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Hofer M, Hoferová Z, Falk M. Pharmacological Modulation of Radiation Damage. Does It Exist a Chance for Other Substances than Hematopoietic Growth Factors and Cytokines? Int J Mol Sci 2017; 18:E1385. [PMID: 28657605 PMCID: PMC5535878 DOI: 10.3390/ijms18071385] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 06/21/2017] [Accepted: 06/26/2017] [Indexed: 02/03/2023] Open
Abstract
In recent times, cytokines and hematopoietic growth factors have been at the center of attention for many researchers trying to establish pharmacological therapeutic procedures for the treatment of radiation accident victims. Two granulocyte colony-stimulating factor-based radiation countermeasures have been approved for the treatment of the hematopoietic acute radiation syndrome. However, at the same time, many different substances with varying effects have been tested in animal studies as potential radioprotectors and mitigators of radiation damage. A wide spectrum of these substances has been studied, comprising various immunomodulators, prostaglandins, inhibitors of prostaglandin synthesis, agonists of adenosine cell receptors, herbal extracts, flavonoids, vitamins, and others. These agents are often effective, relatively non-toxic, and cheap. This review summarizes the results of animal experiments, which show the potential for some of these untraditional or new radiation countermeasures to become a part of therapeutic procedures applicable in patients with the acute radiation syndrome. The authors consider β-glucan, 5-AED (5-androstenediol), meloxicam, γ-tocotrienol, genistein, IB-MECA (N⁶-(3-iodobezyl)adenosine-5'-N-methyluronamide), Ex-RAD (4-carboxystyryl-4-chlorobenzylsulfone), and entolimod the most promising agents, with regards to their contingent use in clinical practice.
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Affiliation(s)
- Michal Hofer
- Department of Cell Biology and Radiobiology, Institute of Biophysics, v.v.i., Czech Academy of Sciences, Královopolská 135, 61265 Brno, Czech Republic.
| | - Zuzana Hoferová
- Department of Cell Biology and Radiobiology, Institute of Biophysics, v.v.i., Czech Academy of Sciences, Královopolská 135, 61265 Brno, Czech Republic.
| | - Martin Falk
- Department of Cell Biology and Radiobiology, Institute of Biophysics, v.v.i., Czech Academy of Sciences, Královopolská 135, 61265 Brno, Czech Republic.
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Anwar M, Ahmad S, Akhtar R, Mahmood A, Mahmood S. Antioxidant Supplementation: A Linchpin in Radiation-Induced Enteritis. Technol Cancer Res Treat 2017; 16:676-691. [PMID: 28532242 PMCID: PMC5762044 DOI: 10.1177/1533034617707598] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Radiation enteritis is one of the most feared complications of abdominal and pelvic regions. Thus, radiation to abdominal or pelvic malignancies unavoidably injures the intestine. Because of rapid cell turnover, the intestine is highly sensitive to radiation injury, which is the limiting factor in the permissible dosage of irradiation. Bowel injuries such as fistulas, strictures, and chronic malabsorption are potentially life-threatening complications and have an impact on patient quality of life. The incidence of radiation enteritis is increasing because of the current trend of combined chemotherapy and radiation. The consequences of radiation damage to the intestine may result in considerable morbidity and even mortality. The observed effects of ionizing radiation are mediated mainly by oxygen-free radicals that are generated by its action on water and are involved in several steps of signal transduction cascade, leading to apoptosis. The oxyradicals also induce DNA strand breaks and protein oxidation. An important line of defense against free radical damage is the presence of antioxidants. Therefore, administration of antioxidants may ameliorate the radiation-induced damage to the intestine.
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Affiliation(s)
- Mumtaz Anwar
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Shabeer Ahmad
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Reyhan Akhtar
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Akhtar Mahmood
- Department of Biochemistry, Panjab University, Chandigarh, India
| | - Safrun Mahmood
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Satyamitra M, Kumar VP, Biswas S, Cary L, Dickson L, Venkataraman S, Ghosh SP. Impact of Abbreviated Filgrastim Schedule on Survival and Hematopoietic Recovery after Irradiation in Four Mouse Strains with Different Radiosensitivity. Radiat Res 2017; 187:659-671. [PMID: 28362168 DOI: 10.1667/rr14555.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Filgrastim (Neupogen®, granulocyte-colony stimulating factor) is among the few countermeasures recommended for management of patients in the event of lethal total-body irradiation. Despite the plethora of studies using filgrastim as a radiation countermeasure, relatively little is known about the optimal dose schedule of filgrastim to mitigate radiation lethality. We evaluated the efficacy of filgrastim in improving 30-day survival of CD2F1 mice irradiated with a lethal dose (LD70/30) in the AFRRI cobalt-60 facility. We tested different schedules of 1, 3, 5, 10 or 16 once-daily injections of filgrastim initiated one day after irradiation. Time optimization studies with filgrastim treatment were also performed, beginning 6-48 h postirradiation. Maximum survival was observed with 3 daily doses of 0.17 mg/kg filgrastim. Survival efficacy of the 3-day treatment was compared against the conventional 16-day filgrastim treatment after irradiation in four mouse strains with varying radiation sensitivities: C3H/HeN, C57BL/6, B6C3F1 and CD2F1. Blood indices, bone marrow histopathology and colony forming unit assays were also evaluated. Filgrastim significantly increased 30-day survival (P < 0.001) with a 3-day treatment compared to 16-day treatment. Filgrastim did not prevent cytopenia nadirs, but facilitated faster recovery of white blood cells, neutrophils, red blood cells, platelets, lymphocytes and hematocrits in all four strains. Accelerated hematopoietic recovery was also reflected in faster bone marrow reconstitution and significant increase in hematopoietic progenitors (P < 0.001) in all four mouse strains. These data indicate that prompt and abbreviated filgrastim treatment has potential benefit for triage in the event of a radiological incident for treating acute hematopoietic syndrome.
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Affiliation(s)
- Merriline Satyamitra
- a Radiation and Nuclear Countermeasure Program, DAIT, NIAID, NIH, Bethesda, Maryland 20889
| | - Vidya P Kumar
- b Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, Maryland 20889
| | - Shukla Biswas
- b Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, Maryland 20889
| | - Lynnette Cary
- b Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, Maryland 20889
| | - Leonora Dickson
- b Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, Maryland 20889
| | - Srinivasan Venkataraman
- b Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, Maryland 20889
| | - Sanchita P Ghosh
- b Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, Maryland 20889
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Li ZT, Wang LM, Yi LR, Jia C, Bai F, Peng RJ, Yu ZY, Xiong GL, Xing S, Shan YJ, Yang RF, Dong JX, Cong YW. Succinate ester derivative of δ-tocopherol enhances the protective effects against 60Co γ-ray-induced hematopoietic injury through granulocyte colony-stimulating factor induction in mice. Sci Rep 2017; 7:40380. [PMID: 28145432 PMCID: PMC5286428 DOI: 10.1038/srep40380] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 12/06/2016] [Indexed: 12/20/2022] Open
Abstract
α-tocopherol succinate (α-TOS), γ-tocotrienol (GT3) and δ-tocotrienol (DT3) have drawn large attention due to their efficacy as radioprotective agents. α-TOS has been shown to act superior to α-tocopherol (α-TOH) in mice by reducing lethality following total body irradiation (TBI). Because α-TOS has been shown to act superior to α-tocopherol (α-TOH) in mice by reducing lethality following total body irradiation (TBI), we hypothesized succinate may be contribute to the radioprotection of α-TOS. To study the contributions of succinate and to identify stronger radioprotective agents, we synthesized α-, γ- and δ-TOS. Then, we evaluated their radioprotective effects and researched further mechanism of δ-TOS on hematological recovery post-irradiation. Our results demonstrated that the chemical group of succinate enhanced the effects of α-, γ- and δ-TOS upon radioprotection and granulocyte colony-stimulating factor (G-CSF) induction, and found δ-TOS a higher radioprotective efficacy at a lower dosage. We further found that treatment with δ-TOS ameliorated radiation-induced pancytopenia, augmenting cellular recovery in bone marrow and the colony forming ability of bone marrow cells in sublethal irradiated mice, thus promoting hematopoietic stem and progenitor cell recovery following irradiation exposure. δ-TOS appears to be an attractive radiation countermeasure without known toxicity, but further exploratory efficacy studies are still required.
