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Shi G, Du Y, Gao Y, Jia H, Hong H, Han L, Zhu N. Reduction of Nitro Group by Sulfide and Its Applications in Amine Synthesis. CHINESE J ORG CHEM 2023. [DOI: 10.6023/cjoc202207029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
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2
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Heidarizadi S, Rashidi Z, Jalili C, Gholami M. Overview of biological effects of melatonin on testis: A review. Andrologia 2022; 54:e14597. [PMID: 36168927 DOI: 10.1111/and.14597] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/29/2022] Open
Abstract
Infertility is a major global health issue and male factors account for half of all infertility cases. One of the causes of male infertility is the loss of spermatogonial stem cells, which may occur because of chemotherapy, radiotherapy or genetic defects. In numerous animal species, the evidence suggests the pineal gland and melatonin secretion in their reproductive activities are involved. Recently, considerable attention has pointed to the usage of melatonin in the treatment of diseases. Melatonin is associated with the regulation of circadian and seasonal rhythmic functions, immune system functions, retinal physiology, spermatogenesis and inhibition of tumour growth in different species. Several studies demonstrated that melatonin acts as an anti-apoptotic, anti-inflammatory, anticancer and antioxidant agent. Melatonin can also protect testicles and spermatogonia against oxidative damage, chemotherapy drugs, environmental radiation, toxic substances, hyperthermia, ischemia/reperfusion, diabetes-induced testicular damage, metal-induced testicular toxicity, improve sperm quality and it affects the testosterone secretion pathway by affecting Leydig cells. Therefore, the objective of this study is to investigate the biological effects of melatonin as a natural antioxidant on testicles and their disorders.
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Affiliation(s)
- Somayeh Heidarizadi
- Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Zahra Rashidi
- Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Fertility and Infertility Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Cyrus Jalili
- Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mohammadreza Gholami
- Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
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3
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Chen Q, Wang Q, Wang Y, Chu Y, Luo Y, You H, Su B, Li C, Guo Q, Sun T, Jiang C. Penetrating Micelle for Reversing Immunosuppression and Drug Resistance in Pancreatic Cancer Treatment. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2107712. [PMID: 35285149 DOI: 10.1002/smll.202107712] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/11/2022] [Indexed: 06/14/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is on of the most lethal malignant tumors with relatively poor prognosis, characterized with insufficient drug penetration, low immune response and obvious drug resistances. The therapeutic inefficiency is multifactorially related to its specific tumor microenvironment (TME), which is representatively featured as rich stroma and immunosuppression. In this work, a versatile drug delivery system is developed that can coencapsulate two prodrugs modified from gemcitabine (GEM) and a signal transducer and activator of transcription 3 (STAT3) inhibitor (HJC0152), and the gradient pH variation is further sensed in the TME of PDAC to achieve a higher penetration by reversing its surficial charges. The escorted prodrugs can release GEM intracellularly, and respond to the hypoxic condition to yield the parental STAT3 inhibitor HJC0152, respectively. By inhibiting STAT3, the tumor immunosuppression microenvironment can be re-educated through the reversion of M2-like tumor associated macrophages (M2-TAMs), recruitment of cytotoxic T lymphocytes and downregulation of regulatory T cells (Treg s). Furthermore, cytidine deaminase (CDA) and α-smooth muscle actin (α-SMA) expression can be downregulated, plus the lipid modification of GEM, the drug resistance of GEM can be greatly relieved. Based on the above design, a synergetic therapeutic efficacy in PDAC treatment can be achieved to provide more opportunity for clinical applications.
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Affiliation(s)
- Qinjun Chen
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
| | - Qingbing Wang
- Department of Interventional Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, P. R. China
| | - Yu Wang
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
| | - Yongchao Chu
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
| | - Yifan Luo
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
| | - Haoyu You
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
| | - Boyu Su
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
| | - Chao Li
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
| | - Qin Guo
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
| | - Tao Sun
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
| | - Chen Jiang
- Key Laboratory of Smart Drug Delivery (Ministry of Education), Minhang Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Pharmaceutics, School of Pharmacy, Research Center on Aging and Medicine, Fudan University, Shanghai, 201203, P. R. China
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Novel cytotoxic amphiphilic nitro-compounds derived from a synthetic route for paraconic acids. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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Allegra AG, Mannino F, Innao V, Musolino C, Allegra A. Radioprotective Agents and Enhancers Factors. Preventive and Therapeutic Strategies for Oxidative Induced Radiotherapy Damages in Hematological Malignancies. Antioxidants (Basel) 2020; 9:antiox9111116. [PMID: 33198328 PMCID: PMC7696711 DOI: 10.3390/antiox9111116] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/08/2020] [Accepted: 11/10/2020] [Indexed: 12/13/2022] Open
Abstract
Radiation therapy plays a critical role in the management of a wide range of hematologic malignancies. It is well known that the post-irradiation damages both in the bone marrow and in other organs are the main causes of post-irradiation morbidity and mortality. Tumor control without producing extensive damage to the surrounding normal cells, through the use of radioprotectors, is of special clinical relevance in radiotherapy. An increasing amount of data is helping to clarify the role of oxidative stress in toxicity and therapy response. Radioprotective agents are substances that moderate the oxidative effects of radiation on healthy normal tissues while preserving the sensitivity to radiation damage in tumor cells. As well as the substances capable of carrying out a protective action against the oxidative damage caused by radiotherapy, other substances have been identified as possible enhancers of the radiotherapy and cytotoxic activity via an oxidative effect. The purpose of this review was to examine the data in the literature on the possible use of old and new substances to increase the efficacy of radiation treatment in hematological diseases and to reduce the harmful effects of the treatment.
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Affiliation(s)
- Andrea Gaetano Allegra
- Radiation Oncology Unit, Department of Biomedical, Experimental, and Clinical Sciences “Mario Serio”, Azienda Ospedaliero-Universitaria Careggi, University of Florence, 50100 Florence, Italy;
| | - Federica Mannino
- Department of Clinical and Experimental Medicine, University of Messina, c/o AOU Policlinico G. Martino, Via C. Valeria Gazzi, 98125 Messina, Italy;
| | - Vanessa Innao
- Department of Human Pathology in Adulthood and Childhood “Gaetano Barresi”, Division of Haematology, University of Messina, 98125 Messina, Italy; (V.I.); (C.M.)
| | - Caterina Musolino
- Department of Human Pathology in Adulthood and Childhood “Gaetano Barresi”, Division of Haematology, University of Messina, 98125 Messina, Italy; (V.I.); (C.M.)
| | - Alessandro Allegra
- Department of Human Pathology in Adulthood and Childhood “Gaetano Barresi”, Division of Haematology, University of Messina, 98125 Messina, Italy; (V.I.); (C.M.)
- Correspondence: ; Tel.: +39-090-221-2364
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2-Nitroimidazoles induce mitochondrial stress and ferroptosis in glioma stem cells residing in a hypoxic niche. Commun Biol 2020; 3:450. [PMID: 32807853 PMCID: PMC7431527 DOI: 10.1038/s42003-020-01165-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 07/20/2020] [Indexed: 01/09/2023] Open
Abstract
Under hypoxic conditions, nitroimidazoles can replace oxygen as electron acceptors, thereby enhancing the effects of radiation on malignant cells. These compounds also accumulate in hypoxic cells, where they can act as cytotoxins or imaging agents. However, whether these effects apply to cancer stem cells has not been sufficiently explored. Here we show that the 2-nitroimidazole doranidazole potentiates radiation-induced DNA damage in hypoxic glioma stem cells (GSCs) and confers a significant survival benefit in mice harboring GSC-derived tumors in radiotherapy settings. Furthermore, doranidazole and misonidazole, but not metronidazole, manifested radiation-independent cytotoxicity for hypoxic GSCs that was mediated by ferroptosis induced partially through blockade of mitochondrial complexes I and II and resultant metabolic alterations in oxidative stress responses. Doranidazole also limited the growth of GSC-derived subcutaneous tumors and that of tumors in orthotopic brain slices. Our results thus reveal the theranostic potential of 2-nitroimidazoles as ferroptosis inducers that enable targeting GSCs in their hypoxic niche. Koike et al. show that the 2-nitroimidazole doranidazole increases radiation-induced DNA damage in hypoxic glioma stem cells (GSCs). They further demonstrate that additional radiation-independent cytotoxicity of 2-nitroimidazoles is due to ferroptosis that occurs through blockade of mitochondrial complexes I and II leading to metabolic changes in the oxidative stress response.
