Accepted: 11/15/2021] [Indexed: 02/07/2023]
Abstract
Mitochondria are vital organelles with a multifaceted role in cellular bioenergetics, biosynthesis, signaling and calcium homeostasis. During oxidative phosphorylation, sperm mitochondria generate reactive oxygen species (ROS) at physiological levels mediating signaling pathways essential for sperm fertilizing competence. Moreover, sperm subpopulation with active mitochondria is positively associated with sperm motility, chromatin and plasma membrane integrity, and normal morphology. However, the osmotic and thermal stress, and intracellular ice crystal formation generate excess ROS to cause mitochondrial dysfunction, potentiating cryoprotectant-induced calcium overload in the mitochondrial matrix. It further stimulates the opening of mitochondrial permeability transition pores (mPTP) to release pro-apoptotic factors from mitochondria and initiate apoptotic cascade, with a decrease in Mitochondrial Membrane Potential (MMP) and altered sperm functions. To improve the male reproductive potential, it is essential to address challenges in semen cryopreservation, precisely the deleterious effects of oxidative stress on sperm quality. During semen cryopreservation, the supplementation of extended semen with conventional antioxidants is extensively reported. However, the outcomes of supplementation to improve semen quality are inconclusive across different species, which is chiefly attributed to the unknown bioavailability of antioxidants at the primary site of ROS generation, i.e., mitochondria. Increasing evidence suggests that the targeted delivery of antioxidants to sperm mitochondria is superior in mitigating oxidative stress and improving semen freezability than conventional antioxidants. Therefore, the present review comprehensively describes mitochondrial-targeted antioxidants, their mechanism of action and effects of supplementation on improving semen cryopreservation efficiency in different species. Moreover, it also discusses the significance of active mitochondria in determining sperm fertilizing competence, cryopreservation-induced oxidative stress and mitochondrial dysfunction, and its implications on sperm fertility. The potential of mitochondrial-targeted antioxidants to modulate mitochondrial functions and improve semen quality has been reviewed extensively.
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Affiliation(s)
- Saurabh Tiwari
- Artificial Breeding Research Centre, LPM Division, ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India.
| | - R K Dewry
- Artificial Breeding Research Centre, LPM Division, ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - Rashika Srivastava
- Artificial Breeding Research Centre, LPM Division, ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - Sapna Nath
- Artificial Breeding Research Centre, LPM Division, ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
| | - T K Mohanty
- Artificial Breeding Research Centre, LPM Division, ICAR-National Dairy Research Institute, Karnal, 132001, Haryana, India
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Potnuri AG, Purushothaman S, Saheera S, Nair RR. Mito-targeted antioxidant prevents cardiovascular remodelling in spontaneously hypertensive rat by modulation of energy metabolism. Clin Exp Pharmacol Physiol 2021; 49:35-45. [PMID: 34459495 DOI: 10.1111/1440-1681.13585] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 08/17/2021] [Accepted: 08/26/2021] [Indexed: 12/30/2022]
Abstract
Hypertension induced left ventricular hypertrophy (LVH) augments the risk of cardiovascular anomalies. Mitochondrial alterations result in oxidative stress, accompanied by decrease in fatty acid oxidation, leading to the activation of the hypertrophic program. Targeted antioxidants are expected to reduce mitochondrial reactive oxygen species more effectively than general antioxidants. This study was designed to assess whether the mito-targeted antioxidant, Mito-Tempol (Mito-TEMP) is more effective than the general oxidant, Tempol (TEMP) in reduction of hypertension and hypertrophy and prevention of shift in cardiac energy metabolism. Spontaneously hypertensive rats were administered either TEMP (20 mg/kg/day) or Mito-TEMP (2 mg/kg/day) intraperitoneally for 30 days. Post treatment, animals were subjected to 2D-echocardiography. Myocardial lysates were subjected to RPLC - LTQ-Orbitrap-MS analysis. Mid-ventricular sections were probed for markers of energy metabolism and fibrosis. The beneficial effect on cardiovascular structure and function was significantly higher for Mito-TEMP. Increase in mitochondrial antioxidants and stimulation of fatty acid metabolism; with significant improvement in cardiovascular function was apparent in spontaneously hypertensive rats (SHR) treated with Mito-TEMP. The study indicates that Mito-TEMP is superior to its non- targeted isoform in preventing hypertension induced LVH, and the beneficial effects on heart are possibly mediated by reversal of metabolic remodelling.
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Affiliation(s)
- Ajay Godwin Potnuri
- Department of Animal Physiology, Resource Facility for Biomedical Research, Indian Council for Medical Research - National Animal, Hyderabad, India.,Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrom, India
| | - Sreeja Purushothaman
- Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrom, India
| | - Sherin Saheera
- Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrom, India
| | - Renuka R Nair
- Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrom, India
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Tempol differently affects cellular redox changes and antioxidant enzymes in various lung-related cells. Sci Rep 2021; 11:14869. [PMID: 34290305 PMCID: PMC8295274 DOI: 10.1038/s41598-021-94340-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 07/12/2021] [Indexed: 01/12/2023] Open
Abstract
Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl) is a potential redox agent in cells. The present study investigated changes in cellular reactive oxygen species (ROS) and glutathione (GSH) levels and in antioxidant enzymes, in Tempol-treated Calu-6 and A549 lung cancer cells, normal lung WI-38 VA-13 cells, and primary pulmonary fibroblasts. Results demonstrated that Tempol (0.5–4 mM) either increased or decreased general ROS levels in lung cancer and normal cells at 48 h and specifically increased O2•− levels in these cells. In addition, Tempol differentially altered the expression and activity of antioxidant enzymes such as superoxide dismutase, catalase, and thioredoxin reductase1 (TrxR1) in A549, Calu-6, and WI-38 VA-13 cells. In particular, Tempol treatment increased TrxR1 protein levels in these cells. Tempol at 1 mM inhibited the growth of lung cancer and normal cells by about 50% at 48 h but also significantly induced cell death, as evidenced by annexin V-positive cells. Furthermore, down-regulation of TrxR1 by siRNA had some effect on ROS levels as well as cell growth inhibition and death in Tempol-treated or -untreated lung cells. In addition, some doses of Tempol significantly increased the numbers of GSH-depleted cells in both cancer cells and normal cells at 48 h. In conclusion, Tempol differentially increased or decreased levels of ROS and various antioxidant enzymes in lung cancer and normal cells, and induced growth inhibition and death in all lung cells along with an increase in O2•− levels and GSH depletion.
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Meng L, How ZT, Ganiyu SO, Gamal El-Din M. Solar photocatalytic treatment of model and real oil sands process water naphthenic acids by bismuth tungstate: Effect of catalyst morphology and cations on the degradation kinetics and pathways. JOURNAL OF HAZARDOUS MATERIALS 2021; 413:125396. [PMID: 33626477 DOI: 10.1016/j.jhazmat.2021.125396] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/24/2020] [Accepted: 02/09/2021] [Indexed: 06/12/2023]
Abstract
Bitumen extraction from oil sands produces large quantities of oil sands process water (OSPW), which contains recalcitrant naphthenic acids (NAs). In this study, three different morphologies of bismuth tungstate (Bi2WO6) photocatalysts were prepared by hydrothermal method. The prepared catalyst was characterized to obtain its structural, textural and chemical properties and tested for the degradation of model NAs and real OSPW under simulated solar irradiation. Nanoplate, flower-like and swirl-like Bi2WO6 were prepared and the results showed that the flower-like structure exhibited the highest specific surface area and total pore volume. The highest photocatalytic activity for the degradation of NAs was also demonstrated by the flower-like Bi2WO6, achieving complete degradation of cyclohexanoic acid (CHA) at fluence-based rate constant of 0.0929 cm2/J. Superoxide radicals (O2•-) and holes were identified as the major reactive species generated during the photocatalytic process. The effect of metallic ions on the degradation rates of S-containing and N-containing NAs differed and the heteroatom was found to be the main reactive site. The by-products of heteroatomic NAs were identified and degradation pathways were reported for the first time. The concentration changes of each byproduct were further estimated by mass balance. This research provides valuable information for the treatment of NAs by engineered passive solar-based approaches.