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Affiliation(s)
- Zhong-Tang Li
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Li-Mei Wang
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Li-Rong Yi
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Chao Jia
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Fan Bai
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Ren-Jun Peng
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Zu-Yin Yu
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Guo-Lin Xiong
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Shuang Xing
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Ya-Jun Shan
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Ri-Fang Yang
- Department of Medicinal Chemistry, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Jun-Xing Dong
- Department of Pharmaceutical Sciences, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Beijing, China
| | - Yu-Wen Cong
- Department of Pathophysiology, Beijing Institute of Radiation Medicine, Beijing, China
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Ledet GA, Biswas S, Kumar VP, Graves RA, Mitchner DM, Parker TM, Bostanian LA, Ghosh SP, Mandal TK. Development of Orally Administered γ-Tocotrienol (GT3) Nanoemulsion for Radioprotection. Int J Mol Sci 2016; 18:ijms18010028. [PMID: 28029115 PMCID: PMC5297663 DOI: 10.3390/ijms18010028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 12/02/2016] [Accepted: 12/14/2016] [Indexed: 12/31/2022] Open
Abstract
The purpose of this study was two-fold: (1) to formulate γ-tocotrienol (GT3) in a nanoemulsion formulation as a prophylactic orally administered radioprotective agent; and (2) to optimize the storage conditions to preserve the structural integrity of both the formulation and the compound. γ-tocotrienol was incorporated into a nanoemulsion and lyophilized with lactose. Ultra performance liquid chromatography–mass spectroscopy (UPLC–MS) was used to monitor the chemical stability of GT3 over time, the particle size and ζ potential, and scanning electron microscopy (SEM) were used to study the physical stability of the nanoemulsion. Radioprotective and toxicity studies were performed in mice. The liquid formulation exhibited GT3 degradation at all storage temperatures. Lyophilization, in the presence of lactose, significantly reduced GT3 degradation. Both the liquid and lyophilized nanoemulsions had stable particle size and ζ potential when stored at 4 °C. Toxicity studies of the nanoemulsion resulted in no observable toxicity in mice at an oral dose of 600 mg/kg GT3. The nano-formulated GT3 (300 mg/kg) demonstrated enhanced survival efficacy compared to GT3 alone (200 and 400 mg/kg) in CD2F1 mice exposed to total body gamma radiation. The optimal long-term storage of formulated GT3 is as a powder at −20 °C to preserve drug and formulation integrity. Formulation of GT3 as a nanoemulsion for oral delivery as a prophylactic radioprotectant shows promise and warrants further investigation.
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Affiliation(s)
- Grace A Ledet
- Center for Nanomedicine & Drug Delivery, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA 70125, USA.
| | - Shukla Biswas
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
| | - Vidya P Kumar
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
| | - Richard A Graves
- Center for Nanomedicine & Drug Delivery, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA 70125, USA.
| | - Demaurian M Mitchner
- Center for Nanomedicine & Drug Delivery, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA 70125, USA.
| | - Taylor M Parker
- Center for Nanomedicine & Drug Delivery, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA 70125, USA.
| | - Levon A Bostanian
- Center for Nanomedicine & Drug Delivery, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA 70125, USA.
| | - Sanchita P Ghosh
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
| | - Tarun K Mandal
- Center for Nanomedicine & Drug Delivery, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA 70125, USA.
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Sharma D, Goel HC, Chauhan S. Radioprotective potential of Lagenaria siceraria extract against radiation-induced gastrointestinal injury. Appl Physiol Nutr Metab 2016; 41:1248-1254. [DOI: 10.1139/apnm-2016-0136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The cucurbits (prebiotics) were investigated as novel agents for radio-modification against gastrointestinal injury. The cell-cycle fractions and DNA damage were monitored in HCT-15 cells. A cucurbit extract was added to culture medium 2 h before irradiation (6 Gy) and was substituted by fresh medium at 4 h post-irradiation. The whole extract of the fruits of Lagenaria siceraria, Luffa cylindrica, or Cucurbita pepo extract enhanced G2 fractions (42%, 34%, and 37%, respectively) as compared with control (20%) and irradiated control (31%). With cucurbits, the comet tail length remained shorter (L. siceraria, 28 μm; L. cylindrica, 34.2 μm; C. pepo, 36.75 μm) than irradiated control (41.75 μm). For in vivo studies, L. siceraria extract (2 mg/kg body weight) was administered orally to mice at 2 h before and 4 and 24 h after whole-body irradiation (10 Gy). L. siceraria treatment restored the glutathione contents to 48.8 μmol/gm as compared with control (27.6 μmol/gm) and irradiated control (19.6 μmol/gm). Irradiation reduced the villi height from 379 to 350 μm and width from 54 to 27 μm. L. siceraria administration countered the radiation effects (length, 366 μm; width, 30 μm, respectively) and improved the villi morphology and tight junction integrity. This study reveals the therapeutic potential of cucurbits against radiation-induced gastrointestinal injury.
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Affiliation(s)
- Dhara Sharma
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
| | - Harish Chandra Goel
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
| | - Sonal Chauhan
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
- Dhara Sharma, Amity Center for Radiation Biology, Amity University, Sector-125, Noida-201303, U.P., India
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Menon N, Rogers CJ, Lukaszewicz AI, Axtelle J, Yadav M, Song F, Chakravarti A, Jacob NK. Detection of Acute Radiation Sickness: A Feasibility Study in Non-Human Primates Circulating miRNAs for Triage in Radiological Events. PLoS One 2016; 11:e0167333. [PMID: 27907140 PMCID: PMC5132176 DOI: 10.1371/journal.pone.0167333] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/11/2016] [Indexed: 11/19/2022] Open
Abstract
Development of biomarkers capable of estimating absorbed dose is critical for effective triage of affected individuals after radiological events. Levels of cell-free circulating miRNAs in plasma were compared for dose-response analysis in non-human primates (NHP) exposed to lethal (6.5 Gy) and sub-lethal (1 and 3 Gy) doses over a 7 day period. The doses and test time points were selected to mimic triage needs in the event of a mass casualty radiological event. Changes in miRNA abundance in irradiated animals were compared to a non-irradiated cohort and a cohort experiencing acute inflammation response from exposure to lipopolysaccharide (LPS). An amplification-free, hybridization-based direct digital counting method was used for evaluation of changes in microRNAs in plasma from all animals. Consistent with previous murine studies, circulating levels of miR-150-5p exhibited a dose- and time-dependent decrease in plasma. Furthermore, plasma miR-150-5p levels were found to correlate well with lymphocyte and neutrophil depletion kinetics. Additionally, plasma levels of several other evolutionarily and functionally conserved miRNAs were found altered as a function of dose and time. Interestingly, miR-574-5p exhibited a distinct, dose-dependent increase 24 h post irradiation in NHPs with lethal versus sub-lethal exposure before returning to the baseline level by day 3. This particular miRNA response was not detected in previous murine studies but was observed in animals exposed to LPS, indicating distinct molecular and inflammatory responses. Furthermore, an increase in low-abundant miR-126, miR-144, and miR-21 as well as high-abundant miR-1-3p and miR-206 was observed in irradiated animals on day 3 and/or day 7. The data from this study could be used to develop a multi-marker panel with known tissue-specific origin that could be used for developing rapid assays for dose assessment and evaluation of radiation injury on multiple organs. Furthermore this approach may be utilized to screen for tissue toxicity in patients who receive myeloablative and therapeutic radiation.
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Affiliation(s)
- Naresh Menon
- ChromoLogic LLC, Monrovia, California, United States of America
| | | | | | - James Axtelle
- ChromoLogic LLC, Monrovia, California, United States of America
| | - Marshleen Yadav
- Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center Columbus, Ohio, United States of America
| | - Feifei Song
- Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center Columbus, Ohio, United States of America
| | - Arnab Chakravarti
- Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center Columbus, Ohio, United States of America
| | - Naduparambil K. Jacob
- Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center Columbus, Ohio, United States of America
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Koch A, Gulani J, King G, Hieber K, Chappell M, Ossetrova N. Establishment of Early Endpoints in Mouse Total-Body Irradiation Model. PLoS One 2016; 11:e0161079. [PMID: 27579862 PMCID: PMC5007026 DOI: 10.1371/journal.pone.0161079] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/29/2016] [Indexed: 01/31/2023] Open
Abstract
Acute radiation sickness (ARS) following exposure to ionizing irradiation is characterized by radiation-induced multiorgan dysfunction/failure that refers to progressive dysfunction of two or more organ systems, the etiological agent being radiation damage to cells and tissues over time. Radiation sensitivity data on humans and animals has made it possible to describe the signs associated with ARS. A mouse model of total-body irradiation (TBI) has previously been developed that represents the likely scenario of exposure in the human population. Herein, we present the Mouse Intervention Scoring System (MISS) developed at the Veterinary Sciences Department (VSD) of the Armed Forces Radiobiology Research Institute (AFRRI) to identify moribund mice and decrease the numbers of mice found dead, which is therefore a more humane refinement to death as the endpoint. Survival rates were compared to changes in body weights and temperatures in the mouse (CD2F1 male) TBI model (6–14 Gy, 60Co γ-rays at 0.6 Gy min-1), which informed improvements to the Scoring System. Individual tracking of animals via implanted microchips allowed for assessment of criteria based on individuals rather than by group averages. From a total of 132 mice (92 irradiated), 51 mice were euthanized versus only four mice that were found dead (7% of non-survivors). In this case, all four mice were found dead after overnight periods between observations. Weight loss alone was indicative of imminent succumbing to radiation injury, however mice did not always become moribund within 24 hours while having weight loss >30%. Only one survivor had a weight loss of greater than 30%. Temperature significantly dropped only 2–4 days before death/euthanasia in 10 and 14 Gy animals. The score system demonstrates a significant refinement as compared to using subjective assessment of morbidity or death as the endpoint for these survival studies.