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Haghi-Aminjan H, Asghari MH, Farhood B, Rahimifard M, Hashemi Goradel N, Abdollahi M. The role of melatonin on chemotherapy-induced reproductive toxicity. J Pharm Pharmacol 2017; 70:291-306. [DOI: 10.1111/jphp.12855] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/24/2017] [Indexed: 12/11/2022]
Abstract
Abstract
Objectives
Reproductive malfunctions after chemotherapy still are a reason of reducing fertility and need specialized intensive care. The aim of this review was to investigate the effect of melatonin on the reproductive system under threatening with chemotherapeutic drugs.
Methods
To find the role of melatonin in the reproductive system during chemotherapy, a full systematic literature search was carried out based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in the electronic databases up to 17 April 2017 using search terms in the titles and abstracts. A total of 380 articles are screened according to our inclusion and exclusion criteria. Finally, 18 articles were included in this study.
Key findings
It has been cleared that melatonin has bilateral effects on reproductive cells. Melatonin protects normal cells via mechanisms, including decrease in oxidative stress, apoptosis, inflammation and modulating mitochondrial function, and sexual hormones. Furthermore, melatonin with antiproliferative properties and direct effects on its receptors improves reproductive injury and function during chemotherapy. On the other hand, melatonin sensitizes the effects of chemotherapeutic drugs and enhances chemotherapy-induced toxicity in cancerous cells through increasing apoptosis, oxidative stress and mitochondrial malfunction.
Conclusions
The study provides evidence of the bilateral role of melatonin in the reproductive system during chemotherapy.
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Affiliation(s)
- Hamed Haghi-Aminjan
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Hossein Asghari
- Department of Pharmacology, Faculty of Medicine, Babol University of Medical Sciences, Babol, Iran
| | - Bagher Farhood
- Departments of Medical Physics and Radiology, Faculty of Paramedical Sciences, Kashan University of Medical Sciences, Kashan, Iran
| | - Mahban Rahimifard
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Nasser Hashemi Goradel
- Young Researchers and Elite Club, Ardabil Branch, Islamic Azad University, Ardabil, Iran
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Abdollahi
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran
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Rigalli JP, Perdomo VG, Ciriaci N, Francés DEA, Ronco MT, Bataille AM, Ghanem CI, Ruiz ML, Manautou JE, Catania VA. The trypanocidal benznidazole promotes adaptive response to oxidative injury: Involvement of the nuclear factor-erythroid 2-related factor-2 (Nrf2) and multidrug resistance associated protein 2 (MRP2). Toxicol Appl Pharmacol 2016; 304:90-8. [PMID: 27180241 PMCID: PMC4930729 DOI: 10.1016/j.taap.2016.05.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 05/09/2016] [Accepted: 05/10/2016] [Indexed: 02/08/2023]
Abstract
Oxidative stress is a frequent cause underlying drug-induced hepatotoxicity. Benznidazole (BZL) is the only trypanocidal agent available for treatment of Chagas disease in endemic areas. Its use is associated with side effects, including increases in biomarkers of hepatotoxicity. However, BZL potential to cause oxidative stress has been poorly investigated. Here, we evaluated the effect of a pharmacologically relevant BZL concentration (200μM) at different time points on redox status and the counteracting mechanisms in the human hepatic cell line HepG2. BZL increased reactive oxygen species (ROS) after 1 and 3h of exposure, returning to normality at 24h. Additionally, BZL increased glutathione peroxidase activity at 12h and the oxidized glutathione/total glutathione (GSSG/GSSG+GSH) ratio that reached a peak at 24h. Thus, an enhanced detoxification of peroxide and GSSG formation could account for ROS normalization. GSSG/GSSG+GSH returned to control values at 48h. Expression of the multidrug resistance-associated protein 2 (MRP2) and GSSG efflux via MRP2 were induced by BZL at 24 and 48h, explaining normalization of GSSG/GSSG+GSH. BZL activated the nuclear erythroid 2-related factor 2 (Nrf2), already shown to modulate MRP2 expression in response to oxidative stress. Nrf2 participation was confirmed using Nrf2-knockout mice in which MRP2 mRNA expression was not affected by BZL. In summary, we demonstrated a ROS increase by BZL in HepG2 cells and a glutathione peroxidase- and MRP2 driven counteracting mechanism, being Nrf2 a key modulator of this response. Our results could explain hepatic alterations associated with BZL therapy.
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Affiliation(s)
- Juan Pablo Rigalli
- Institute of Experimental Physiology (IFISE-CONICET), Suipacha 570, 2000 Rosario, Argentina; Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany
| | | | - Nadia Ciriaci
- Institute of Experimental Physiology (IFISE-CONICET), Suipacha 570, 2000 Rosario, Argentina
| | | | - María Teresa Ronco
- Institute of Experimental Physiology (IFISE-CONICET), Suipacha 570, 2000 Rosario, Argentina
| | - Amy Michele Bataille
- University of Connecticut, School of Pharmacy, Department of Pharmaceutical Sciences, Storrs, CT, USA
| | - Carolina Inés Ghanem
- Institute of Pharmacological Investigations (ININFA-CONICET), University of Buenos Aires, Buenos Aires, Argentina
| | - María Laura Ruiz
- Institute of Experimental Physiology (IFISE-CONICET), Suipacha 570, 2000 Rosario, Argentina
| | - José Enrique Manautou
- University of Connecticut, School of Pharmacy, Department of Pharmaceutical Sciences, Storrs, CT, USA
| | - Viviana Alicia Catania
- Institute of Experimental Physiology (IFISE-CONICET), Suipacha 570, 2000 Rosario, Argentina.
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Shinkai Y, Nishihara Y, Amamiya M, Wakayama T, Li S, Kikuchi T, Nakai Y, Shimojo N, Kumagai Y. NADPH-cytochrome P450 reductase-mediated denitration reaction of 2,4,6-trinitrotoluene to yield nitrite in mammals. Free Radic Biol Med 2016; 91:178-87. [PMID: 26454083 DOI: 10.1016/j.freeradbiomed.2015.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/01/2015] [Accepted: 09/03/2015] [Indexed: 10/22/2022]
Abstract
While the biodegradation of 2,4,6-trinitrotoluene (TNT) via the release of nitrite is well established, mechanistic details of the reaction in mammals are unknown. To address this issue, we attempted to identify the enzyme from rat liver responsible for the production of nitrite from TNT. A NADPH-cytochrome P450 reductase (P450R) was isolated and identified from rat liver microsomes as the enzyme responsible for not only the release of nitrite from TNT but also formation of superoxide and 4-hydroxyamino-2,6-dinitrotoluene (4-HADNT) under aerobic conditions. In this context, reactive oxygen species generated during P450R-catalyzed TNT reduction were found to be, at least in part, a mediator for the production of 4-HADNT from TNT via formation of 4-nitroso-2,6-dinitrotoluene. P450R did not catalyze the formation of the hydride-Meisenheimer complex (H(-)-TNT) that is thought to be an intermediate for nitrite release from TNT. Furthermore, in a time-course experiment, 4-HADNT formation reached a plateau level and then declined during the reaction between TNT and P450R with NADPH, while the release of nitrite was subjected to a lag period. Notably, the produced 4-HADNT can react with the parent compound TNT to produce nitrite and dimerized products via formation of a Janovsky complex. Our results demonstrate for the first time that P450R-mediated release of nitrite from TNT results from the process of chemical interaction of TNT and its 4-electron reduction metabolite 4-HADNT.