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Affiliation(s)
- Lingjun Meng
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton T6G 1H9, Alberta, Canada
| | - Zuo Tong How
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton T6G 1H9, Alberta, Canada
| | - Soliu O Ganiyu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton T6G 1H9, Alberta, Canada
| | - Mohamed Gamal El-Din
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton T6G 1H9, Alberta, Canada.
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Dihydroxy-Substituted Coumarins as Fluorescent Probes for Nanomolar-Level Detection of the 4-Amino-TEMPO Spin Label. Int J Mol Sci 2019; 20:ijms20153802. [PMID: 31382639 PMCID: PMC6696051 DOI: 10.3390/ijms20153802] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/18/2022] Open
Abstract
This paper reports on dihydroxycoumarins as fluorescent probes suitable for the detection and determination of the nitroxide radical, namely 4-amino-TEMPO. Since 4-amino-TEMPO is used as a spin label for the detection of various radicals and damage caused by these species, its determination under physiological conditions might help us to understand the mechanism of the oxidative stress. Among different coumarins studied, only dihydroxy-substituted derivatives show high sensitivity, specificity, and selectivity for the nitroxide radical. In this assay, dihydroxy-substituted coumarins under the action of 4-amino-TEMPO show a very fast and significant increase in fluorescence intensity and lifetime. Among them 6,7-dihydroxycoumarin (esculetin) exhibits the strongest fluorescence enhancement (up to 40 times), with an estimated limit of detection equal to 16.7 nM—a significantly lower value when compared with UV-Vis or electron paramagnetic resonance (EPR) spectroscopy. The method is characterized by an easy procedure of sample preparation and very short time of analysis. The mechanism of the interaction between 6,7-dihydroxycoumarin and 4-amino-TEMPO has been examined with the use of a series of complementary techniques, such as steady-state and time-resolved fluorescence spectroscopy, UV-Vis spectroscopy, electron paramagnetic resonance spectroscopy, potentiometric titration, and high-performance liquid chromatography. It has been proven that the only route of the reaction in the system studied is a proton transfer from the molecule of esculetin to the amino group of the nitroxide. Biological studies performed on prostate cancer cells, breast cancer cells, and normal skin fibroblasts revealed significant anticancer properties of 6,7-dihydroxycoumarin, which caused a considerable decrease in the viability and number of cancer cells, and affected their morphology, contrary to normal fibroblasts. Furthermore, the experiment performed on prostate cancer cells showed that fluorescence emission of esculetin is closely related to intracellular pH—the higher pH, the higher observed fluorescence intensity (in accordance with a chemical experiment). On the other hand, the studies performed in different pH levels revealed that when pH of the solution increases, the observed fluorescence intensity enhancement under the action of 4-amino-TEMPO decreases (better sensing properties of esculetin towards the nitroxide in lower pH).
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12
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Gonzalez-Vicente A, Hong N, Garvin JL. Effects of reactive oxygen species on renal tubular transport. Am J Physiol Renal Physiol 2019; 317:F444-F455. [PMID: 31215804 DOI: 10.1152/ajprenal.00604.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) play a critical role in regulating nephron transport both via transcellular and paracellular pathways under physiological and pathological circumstances. Here, we review the progress made in the past ~10 yr in understanding how ROS regulate solute and water transport in individual nephron segments. Our knowledge in this field is still rudimentary, with basic information lacking. This is most obvious when looking at the reported disparate effects of superoxide ([Formula: see text]) and H2O2 on proximal nephron transport, where there are no easy explanations as to how to reconcile the data. Similarly, we know almost nothing about the regulation of transport in thin descending and ascending limbs, information that is likely critical to understanding the urine concentrating mechanism. In the thick ascending limb, there is general agreement that ROS enhance transcellular reabsorption of NaCl, but we know very little about their effects on the paracellular pathway and therefore Ca2+ and Mg2+ transport. In the distal convoluted tubule, precious little is known. In the collecting duct, there is general agreement that ROS stimulate the epithelial Na+ channel.
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Affiliation(s)
- Agustin Gonzalez-Vicente
- Department of Inflammation and Immunity, Cleveland Clinic, Lerner Research Institute, Cleveland, Ohio
| | - Nancy Hong
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University Cleveland, Ohio
| | - Jeffrey L Garvin
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University Cleveland, Ohio
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Nolte TM, Peijnenburg WJGM. Use of quantum-chemical descriptors to analyse reaction rate constants between organic chemicals and superoxide/hydroperoxyl (O2•−/HO2•). Free Radic Res 2018; 52:1118-1131. [DOI: 10.1080/10715762.2018.1529867] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Tom M. Nolte
- Department of Environmental Science, Institute for Water and Wetland Research, Radboud University Nijmegen, Nijmegen, the Netherlands
- Laboratory of Inorganic Chemistry, Eidgenossische Technische Hochschule (ETH) Zurich, Zurich, Switzerland
| | - Willie J. G. M. Peijnenburg
- National Institute of Public Health and the Environment, Bilthoven, The Netherlands
- Institute of Environmental Sciences (CML), Leiden University, Leiden, The Netherlands
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Alzoubi KH, Rababa'h AM, Al Yacoub ON. Tempol prevents post-traumatic stress disorder induced memory impairment. Physiol Behav 2018; 184:189-195. [PMID: 29217357 DOI: 10.1016/j.physbeh.2017.12.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 10/14/2017] [Accepted: 12/02/2017] [Indexed: 12/14/2022]
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15
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Shi JL, Hao H, Li X, Lang X. Merging the catechol–TiO2 complex photocatalyst with TEMPO for selective aerobic oxidation of amines into imines. Catal Sci Technol 2018. [DOI: 10.1039/c8cy01096j] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Merging of catechol–TiO2 complex photocatalysis with TEMPO catalysis can successfully facilitate the selective oxidation of amines into imines with air under blue LED irradiation.