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Affiliation(s)
- Amory Koch
- Veterinary Science Department, Armed Forces Radiobiology Research Institute (AFRRI) Uniformed Services University (USU), Bethesda, Maryland, United States of America
- * E-mail:
| | - Jatinder Gulani
- Veterinary Science Department, Armed Forces Radiobiology Research Institute (AFRRI) Uniformed Services University (USU), Bethesda, Maryland, United States of America
- The Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
| | - Gregory King
- Scientific Research Department, Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University (USU), Bethesda, Maryland, United States of America
| | - Kevin Hieber
- The Henry M. Jackson Foundation, Bethesda, Maryland, United States of America
- Scientific Research Department, Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University (USU), Bethesda, Maryland, United States of America
| | - Mark Chappell
- Veterinary Science Department, Armed Forces Radiobiology Research Institute (AFRRI) Uniformed Services University (USU), Bethesda, Maryland, United States of America
| | - Natalia Ossetrova
- Scientific Research Department, Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University (USU), Bethesda, Maryland, United States of America
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Ossetrova NI, Ney PH, Condliffe DP, Krasnopolsky K, Hieber KP. Acute Radiation Syndrome Severity Score System in Mouse Total-Body Irradiation Model. HEALTH PHYSICS 2016; 111:134-144. [PMID: 27356057 DOI: 10.1097/hp.0000000000000499] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Radiation accidents or terrorist attacks can result in serious consequences for the civilian population and for military personnel responding to such emergencies. The early medical management situation requires quantitative indications for early initiation of cytokine therapy in individuals exposed to life-threatening radiation doses and effective triage tools for first responders in mass-casualty radiological incidents. Previously established animal (Mus musculus, Macaca mulatta) total-body irradiation (γ-exposure) models have evaluated a panel of radiation-responsive proteins that, together with peripheral blood cell counts, create a multiparametic dose-predictive algorithm with a threshold for detection of ~1 Gy from 1 to 7 d after exposure as well as demonstrate the acute radiation syndrome severity score systems created similar to the Medical Treatment Protocols for Radiation Accident Victims developed by Fliedner and colleagues. The authors present a further demonstration of the acute radiation sickness severity score system in a mouse (CD2F1, males) TBI model (1-14 Gy, Co γ-rays at 0.6 Gy min) based on multiple biodosimetric endpoints. This includes the acute radiation sickness severity Observational Grading System, survival rate, weight changes, temperature, peripheral blood cell counts and radiation-responsive protein expression profile: Flt-3 ligand, interleukin 6, granulocyte-colony stimulating factor, thrombopoietin, erythropoietin, and serum amyloid A. Results show that use of the multiple-parameter severity score system facilitates identification of animals requiring enhanced monitoring after irradiation and that proteomics are a complementary approach to conventional biodosimetry for early assessment of radiation exposure, enhancing accuracy and discrimination index for acute radiation sickness response categories and early prediction of outcome.
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Affiliation(s)
- Natalia I Ossetrova
- *Uniformed Services University (USU), Armed Forces Radiobiology Research Institute (AFRRI), Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889-5603; †United States Army Medical Command (MEDCOM), United States Army Medical Research Institute of Chemical Defense (USAMRICD), 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010-5400
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Protection against Radiotherapy-Induced Toxicity. Antioxidants (Basel) 2016; 5:antiox5030022. [PMID: 27399787 PMCID: PMC5039571 DOI: 10.3390/antiox5030022] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 06/27/2016] [Accepted: 06/28/2016] [Indexed: 01/18/2023] Open
Abstract
Radiation therapy is a highly utilized therapy in the treatment of malignancies with up to 60% of cancer patients receiving radiation therapy as a part of their treatment regimen. Radiation therapy does, however, cause a wide range of adverse effects that can be severe and cause permanent damage to the patient. In an attempt to minimize these effects, a small number of compounds have been identified and are in use clinically for the prevention and treatment of radiation associated toxicities. Furthermore, there are a number of emerging therapies being developed for use as agents that protect against radiation-induced toxicities. The aim of this review was to evaluate and summarise the evidence that exists for both the known radioprotectant agents and the agents that show promise as future radioprotectant agents.
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Liu X, Gujarathi S, Zhang X, Shao L, Boerma M, Compadre CM, Crooks PA, Hauer-Jensen M, Zhou D, Zheng G. Synthesis of (2 R,8' S,3' E)-δ-tocodienol, a tocoflexol family member designed to have a superior pharmacokinetic profile compared to δ-tocotrienol. Tetrahedron 2016; 72:4001-4006. [PMID: 27773949 PMCID: PMC5070675 DOI: 10.1016/j.tet.2016.05.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A group of side chain partially saturated tocotrienol analogues, namely tocoflexols, have been previously designed in an effort to improve the pharmacokinetic properties of tocotrienols. (2R,8'S,3'E,11'E)-δ-Tocodienol (1) was predicted to be a high value tocoflexol for further pharmacological evaluation. We now report here an efficient 8-step synthetic route to compound 1 utilizing naturally-occurring δ-tocotrienol as a starting material (24% total yield). The key step in the synthesis is oxidative olefin cleavage of δ-tocotrienol to afford the chroman core of 1 with retention of chirality at the C-2 stereocenter.
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Affiliation(s)
- Xingui Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Satheesh Gujarathi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Xuan Zhang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Lijian Shao
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Marjan Boerma
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Cesar M. Compadre
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Peter A. Crooks
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Martin Hauer-Jensen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Daohong Zhou
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Guangrong Zheng
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
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Pathak R, Bachri A, Ghosh SP, Koturbash I, Boerma M, Binz RK, Sawyer JR, Hauer-Jensen M. The Vitamin E Analog Gamma-Tocotrienol (GT3) Suppresses Radiation-Induced Cytogenetic Damage. Pharm Res 2016; 33:2117-25. [PMID: 27216753 PMCID: PMC4967083 DOI: 10.1007/s11095-016-1950-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/13/2016] [Indexed: 01/24/2023]
Abstract
Purpose Ionizing radiation (IR) generates reactive oxygen species (ROS), which cause DNA double-strand breaks (DSBs) that are responsible for cytogenetic alterations. Because antioxidants are potent ROS scavengers, we determined whether the vitamin E isoform γ-tocotrienol (GT3), a radio-protective multifunctional dietary antioxidant, can suppress IR-induced cytogenetic damage. Methods We measured DSB formation in irradiated primary human umbilical vein endothelial cells (HUVECs) by quantifying the formation of γ-H2AX foci. Chromosomal aberrations (CAs) were analyzed in irradiated HUVECs and in the bone marrow cells of irradiated mice by conventional and fluorescence-based chromosome painting techniques. Gene expression was measured in HUVECs with quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Results GT3 pretreatment reduced DSB formation in HUVECS, and also decreased CAs in HUVECs and mouse bone marrow cells after irradiation. Moreover, GT3 increased expression of the DNA-repair gene RAD50 and attenuated radiation-induced RAD50 suppression. Conclusions GT3 attenuates radiation-induced cytogenetic damage, possibly by affecting RAD50 expression. GT3 should be explored as a therapeutic to reduce the risk of developing genetic diseases after radiation exposure.