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Affiliation(s)
- Yasuhiro Shinkai
- Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan; Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yuya Nishihara
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Masahiro Amamiya
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Toshihiko Wakayama
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Song Li
- Doctoral Program in Medical Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Tomohiro Kikuchi
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yumi Nakai
- Application and Research Center, JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan
| | - Nobuhiro Shimojo
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan; Doctoral Program in Medical Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoshito Kumagai
- Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan; Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan; Doctoral Program in Medical Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
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Kumar P, Bacchu V, Wiebe LI. The chemistry and radiochemistry of hypoxia-specific, radiohalogenated nitroaromatic imaging probes. Semin Nucl Med 2015; 45:122-35. [PMID: 25704385 DOI: 10.1053/j.semnuclmed.2014.10.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hypoxia is prevalent in many solid tumors. Hypoxic tumors tend to exhibit rapid growth and aberrant vasculature, which lead to oxygen (O2) depletion and impaired drug delivery. The reductive environment in hypoxic tumors alters cellular metabolism, which can trigger transcriptional responses; induce genetic alterations; promote invasion, metastasis, resistance to radiotherapy and chemotherapy, tumor progression, and recurrence; and leads to poor local control and reduced survival rates. Therefore, exploiting the reductive microenvironment in hypoxic tumors by delivering electron-affinic, O2-mimetic radioactive drugs that bioreductively activate selectively in the hypoxic microenvironment offers a logical approach to molecular imaging of focal hypoxia. Because these agents also radiosensitize hypoxic cells, they provide an innovative approach to the therapy management of such tumors. To date, nuclear imaging of hypoxic tumor has proven to be clinically effective, whereas chemical radiosensitization by these compounds has not been helpful. The current review provides an insight into the chemistry, radiochemistry, and purification strategies for selected nitroaromatics that directly exploit the bioreductive environment in hypoxic cells. Both experimental and calculated single-electron reduction potentials of electron-affinic compounds, nitroimidazoles in particular, correlate with in vitro radiosensitizing properties, making them preferred choices for use as radiopharmaceuticals for diagnostic imaging and as sensitizers to enhance the killing effects of low-energy-transfer x-rays (O2-mimetic radiosensitization). Extensive research and careful drug design have led to the development of several potentially useful hypoxia-targeting drugs, for example, [(18)F]FAZA, [(18)F]FMISO, [(18)F]EF5, and [(123)I]IAZA, that accrue selectively in hypoxic cells. These molecular probes are now globally used in clinical hypoxia imaging, including cancer. Future innovative developments must, however, consider hypoxia-selective molecular processes and the physicochemical properties of the drugs that dictate their biodistribution, hypoxia-selective accumulation, pharmacokinetics, clearance, biochemical behavior, and metabolism. This will facilitate their ultimate transformation to effective molecular theranostics, leading to improved multimodal management of cancer.
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Affiliation(s)
- Piyush Kumar
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada.
| | - Veena Bacchu
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
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Shinkai Y, Li S, Kikuchi T, Kumagai Y. Participation of metabolic activation of 2,4,6-trinitrotoluene to 4-hydroxylamino-2,6-dinitrotoluene in hematotoxicity. J Toxicol Sci 2015; 40:597-604. [DOI: 10.2131/jts.40.597] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Yasuhiro Shinkai
- Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba
| | - Song Li
- Doctoral Program in Medical Sciences, University of Tsukuba
| | - Tomohiro Kikuchi
- Master’s program in Environmental Sciences, University of Tsukuba
| | - Yoshito Kumagai
- Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba
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12
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Negi B, Raj KK, Siddiqui SM, Ramachandran D, Azam A, Rawat DS. In vitro antiamoebic activity evaluation and docking studies of metronidazole-triazole hybrids. ChemMedChem 2014; 9:2439-44. [PMID: 25146853 DOI: 10.1002/cmdc.201402240] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Indexed: 11/07/2022]
Abstract
An in-house database of 520 compounds was docked against Entamoeba histolytica thioredoxin reductase (EhTrR), a promising target for the treatment of amoebiasis. Amongst these, some metronidazole (MTZ)-triazole hybrids were ranked high, with docking scores from -10.23 to -7.56. Studies of the binding orientations and conformations show that the head groups of MTZ-triazole hybrids interact with the arginine residues within the binding pocket of EhTrR, making it clear that such is the optimal and most reliable orientation for this class of compounds. The top-ten MTZ-triazole hybrids were then selected for evaluation of their activity against the HM1:IMSS strain of amoeba. The most active compound, 2-pyridyl-(1,2,3-triazolyl)metronidazole 10, with an IC50 value of 8.4 nM, was significantly more active than the standard drug MTZ alone. Docking studies revealed that compound 10 may act as an EhTrR inhibitor with activity in the nanomolar range and satisfactory ADME properties; it is a suitable candidate to be carried forward as a potential lead in the discovery of drugs to combat amoebiasis.
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Affiliation(s)
- Beena Negi
- Department of Chemistry, University of Delhi, Delhi 110007 (India)
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Mondjinou YA, McCauliff LA, Kulkarni A, Paul L, Hyun SH, Zhang Z, Wu Z, Wirth M, Storch J, Thompson DH. Synthesis of 2-hydroxypropyl-β-cyclodextrin/pluronic-based polyrotaxanes via heterogeneous reaction as potential Niemann-Pick type C therapeutics. Biomacromolecules 2013; 14:4189-97. [PMID: 24180231 PMCID: PMC4314287 DOI: 10.1021/bm400922a] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Five polyrotaxanes were synthesized by threading 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) onto a variety of α,ω-ditriethylenediamino-N-carbamoyl-poly-(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (Pluronic) triblock copolymers using a two-pot strategy under heterogeneous, nonaqueous conditions. The threaded HP-β-CD units were retained on the pseudopolyrotaxane precursors by end-capping the branched diamine termini with sodium 2,4,6-trinitrobenzene sulfonate. Inclusion of the Pluronic copolymers within the HP-β-CD cavities was more favorable in nonpolar solvents, such as diethyl ether and n-hexane, both of which gave better coverage ratios than polar solvents. (1)H NMR and MALDI-TOF were used to estimate the average molecular weights of the purified polyrotaxane products. A globular morphology of aggregated polyrotaxanes was observed by tapping-mode AFM imaging of dried samples. Treatment of Niemann-Pick C (NPC) type 2-deficient fibroblasts with the polyrotaxane derivatives produced substantial reductions in sterol accumulation, as seen by diminished filipin staining in these cells, suggesting that Pluronic-based polyrotaxanes may be promising vehicles for delivery of HP-β-CD to cells with abnormal cholesterol accumulation.
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Affiliation(s)
- Yawo A. Mondjinou
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Leslie A. McCauliff
- Department of Nutritional Sciences, Rutgers University, 96 Lipman Drive, New Brunswick, New Jersey 08901-8525, United States
| | - Aditya Kulkarni
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Lake Paul
- Discovery Park - Bindley Biosciences Center, Purdue University, 1203 West State Street, West Lafayette, Indiana 47907, United States
| | - Seok-Hee Hyun
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Zhaorui Zhang
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Zhen Wu
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Mary Wirth
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Judith Storch
- Department of Nutritional Sciences, Rutgers University, 96 Lipman Drive, New Brunswick, New Jersey 08901-8525, United States
| | - David H. Thompson
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
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Dassow C, Armbruster C, Friedrich C, Smudde E, Guttmann J, Schumann S. A method to measure mechanical properties of pulmonary epithelial cell layers. J Biomed Mater Res B Appl Biomater 2013; 101:1164-71. [PMID: 23564730 DOI: 10.1002/jbm.b.32926] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 01/16/2013] [Accepted: 02/11/2013] [Indexed: 01/09/2023]
Abstract
The lung has a huge inner alveolar surface composed of epithelial cell layers. The knowledge about mechanical properties of lung epithelia is helpful to understand the complex lung mechanics and biomechanical interactions. Methods have been developed to determine mechanical indices (e.g., tissue elasticity) which are both very complex and in need of costly equipment. Therefore, in this study, a mechanostimulator is presented to dynamically stimulate lung epithelial cell monolayers in order to determine their mechanical properties based on a simple mathematical model. First, the method was evaluated by comparison to classical tensile testing using silicone membranes as substitute for biological tissue. Second, human pulmonary epithelial cells (A549 cell line) were grown on flexible silicone membranes and stretched at a defined magnitude. Equal secant moduli were determined in the mechanostimulator and in a conventional tension testing machine (0.49 ± 0.05 MPa and 0.51 ± 0.03 MPa, respectively). The elasticity of the cell monolayer could be calculated by the volume-pressure relationship resulting from inflation of the membrane-cell construct. The secant modulus of the A549 cell layer was calculated as 0.04 ± 0.008 MPa. These findings suggest that the mechanostimulator may represent an adequate device to determine mechanical properties of cell layers.