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Affiliation(s)
- Ji-Long Shi
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- China
| | - Huimin Hao
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- China
| | - Xia Li
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- China
| | - Xianjun Lang
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan 430072
- China
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16
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Lewandowski M, Gwozdzinski K. Nitroxides as Antioxidants and Anticancer Drugs. Int J Mol Sci 2017; 18:ijms18112490. [PMID: 29165366 PMCID: PMC5713456 DOI: 10.3390/ijms18112490] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 02/07/2023] Open
Abstract
Nitroxides are stable free radicals that contain a nitroxyl group with an unpaired electron. In this paper, we present the properties and application of nitroxides as antioxidants and anticancer drugs. The mostly used nitroxides in biology and medicine are a group of heterocyclic nitroxide derivatives of piperidine, pyrroline and pyrrolidine. The antioxidant action of nitroxides is associated with their redox cycle. Nitroxides, unlike other antioxidants, are characterized by a catalytic mechanism of action associated with a single electron oxidation and reduction reaction. In biological conditions, they mimic superoxide dismutase (SOD), modulate hemoprotein’s catalase-like activity, scavenge reactive free radicals, inhibit the Fenton and Haber-Weiss reactions and suppress the oxidation of biological materials (peptides, proteins, lipids, etc.). The use of nitroxides as antioxidants against oxidative stress induced by anticancer drugs has also been investigated. The application of nitroxides and their derivatives as anticancer drugs is discussed in the contexts of breast, hepatic, lung, ovarian, lymphatic and thyroid cancers under in vivo and in vitro experiments. In this article, we focus on new natural spin-labelled derivatives such as camptothecin, rotenone, combretastatin, podophyllotoxin and others. The applications of nitroxides in the aging process, cardiovascular disease and pathological conditions were also discussed.
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Affiliation(s)
- Marcin Lewandowski
- Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 90-136 Lodz, Poland.
| | - Krzysztof Gwozdzinski
- Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 90-136 Lodz, Poland.
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Wang F, Gao P, Guo L, Meng P, Fan Y, Chen Y, Lin Y, Guo G, Ding G, Wang H. Radio-protective effect and mechanism of 4-Acetamido-2,2,6,6- tetramethylpiperidin-1-oxyl in HUVEC cells. Environ Health Prev Med 2017; 22:14. [PMID: 29165102 PMCID: PMC5664570 DOI: 10.1186/s12199-017-0616-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 03/04/2017] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVES To search for more effective radiation protectors with minimal toxicity, a water-soluble nitroxides Acetamido-Tempol (AA-Tempol) was evaluated for potential radioprotective properties in HUVEC cells (Human Umbilical Vein Endothelial cell line). METHODS To study the anti-radiation effect of AA-Tempol in cell culture, the viability of irradiated HUVEC cells using a clonogenic survival assay was examined. The anti-apoptosis effects of AA-Tempol using Annexin V/propidium iodide staining in a flow cytometry assay was also evaluated. To elucidate the molecular mechanism of the anti-apoptosis effect of AA-Tempol against X-radiation induced HUVEC cell apoptosis, the expression of Bax, Bcl-2 and p53 and caspase-3 were examined. The changes in the level of malondialdehyde (MDA) and glutathione (GSH) in HUVEC cells after X-radiation were also investigated. RESULTS Pretreatment of the HUVEC cells colony with AA-Tempol 1 h before X-radiation significantly increased the colony survival (p < 0.05) compared with the cells without pretreatment. This demonstrates that AA-Tempol provides an effective radiation protection in the irradiated HUVEC cells, thus reducing apoptosis from 20.1 ± 1.3% in 8 Gy X-radiated cells to 12.2 ± 0.9% (1.0 mmol/L-1 AA-Tempol) in AA-Tempo pretreated HUVEC cells. This implies that 1.0 mM AA-Tempol treatment significantly block the increase of caspase-3 activity in radiated HUVEC cells (P < 0.01), causing down-regulation in expressions of Bax and P53 and up-regulation in the expression of Bcl-2. Pretreatment with AA-Tempol also decreased the MDA activities (P < 0.01) and increase the GSH level (P < 0.05) in HUVEC cells compared to the 8Gy X-radiated cells without pretreatment. CONCLUSIONS These observations indicate that AA-Tempol is a potential therapeutic agent against the radiation damage.
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Affiliation(s)
- Feng Wang
- School of Preventive Medicine, Fourth Military Medical University, Xi'an, 710032, People's Republic of China
- Shanxi Province Corps Hospital, Chinese People's Armed Police Forces, Taiyuan, 030006, People's Republic of China
| | - Peng Gao
- School of Preventive Medicine, Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Ling Guo
- School of Preventive Medicine, Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Ping Meng
- Department of urology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Yuexing Fan
- Shanxi Province Corps Hospital, Chinese People's Armed Police Forces, Taiyuan, 030006, People's Republic of China
| | - Yongbin Chen
- School of Preventive Medicine, Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Yanyun Lin
- School of Preventive Medicine, Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Guozhen Guo
- School of Preventive Medicine, Fourth Military Medical University, Xi'an, 710032, People's Republic of China
| | - Guirong Ding
- School of Preventive Medicine, Fourth Military Medical University, Xi'an, 710032, People's Republic of China.
| | - Haibo Wang
- School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, People's Republic of China.
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18
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Jamwal A, Niyogi S. Dose and chemical species-specific effects of selenium against arsenite toxicity in cultured hepatocytes of rainbow trout (Oncorhynchus mykiss). Metallomics 2017; 9:744-756. [DOI: 10.1039/c7mt00006e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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19
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Lee CP, Maksaev G, Jensen GS, Murcha MW, Wilson ME, Fricker M, Hell R, Haswell ES, Millar AH, Sweetlove LJ. MSL1 is a mechanosensitive ion channel that dissipates mitochondrial membrane potential and maintains redox homeostasis in mitochondria during abiotic stress. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 88:809-825. [PMID: 27505616 PMCID: PMC5195915 DOI: 10.1111/tpj.13301] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 05/18/2023]
Abstract
Mitochondria must maintain tight control over the electrochemical gradient across their inner membrane to allow ATP synthesis while maintaining a redox-balanced electron transport chain and avoiding excessive reactive oxygen species production. However, there is a scarcity of knowledge about the ion transporters in the inner mitochondrial membrane that contribute to control of membrane potential. We show that loss of MSL1, a member of a family of mechanosensitive ion channels related to the bacterial channel MscS, leads to increased membrane potential of Arabidopsis mitochondria under specific bioenergetic states. We demonstrate that MSL1 localises to the inner mitochondrial membrane. When expressed in Escherichia coli, MSL1 forms a stretch-activated ion channel with a slight preference for anions and provides protection against hypo-osmotic shock. In contrast, loss of MSL1 in Arabidopsis did not prevent swelling of isolated mitochondria in hypo-osmotic conditions. Instead, our data suggest that ion transport by MSL1 leads to dissipation of mitochondrial membrane potential when it becomes too high. The importance of MSL1 function was demonstrated by the observation of a higher oxidation state of the mitochondrial glutathione pool in msl1-1 mutants under moderate heat- and heavy-metal-stress. Furthermore, we show that MSL1 function is not directly implicated in mitochondrial membrane potential pulsing, but is complementary and appears to be important under similar conditions.