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Affiliation(s)
- Rupak Pathak
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Biomed I, Suite 238, 4301 West Markham, Slot 522-3, Little Rock, Arkansas, 72205, USA.
| | - Abdel Bachri
- Department of Engineering and Engineering Physics, Southern Arkansas University, Magnolia, Arkansas, USA
| | - Sanchita P Ghosh
- Armed Forces Radiobiology Research Institute, USUHS, Bethesda, Maryland, USA
| | - Igor Koturbash
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Marjan Boerma
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Biomed I, Suite 238, 4301 West Markham, Slot 522-3, Little Rock, Arkansas, 72205, USA
| | - Regina K Binz
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jeffrey R Sawyer
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Martin Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Biomed I, Suite 238, 4301 West Markham, Slot 522-3, Little Rock, Arkansas, 72205, USA
- Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA
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Singh VK, Hauer-Jensen M. γ-Tocotrienol as a Promising Countermeasure for Acute Radiation Syndrome: Current Status. Int J Mol Sci 2016; 17:E663. [PMID: 27153057 PMCID: PMC4881489 DOI: 10.3390/ijms17050663] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/03/2016] [Accepted: 04/25/2016] [Indexed: 01/13/2023] Open
Abstract
The hazard of ionizing radiation exposure due to nuclear accidents or terrorist attacks is ever increasing. Despite decades of research, still, there is a shortage of non-toxic, safe and effective medical countermeasures for radiological and nuclear emergency. To date, the U.S. Food and Drug Administration (U.S. FDA) has approved only two growth factors, Neupogen (granulocyte colony-stimulating factor (G-CSF), filgrastim) and Neulasta (PEGylated G-CSF, pegfilgrastim) for the treatment of hematopoietic acute radiation syndrome (H-ARS) following the Animal Efficacy Rule. Promising radioprotective efficacy results of γ-tocotrienol (GT3; a member of the vitamin E family) in the mouse model encouraged its further evaluation in the nonhuman primate (NHP) model. These studies demonstrated that GT3 significantly aided the recovery of radiation-induced neutropenia and thrombocytopenia compared to the vehicle controls; these results particularly significant after exposure to 5.8 or 6.5 Gray (Gy) whole body γ-irradiation. The stimulatory effect of GT3 on neutrophils and thrombocytes (platelets) was directly and positively correlated with dose; a 75 mg/kg dose was more effective compared to 37.5 mg/kg. GT3 was also effective against 6.5 Gy whole body γ-irradiation for improving neutrophils and thrombocytes. Moreover, a single administration of GT3 without any supportive care was equivalent, in terms of improving hematopoietic recovery, to multiple doses of Neupogen and two doses of Neulasta with full supportive care (including blood products) in the NHP model. GT3 may serve as an ultimate radioprotector for use in humans, particularly for military personnel and first responders. In brief, GT3 is a promising radiation countermeasure that ought to be further developed for U.S. FDA approval for the ARS indication.
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Affiliation(s)
- Vijay K Singh
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20889, USA.
| | - Martin Hauer-Jensen
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare Systems, Little Rock, AR 72205, USA.
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Ghosh SP, Pathak R, Kumar P, Biswas S, Bhattacharyya S, Kumar VP, Hauer-Jensen M, Biswas R. Gamma-Tocotrienol Modulates Radiation-Induced MicroRNA Expression in Mouse Spleen. Radiat Res 2016; 185:485-95. [PMID: 27128741 DOI: 10.1667/rr14248.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Ionizing radiation causes depletion of hematopoietic cells and enhances the risk of developing secondary hematopoietic malignancies. Vitamin E analog gamma-tocotrienol (GT3), which has anticancer properties, promotes postirradiation hematopoietic cell recovery by enhancing spleen colony-forming capacity, and provides protection against radiation-induced lethality in mice. However, the underlying molecular mechanism involved in GT3-mediated postirradiation survival is not clearly understood. Recent studies have shown that natural dietary products including vitamin E provide a benefit to biological systems by modulating microRNA (miR) expression. In this study, we show that GT3 differentially modulates the miR footprint in the spleen of irradiated mice compared to controls at early times (day 1), as well as later times (day 4 and 15) after total-body irradiation. We observed that miR expression was altered in a dose- and time-dependent manner in GT3-pretreated spleen tissues from total-body irradiated mice. GT3 appeared to affect the expression of a number of radiation-modulated miRs known to be involved in hematopoiesis and lymphogenesis. Moreover, GT3 pretreatment also suppressed the upregulation of radiation-induced p53, suggesting the function of GT3 in the prevention of radiation-induced damage to the spleen. In addition, we have shown that GT3 significantly reduced serum levels of Flt3L, a biomarker of radiation-induced bone marrow aplasia. Further in silico analyses of the effect of GT3 implied the association of p38 MAPK, ERK and insulin signaling pathways. Our study provides initial insight into the mechanism by which GT3 mediates protection of spleen after total-body irradiation.
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Affiliation(s)
- Sanchita P Ghosh
- a Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences Scientific Research Department, Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Rupak Pathak
- b Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Parameet Kumar
- c Anatomy, Physiology and Genetics, School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland; and
| | - Shukla Biswas
- a Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences Scientific Research Department, Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | | | - Vidya P Kumar
- a Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences Scientific Research Department, Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Martin Hauer-Jensen
- b Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Roopa Biswas
- c Anatomy, Physiology and Genetics, School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland; and
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Singh VK, Kulkarni S, Fatanmi OO, Wise SY, Newman VL, Romaine PLP, Hendrickson H, Gulani J, Ghosh SP, Kumar KS, Hauer-Jensen M. Radioprotective Efficacy of Gamma-Tocotrienol in Nonhuman Primates. Radiat Res 2016; 185:285-98. [DOI: 10.1667/rr14127.1] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Vijay K. Singh
- Department of Radiation Biology, F. Edward Hébert School of Medicine, “America's Medical School” Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Shilpa Kulkarni
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland
| | | | - Stephen Y. Wise
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland
| | | | | | - Howard Hendrickson
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare Systems, Little Rock, Arkansas; and
| | - Jatinder Gulani
- Veterinary Sciences Department, Armed Forces Radiobiology Research Institute, Bethesda, Maryland
| | | | - K. Sree Kumar
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland
| | - Martin Hauer-Jensen
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare Systems, Little Rock, Arkansas; and
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Abstract
The discovery of vitamin E (α-tocopherol) began in 1922 as a vital component required in reproduction. Today, there are eight naturally occurring vitamin E isoforms, namely α-, β-, γ- and δ-tocopherol and α-, β-, γ- and δ-tocotrienol. Vitamin E is potent antioxidants, capable of neutralizing free radicals directly by donating hydrogen from its chromanol ring. α-Tocopherol is regarded the dominant form in vitamin E as the α-tocopherol transfer protein in the liver binds mainly α-tocopherol, thus preventing its degradation. That contributed to the oversight of tocotrienols and resulted in less than 3% of all vitamin E publications studying tocotrienols. Nevertheless, tocotrienols have been shown to possess superior antioxidant and anti-inflammatory properties over α-tocopherol. In particular, inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reductase to lower cholesterol, attenuating inflammation via downregulation of transcription factor NF-κB activation, and potent radioprotectant against radiation damage are some properties unique to tocotrienols, not tocopherols. Aside from cancer, vitamin E has also been shown protective in bone, cardiovascular, eye, nephrological and neurological diseases. In light of the different pharmacological properties of tocopherols and tocotrienols, it becomes critical to specify which vitamin E isoform(s) are being studied in any future vitamin E publications. This review provides an update on vitamin E therapeutic potentials, protective effects and modes of action beyond cancer, with comparison of tocopherols against tocotrienols. With the concerted efforts in synthesizing novel vitamin E analogs and clinical pharmacology of vitamin E, it is likely that certain vitamin E isoform(s) will be therapeutic agents against human diseases besides cancer.
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Affiliation(s)
- Hong Yong Peh
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, Singapore
| | - W S Daniel Tan
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, Singapore
| | - Wupeng Liao
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, Singapore
| | - W S Fred Wong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, Singapore; Immunology Program, Life Science Institute, National University of Singapore, Singapore.
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Vitamin E Analogs as Radiation Response Modifiers. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:741301. [PMID: 26366184 PMCID: PMC4558447 DOI: 10.1155/2015/741301] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/06/2015] [Accepted: 07/22/2015] [Indexed: 02/07/2023]
Abstract
The potentially life-threatening effects of total body ionizing radiation exposure have been known for more than a century. Despite considerable advances in our understanding of the effects of radiation over the past six decades, efforts to identify effective radiation countermeasures for use in case of a radiological/nuclear emergency have been largely unsuccessful. Vitamin E is known to have antioxidant properties capable of scavenging free radicals, which have critical roles in radiation injuries. Tocopherols and tocotrienols, vitamin E analogs together known as tocols, have shown promise as radioprotectors. Although the pivotal mechanisms of action of tocols have long been thought to be their antioxidant properties and free radical scavenging activities, other alternative mechanisms have been proposed to drive their activity as radioprotectors. Here we provide a brief overview of the effects of ionizing radiation, the mechanistic mediators of radiation-induced damage, and the need for radiation countermeasures. We further outline the role for, efficacy of, and mechanisms of action of tocols as radioprotectors, and we compare and contrast their efficacy and mode of action with that of another well-studied chemical radioprotector, amifostine.