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Affiliation(s)
- Constanze Dassow
- Department of Experimental Anaesthesiology, University Medical Centre, Hugstetter Straße 55, 79106 Freiburg, Germany
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15
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Abdi K, Nafisi S, Manouchehri F, Bonsaii M, Khalaj A. Interaction of 5-Fluorouracil and its derivatives with bovine serum albumin. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2012; 107:20-6. [DOI: 10.1016/j.jphotobiol.2011.11.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 11/14/2011] [Accepted: 11/17/2011] [Indexed: 01/18/2023]
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16
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Catalán M, Álvarez-Lueje A, Bollo S. Electrochemistry of interaction of 2-(2-nitrophenyl)-benzimidazole derivatives with DNA. Bioelectrochemistry 2010; 79:162-7. [DOI: 10.1016/j.bioelechem.2010.02.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 09/22/2009] [Accepted: 02/12/2010] [Indexed: 10/19/2022]
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17
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Sweeney LM, Kirman CR, Gannon SA, Thrall KD, Gargas ML, Kinzell JH. Development of a physiologically based pharmacokinetic (PBPK) model for methyl iodide in rats, rabbits, and humans. Inhal Toxicol 2010; 21:552-82. [PMID: 19519155 DOI: 10.1080/08958370802601569] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Methyl iodide (MeI) has been proposed as an alternative to methyl bromide as a pre-plant soil fumigant that does not deplete stratospheric ozone. In inhalation toxicity studies performed in animals as part of the registration process, three effects have been identified that warrant consideration in developing toxicity reference values for human risk assessment: nasal lesions (rat), acute neurotoxicity (rat), and fetal loss (rabbit). Uncertainties in the risk assessment can be reduced by using an internal measure of target tissue dose that is linked to the likely mode of action (MOA) for the toxicity of MeI, rather than the external exposure concentration. Physiologically based pharmacokinetic (PBPK) models have been developed for MeI and used to reduce uncertainties in the risk assessment extrapolations (e.g. interspecies, high to low dose, exposure scenario). PBPK model-derived human equivalent concentrations comparable to the animal study NOAELs (no observed adverse effect levels) for the endpoints of interest were developed for a 1-day, 24-hr exposure of bystanders or 8 hr/day exposure of workers. Variability analyses of the PBPK models support application of uncertainty factors (UF) of approximately 2 for intrahuman pharmacokinetic variability for the nasal effects and acute neurotoxicity.
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18
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Eu JB, Kim SO, Seoung TJ, Choi SG, Cho SH, Choi CY. Protective Effect of Theanine on the Acetaminophen-induced Hepatotoxicity. ACTA ACUST UNITED AC 2010. [DOI: 10.3746/jkfn.2010.39.3.350] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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19
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Kumar P, Naimi E, McEwan AJ, Wiebe LI. Synthesis, radiofluorination, and hypoxia-selective studies of FRAZ: A configurational and positional analogue of the clinical hypoxia marker, [18F]-FAZA. Bioorg Med Chem 2010; 18:2255-2264. [DOI: 10.1016/j.bmc.2010.01.064] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 01/20/2010] [Accepted: 01/22/2010] [Indexed: 01/03/2023]
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20
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Ilbey YO, Ozbek E, Simsek A, Otunctemur A, Cekmen M, Somay A. Potential chemoprotective effect of melatonin in cyclophosphamide- and cisplatin-induced testicular damage in rats. Fertil Steril 2009; 92:1124-1132. [DOI: 10.1016/j.fertnstert.2008.07.1758] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2008] [Revised: 07/03/2008] [Accepted: 07/17/2008] [Indexed: 10/21/2022]
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21
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Electrochemical study and analytical applications for new biologically active 2-nitrophenylbenzimidazole derivatives. Talanta 2009; 79:687-94. [DOI: 10.1016/j.talanta.2009.04.054] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 04/23/2009] [Accepted: 04/25/2009] [Indexed: 11/19/2022]
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22
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Mizuno K, Katoh M, Okumura H, Nakagawa N, Negishi T, Hashizume T, Nakajima M, Yokoi T. Metabolic Activation of Benzodiazepines by CYP3A4. Drug Metab Dispos 2008; 37:345-51. [DOI: 10.1124/dmd.108.024521] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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23
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Kumar P, Emami S, McEwan AJ, Wiebe LI. Stereospecific deuteration of α-furanosyl azomycin nucleosides: A model reaction for tritium radiolabeling. Bioorg Med Chem Lett 2008; 18:3256-60. [DOI: 10.1016/j.bmcl.2008.04.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2008] [Revised: 04/17/2008] [Accepted: 04/21/2008] [Indexed: 11/26/2022]
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24
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Kirman CR, Sweeney LM, Gargas ML, Kinzell JH. Evaluation of possible modes of action for acute effects of methyl iodide in laboratory animals. Inhal Toxicol 2008; 21:537-51. [DOI: 10.1080/08958370802601510] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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25
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Nichols KD, Kirby GM. Expression of cytochrome P450 2A5 in a glucose-6-phosphate dehydrogenase-deficient mouse model of oxidative stress. Biochem Pharmacol 2007; 75:1230-9. [PMID: 18068688 DOI: 10.1016/j.bcp.2007.10.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 10/29/2007] [Accepted: 10/30/2007] [Indexed: 10/22/2022]
Abstract
Murine hepatic cytochrome P450 2A5 (CYP2A5), unlike most CYP enzymes, is upregulated during hepatitis and hepatotoxic conditions, but the common stimulus for its induction remains unknown. We investigated the involvement of oxidative stress in the regulation of CYP2A5 expression using an oxidative stress-sensitive glucose-6-phosphate dehydrogenase (G6PD)-deficient mouse model. Treatment of deficient and wild-type mice with the prototypical CYP2A5-inducer pyrazole for 72h led to a significantly greater degree of induction of CYP2A5 mRNA, protein and activity in deficient mice, with the greatest increase observed in animals homozygous for the deficiency. However, markers of oxidative stress including protein carbonyl, 8-hydroxydeoxyguanosine, malondiadehyde and 4-hydroxyalkenal levels were unaltered with pyrazole treatment. Furthermore, CYP2A5 expression was not altered in G6PD-deficient mice treated with the pro-oxidant menadione whereas DNA, lipid, and protein markers of oxidative stress were significantly increased. The antioxidant polyethylene glycol-conjugated catalase, while decreasing oxidative stress in menadione-treated mice, did not prevent the induction of CYP2A5 by pyrazole. Finally, the ER stress marker protein, GRP78, was increased following pyrazole treatment in G6PD-deficient compared to wild-type mice. These findings do not support a central role for generalized cellular oxidative stress in the regulation of CYP2A5 and suggest that additional factors related to G6PD-deficiency, such as ER stress, may be involved.
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Affiliation(s)
- Kathleen D Nichols
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
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26
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Testa B, Krämer SD. The biochemistry of drug metabolism--an introduction: Part 2. Redox reactions and their enzymes. Chem Biodivers 2007; 4:257-405. [PMID: 17372942 DOI: 10.1002/cbdv.200790032] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This review continues a general presentation of the metabolism of drugs and other xenobiotics started in a recent issue of Chemistry & Biodiversity. This Part 2 presents the numerous oxidoreductases involved, their nomenclature, relevant biochemical properties, catalytic mechanisms, and the very diverse reactions they catalyze. Many medicinally, environmentally, and toxicologically relevant examples are presented and discussed. Cytochromes P450 occupy a majority of the pages of Part 2, but a large number of relevant oxidoreductases are also considered, e.g., flavin-containing monooxygenases, amine oxidases, molybdenum hydroxylases, peroxidases, and the innumerable dehydrogenases/reductases.
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Affiliation(s)
- Bernard Testa
- Department of Pharmacy, University Hospital Centre (CHUV), Rue du Bugnon, CH-1011 Lausanne.