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Affiliation(s)
- Chun Pong Lee
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Bayliss Building M316, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia
| | - Grigory Maksaev
- Department of Biology, Washington University in Saint Louis, One Brookings Drive, Mailcode 1137, Saint Louis, MO, 63130, USA
| | - Gregory S Jensen
- Department of Biology, Washington University in Saint Louis, One Brookings Drive, Mailcode 1137, Saint Louis, MO, 63130, USA
| | - Monika W Murcha
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Bayliss Building M316, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia
| | - Margaret E Wilson
- Department of Biology, Washington University in Saint Louis, One Brookings Drive, Mailcode 1137, Saint Louis, MO, 63130, USA
| | - Mark Fricker
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Ruediger Hell
- Department of Plant Molecular Biology, Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 360, D-69120, Heidelberg, Germany
| | - Elizabeth S Haswell
- Department of Biology, Washington University in Saint Louis, One Brookings Drive, Mailcode 1137, Saint Louis, MO, 63130, USA
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Bayliss Building M316, 35 Stirling Highway, Crawley, 6009, Western Australia, Australia
| | - Lee J Sweetlove
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
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20
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Tassopoulos A, Chalkias A, Papalois A, Iacovidou N, Xanthos T. The effect of antioxidant supplementation on bacterial translocation after intestinal ischemia and reperfusion. Redox Rep 2016; 22:1-9. [PMID: 27734759 DOI: 10.1080/13510002.2016.1229893] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The intestine is highly sensitive to ischemia/reperfusion (I/R) injury. Intestinal I/R may cause local tissue injury and disruption of the intestinal mucosal barrier, allowing the passage of viable bacteria and endotoxins from the gastrointestinal lumen to distant organs. This phenomenon, known as bacterial translocation (BT), may lead to systemic disorders with high morbidity and mortality. Oxidative stress mediators such as reactive oxygen species, polymorphonuclear neutrophils and nitric oxide are believed to contribute to the intestinal I/R injury. Many antioxidants have shown protective effects against I/R injury of various organs. The present article provides an overview of studies investigating the effect of antioxidant supplementation on BT after intestinal I/R.
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Affiliation(s)
- A Tassopoulos
- a National and Kapodistrian University of Athens, Medical School , Athens , Greece
| | - A Chalkias
- b Hellenic Society of Cardiopulmonary Resuscitation , Athens , Greece.,c National and Kapodistrian University of Athens, Medical School , Athens , Greece
| | - A Papalois
- f Experimental-Research Centre ELPEN Pharmaceutical Co. Inc. , Athens , Greece
| | - N Iacovidou
- e Department of Neonatology, Aretaieio Hospital , National and Kapodistrian University of Athens, Medical School , Athens , Greece
| | - T Xanthos
- d European University Cyprus , School of Medicine , Nicosia , Cyprus
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21
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Gorbanev Y, Stehling N, O’Connell D, Chechik V. Reactions of nitroxide radicals in aqueous solutions exposed to non-thermal plasma: limitations of spin trapping of the plasma induced species. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/0963-0252/25/5/055017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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22
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Higgins RF, Fatur SM, Shepard SG, Stevenson SM, Boston DJ, Ferreira EM, Damrauer NH, Rappé AK, Shores MP. Uncovering the Roles of Oxygen in Cr(III) Photoredox Catalysis. J Am Chem Soc 2016; 138:5451-64. [DOI: 10.1021/jacs.6b02723] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Robert F. Higgins
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Steven M. Fatur
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Samuel G. Shepard
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Susan M. Stevenson
- Department
of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - David J. Boston
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Eric M. Ferreira
- Department
of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Niels H. Damrauer
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Anthony K. Rappé
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Matthew P. Shores
- Department
of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
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23
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Tempol prevents chronic sleep-deprivation induced memory impairment. Brain Res Bull 2016; 120:144-50. [DOI: 10.1016/j.brainresbull.2015.11.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 10/11/2015] [Accepted: 11/18/2015] [Indexed: 01/05/2023]
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24
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Araki Y, Koshiishi I. Simultaneous evaluation of one-electron reducing systems and radical reactions in cells by nitroxyl biradical as probe. Biomed Chromatogr 2015; 30:1131-1137. [DOI: 10.1002/bmc.3661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/01/2015] [Accepted: 11/20/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Yoko Araki
- Gunma University; 3-39-22 Showa-machi Maebashi Gunma 371-8511 Japan
| | - Ichiro Koshiishi
- Gunma University; 3-39-22 Showa-machi Maebashi Gunma 371-8511 Japan
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25
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Nano-antioxidants: An emerging strategy for intervention against neurodegenerative conditions. Neurochem Int 2015; 89:209-26. [PMID: 26315960 DOI: 10.1016/j.neuint.2015.08.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 08/08/2015] [Accepted: 08/15/2015] [Indexed: 02/08/2023]
Abstract
Oxidative stress has for long been linked to the neuronal cell death in many neurodegenerative conditions. Conventional antioxidant therapies have been less effective in preventing neuronal damage caused by oxidative stress due to their inability to cross the blood brain barrier. Nanoparticle antioxidants constitute a new wave of antioxidant therapies for prevention and treatment of diseases involving oxidative stress. It is believed that nanoparticle antioxidants have strong and persistent interactions with biomolecules and would be more effective against free radical induced damage. Nanoantioxidants include inorganic nanoparticles possessing intrinsic antioxidant properties, nanoparticles functionalized with antioxidants or antioxidant enzymes to function as an antioxidant delivery system. Nanoparticles containing antioxidants have shown promise as high-performance therapeutic nanomedicine in attenuating oxidative stress with potential applications in treating and preventing neurodegenerative conditions. However, to realize the full potential of nanoantioxidants, negative aspects associated with the use of nanoparticles need to be overcome to validate their long term applications.
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26
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4-hydroxy tempo improves mitochondrial and neurobehavioral deficits in experimental model of Huntington's disease. Synapse 2015; 69:128-38. [DOI: 10.1002/syn.21793] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 11/27/2014] [Indexed: 11/07/2022]
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27
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Suthar SK, Sharma M. Recent Developments in Chimeric NSAIDs as Safer Anti-Inflammatory Agents. Med Res Rev 2014; 35:341-407. [DOI: 10.1002/med.21331] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Sharad Kumar Suthar
- Department of Pharmacy; Jaypee University of Information Technology; Waknaghat 173234 India
| | - Manu Sharma
- Department of Pharmacy; Jaypee University of Information Technology; Waknaghat 173234 India
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28
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Kajer TB, Fairfull-Smith KE, Yamasaki T, Yamada KI, Fu S, Bottle SE, Hawkins CL, Davies MJ. Inhibition of myeloperoxidase- and neutrophil-mediated oxidant production by tetraethyl and tetramethyl nitroxides. Free Radic Biol Med 2014; 70:96-105. [PMID: 24566469 DOI: 10.1016/j.freeradbiomed.2014.02.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/23/2014] [Accepted: 02/12/2014] [Indexed: 12/17/2022]
Abstract
The powerful oxidant HOCl (hypochlorous acid and its corresponding anion, (-)OCl) generated by the myeloperoxidase (MPO)-H2O2-Cl(-) system of activated leukocytes is strongly associated with multiple human inflammatory diseases; consequently there is considerable interest in inhibition of this enzyme. Nitroxides are established antioxidants of low toxicity that can attenuate oxidation in animal models, with this ascribed to superoxide dismutase or radical-scavenging activities. We have shown (M.D. Rees et al., Biochem. J. 421, 79-86, 2009) that nitroxides, including 4-amino-TEMPO (4-amino-2,2,6,6-tetramethylpiperidin-1-yloxyl radical), are potent inhibitors of HOCl formation by isolated MPO and activated neutrophils, with IC50 values of ~1 and ~6 µM respectively. The utility of tetramethyl-substituted nitroxides is, however, limited by their rapid reduction by biological reductants. The corresponding tetraethyl-substituted nitroxides have, however, been reported to be less susceptible to reduction. In this study we show that the tetraethyl species were reduced less rapidly than the tetramethyl species by both human plasma (89-99% decreased rate of reduction) and activated human neutrophils (62-75% decreased rate). The tetraethyl-substituted nitroxides retained their ability to inhibit HOCl production by MPO and activated neutrophils with IC50 values in the low-micromolar range; in some cases inhibition was enhanced compared to tetramethyl substitution. Nitroxides with rigid structures (fused oxaspiro rings) were, however, inactive. Overall, these data indicate that tetraethyl-substituted nitroxides are potent inhibitors of oxidant formation by MPO, with longer plasma and cellular half-lives compared to the tetramethyl species, potentially allowing lower doses to be employed.