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Nimesh H, Tiwari V, Yang C, Gundala SR, Chuttani K, Hazari PP, Mishra AK, Sharma A, Lal J, Katyal A, Aneja R, Tandon V. Preclinical Evaluation of DMA, a Bisbenzimidazole, as Radioprotector: Toxicity, Pharmacokinetics, and Biodistribution Studies in Balb/c Mice. Mol Pharmacol 2015; 88:768-78. [DOI: 10.1124/mol.115.098376] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 07/29/2015] [Indexed: 11/22/2022] Open
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Kordsmeier M, Howard LR, Brownmiller C, Proctor A, Hauer-Jensen M. Isolation of Gamma and Delta Tocotrienols from Rice Bran Oil Deodorizer Distillate Using Flash Chromatography. J AM OIL CHEM SOC 2015. [DOI: 10.1007/s11746-015-2696-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Singh VK, Romaine PL, Seed TM. Medical Countermeasures for Radiation Exposure and Related Injuries: Characterization of Medicines, FDA-Approval Status and Inclusion into the Strategic National Stockpile. HEALTH PHYSICS 2015; 108:607-630. [PMID: 25905522 PMCID: PMC4418776 DOI: 10.1097/hp.0000000000000279] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/05/2015] [Indexed: 05/28/2023]
Abstract
World events over the past decade have highlighted the threat of nuclear terrorism as well as an urgent need to develop radiation countermeasures for acute radiation exposures and subsequent bodily injuries. An increased probability of radiological or nuclear incidents due to detonation of nuclear weapons by terrorists, sabotage of nuclear facilities, dispersal and exposure to radioactive materials, and accidents provides the basis for such enhanced radiation exposure risks for civilian populations. Although the search for suitable radiation countermeasures for radiation-associated injuries was initiated more than half a century ago, no safe and effective radiation countermeasure for the most severe of these injuries, namely acute radiation syndrome (ARS), has been approved by the United States Food and Drug Administration (FDA). The dearth of FDA-approved radiation countermeasures has prompted intensified research for a new generation of radiation countermeasures. In this communication, the authors have listed and reviewed the status of radiation countermeasures that are currently available for use, or those that might be used for exceptional nuclear/radiological contingencies, plus a limited few medicines that show early promise but still remain experimental in nature and unauthorized for human use by the FDA.
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Affiliation(s)
- Vijay K. Singh
- *Radiation Countermeasures Program, Armed Forces Radiobiology Research Institute, Bethesda, MD; †Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD; ‡Tech Micro Services, Bethesda, MD
| | - Patricia L.P. Romaine
- *Radiation Countermeasures Program, Armed Forces Radiobiology Research Institute, Bethesda, MD; †Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD; ‡Tech Micro Services, Bethesda, MD
| | - Thomas M. Seed
- *Radiation Countermeasures Program, Armed Forces Radiobiology Research Institute, Bethesda, MD; †Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD; ‡Tech Micro Services, Bethesda, MD
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71
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Pathak R, Shao L, Ghosh SP, Zhou D, Boerma M, Weiler H, Hauer-Jensen M. Thrombomodulin contributes to gamma tocotrienol-mediated lethality protection and hematopoietic cell recovery in irradiated mice. PLoS One 2015; 10:e0122511. [PMID: 25860286 PMCID: PMC4393275 DOI: 10.1371/journal.pone.0122511] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 02/12/2015] [Indexed: 01/09/2023] Open
Abstract
Systemic administration of recombinant thrombomodulin (TM) confers radiation protection partly by accelerating hematopoietic recovery. The uniquely potent radioprotector gamma tocotrienol (GT3), in addition to being a strong antioxidant, inhibits the enzyme hydroxy-methyl-glutaryl-coenzyme A reductase (HMGCR) and thereby likely modulates the expression of TM. We hypothesized that the mechanism underlying the exceptional radioprotective properties of GT3 partly depends on the presence of endothelial TM. In vitro studies confirmed that ionizing radiation suppresses endothelial TM (about 40% at 4 hr after 5 Gy γ-irradiation) and that GT3 induces TM expression (about 2 fold at the mRNA level after 5 μM GT3 treatment for 4 hr). In vivo survival studies showed that GT3 was significantly more effective as a radioprotector in TM wild type (TM+/+) mice than in mice with low TM function (TMPro/-). After exposure to 9 Gy TBI, GT3 pre-treatment conferred 85% survival in TM+/+ mice compared to only 50% in TMPro/-. Thus, GT3-mediated radiation lethality protection is partly dependent on endothelial TM. Significant post-TBI recovery of hematopoietic cells, particularly leukocytes, was observed in TM+/+ mice (p = 0.003), but not in TMPro/- mice, despite the fact that GT3 induced higher levels of granulocyte colony stimulating factor (G-CSF) in TMPro/- mice (p = 0.0001). These data demonstrate a critical, G-CSF-independent, role for endothelial TM in GT3-mediated lethality protection and hematopoietic recovery after exposure to TBI and may point to new strategies to enhance the efficacy of current medical countermeasures in radiological/nuclear emergencies.
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Affiliation(s)
- Rupak Pathak
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
- * E-mail:
| | - Lijian Shao
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Sanchita P. Ghosh
- Armed Forces Radiobiology Research Institute, USUHS, Bethesda, MD, United States of America
| | - Daohong Zhou
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Marjan Boerma
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Hartmut Weiler
- Blood Research Institute, Blood Center of Wisconsin and the Medical College of Wisconsin, Milwaukee, WI, United States of America
| | - Martin Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
- Surgical Service, Central Arkansas Veterans Healthcare System, Little Rock, AR, United States of America
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Sridharan V, Tripathi P, Aykin-Burns N, Krager KJ, Sharma SK, Moros EG, Melnyk SB, Pavliv O, Hauer-Jensen M, Boerma M. A tocotrienol-enriched formulation protects against radiation-induced changes in cardiac mitochondria without modifying late cardiac function or structure. Radiat Res 2015; 183:357-66. [PMID: 25710576 PMCID: PMC4688041 DOI: 10.1667/rr13915.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Radiation-induced heart disease (RIHD) is a common and sometimes severe late side effect of radiation therapy for intrathoracic and chest wall tumors. We have previously shown that local heart irradiation in a rat model caused prolonged changes in mitochondrial respiration and increased susceptibility to mitochondrial permeability transition pore (mPTP) opening. Because tocotrienols are known to protect against oxidative stress-induced mitochondrial dysfunction, in this study, we examined the effects of tocotrienols on radiation-induced alterations in mitochondria, and structural and functional manifestations of RIHD. Male Sprague-Dawley rats received image-guided localized X irradiation to the heart to a total dose of 21 Gy. Twenty-four hours before irradiation, rats received a tocotrienol-enriched formulation or vehicle by oral gavage. Mitochondrial function and mitochondrial membrane parameters were studied at 2 weeks and 28 weeks after irradiation. In addition, cardiac function and histology were examined at 28 weeks. A single oral dose of the tocotrienol-enriched formulation preserved Bax/Bcl2 ratios and prevented mPTP opening and radiation-induced alterations in succinate-driven mitochondrial respiration. Nevertheless, the late effects of local heart irradiation pertaining to myocardial function and structure were not modified. Our studies suggest that a single dose of tocotrienols protects against radiation-induced mitochondrial changes, but these effects are not sufficient against long-term alterations in cardiac function or remodeling.