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27
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Mascarenhas RJ, Namboothiri IN, Sherigara BS, Reddy VK. A study of quasi reversible nitro radical anion from β-nitrostyrene at wax-impregnated carbon paste electrode. J CHEM SCI 2006. [DOI: 10.1007/bf02708288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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28
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Fotouhi L, Kohestanian E, Heravi MM. The effect of metal ions on the electrochemistry of the furazolidone. Electrochem commun 2006. [DOI: 10.1016/j.elecom.2006.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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29
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Ask K, Décologne N, Ginies C, Låg M, Boucher JL, Holme JA, Pelczar H, Camus P. Metabolism of nilutamide in rat lung. Biochem Pharmacol 2006; 71:377-85. [PMID: 16313887 DOI: 10.1016/j.bcp.2005.10.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 10/14/2005] [Accepted: 10/20/2005] [Indexed: 11/29/2022]
Abstract
Nilutamide is a non-steroidal anti-androgen drug proposed in the treatment of metastatic prostatic carcinoma. Its therapeutic effects are overshadowed by the occurrence of adverse reactions, mediated by mechanisms that remain elusive. To elucidate possible mechanisms for nilutamide toxicity, we investigated the metabolism of nilutamide in rat lung homogenates, in subcellular fractions and in freshly isolated cells. In whole lung homogenates, the nitro group of nilutamide was reduced to the amine and hydroxylamine moieties. These conversions occurred exclusively in the absence of dioxygen, were increased by the addition of FMN, FAD, or NADPH. Reductive metabolism of nilutamide to the amine and hydroxylamine was further evidenced in subcellular fractions obtained by differential ultracentrifugation. It was found to take place mainly in the cytosol of rat lung and to be stimulated, strongly, upon co-addition of NADPH and FMN. Addition of inhibitors of enzymes involved in the reductive metabolism of nitroaromatic compounds indicated that reduction of nilutamide involved, mainly, soluble flavoproteins. Incubations with freshly isolated lung cells revealed that macrophages were the main players in nitroreduction of nilutamide whereas the epithelial type II cells and the non-ciliated Clara cells were less efficient in catalyzing this reaction. Our results show that nilutamide is extensively reduced by lung tissues in the absence of oxygen, especially by enzymes found in alveolar macrophages. In accordance with recent findings, subcellular localization, oxygen sensitivity, cofactor requirements and inhibitor studies lead us to suggest the involvement of a soluble nitric oxide synthase in lung cytosolic nitroreduction.
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Affiliation(s)
- Kjetil Ask
- Laboratory of Pulmonary Pharmacology and Toxicology, UMR INRA/Université de Bourgogne 1234, Faculté de Médecine et de Pharmacie, Dijon, France.
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30
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Kumar P, McQuarrie SA, Zhou A, McEwan AJB, Wiebe LI. [131I]Iodoazomycin arabinoside for low-dose-rate isotope radiotherapy: radiolabeling, stability, long-term whole-body clearance and radiation dosimetry estimates in mice. Nucl Med Biol 2005; 32:647-53. [PMID: 16026712 DOI: 10.1016/j.nucmedbio.2005.04.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Revised: 04/17/2005] [Accepted: 04/27/2005] [Indexed: 11/24/2022]
Abstract
BACKGROUND The preliminary characterization of [(131)I]iodoazomycin arabinoside ([(131)I]IAZA) as a potential radiotherapeutic radiopharmaceutical is described. METHODS High-specific-activity [(131)I]IAZA was prepared in therapeutic doses (up to 3 GBq per batch) by isotope exchange in pivalic acid melt and was purified on Sep-Pak cartridges. Stability in 15% ethanol in saline at 4 degrees C was determined by high-performance liquid chromatography. IAZA cytotoxicity (IC(50), approximately 0.1 mM) against both murine (EMT-6) and human (143B, 143B-LTK) tumor cells determined by MTT test was in the range previously reported for EMT-6 cells using a clonogenic assay. Tissue radioactivity levels were measured in a murine tumor model for the 24- to 168-h postinjection period. Radiation dose estimates obtained from the tissue activity levels for this period were calculated from pharmacokinetic (WinNonlin) and dosimetry (MIRD and RAdiation Dose Assessment Resource) parameters. RESULTS The radioiodination efficiency was >90%, but with systematic losses during Sep-Pak purification, the recovered yields of [(131)I]IAZA were approximately 75%. The product (specific activity, 4.6-6.4 GBq/micromol) was stable for at least 2 weeks, with only approximately 6% degradation over this storage period. Extended biodistribution studies in Balb/c mice bearing implanted EMT-6 tumors showed that the highest tumor/blood radioactivity ratio (T/B; 4.8) occurred 24 h after dosing; the T/B ratio was approximately 1.5 at the end of the 7-day study. The 24- to 168-h tissue radioactivity data fit a one-compartment model except for liver data, which best fit a two-compartment model. Dosimetry estimates showed a tumor self-dose of 7.4 mGy/MBq, which is several-fold higher than for the liver or the kidney. CONCLUSIONS [(131)I]IAZA can be efficiently radiolabeled at high specific activity, purified by a simple Sep-Pak technique and stored with little radiolysis or chemical decomposition at these specific activities. Based on measured radioactivity burdens during the week following injection and on published animal ([(125)I]IAZA) and clinical ([(123)I]IAZA) dosimetry data, the current dose estimates point to selective tumor irradiation at low dose rates.
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Affiliation(s)
- Piyush Kumar
- Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada T6G 2N8
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31
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Sun Y, Iemitsu M, Shimojo N, Miyauchi T, Amamiya M, Sumi D, Hayashi T, Sun G, Shimojo N, Kumagai Y. 2,4,6-Trinitrotoluene inhibits endothelial nitric oxide synthase activity and elevates blood pressure in rats. Arch Toxicol 2005; 79:705-10. [PMID: 16025313 DOI: 10.1007/s00204-005-0003-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2005] [Accepted: 06/01/2005] [Indexed: 10/25/2022]
Abstract
2,4,6-Trinitrotoluene (TNT), which is widely used in explosives, is an important occupational and environmental pollutant. Human exposure to TNT has been reported to be associated with cardiovascular dysfunction, but the mechanism is not well understood. In this study, we examine the endothelial nitric oxide synthase (eNOS) activity and blood pressure value following TNT exposure. With a crude enzyme preparation, we found that TNT inhibited the enzyme activity of eNOS in a concentration-dependent manner (IC50 value = 49.4 microM). With an intraperitoneal administration of TNT (10 and 30 mg/kg) to rats, systolic blood pressure was significantly elevated 1 h after TNT exposure (1.2- and 1.3-fold of that of the control, respectively). Under the conditions, however, experiments with the inducible NOS inhibitor aminoguanidine revealed that an adaptive response against hypertension caused by TNT occurs. These results suggest that TNT is an environmental chemical that acts as an uncoupler of constitutive NOS isozymes, resulting in decreased nitric oxide formation associated with hypertension in rats.
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Affiliation(s)
- Yang Sun
- Doctoral Programs in Medicine Sciences, Graduate School of Comprehensive Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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Stair EL, Reddy G, Ritchey JW, Saliki JT, Quails CW. Effects of 1,3,5-Trinitrobenzene on cytotoxicity and metabolic activity of type I astrocytes of rats. Int J Toxicol 2005; 24:51-7. [PMID: 15981740 DOI: 10.1080/10915810590918724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
1,3,5-Trinitrobenzene (TNB) is a munitions chemical that causes gliovascular lesions in the brain stem of rats similar to those produced by thiamine deficiency and nitroaromatic compounds, including m-dinitrobenzene. To identify neuropathic indices of toxicity, the effects of varying concentrations (0 to 2 mM) of TNB on cytotoxicity and cellular metabolic activity were examined using cultured astrocytes from Fischer-344 rats. The cytotoxicity was assessed by lactate dehydrogenase (LDH) leakage into the culture medium. Astrocyte metabolic activity was assessed by measuring the conversion of a tetrazolium salt to a formazan product. Additionally, the effects of oxidative stress on cellular metabolic activity were determined by varying oxygen tension via alteration of culture media depth. In vitro, the toxic concentration 50% (TC50) of TNB, which induced cell death, was 16 microM following a 24-h exposure. The concentration of TNB that reduced cellular metabolic activity by 50% was 29 microM following a 24-h exposure. Varying the depth of the culture media did not influence the cellular metabolic activity in control or TNB-treated astrocytes. These results support the hypothesis that TNB induced neurotoxicity could partially be mediated via injury to astrocytes, a major component of the blood-brain barrier.
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Affiliation(s)
- Eric L Stair
- Department of Pathology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
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Abstract
Giardiasis is a worldwide disease that can cause serious morbidity. Metronidozole is the current recommended drug for treatment, and is mostly still effective. However, Giardia duodenalis, the causative agent, is capable of developing resistance to high levels of metronidozole and other drugs, in vitro, via a number of mechanisms. Resistance, in vivo, has been reported and many cases of treatment failure have been variously attributed to a number of causes, including resistance. Here, Jacqueline and Peter Upcroft ask: is this the beginning of another chapter of drug resistance? or is the situation likely to remain as a 'few refractory cases'? Should we wait to find out or can we act positively to avert the possibility of yet another valuable drug in our limited pharmacopoeia becoming obsolete?