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Affiliation(s)
- Tracey B Kajer
- Heart Research Institute, Newtown, Sydney, NSW 2042, Australia; Faculty of Medicine, University of Sydney, Sydney, NSW, Australia
| | - Kathryn E Fairfull-Smith
- School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Toshihide Yamasaki
- Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Kyushu, Japan
| | - Ken-ichi Yamada
- Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Kyushu, Japan
| | - Shanlin Fu
- Centre for Forensic Science, University of Technology, Sydney, NSW, Australia
| | - Steven E Bottle
- School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Clare L Hawkins
- Heart Research Institute, Newtown, Sydney, NSW 2042, Australia; Faculty of Medicine, University of Sydney, Sydney, NSW, Australia
| | - Michael J Davies
- Heart Research Institute, Newtown, Sydney, NSW 2042, Australia; Faculty of Medicine, University of Sydney, Sydney, NSW, Australia.
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Bateni Z, Azadi L, Tavalaee M, Kiani-Esfahani A, Fazilati M, Nasr-Esfahani MH. Addition of Tempol in semen cryopreservation medium improves the post-thaw sperm function. Syst Biol Reprod Med 2014; 60:245-50. [DOI: 10.3109/19396368.2014.897773] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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30
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Guellich A, Damy T, Conti M, Claes V, Samuel JL, Pineau T, Lecarpentier Y, Coirault C. Tempol prevents cardiac oxidative damage and left ventricular dysfunction in the PPAR-α KO mouse. Am J Physiol Heart Circ Physiol 2013; 304:H1505-12. [PMID: 23542920 DOI: 10.1152/ajpheart.00669.2012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Peroxisome proliferator-activated receptor (PPAR)-α deletion induces a profound decrease in MnSOD activity, leading to oxidative stress and left ventricular (LV) dysfunction. We tested the hypothesis that treatment of PPAR-α knockout (KO) mice with the SOD mimetic tempol prevents the heart from pathological remodelling and preserves LV function. Twenty PPAR-α KO mice and 20 age-matched wild-type mice were randomly treated for 8 wk with vehicle or tempol in the drinking water. LV contractile parameters were determined both in vivo using echocardiography and ex vivo using papillary muscle mechanics. Translational and posttranslational modifications of myosin heavy chain protein as well as the expression and activity of major antioxidant enzymes were measured. Tempol treatment did not affect LV function in wild-type mice; however, in PPAR-α KO mice, tempol prevented the decrease in LV ejection fraction and restored the contractile parameters of papillary muscle, including maximum shortening velocity, maximum extent of shortening, and total tension. Moreover, compared with untreated PPAR-α KO mice, myosin heavy chain tyrosine nitration and anion superoxide production were markedly reduced in PPAR-α KO mice after treatment. Tempol also significantly increased glutathione peroxidase and glutathione reductase activities (~ 50%) in PPAR-α KO mice. In conclusion, these findings demonstrate that treatment with the SOD mimetic tempol can prevent cardiac dysfunction in PPAR-α KO mice by reducing the oxidation of contractile proteins. In addition, we show that the beneficial effects of tempol in PPAR-α KO mice involve activation of the glutathione peroxidase/glutathione reductase system.
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Affiliation(s)
- Aziz Guellich
- Unité (U)69, Institut National de la Santé et de la Recherche Médicale (INSERM), Labex-Laboratoire d'Excellence en Recherche sur le Médicament et l'Innovation Thérapeutique, Université Paris Sud, Paris, France
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31
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Santiani Acosta A, Evangelista Vargas S, Valdivia Cuya M, Risopatrón González J, Sánchez Gutiérrez R. Effect of the addition of two superoxide dismutase analogues (Tempo and Tempol) to alpaca semen extender for cryopreservation. Theriogenology 2013; 79:842-6. [DOI: 10.1016/j.theriogenology.2012.12.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 12/20/2012] [Accepted: 12/20/2012] [Indexed: 11/29/2022]
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Potential implication of the chemical properties and bioactivity of nitrone spin traps for therapeutics. Future Med Chem 2012; 4:1171-207. [PMID: 22709256 DOI: 10.4155/fmc.12.74] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nitrone therapeutics has been employed in the treatment of oxidative stress-related diseases such as neurodegeneration, cardiovascular disease and cancer. The nitrone-based compound NXY-059, which is the first drug to reach clinical trials for the treatment of acute ischemic stroke, has provided promise for the development of more robust pharmacological agents. However, the specific mechanism of nitrone bioactivity remains unclear. In this review, we present a variety of nitrone chemistry and biological activity that could be implicated for the nitrone's pharmacological activity. The chemistries of spin trapping and spin adduct reveal insights on the possible roles of nitrones for altering cellular redox status through radical scavenging or nitric oxide donation, and their biological effects are presented. An interdisciplinary approach towards the development of novel synthetic antioxidants with improved pharmacological properties encompassing theoretical, synthetic, biochemical and in vitro/in vivo studies is covered.
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Flores-Santana W, Moody T, Chen W, Gorczynski MJ, Shoman ME, Velázquez C, Thetford A, Mitchell JB, Cherukuri MK, King SB, Wink DA. Nitroxide derivatives of non-steroidal anti-inflammatory drugs exert anti-inflammatory and superoxide dismutase scavenging properties in A459 cells. Br J Pharmacol 2012; 165:1058-67. [PMID: 21658022 PMCID: PMC3346241 DOI: 10.1111/j.1476-5381.2011.01527.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 04/20/2011] [Accepted: 05/18/2011] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND AND PURPOSE Inflammation and reactive oxygen species are associated with the promotion of various cancers. The use of non-steroidal anti-inflammatory drugs (NSAIDs) in cancer prevention treatments has been promising in numerous cancers. We report the evaluation of NSAIDs chemically modified by the addition of a redox-active nitroxide group. TEMPO-aspirin (TEMPO-ASA) and TEMPO-indomethacin (TEMPO-IND) were synthesized and evaluated in the lung cancer cell line A549. EXPERIMENTAL APPROACHES We evaluated physico-chemical properties of TEMPO-ASA and TEMPO-IND by electron paramagnetic resonance and cyclic voltammetry. Superoxide dismutase-like properties was assayed by measuring cytochrome c reduction and anti-inflammatory effects were assayed by measuring production of prostaglandin E(2) (PGE(2) ) and leukotriene B(4) (LTB(4) ). MTT proliferation assay and clonogenic assay were evaluated in the A549 lung carcinoma cell line. Maximum tolerated doses (MTD) and acute ulcerogenic index were also evaluated in in vivo. KEY RESULTS MTD were: TEMPO (140 mg·kg(-1) ), ASA (100 mg·kg(-1) ), indomethacin (5 mg·kg(-1) ), TEMPO-ASA (100 mg·kg(-1) ) and TEMPO-IND (40 mg·kg(-1) ). While TEMPO-ASA was as well tolerated as ASA, TEMPO-IND showed an eightfold improvement over indomethacin. TEMPO-IND showed markedly less gastric toxicity than the parent NSAID. Both TEMPO-ASA and TEMPO-IND inhibited production of PGE(2) and LTB(4) in A549 cells with maximum effects at 100 µg·mL(-1) or 10 µg·mL(-1) respectively. CONCLUSIONS AND IMPLICATIONS The nitroxide-NSAIDs retained superoxide scavenging capacity of the parent nitroxide and anti-inflammatory effects, inhibiting cyclooxygenase and 5-lipoxygenase enzymes. These redox-modified NSAIDs might be potential drug candidates, as they exhibit the pharmacological properties of the parent NSAID with antioxidant activity decreasing NSAID-associated toxicity.