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Affiliation(s)
- Vijayalakshmi Sridharan
- University of Arkansas for Medical Sciences, Department of Pharmaceutical Sciences, Division of Radiation Health, Little Rock, Arkansas
| | - Preeti Tripathi
- University of Arkansas for Medical Sciences, Department of Pharmaceutical Sciences, Division of Radiation Health, Little Rock, Arkansas
| | - Nukhet Aykin-Burns
- University of Arkansas for Medical Sciences, Department of Pharmaceutical Sciences, Division of Radiation Health, Little Rock, Arkansas
| | - Kimberly J Krager
- University of Arkansas for Medical Sciences, Department of Pharmaceutical Sciences, Division of Radiation Health, Little Rock, Arkansas
| | - Sunil K. Sharma
- University of Arkansas for Medical Sciences, Department of Radiation Oncology, Little Rock, Arkansas
| | - Eduardo G. Moros
- Moffitt Cancer Center and Research Institute, Department of Radiation Oncology, Tampa, Florida
| | - Stepan B. Melnyk
- University of Arkansas for Medical Sciences, Department of Pediatrics, Little Rock Arkansas
| | - Oleksandra Pavliv
- University of Arkansas for Medical Sciences, Department of Pediatrics, Little Rock Arkansas
| | - Martin Hauer-Jensen
- University of Arkansas for Medical Sciences, Department of Pharmaceutical Sciences, Division of Radiation Health, Little Rock, Arkansas
- Surgical Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Marjan Boerma
- University of Arkansas for Medical Sciences, Department of Pharmaceutical Sciences, Division of Radiation Health, Little Rock, Arkansas
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Rosen EM, Day R, Singh VK. New approaches to radiation protection. Front Oncol 2015; 4:381. [PMID: 25653923 PMCID: PMC4299410 DOI: 10.3389/fonc.2014.00381] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 12/19/2014] [Indexed: 12/16/2022] Open
Abstract
Radioprotectors are compounds that protect against radiation injury when given prior to radiation exposure. Mitigators can protect against radiation injury when given after exposure but before symptoms appear. Radioprotectors and mitigators can potentially improve the outcomes of radiotherapy for cancer treatment by allowing higher doses of radiation and/or reduced damage to normal tissues. Such compounds can also potentially counteract the effects of accidental exposure to radiation or deliberate exposure (e.g., nuclear reactor meltdown, dirty bomb, or nuclear bomb explosion); hence they are called radiation countermeasures. Here, we will review the general principles of radiation injury and protection and describe selected examples of radioprotectors/mitigators ranging from small-molecules to proteins to cell-based treatments. We will emphasize agents that are in more advanced stages of development.
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Affiliation(s)
- Eliot M Rosen
- Departments of Oncology, Biochemistry and Molecular & Cellular Biology, and Radiation Medicine, Lombardi Comprehensive Cancer Center, Georgetown University School of Medicine , Washington, DC , USA
| | - Regina Day
- Department of Pharmacology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences , Bethesda, MD , USA
| | - Vijay K Singh
- Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences , Bethesda, MD , USA ; Radiation Countermeasures Program, Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences , Bethesda, MD , USA
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74
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Loganathan R, Radhakrishnan AK, Selvaduray KR, Nesaretnam K. Selective anti-cancer effects of palm phytonutrients on human breast cancer cells. RSC Adv 2015. [DOI: 10.1039/c4ra12343c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Palm TRF exhibited higher potential to induce death by apoptosis and cleavage of the PARP enzyme as well as suppress expression of NF-κB induced by exposure to TNF-α in human breast cancer cells compared to carotenoids, squalene and co-enzyme Q10.
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Affiliation(s)
- Radhika Loganathan
- Malaysian Palm Oil Board
- Bandar Baru Bangi
- Malaysia
- Pathology Division
- School of Medicine
| | - Ammu K. Radhakrishnan
- Pathology Division
- School of Medicine
- Faculty of Medicine and Health
- International Medical University
- 57000 Kuala Lumpur
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Singh VK, Wise SY, Fatanmi OO, Scott J, Romaine PLP, Newman VL, Verma A, Elliott TB, Seed TM. Progenitors mobilized by gamma-tocotrienol as an effective radiation countermeasure. PLoS One 2014; 9:e114078. [PMID: 25423021 PMCID: PMC4244184 DOI: 10.1371/journal.pone.0114078] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 11/03/2014] [Indexed: 11/18/2022] Open
Abstract
The purpose of this study was to elucidate the role of gamma-tocotrienol (GT3)-mobilized progenitors in mitigating damage to mice exposed to a supralethal dose of cobalt-60 gamma-radiation. CD2F1 mice were transfused 24 h post-irradiation with whole blood or isolated peripheral blood mononuclear cells (PBMC) from donors that had received GT3 72 h prior to blood collection and recipient mice were monitored for 30 days. To understand the role of GT3-induced granulocyte colony-stimulating factor (G-CSF) in mobilizing progenitors, donor mice were administered a neutralizing antibody specific to G-CSF or its isotype before blood collection. Bacterial translocation from gut to heart, spleen and liver of irradiated recipient mice was evaluated by bacterial culture on enriched and selective agar media. Endotoxin in serum samples also was measured. We also analyzed the colony-forming units in the spleens of irradiated mice. Our results demonstrate that whole blood or PBMC from GT3-administered mice mitigated radiation injury when administered 24 h post-irradiation. Furthermore, administration of a G-CSF antibody to GT3-injected mice abrogated the efficacy of blood or PBMC obtained from such donors. Additionally, GT3-mobilized PBMC inhibited the translocation of intestinal bacteria to the heart, spleen, and liver, and increased colony forming unit-spleen (CFU-S) numbers in irradiated mice. Our data suggests that GT3 induces G-CSF, which mobilizes progenitors and these progenitors mitigate radiation injury in recipient mice. This approach using mobilized progenitor cells from GT3-injected donors could be a potential treatment for humans exposed to high doses of radiation.
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Affiliation(s)
- Vijay K. Singh
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
- Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
- * E-mail:
| | - Stephen Y. Wise
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Oluseyi O. Fatanmi
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Jessica Scott
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Patricia L. P. Romaine
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Victoria L. Newman
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Amit Verma
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Thomas B. Elliott
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Thomas M. Seed
- Tech Micro Services, Bethesda, Maryland, United States of America
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Ahsan H, Ahad A, Iqbal J, Siddiqui WA. Pharmacological potential of tocotrienols: a review. Nutr Metab (Lond) 2014; 11:52. [PMID: 25435896 PMCID: PMC4247006 DOI: 10.1186/1743-7075-11-52] [Citation(s) in RCA: 166] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 10/15/2014] [Indexed: 02/06/2023] Open
Abstract
Tocotrienols, members of the vitamin E family, are natural compounds found in a number of vegetable oils, wheat germ, barley, and certain types of nuts and grains. Like tocopherols, tocotrienols are also of four types viz. alpha, beta, gamma and delta. Unlike tocopherols, tocotrienols are unsaturated and possess an isoprenoid side chain. Tocopherols are lipophilic in nature and are found in association with lipoproteins, fat deposits and cellular membranes and protect the polyunsaturated fatty acids from peroxidation reactions. The unsaturated chain of tocotrienol allows an efficient penetration into tissues that have saturated fatty layers such as the brain and liver. Recent mechanistic studies indicate that other forms of vitamin E, such as γ-tocopherol, δ-tocopherol, and γ-tocotrienol, have unique antioxidant and anti-inflammatory properties that are superior to those of α-tocopherol against chronic diseases. These forms scavenge reactive nitrogen species, inhibit cyclooxygenase- and 5-lipoxygenase-catalyzed eicosanoids and suppress proinflammatory signalling, such as NF-κB and STAT. The animal and human studies show tocotrienols may be useful against inflammation-associated diseases. Many of the functions of tocotrienols are related to its antioxidant properties and its varied effects are due to it behaving as a signalling molecule. Tocotrienols exhibit biological activities that are also exhibited by tocopherols, such as neuroprotective, anti-cancer, anti-inflammatory and cholesterol lowering properties. Hence, effort has been made to compile the different functions and properties of tocotrienols in experimental model systems and humans. This article constitutes an in-depth review of the pharmacology, metabolism, toxicology and biosafety aspects of tocotrienols. Tocotrienols are detectable at appreciable levels in the plasma after supplementations. However, there is inadequate data on the plasma concentrations of tocotrienols that are sufficient to demonstrate significant physiological effect and biodistribution studies show their accumulation in vital organs of the body. Considering the wide range of benefits that tocotrienols possesses against some common human ailments and having a promising potential, the experimental analysis accounts for about a small fraction of all vitamin E research. The current state of knowledge deserves further investigation into this lesser known form of vitamin E.