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Affiliation(s)
- J A Upcroft
- The Queensland Institute of Medical Research, The Bancroft Centre, 300 Herston Rd, Herston, Queensland 4029, Australia
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Kumagai Y, Kikushima M, Nakai Y, Shimojo N, Kunimoto M. Neuronal nitric oxide synthase (NNOS) catalyzes one-electron reduction of 2,4,6-trinitrotoluene, resulting in decreased nitric oxide production and increased nNOS gene expression: implication for oxidative stress. Free Radic Biol Med 2004; 37:350-7. [PMID: 15223068 DOI: 10.1016/j.freeradbiomed.2004.04.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2003] [Revised: 03/22/2004] [Accepted: 04/22/2004] [Indexed: 11/23/2022]
Abstract
To determine the mechanism of 2,4,6-trinitrotoluene (TNT)-induced oxidative stress involving neuronal nitric oxide synthase (nNOS), we examined alterations in enzyme activity and gene expression of nNOS by TNT, with an enzyme preparation and rat cerebellum primary neuronal cells. TNT inhibited nitric oxide formation (IC(50) = 12.4 microM) as evaluated by citrulline formation in a 20,000 g cerebellar supernatant preparation. A kinetic study revealed that TNT was a competitive inhibitor with respect to NADPH and a noncompetitive inhibitor with respect to L-arginine. It was found that purified nNOS was capable of reducing TNT, with a specific activity of 3900 nmol of NADPH oxidized/mg/min, but this reaction required CaCl(2)/calmodulin (CaM). An electron spin resonance (ESR) study indicated that superoxide (O(2)(.-)) was generated during reduction of TNT by nNOS. Exposure of rat cerebellum primary neuronal cells to TNT (25 microM) caused an intracellular generation of H(2)O(2), accompanied by a significant increase in nNOS mRNA levels. These results indicate that CaM-dependent one-electron reduction of TNT is catalyzed by nNOS, leading to a reduction in NO formation and generation of H(2)O(2) derived from O(2)(.-). Thus, it is suggested that upregulation of nNOS may represent an acute adaptation to an increase in oxidative stress during exposure to TNT.
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Affiliation(s)
- Yoshito Kumagai
- Social and Environmental Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
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Voltammetric studies on nitro radical anion formation from furazolidone and kinetic of the coupled chemical reaction. J Electroanal Chem (Lausanne) 2004. [DOI: 10.1016/j.jelechem.2004.01.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Gilmore WJ, Kirby GM. Endoplasmic reticulum stress due to altered cellular redox status positively regulates murine hepatic CYP2A5 expression. J Pharmacol Exp Ther 2003; 308:600-8. [PMID: 14610226 DOI: 10.1124/jpet.103.060111] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Murine hepatic cytochrome P450 2A5 (CYP2A5) is uniquely induced by a variety of agents that cause liver injury and inflammation, conditions that are typically associated with downregulation of P450s. We hypothesized that induction of CYP2A5 occurs in response to hepatocellular damage resulting in endoplasmic reticulum (ER) stress. Treatment of mice in vivo and mouse hepatocytes in primary culture with the CYP2A5 inducer pyrazole resulted in overexpression of the ER stress biomarker glucose-regulated protein (GRP) 78. Treatment of primary hepatocytes with ER stress activators thapsigargin, tunicamycin, and trans-4,5-dihydroxy-1,2-dithiane (DTT(ox)) and the calcium ionophore A23187 (calcimycin) resulted in elevated GRP78 mRNA levels; however, only the reducing agent DTT(ox) induced levels of CYP2A5 mRNA, protein, and coumarin 7-hydroxylase activity. To test the hypothesis that CYP2A5 induction is due to liver injury resulting from altered cellular redox status, we demonstrated that CYP2A5 induction, elevated serum alanine aminotransferase, and oxidative protein damage occur concurrently in pyrazole-treated mice. Pyrazole also induced the expression of cytosolic alpha and mu class glutathione S-transferase expression both in vivo and in primary mouse hepatocytes. Moreover, treatment of hepatocytes with the redox cycling quinone menadione resulted in overexpression of CYP2A5 and GSTM1 mRNA. Finally, pretreatment of hepatocytes with the antioxidants N-acetylcysteine and vitamin E attenuated pyrazole-mediated increases in CYP2A5 mRNA levels. These findings clearly indicate that induction of mouse hepatic CYP2A5 during liver injury occurs via a novel mechanism involving ER stress due to altered cellular redox status.
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Affiliation(s)
- W James Gilmore
- Department of Biomedical Sciences, University of Guelph, ON, Canada
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Biaglow JE, Ayene IS, Koch CJ, Donahue J, Stamato TD, Mieyal JJ, Tuttle SW. Radiation response of cells during altered protein thiol redox. Radiat Res 2003; 159:484-94. [PMID: 12643793 DOI: 10.1667/0033-7587(2003)159[0484:rrocda]2.0.co;2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The major focus of this work was to investigate how altered protein thiol redox homeostasis affects radiation-induced cell death. We used the cells of wild-type CHO cell line K1, the CHO cell line E89, which is null for G6PD activity, and a radiation-sensitive CHO cell line, XRS5. The protein-thiol redox status of cells was altered with cell-permeable disulfides, hydroxyethyldisulfide (HEDS) or lipoate. HEDS is primarily reduced by thioltransferase (glutaredoxin), with GSH as the electron donor. In contrast, lipoate is reduced by thioredoxin reductase. HEDS was reduced at a greater rate than lipoate by G6PD-containing K1 (wild-type) cells. Reduction of disulfides by G6PD-deficient cells was significantly slower with HEDS as substrate and was nearly absent with lipoate. The rate of reduction of HEDS by E89 cells decelerated to near zero by 30 min, whereas the reduction continued at nearly the same rate during the entire measurement period for K1 cells. HEDS treatment decreased the GSH and protein thiol (PSH) content more in G6PD-deficient cells than in G6PD-containing cells. On the other hand, lipoate did not significantly alter the protein thiol, but it increased the GSH in K1 cells. Acute depletion of GSH by l-buthionine-sulfoximine (l-BSO) in combination with dimethylfumarate significantly decreased the rate of reduction of HEDS by K1 cells close to that of G6PD-deficient cells. Prior GSH depletion by l-BSO alone significantly decreased the PSH in glucose-depleted E89 cells exposed to HEDS, but this did not occur with K1 cells. The radiation response of G6PD-deficient cells was significantly sensitized by HEDS, but HEDS did not have this effect on K1 cells. The DNA repair-deficient XRS5 CHO cells displayed the same capacity as K1 cells for HEDS reduction, and like K1 cells the XRS5 cells were not sensitized to radiation by HEDS treatment. Deprivation of glucose, which provides the substrate for G6PD in the oxidative pentose phosphate cycle, decreased the rate of bioreduction of HEDS and lipoate in G6PD-containing cells to the level in G6PD-deficient cells. In the absence of glucose, HEDS treatment diminished non-protein thiol and protein thiol to the same level as those in G6PD-deficient cells and sensitized the K1 cells to HEDS treatment. However, depletion of glucose did not alter the sensitivity of XRS5 cells in either the presence or absence of HEDS. Overall the results suggest a major role for pentose cycle control of protein redox state coupled to the activities of the thioltransferase and thioredoxin systems. The results also show that protein thiol status is a critical factor in cell survival after irradiation.
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Affiliation(s)
- John E Biaglow
- Department of Radiation Oncology and Biochemistry, University of Pennsylvania Medical School, Philadelphia, Pennsylvania 19104, USA.
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Kumar P, Ohkura K, Beiki D, Wiebe LI, Seki KI. Synthesis of 1-beta-D-(5-deoxy-5-iodoarabinofuranosyl)-2-nitroimidazole (beta-IAZA): a novel marker of tissue hypoxia. Chem Pharm Bull (Tokyo) 2003; 51:399-403. [PMID: 12672991 DOI: 10.1248/cpb.51.399] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present work describes the synthesis of the beta-isomer of 1-alpha-D-(5-deoxy-5-iodoarabinofuranosyl)-2-nitroimidazole (IAZA). Radioiodinated IAZA ((123)I-IAZA) has been extensively studied as a radiopharmaceutical for the diagnosis of regional and/or focal tissue hypoxia in a variety of clinical pathologies. The beta-anomer of IAZA, 1-beta-D-(5-deoxy-5-iodoarabinofuranosyl)-2-nitroimidazole (beta-IAZA, 1), was synthesized via an unconventional route starting from 1-beta-D-(ribofuranosyl)-2-nitroimidazole (AZR), with a change of configuration at the C-2'-position to afford 1-beta-D-(arabinofuranosyl)-2-nitroimidazole (beta-AZA, 7). Nucleophilic iodination of the 5'-O-toluenesulfonyl-2',3'-di-O-acetyl precursor of beta-AZA, 9, followed by deprotection, afforded 1 in satisfactory yield. beta-IAZA (1) was also synthesized from 7 using molecular iodine and triphenylphosphine.