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Affiliation(s)
- Wilmarie Flores-Santana
- Radiation Biology Branch National Cancer Institute, National Institutes of HealthBethesda, MD, USA
| | - Terry Moody
- National Cancer Institute, Office of the Director, Center for Cancer ResearchBethesda, MD, USA
| | - Weibin Chen
- Department of Chemistry, Wake Forest UniversityWinston-Salem, NC, USA
| | | | - Mai E Shoman
- Department of Chemistry, Wake Forest UniversityWinston-Salem, NC, USA
| | - Carlos Velázquez
- Faculty of Pharmacy and Pharmaceutical Sciences, University of AlbertaEdmonton, Canada
| | - Angela Thetford
- Radiation Biology Branch National Cancer Institute, National Institutes of HealthBethesda, MD, USA
| | - James B Mitchell
- Radiation Biology Branch National Cancer Institute, National Institutes of HealthBethesda, MD, USA
| | - Murali K Cherukuri
- Radiation Biology Branch National Cancer Institute, National Institutes of HealthBethesda, MD, USA
| | - S Bruce King
- Department of Chemistry, Wake Forest UniversityWinston-Salem, NC, USA
| | - David A Wink
- Radiation Biology Branch National Cancer Institute, National Institutes of HealthBethesda, MD, USA
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Davis RM, Mitchell JB, Krishna MC. Nitroxides as cancer imaging agents. Anticancer Agents Med Chem 2011; 11:347-58. [PMID: 21434855 DOI: 10.2174/187152011795677526] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 03/09/2011] [Indexed: 01/13/2023]
Abstract
Nitroxides are low molecular weight (150-400 Da) superoxide dismutase mimics that exhibit antioxidant, radical scavenging, and radioprotective activity. Additionally, the paramagnetic nature of nitroxides makes them viable as both spin probes for electron paramagnetic resonance imaging as well as contrast agents for magnetic resonance imaging. These imaging techniques enable in vivo monitoring of nitroxide metabolism. In biological systems, nitroxide metabolism occurs predominantly via reduction of the nitroxide to a hydroxylamine. The rate of nitroxide reduction can increase or decrease due to either oxidative stress, suggesting that nitroxides can provide an imaging-based assay of tissue redox status. The current review briefly summarizes the potential clinical applications of nitroxides, and focuses on the biochemical and tumor microenvironmental factors that affect the rate of nitroxide reduction. The potential therapeutic applications and bio-reduction mechanisms are discussed in the context of their relevance to oncology.
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Affiliation(s)
- Ryan M Davis
- Radiation Biology Branch, Center for Cancer Research, National Institutes of Health, Bethesda, MD 20892, USA.
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35
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Palm F, Nordquist L. Renal oxidative stress, oxygenation, and hypertension. Am J Physiol Regul Integr Comp Physiol 2011; 301:R1229-41. [PMID: 21832206 DOI: 10.1152/ajpregu.00720.2010] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Hypertension is closely associated with progressive kidney dysfunction, manifested as glomerulosclerosis, interstitial fibrosis, proteinuria, and eventually declining glomerular filtration. The postulated mechanism for development of glomerulosclerosis is barotrauma caused by increased capillary pressure, but the reason for development of interstitial fibrosis and the subsequently reduced kidney function is less clear. However, it has been hypothesized that tissue hypoxia induces fibrogenesis and progressive renal failure. This is very interesting, since recent reports highlight several different mechanisms resulting in altered oxygen handling and availability in the hypertensive kidney. Such mechanisms include decreased renal blood flow due to increased vascular tone induced by ANG II that limits oxygen delivery and increases oxidative stress, resulting in increased mitochondrial oxygen usage, increased oxygen usage for tubular electrolyte transport, and shunting of oxygen from arterial to venous blood in preglomerular vessels. It has been shown in several studies that interventions to prevent oxidative stress and to restore kidney tissue oxygenation prevent progression of kidney dysfunction. Furthermore, inhibition of ANG II activity, by either blocking ANG II type 1 receptors or angiotensin-converting enzyme, or by preventing oxidative stress by administration of antioxidants also results in improved blood pressure control. Therefore, it seems likely that tissue hypoxia in the hypertensive kidney contributes to progression of kidney damage, and perhaps also persistence the high blood pressure.
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Affiliation(s)
- Fredrik Palm
- Dept. of Medical Cell Biology, Uppsala Univ., Biomedical Center, Box 571, 751 23 Uppsala, Sweden.
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Walker JR, Fairfull-Smith KE, Anzai K, Lau S, White PJ, Scammells PJ, Bottle SE. Edaravone containing isoindoline nitroxides for the potential treatment of cardiovascular ischaemia. MEDCHEMCOMM 2011. [DOI: 10.1039/c1md00041a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Bonne C, Latour E, Modat G, Muller A, Palluy O, Regnouf De Vains JB, Tissie G, Veriac S. Tempo, a Superoxide Dismutase Mimic. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bscb.19911000906] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
Heme is an essential molecule in aerobic organisms. Heme consists of protoporphyrin IX and a ferrous (Fe(2+)) iron atom, which has high affinity for oxygen (O(2)). Hemoglobin, the major oxygen-carrying protein in blood, is the most abundant heme-protein in animals and humans. Hemoglobin consists of four globin subunits (alpha(2)beta(2)), with each subunit carrying a heme group. Ferrous (Fe(2+)) hemoglobin is easily oxidized in circulation to ferric (Fe(3+)) hemoglobin, which readily releases free hemin. Hemin is hydrophobic and intercalates into cell membranes. Hydrogen peroxide can split the heme ring and release "free" redox-active iron, which catalytically amplifies the production of reactive oxygen species. These oxidants can oxidize lipids, proteins, and DNA; activate cell-signaling pathways and oxidant-sensitive, proinflammatory transcription factors; alter protein expression; perturb membrane channels; and induce apoptosis and cell death. Heme-derived oxidants induce recruitment of leukocytes, platelets, and red blood cells to the vessel wall; oxidize low-density lipoproteins; and consume nitric oxide. Heme metabolism, extracellular and intracellular defenses against heme, and cellular cytoprotective adaptations are emphasized. Sickle cell disease, an archetypal example of hemolysis, heme-induced oxidative stress, and cytoprotective adaptation, is reviewed.