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Affiliation(s)
- Haseeb Ahsan
- Department of Biochemistry, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, 110025 India
| | - Amjid Ahad
- Department of Biochemistry, Jamia Hamdard (Hamdard University), New Delhi, 110062 India
| | - Jahangir Iqbal
- Department of Cell Biology and Pediatrics, SUNY Downstate Medical Center, Brooklyn, NY 11203 USA
| | - Waseem A Siddiqui
- Department of Biochemistry, Jamia Hamdard (Hamdard University), New Delhi, 110062 India
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77
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Swift SN, Pessu RL, Chakraborty K, Villa V, Lombardini E, Ghosh SP. Acute toxicity of subcutaneously administered vitamin E isomers delta- and gamma-tocotrienol in mice. Int J Toxicol 2014; 33:450-8. [PMID: 25355734 DOI: 10.1177/1091581814554929] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The toxicity of parenterally administered vitamin E isomers, delta-tocotrienol (DT3) and gamma-tocotrienol (GT3), was evaluated in male and female CD2F1 mice. In an acute toxicity study, a single dose of DT3 or GT3 was administered subcutaneously in a dose range of 200 to 800 mg/kg. A mild to moderately severe dermatitis was observed clinically and microscopically in animals at the injection site at doses above 200 mg/kg. The severity of the reaction was reduced when the drug concentration was lowered. Neither drug produced detectable toxic effects in any other tissue at the doses tested. Based on histopathological analysis for both DT3 and GT3, and macroscopic observations of inflammation at the injection site, a dose of 300 mg/kg was selected as the lowest toxic dose in a 30-day toxicity study performed in male mice. At this dose, a mild skin irritation occurred at the injection site that recovered completely by the end of the experimental period. At a dose of 300 mg/kg of DT3 or GT3, no adverse effects were observed in any tissues or organs.
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Affiliation(s)
- Sibyl N Swift
- Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Roli L Pessu
- Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Kushal Chakraborty
- Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Vilmar Villa
- Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Eric Lombardini
- Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Sanchita P Ghosh
- Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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78
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Singh VK, Newman VL, Romaine PLP, Wise SY, Seed TM. Radiation countermeasure agents: an update (2011-2014). Expert Opin Ther Pat 2014; 24:1229-55. [PMID: 25315070 PMCID: PMC4438421 DOI: 10.1517/13543776.2014.964684] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
INTRODUCTION Despite significant scientific advances over the past 60 years towards the development of a safe, nontoxic and effective radiation countermeasure for the acute radiation syndrome (ARS), no drug has been approved by the US FDA. A radiation countermeasure to protect the population at large from the effects of lethal radiation exposure remains a significant unmet medical need of the US citizenry and, thus, has been recognized as a high priority area by the government. AREA COVERED This article reviews relevant publications and patents for recent developments and progress for potential ARS treatments in the area of radiation countermeasures. Emphasis is placed on the advanced development of existing agents since 2011 and new agents identified as radiation countermeasure for ARS during this period. EXPERT OPINION A number of promising radiation countermeasures are currently under development, seven of which have received US FDA investigational new drug status for clinical investigation. Four of these agents, CBLB502, Ex-RAD, HemaMax and OrbeShield, are progressing with large animal studies and clinical trials. G-CSF has high potential and well-documented therapeutic effects in countering myelosuppression and may receive full licensing approval by the US FDA in the future.
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Affiliation(s)
- Vijay K Singh
- Armed Forces Radiobiology Research Institute , 8901 Wisconsin Ave, Bethesda, MD 20889-5603 , USA +1 301 295 2347 ; +1 301 295 6503 ;
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79
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Perona M, Dagrosa MA, Pagotto R, Casal M, Pignataro O, Pisarev MA, Juvenal GJ. Protective effect of an antithyroid compound against γ-radiation-induced damage in human colon cancer cells. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2014; 53:611-619. [PMID: 24811726 DOI: 10.1007/s00411-014-0542-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 04/13/2014] [Indexed: 06/03/2023]
Abstract
We have previously reported the radioprotective effect of propylthiouracil (PTU) on thyroid cells. The aim of the present study was to analyze whether tumor cells and normal cells demonstrate the same response to PTU. Human colon carcinoma cells were irradiated with γ-irradiation with or without PTU. We evaluated the clonogenic survival, intracellular reactive oxygen species levels, catalase, superoxide dismutase and glutathione peroxidase activities, and apoptosis by nuclear cell morphology and caspase-3 activity assays. Cyclic AMP (cAMP) levels were measured by radioimmunoassay. PTU treatment increased surviving cell fraction at 2 Gy (SF2) from 56.9 ± 3.6 in controls to 75.0 ± 3.5 (p < 0.05) and diminished radiation-induced apoptosis. In addition, we observed that the level of antioxidant enzymes' activity was increased in cells treated with PTU. Moreover, pretreatment with PTU increased intracellular levels of cAMP. Forskolin (p < 0.01) and dibutyryl cAMP (p < 0.05) mimicked the effect of PTU on SF2. Co-treatment with H89, an inhibitor of protein kinase A, abolished the radioprotective effect of PTU. PTU reduces the toxicity of ionizing radiation by increasing cAMP levels and also possibly through a reduction in apoptosis levels and in radiation-induced oxidative stress damage. We therefore conclude that PTU protects both normal and cancer cells during exposure to radiation in conditions mimicking the radiotherapy.
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Affiliation(s)
- Marina Perona
- Department of Radiobiology (CAC), National Atomic Energy Commission (CNEA), San Martín, Buenos Aires, Argentina
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80
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Singh VK, Wise SY, Fatanmi OO, Beattie LA, Seed TM. Preclinical development of a bridging therapy for radiation casualties: appropriate for high risk personnel. HEALTH PHYSICS 2014; 106:689-698. [PMID: 24776901 DOI: 10.1097/hp.0000000000000089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The authors demonstrate the efficacy of a bridging therapy in a preclinical animal model that allows the lymphohematopoietic system of severely immunocompromised individuals exposed to acute, high-dose ionizing irradiation to recover and to survive. CD2F1 mice were irradiated acutely with high doses causing severe, potentially fatal hematopoietic or gastrointestinal injuries and then transfused intravenously with progenitor-enriched, whole blood, or peripheral blood mononuclear cells from mice injected with tocopherol succinate- and AMD3100- (a chemokine receptor anatogonist used to improve the yield of mobilized progenitors). Survival of these mice over a 30-d period was used as the primary measured endpoint of therapeutic effectiveness. The authors demonstrate that tocopherol succinate and AMD3100 mobilize progenitors into peripheral circulation and that the infusion of mobilized progenitor enriched blood or mononuclear cells acts as a bridging therapy for lymphohematopoietic system recovery in mice exposed to whole-body ionizing irradiation. The results demonstrate that infusion of whole blood or blood mononuclear cells from tocopherol succinate (TS)- and AMD3100-injected mice improved the survival of mice receiving high radiation doses significantly. The efficacy of TS-injected donor mice blood or mononuclear cells was comparable to that of blood or cells obtained from mice injected with granulocyte colony-stimulating factor. Donor origin-mobilized progenitors were found to localize in various tissues. The authors suggest that tocopherol succinate is an optimal agent for mobilizing progenitors with significant therapeutic potential. The extent of progenitor mobilization that tocopherol succinate elicits in experimental mice is comparable quantitatively to clinically used drugs such as granulocyte-colony stimulating factor and AMD3100. Therefore, it is proposed that tocopherol succinate be considered for further translational development and ultimately for use in humans.
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Affiliation(s)
- Vijay K Singh
- *Armed Forces Radiobiology Research Institute, Bethesda, MD; †Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD; ‡Tech Micro Services, 4417 Maple Avenue, Bethesda, MD
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81
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Tissue distribution of emulsified γ-tocotrienol and its long-term biological effects after subcutaneous administration. Lipids Health Dis 2014; 13:66. [PMID: 24712339 PMCID: PMC4040479 DOI: 10.1186/1476-511x-13-66] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 04/05/2014] [Indexed: 01/11/2023] Open
Abstract
Background γ-tocotrienol (GT3), an analogue of vitamin E, has gained increasing scientific interest recently as it provides significant health benefits. It has been shown that emulsified GT3, after subcutaneous administration, has long-term biological effects. However, whether the effects are due to the increase of GT3 level in the early phase following administration or the persistent functions after accumulation in tissues is unknown. This study was conducted to determine the levels of GT3 in different tissues by high performance liquid chromatography (HPLC) with a fluorescence detector after a single-dose of GT3 with polyethylene glycol (PEG-400) emulsion via subcutaneous injection. Previous studies have explored that GT3 has favorable effects on bone and can inhibit osteoclast formation. To confirm the persistent biological activity of accumulated GT3 in tissues, receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) gene expressions, which have an important role in regulating osteoclast formation, were also evaluated in bone tissue on day 1, 3, 7 and 14 after a signal subcutaneous injection of GT3. Methods C57BL/6 female mice were administrated GT3 (100 mg/kg body weight) with PEG-400 emulsion by subcutaneous injection. GT3 levels in different tissues were determined by HPLC with a fluorescence detector. Gene expressions were measured by real-time PCR. Results GT3 predominantly accumulated in adipose and heart tissue, and was maintained at a relatively stable level in bone tissues after a single-dose administration. Accumulated GT3 in bone tissues significantly inhibited the increase in RANKL expression and the decrease in OPG expression induced by db-cAMP. Conclusions We investigated the tissue distribution of GT3 with PEG emulsion by subcutaneous administration, which has never been reported so far. Our results suggest that GT3 with PEG emulsion accumulated in tissues is able to carry out a long-term biological effect and has therapeutic value for treating and preventing osteoporosis.