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Affiliation(s)
- Piyush Kumar
- Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
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Gilmore WJ, Hartmann G, Piquette-Miller M, Marriott J, Kirby GM. Effects of lipopolysaccharide-stimulated inflammation and pyrazole-mediated hepatocellular injury on mouse hepatic Cyp2a5 expression. Toxicology 2003; 184:211-26. [PMID: 12499123 DOI: 10.1016/s0300-483x(02)00581-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Murine hepatic cytochrome P450 2a5 (Cyp2a5) is induced during hepatotoxicity and hepatitis, however, the specific regulatory mechanisms have not been determined. We compared the influence of acute inflammation elicited in vivo by bacterial endotoxin lipopolysaccharide (LPS) and liver injury caused by the hepatotoxin pyrazole on hepatic Cyp2a5 expression in mice. Pyrazole treatment resulted in statistically significant increases in levels of Cyp2a5 mRNA, protein and catalytic activity by 540, 273 and 711%, respectively (P<0.05). In LPS-treated livers Cyp2a5 expression was significantly reduced compared to controls at the mRNA (46%) protein (35%), and activity (23%) levels (P<0.05). Treatment of mice with recombinant murine interleukin-1 beta and interleukin-6 had no significant effect on Cyp2a5 mRNA and protein levels. Liver injury, as assessed by serum alanine aminotransferase, was greater with pyrazole than with LPS treatment (609 vs 354% of control levels respectively). ER stress, determined by hepatic glucose regulated protein 78 (grp78) levels, was greater with pyrazole (185% of controls) than with LPS (128% of controls). In pyrazole-treated liver, overexpression of immunoreactive grp78 protein revealed that ER stress was localized to pericentral hepatocytes in which Cyp2a5 was induced. Evidence of glycogen loss and membrane damage in these cells was suggestive of oxidative damage. Moreover, vitamin E attenuated Cyp2a5 induction by pyrazole in vivo. These results suggest that induction of Cyp2a5 that has been observed in mouse models of hepatitis and hepatoxicity may be related to oxidative injury to the endoplasmic reticulum of pericentral hepatocytes rather than exposure to pro-inflammatory cytokines.
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Affiliation(s)
- W James Gilmore
- Department of Biomedical Sciences, University of Guelph, Ont., Canada
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Miller TJ, Phelka AD, Tjalkens RB, Dethloff LA, Philbert MA. CI-1010 induced opening of the mitochondrial permeability transition pore precedes oxidative stress and apoptosis in SY5Y neuroblastoma cells. Brain Res 2003; 963:43-56. [PMID: 12560110 DOI: 10.1016/s0006-8993(02)03838-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The hetero-bifunctional nitroimidazole radiosensitizer CI-1010, R-alpha-[[(2-bromoethyl)-amino]methyl]-2-nitro-1H-imidazole-1-ethanol monohydrobromide, causes selective irreversible apoptotic loss of retinal photoreceptor cells in vivo. The human neuroblastoma cell line, SH-SY5Y, was used as a neuronotypic model of CI-1010-mediated retinal degeneration. Exposure to CI-1010 for 24 h induced apoptosis in neuroblastoma cells, as determined by histopathological and ultrastructural analysis and by TUNEL technique. CI-1010 causes a dose-dependent decrease in cell viability in SY5Y cells, as measured by the reduction of MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. Superoxide dismutase reduced loss of cell viability following CI-1010 treatment suggesting an oxidative stress-mediated mechanism of toxicity. The effects of CI-1010 on mitochondrial membrane potential and intracellular levels of reactive oxygen species were assessed in live SY5Y cells by confocal microscopy using the fluorescent dyes, tetramethylrhodamine methyl ester and 5,6-carboxy-2',7'-dihydrodichlorofluorescein diacetate. CI-1010 caused a rapid depolarization of mitochondria in SY5Y cells followed by an increase in ROS. Both CI-1010-induced mitochondrial depolarization and subsequent increases in ROS were prevented by pretreatment with either the permeability transition pore inhibitor, cyclosporin A (CsA), and by the antioxidant, alpha-tocopherol. However, CsA and alpha-tocopherol were unable to prevent apoptosis in CI-1010-treated cells, suggesting the influence of additional mechanism(s) of CI-1010-induced toxicity. This study evaluates intracellular oxidative stress associated with pore opening prior to apoptosis and provides evidence in support of a mitochondrial mechanism of CI-1010-induced neuronal cell death.
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Affiliation(s)
- Terry J Miller
- Toxicology Program, Department of Environmental Health Sciences, The University of Michigan, 1420 Washington Heights, SPH II Ann Arbor, MI 48109-2029, USA
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Kumar P, Wiebe LI, Mannan RH, Zhang Z, Xia H, McEwan AJB. [99mTc]Technetium labelled PnAo-azomycin glucuronides: a novel class of imaging markers of tissue hypoxia. Appl Radiat Isot 2002; 57:719-28. [PMID: 12433047 DOI: 10.1016/s0969-8043(02)00188-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Azomycin glucuronate was coupled to a PnAO ligand to create azomycin-based ligands that would form water-soluble 99mTc-azomycin complexes for imaging hypoxic tissue. 1-beta-D-(2-Nitroimidazolyl)glucuronic acid, (see structure in text), was synthesized by coupling 2-nitroimidazole with 1-alpha-bromo-2,3,4-tri-O-acetyl-6-methyl glucuronate, followed by deprotection. Reaction of (see structure in text) with 6-methyl-6-methylamino-HMPnAO (Pn-44) in the presence of BOP reagent in anhydrous dimethyl sulfoxide afforded the PnAO-glucuronides (see structure in text) and (see structure in text). Compound (see structure in text) was isolated in three rotomeric forms. Biological evaluation of (see structure in text) (99mTc-5) indicated selective binding to hypoxic EMT-6 cells, and cytotoxicity to fibroblasts and HeLa, sk24, sk23, and g361 cancer cell lines, at an IC20 <2.5 microgram/ml. In vivo biodistribution of two formulations of (see structure in text) in Balb/c mice with EMT-6 tumor produced diverse results, with one formulation showing no tumor preference, and the other providing a tumor/blood ratio of 2.3 at 4 h post-injection. The latter formulation delineated tumor, large intestine and liver in scintigraphic images.
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Affiliation(s)
- Piyush Kumar
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
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Kumar P, Wiebe LI, Asikoglu M, Tandon M, McEwan AJB. Microwave-assisted (radio)halogenation of nitroimidazole-based hypoxia markers. Appl Radiat Isot 2002; 57:697-703. [PMID: 12433044 DOI: 10.1016/s0969-8043(02)00185-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Microwave-assisted radiohalogenation for the production of short-lived radiopharmaceuticals has now been applied to the synthesis and radiolabelling of azomycin nucleosides. (Radio)halogens were incorporated either by nucleophilic substitution of a leaving group or by halogen-halogen exchange, in the synthesis of IAZA, IAZP and FAZA. A comparison of conventional labelling and microwave-assisted labelling procedures reflects a clear advantage of the microwave technique.