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Affiliation(s)
- John D Belcher
- Department of Medicine, Division of Hematology, Oncology and Transplantation, Minneapolis, Minnesota 55455, USA
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Cicco G, Cicco S. The Influence of Oxygen Supply, Hemorheology and Microcirculation in the Heart and Vascular Systems. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 662:33-9. [DOI: 10.1007/978-1-4419-1241-1_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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40
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Yamato M, Shiba T, Yamada KI, Watanabe T, Utsumi H. Separable detection of lipophilic- and hydrophilic-phase free radicals from the ESR spectrum of nitroxyl radical in transient MCAO mice. Free Radic Res 2009; 43:844-51. [DOI: 10.1080/10715760903089716] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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41
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Trnka J, Blaikie FH, Logan A, Smith RAJ, Murphy MP. Antioxidant properties of MitoTEMPOL and its hydroxylamine. Free Radic Res 2009; 43:4-12. [PMID: 19058062 PMCID: PMC2645131 DOI: 10.1080/10715760802582183] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Piperidine nitroxides such as TEMPOL have been widely used as antioxidants in vitro and in vivo. MitoTEMPOL is a mitochondria-targeted derivative of TEMPOL designed to protect mitochondria from the oxidative damage that they accumulate, but once there is rapidly reduced to its hydroxylamine, MitoTEMPOL-H. As little is known about the antioxidant efficacy of hydroxylamines, this study has assessed the antioxidant activity of both MitoTEMPOL and MitoTEMPOL-H. The hydroxylamine was more effective at preventing lipid-peroxidation than MitoTEMPOL and decreased oxidative damage to mitochondrial DNA caused by menadione. In contrast to MitoTEMPOL, MitoTEMPOL-H has no superoxide dismutase activity and its antioxidant actions are likely to be mediated by hydrogen atom donation. Therefore, even though MitoTEMPOL is rapidly reduced to MitoTEMPOL-H in cells, it remains an effective antioxidant. Furthermore, as TEMPOL is also reduced to a hydroxylamine in vivo, many of its antioxidant effects may also be mediated by its hydroxylamine.
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Affiliation(s)
- Jan Trnka
- MRC Dunn Human Nutrition Unit, Cambridge, UK
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Abstract
Piperidine nitroxides like 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) are persistent free radicals in non-acidic aqueous solutions and organic solvents that may have value as therapeutic agents in medicine. In biological environments, they undergo mostly reduction to stable hydroxylamines but can also undergo oxidation to reactive oxoammonium compounds. Reactions of the oxoammonium derivatives could have adverse consequences including chemical modification of vital macromolecules and deleterious effects on cell signaling. An examination of their reactivity in aqueous solution has shown that oxoammonium compounds can oxidize almost any organic as well as many inorganic molecules found in biological systems. Many of these reactions appear to be one-electron transfers that reduce the oxoammonium to the corresponding nitroxide species, in contrast to a prevalence of two-electron reductions of oxoammonium in organic solvents. Amino acids, alcohols, aldehydes, phospholipids, hydrogen peroxide, other nitroxides, hydroxylamines, phenols and certain transition metal ions and their complexes are among reductants of oxoammonium, causing conversion of this species to the paramagnetic nitroxide. On the other hand, thiols and oxoammonium yield products that cannot be detected by ESR even under conditions that would oxidize hydroxylamines to nitroxides. These products may include hindered secondary amines, sulfoxamides and sulfonamides. Thiol oxidation products other than disulfides cannot be restored to thiols by common enzymatic reduction pathways. Such products may also play a role in cell signaling events related to oxidative stress. Adverse consequences of the reactions of oxoammonium compounds may partially offset the putative beneficial effects of nitroxides in some therapeutic settings.
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Affiliation(s)
- Ileana Dragutan
- Institute of Organic Chemistry, Romanian Academy. P.O.B. 35-108, Bucharest, 060023. Romania
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Abstract
Tissue damage resulting from the extracellular production of HOCl (hypochlorous acid) by the MPO (myeloperoxidase)-hydrogen peroxide-chloride system of activated phagocytes is implicated as a key event in the progression of a number of human inflammatory diseases. Consequently, there is considerable interest in the development of therapeutically useful MPO inhibitors. Nitroxides are well established antioxidant compounds of low toxicity that can attenuate oxidative damage in animal models of inflammatory disease. They are believed to exert protective effects principally by acting as superoxide dismutase mimetics or radical scavengers. However, we show here that nitroxides can also potently inhibit MPO-mediated HOCl production, with the nitroxide 4-aminoTEMPO inhibiting HOCl production by MPO and by neutrophils with IC50 values of approx. 1 and 6 microM respectively. Structure-activity relationships were determined for a range of aliphatic and aromatic nitroxides, and inhibition of oxidative damage to two biologically-important protein targets (albumin and perlecan) are demonstrated. Inhibition was shown to involve one-electron oxidation of the nitroxides by the compound I form of MPO and accumulation of compound II. Haem destruction was also observed with some nitroxides. Inhibition of neutrophil HOCl production by nitroxides was antagonized by neutrophil-derived superoxide, with this attributed to superoxide-mediated reduction of compound II. This effect was marginal with 4-aminoTEMPO, probably due to the efficient superoxide dismutase-mimetic activity of this nitroxide. Overall, these data indicate that nitroxides have considerable promise as therapeutic agents for the inhibition of MPO-mediated damage in inflammatory diseases.
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44
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Wilcox CS, Pearlman A. Chemistry and antihypertensive effects of tempol and other nitroxides. Pharmacol Rev 2009; 60:418-69. [PMID: 19112152 DOI: 10.1124/pr.108.000240] [Citation(s) in RCA: 280] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nitroxides can undergo one- or two-electron reduction reactions to hydroxylamines or oxammonium cations, respectively, which themselves are interconvertible, thereby providing redox metabolic actions. 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol) is the most extensively studied nitroxide. It is a cell membrane-permeable amphilite that dismutates superoxide catalytically, facilitates hydrogen peroxide metabolism by catalase-like actions, and limits formation of toxic hydroxyl radicals produced by Fenton reactions. It is broadly effective in detoxifying these reactive oxygen species in cell and animal studies. When administered intravenously to hypertensive rodent models, tempol caused rapid and reversible dose-dependent reductions in blood pressure in 22 of 26 studies. This was accompanied by vasodilation, increased nitric oxide activity, reduced sympathetic nervous system activity at central and peripheral sites, and enhanced potassium channel conductance in blood vessels and neurons. When administered orally or by infusion over days or weeks to hypertensive rodent models, it reduced blood pressure in 59 of 68 studies. This was accompanied by correction of salt sensitivity and endothelial dysfunction and reduced agonist-evoked oxidative stress and contractility of blood vessels, reduced renal vascular resistance, and increased renal tissue oxygen tension. Thus, tempol is broadly effective in reducing blood pressure, whether given by acute intravenous injection or by prolonged administration, in a wide range of rodent models of hypertension.
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Affiliation(s)
- Christopher S Wilcox
- Division of Nephrology and Hypertension, Kidney and Vascular Disorder Center, Georgetown University, Washington, DC 20007, USA.
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45
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Protective effects of the complex between manganese porphyrins and catalase-poly(ethylene glycol) conjugates against hepatic ischemia/reperfusion injury in vivo. J Control Release 2008; 135:60-4. [PMID: 19162102 DOI: 10.1016/j.jconrel.2008.12.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 11/26/2008] [Accepted: 12/17/2008] [Indexed: 11/21/2022]
Abstract
The complex between manganese (Mn) porphyrins and catalase-poly(ethylene glycol) (PEG) conjugates has been designed for the protective effect against hepatic ischemia/reperfusion injury in vivo. The resulting Mn-porphyrin/catalase-PEG complex with dual enzymatic activity of superoxide dismutase (SOD) and catalase enhanced the blood circulation. The spin reduction rate in the rats treated with the Mn-porphyrin/catalase-PEG complex was significantly higher than that in the untreated rats and almost equal to that in the sham group rats. Furthermore, the Mn-porphyrin/catalase-PEG complex significantly decreased the serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. These results suggest that the Mn-porphyrin/catalase-PEG complex exhibited the antioxidative activity to protect hepatic ischemia/reperfusion injury in vivo.