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Affiliation(s)
- P Kumar
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada
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La-Scalea MA, Serrano SHP, Ferreira EI, Brett AMO. Voltammetric behavior of benznidazole at a DNA-electrochemical biosensor. J Pharm Biomed Anal 2002; 29:561-8. [PMID: 12062657 DOI: 10.1016/s0731-7085(02)00081-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Benznidazole is a drug used commonly as a therapeutic agent against Chagas' disease in Brazil. To clarify the cytotoxic action of benznidazole the electrochemical reduction of benznidazole has been investigated using a DNA-electrochemical biosensor, prepared by modification of a glassy carbon electrode with DNA, and the results compared with reduction at a bare glassy carbon electrode. The dependence of peak potential with pH follows slopes of 59 and 52 mV per pH unit in acid media, respectively, which corresponds to a mechanism involving the same number of electrons and protons. In neutral and alkaline solution no significant dependence of peak potential with pH was found. During the electrochemical reduction of benznidazole the formation of the hydroxylamine derivative occurs, involving a total of four electrons. The potentials for reduction were less negative when using the DNA-modified glassy carbon electrode than at the bare glassy carbon electrode although the mechanism was the same, and at pH 7.51 the peak current was four times higher than that obtained with the bare electrode. The DNA-biosensor enabled pre-concentration of the drug onto the electrode surface and the in situ damage caused to the DNA on the electrode surface by the product of benznidazole reduction could be detected electrochemically. The results are in agreement with the hypothesis that the hydroxylamine derivative is the reactive species responsible for the cytotoxic action of benznidazole.
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Affiliation(s)
- M A La-Scalea
- Departamento de Farmácia, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 580, 05508-900 São Paulo, Brazil
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Magda D, Lepp C, Gerasimchuk N, Lee I, Sessler JL, Lin A, Biaglow JE, Miller RA. Redox cycling by motexafin gadolinium enhances cellular response to ionizing radiation by forming reactive oxygen species. Int J Radiat Oncol Biol Phys 2001; 51:1025-36. [PMID: 11704327 DOI: 10.1016/s0360-3016(01)01810-7] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
PURPOSE To examine the mechanism of radiation enhancement by motexafin gadolinium (Gd-Tex) in vitro. METHODS AND MATERIALS Oxidation of ascorbate and NADPH by Gd-Tex was evaluated in a neutral buffer. Growth inhibition of human uterine cancer cell line MES-SA was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) dye. Clonogenic assays were used to measure radiation response in MES-SA, A549 human lung carcinoma, E89, a CHO cell line variant deficient in glucose-6-phosphate dehydrogenase activity, and murine lymphoma cell lines LYAR and LYAS. RESULTS Gd-Tex catalyzed the oxidation of NADPH and ascorbate under aerobic conditions, forming hydrogen peroxide. Decreased viability was observed in MES-SA cells incubated with Gd-Tex in media containing NADPH or ascorbate. Gd-Tex and ascorbate increased fluorescence in dichlorofluorescin acetate-treated cultures. Synergistic effects on the aerobic radiation response in MES-SA and A549 were seen using Gd-Tex in combination with L-buthionine-(S,R)-sulfoximine (BSO). Incubation with Gd-Tex in the presence of ascorbate increased the aerobic radiation response of E89 and the apoptosis-sensitive B-cell line (LYAS). CONCLUSIONS Gd-Tex sensitizes cells to ionizing radiation by increasing oxidative stress as a consequence of futile redox cycling. Optimization of the concentration of ascorbate (or other reducing species) may be required when evaluating Gd-Tex activity in vitro.
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Affiliation(s)
- D Magda
- Pharmacyclics, Inc., Sunnyvale, CA 94085, USA
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Carbajo J, Bollo S, Núñez-Vergara L, Navarrete P, Squella J. Voltammetric studies of aromatic nitro compounds: pH-dependence on decay of the nitro radical anion in mixed media. J Electroanal Chem (Lausanne) 2000. [DOI: 10.1016/s0022-0728(00)00343-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Kumagai Y, Wakayama T, Lib S, Shinohara A, Iwamatsu A, Sun G, Shimojo N. Zeta-crystallin catalyzes the reductive activation of 2,4,6-trinitrotoluene to generate reactive oxygen species: a proposed mechanism for the induction of cataracts. FEBS Lett 2000; 478:295-8. [PMID: 10930585 DOI: 10.1016/s0014-5793(00)01841-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Exposure to 2,4,6-trinitrotoluene (TNT) has been shown to cause induction of cataract in which oxidative stress plays a critical role. From bovine lens we purified to homogeneity and identified an enzyme that catalyzes the reduction of TNT, resulting in the production of reactive oxygen species. The final preparation of TNT reductase showed a single band with a subunit molecular weight of 38 kDa on SDS-PAGE. Sequence data from peptides obtained by digestion with lysylendopeptidase Achromobacter protease I (API) revealed that TNT reductase is identical to zeta-crystallin. Superoxide anions were formed during reduction of TNT by zeta-crystallin, though negligible enzyme activity or protein content for superoxide dismutase, a superoxide scavenging enzyme, was found in the lens. Thus, the present results suggest that the induction of cataracts by TNT may be associated with increased oxidative stress, as a result of reductive activation of TNT generating superoxide anions, there being minimal antioxidant enzyme activity for defense against reactive oxygen species exogenously produced in the lens.
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Affiliation(s)
- Y Kumagai
- Department of Environment Medicine, Institute of Community Medicine, Master's Program in Environmental Sciences, Tsukuba University, Ibaraki, Japan.
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Wassmann C, Bruchhaus I. Superoxide dismutase reduces susceptibility to metronidazole of the pathogenic protozoan Entamoeba histolytica under microaerophilic but not under anaerobic conditions. Arch Biochem Biophys 2000; 376:236-8. [PMID: 10729211 DOI: 10.1006/abbi.2000.1707] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- C Wassmann
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, Hamburg, 20359, Germany
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Wassmann C, Hellberg A, Tannich E, Bruchhaus I. Metronidazole resistance in the protozoan parasite Entamoeba histolytica is associated with increased expression of iron-containing superoxide dismutase and peroxiredoxin and decreased expression of ferredoxin 1 and flavin reductase. J Biol Chem 1999; 274:26051-6. [PMID: 10473552 DOI: 10.1074/jbc.274.37.26051] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
To obtain insight into the mechanism of metronidazole resistance in the protozoan parasite Entamoeba histolytica, amoeba trophozoites were selected in vitro by stepwise exposures to increasing amounts of metronidazole, starting with sublethal doses of 4 microM. Subsequently, amoebae made resistant were able to continuously multiply in the presence of a 40 microM concentration of the drug. In contrast to mechanisms of metronidazole resistance in other protozoan parasites, resistant amoebae did not substantially down-regulate pyruvate:ferredoxin oxidoreductase or up-regulate P-glycoproteins, but exhibited increased expression of iron-containing superoxide dismutase (Fe-SOD) and peroxiredoxin and decreased expression of flavin reductase and ferredoxin 1. Episomal transfection and overexpression of the various antioxidant enzymes revealed significant reduction in susceptibility to metronidazole only in those cells overexpressing Fe-SOD. Reduction was highest in transfected cells simultaneously overexpressing Fe-SOD and peroxiredoxin. Although induced overexpression of Fe-SOD did not confer metronidazole resistance to the extent found in drug-selected cells, transfected cells quickly adapted to constant exposures of otherwise lethal metronidazole concentrations. Moreover, metronidazole selection of transfected amoebae favored retention of the Fe-SOD-containing plasmid. These results strongly suggest that peroxiredoxin and, in particular, Fe-SOD together with ferredoxin 1 are important components involved in the mechanism of metronidazole resistance in E. histolytica.
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Affiliation(s)
- C Wassmann
- Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Strasse 74, 20359 Hamburg, Germany
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Morais Jr. MAD, Ferreira RDCC, Ferreira LCDS. Mutagenic activation of CL64,855, an anti-Trypanosoma cruzi nitroderivant, by bacterial nitroreductases. Genet Mol Biol 1998. [DOI: 10.1590/s1415-47571998000400026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
CL64,855 is a nitroimidazole-thiodiazole derivate with high anti-Trypanosoma cruzi activity. CL64,855-induced mutagenesis in the Salmonella/microsome test was detected by TA98 and TA98dnp6 strains, but not by the nitroreductase I-deficient TA98nr strain. The lack of mutagenic response of TA98nr was connected with its extreme resistance to the killing effect of the drug. Presence of S9 mix did not restore mutagenic activity of CL64,855 to the TA98nr strain. Additionally, CL64,855 was reduced in vitro by the nitroreductase I-proficient TA98 strain, mainly in the presence of oxygen, but not by the TA98nr strain. Mutagenic activity was detected in serum samples of treated guinea pigs by nitroreductase-proficient strains TA98 and TA98dnp6, but not by nitroductase-deficient strain TA98nr. In the case of urine, mutagenic activity was observed with all three tested strains, suggesting an in vivo metabolic activation of the drug by a distinct metabolic pathway.
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