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46
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Hyodo F, Soule BP, Matsumoto KI, Matusmoto S, Cook JA, Hyodo E, Sowers AL, Krishna MC, Mitchell JB. Assessment of tissue redox status using metabolic responsive contrast agents and magnetic resonance imaging. J Pharm Pharmacol 2008; 60:1049-60. [PMID: 18644197 DOI: 10.1211/jpp.60.8.0011] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Regulation of tissue redox status is important to maintain normal physiological conditions in the living body. Disruption of redox homoeostasis may lead to oxidative stress and can induce many pathological conditions such as cancer, neurological disorders and ageing. Therefore, imaging of tissue redox status could have clinical applications. Redox imaging employing magnetic resonance imaging (MRI) with nitroxides as cell-permeable redox-sensitive contrast agents has been used for non-invasive monitoring of tissue redox status in animal models. The redox imaging applications of nitroxide electron paramagnetic resonance imaging (EPRI) and MRI are reviewed here, with a focus on application of tumour redox status monitoring. While particular emphasis has been placed on differences in the redox status in tumours compared to selected normal tissues, the technique possesses the potential to have broad applications to the study of other disease states, inflammatory processes and other circumstances where oxidative stress is implicated.
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Affiliation(s)
- Fuminori Hyodo
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA
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47
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Blinco JP, Hodgson JL, Morrow BJ, Walker JR, Will GD, Coote ML, Bottle SE. Experimental and Theoretical Studies of the Redox Potentials of Cyclic Nitroxides. J Org Chem 2008; 73:6763-71. [DOI: 10.1021/jo801099w] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- James P. Blinco
- Australian Research Council Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland, 4001, Australia, and Research School of Chemistry, Australian National University, Canberra, ACT, 0200, Australia
| | - Jennifer L. Hodgson
- Australian Research Council Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland, 4001, Australia, and Research School of Chemistry, Australian National University, Canberra, ACT, 0200, Australia
| | - Benjamin J. Morrow
- Australian Research Council Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland, 4001, Australia, and Research School of Chemistry, Australian National University, Canberra, ACT, 0200, Australia
| | - James R. Walker
- Australian Research Council Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland, 4001, Australia, and Research School of Chemistry, Australian National University, Canberra, ACT, 0200, Australia
| | - Geoffrey D. Will
- Australian Research Council Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland, 4001, Australia, and Research School of Chemistry, Australian National University, Canberra, ACT, 0200, Australia
| | - Michelle L. Coote
- Australian Research Council Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland, 4001, Australia, and Research School of Chemistry, Australian National University, Canberra, ACT, 0200, Australia
| | - Steven E. Bottle
- Australian Research Council Centre of Excellence for Free Radical Chemistry and Biotechnology, School of Physical and Chemical Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland, 4001, Australia, and Research School of Chemistry, Australian National University, Canberra, ACT, 0200, Australia
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Tsutsumi T, Ide T, Yamato M, Andou M, Shiba T, Utsumi H, Sunagawa K. Effect of anaesthesia-induced alterations in haemodynamics on in vivo kinetics of nitroxyl probes in electron spin resonance spectroscopy. Free Radic Res 2008; 42:305-11. [PMID: 18404529 DOI: 10.1080/10715760801986542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Although the advent of in vivo electron spin resonance (ESR) spectroscopy has allowed analysis of the redox status of living animals, whether the haemodynamic condition affects the signal decay rate remains unknown. Three kinds of haemodynamic conditions were generated by changing the anaesthetic dosage in mice. Haemodynamics was analysed (n=6 each) and in vivo ESR was performed to measure the signal decay rates of three nitroxyl spin probes (carbamoyl-, carboxy- and methoxycarbonyl-PROXYL) at the chest and head regions (n=6 for each condition and probe). Haemodynamic analysis revealed negative inotropic and chronotropic effects on the cardiovascular system depending on the depth of anaesthesia. Although signal decay rates differed among three probes, they were not affected by heart rate alteration. In this study we report the haemodynamics-independent signal decay rate of nitoxyl probes.
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Affiliation(s)
- Takaki Tsutsumi
- Department of Cardiovascular Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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49
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Watanabe T, Owada S, Kobayashi HP, Kawakami H, Nagaoka S, Murakami E, Ishiuchi A, Enomoto T, Jinnouchi Y, Sakurai J, Tobe N, Koizumi S, Shimamura T, Asakura T, Nakano H, Otsubo T. Protective effects of MnM2Py4P and Mn-salen against small bowel ischemia/reperfusion injury in rats using an in vivo and an ex vivo electron paramagnetic resonance technique with a spin probe. Transplant Proc 2008; 39:3002-6. [PMID: 18089309 DOI: 10.1016/j.transproceed.2007.08.091] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Revised: 06/02/2007] [Accepted: 08/06/2007] [Indexed: 11/26/2022]
Abstract
BACKGROUND Reperfusion of ischemic tissues results in the formation of toxic reactive oxygen species (ROS), such as superoxide anion, hydroxyl radicals, hydroperoxide, and peroxynitrite. ROS are potent oxidizing agents, capable of damaging cellular membranes by lipid peroxidation. In the present study, we applied an in vivo electron paramagnetic resonance (EPR)/spin probe and an ex vivo EPR technique to provide direct evidence of ROS following experimentally induced small bowel ischemia/reperfusion (I/R) injury. MATERIALS AND METHODS We used a rat model of small bowel I/R injury to explore the possibility that MnM2Py4P or Mn-salen can prevent the accumulation of ROS species following experimentally induced I/R injury. We examined the ability of MnM2Py4P and Mn-salen to scavenge radicals in living Sprague-Dawley (SD) rats using an in vivo and an ex vivo EPR technique with a spin probe. RESULTS The CP decay rates in the MnM2Py4P- and Mn-salen-treated rats were significantly higher than those in the untreated rats and almost equal to those in sham group rats. There were no significant differences between the MnM2Py4P-treated group and the Mn-salen-treated group. Superoxide scavenging activities (SSA) in the MnM2Py4P- and EUK-8-treated group were higher than those in the untreated group and almost equal to the sham group. CONCLUSION The present study suggested that the protective effects of MnM2Py4P and Mn-salen against small bowel IR injury were mediated by the inhibition of O2, H2O2, and NO production.
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Affiliation(s)
- T Watanabe
- Department of Gastroenterological and General Surgery, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan.
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Soule BP, Hyodo F, Matsumoto KI, Simone NL, Cook JA, Krishna MC, Mitchell JB. Therapeutic and clinical applications of nitroxide compounds. Antioxid Redox Signal 2007; 9:1731-43. [PMID: 17665971 DOI: 10.1089/ars.2007.1722] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Nitroxide compounds have been used for many years as biophysical tools, but only during the past 15-20 years have the many interesting biochemical interactions been discovered and harnessed for therapeutic applications. By modifying oxidative stress and altering the redox status of tissues, nitroxides have the ability to interact with and alter many metabolic processes. This interaction can be exploited for therapeutic and research use, including protection against ionizing radiation, as probes in functional magnetic resonance imaging, cancer prevention and treatment, control of hypertension and weight, and protection from damage resulting from ischemia/reperfusion injury. Although much remains to be done, many applications have been well studied, and some are presently being tested in clinical trials. The therapeutic and research uses of nitroxides are reviewed here, with a focus on the progress from initial development to modern, state-of-the art trials.
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Affiliation(s)
- Benjamin P Soule
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA.
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