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82
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Singh VK, Wise SY, Scott JR, Romaine PL, Newman VL, Fatanmi OO. Radioprotective efficacy of delta-tocotrienol, a vitamin E isoform, is mediated through granulocyte colony-stimulating factor. Life Sci 2014; 98:113-22. [DOI: 10.1016/j.lfs.2014.01.065] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 11/29/2013] [Accepted: 01/16/2014] [Indexed: 12/31/2022]
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83
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Anzai K, Ueno M, Matsumoto KI, Ikota N, Takata J. Gamma-tocopherol-N,N-dimethylglycine ester as a potent post-irradiation mitigator against whole body X-irradiation-induced bone marrow death in mice. JOURNAL OF RADIATION RESEARCH 2014; 55:67-74. [PMID: 23908555 PMCID: PMC3885127 DOI: 10.1093/jrr/rrt094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 06/05/2013] [Accepted: 06/24/2013] [Indexed: 06/02/2023]
Abstract
We examined the radioprotective and mitigative effects of gamma-tocopherol-N,N-dimethylglycine ester (GTDMG), a novel water-soluble gamma-tocopherol derivative, against X-irradiation-induced bone marrow death in mice. Mice (C3H, 10 weeks, male) were injected intraperitoneally with GTDMG suspended in a 0.5% methyl cellulose solution before or after receiving of 7.5-Gy whole body X-irradiation. GTDMG significantly enhanced the 30-day survival rate when given 30 min before or immediately after the irradiation. Its mitigative activity (administered after exposure) was examined further in detail. The optimal concentration of GTDMG given immediately after irradiation was around 100 mg/kg body weight (bw) and the 30-day survival rate was 97.6 ± 2.4%. When GTDMG was administered 1, 10 and 24 h post-irradiation, the survival rate was 85.7 ± 7.6, 75.0 ± 9.7 and 36.7 ± 8.8%, respectively, showing significant mitigation even at 24 h after irradiation (P < 0.05). The value of the dose reduction factor (100 mg/kg bw, given intraperitoneally (i.p.) immediately after irradiation) was 1.25. GTDMG enhanced the recovery of red blood cell-, white blood cell-, and platelet-counts after irradiation and significantly increased the number of endogenous spleen colonies (P < 0.05). Subcutaneous (s.c.) administration also had mitigative effects. In conclusion, GTDMG is a potent radiation mitigator.
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Affiliation(s)
- Kazunori Anzai
- Nihon Pharmaceutical University
- National Institute of Radiological Sciences
| | | | | | | | - Jiro Takata
- Faculty of Pharmaceutical Sciences, Fukuoka University
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84
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Ahsan H, Ahad A, Iqbal J, Siddiqui WA. Pharmacological potential of tocotrienols: a review. Nutr Metab (Lond) 2014. [PMID: 25435896 DOI: 10.1186/743-7075-11-52] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Abstract
Tocotrienols, members of the vitamin E family, are natural compounds found in a number of vegetable oils, wheat germ, barley, and certain types of nuts and grains. Like tocopherols, tocotrienols are also of four types viz. alpha, beta, gamma and delta. Unlike tocopherols, tocotrienols are unsaturated and possess an isoprenoid side chain. Tocopherols are lipophilic in nature and are found in association with lipoproteins, fat deposits and cellular membranes and protect the polyunsaturated fatty acids from peroxidation reactions. The unsaturated chain of tocotrienol allows an efficient penetration into tissues that have saturated fatty layers such as the brain and liver. Recent mechanistic studies indicate that other forms of vitamin E, such as γ-tocopherol, δ-tocopherol, and γ-tocotrienol, have unique antioxidant and anti-inflammatory properties that are superior to those of α-tocopherol against chronic diseases. These forms scavenge reactive nitrogen species, inhibit cyclooxygenase- and 5-lipoxygenase-catalyzed eicosanoids and suppress proinflammatory signalling, such as NF-κB and STAT. The animal and human studies show tocotrienols may be useful against inflammation-associated diseases. Many of the functions of tocotrienols are related to its antioxidant properties and its varied effects are due to it behaving as a signalling molecule. Tocotrienols exhibit biological activities that are also exhibited by tocopherols, such as neuroprotective, anti-cancer, anti-inflammatory and cholesterol lowering properties. Hence, effort has been made to compile the different functions and properties of tocotrienols in experimental model systems and humans. This article constitutes an in-depth review of the pharmacology, metabolism, toxicology and biosafety aspects of tocotrienols. Tocotrienols are detectable at appreciable levels in the plasma after supplementations. However, there is inadequate data on the plasma concentrations of tocotrienols that are sufficient to demonstrate significant physiological effect and biodistribution studies show their accumulation in vital organs of the body. Considering the wide range of benefits that tocotrienols possesses against some common human ailments and having a promising potential, the experimental analysis accounts for about a small fraction of all vitamin E research. The current state of knowledge deserves further investigation into this lesser known form of vitamin E.
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Affiliation(s)
- Haseeb Ahsan
- Department of Biochemistry, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, 110025 India
| | - Amjid Ahad
- Department of Biochemistry, Jamia Hamdard (Hamdard University), New Delhi, 110062 India
| | - Jahangir Iqbal
- Department of Cell Biology and Pediatrics, SUNY Downstate Medical Center, Brooklyn, NY 11203 USA
| | - Waseem A Siddiqui
- Department of Biochemistry, Jamia Hamdard (Hamdard University), New Delhi, 110062 India
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85
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Compadre CM, Singh A, Thakkar S, Zheng G, Breen PJ, Ghosh S, Kiaei M, Boerma M, Varughese KI, Hauer-Jensen M. Molecular dynamics guided design of tocoflexol: a new radioprotectant tocotrienol with enhanced bioavailability. Drug Dev Res 2013; 75:10-22. [PMID: 24648045 DOI: 10.1002/ddr.21162] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
There is a pressing need to develop safe and effective radioprotector/radiomitigator agents for use in accidental or terrorist-initiated radiological emergencies. Naturally occurring vitamin E family constituents, termed tocols, that include the tocotrienols, are known to have radiation-protection properties. These agents, which work through multiple mechanisms, are promising radioprotectant agents having minimal toxicity. Although α-tocopherol (AT) is the most commonly studied form of vitamin E, the tocotrienols are more potent than AT in providing radioprotection and radiomitigation. Unfortunately, despite their very significant radioprotectant activity, tocotrienols have very short plasma half-lives and require dosing at very high levels to achieve necessary therapeutic benefits. Thus, it would be highly desirable to develop new vitamin E analogues with improved pharmacokinetic properties, specifically increased elimination half-life and increased area under the plasma level versus time curve. The short elimination half-life of the tocotrienols is related to their low affinity for the α-tocopherol transfer protein (ATTP), the protein responsible for maintaining the plasma level of the tocols. Tocotrienols have less affinity for ATTP than does AT, and thus have a longer residence time in the liver, putting them at higher risk for metabolism and biliary excretion. We hypothesized that the low-binding affinity of tocotrienols to ATTP is due to the relatively more rigid tail structure of the tocotrienols in comparison with that of the tocopherols. Therefore, compounds with a more flexible tail would have better binding to ATTP and consequently would have longer elimination half-life and, consequently, an increased exposure to drug, as measured by area under the plasma drug level versus time curve (AUC). This represents an enhanced residence of drug in the systemic circulation. Based on this hypothesis, we developed a new class of vitamin E analogues, the tocoflexols, which maintain the superior bioactivity of the tocotrienols with the potential to achieve the longer half-life and larger AUC of the tocopherols.
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Affiliation(s)
- Cesar M Compadre
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
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86
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Ran Y, Wang R, Lin F, Hasan M, Jia Q, Tang B, Xia Y, Shan S, Wang X, Li Q, Deng Y, Qing H. Radioprotective effects of Dragon's blood and its extract against gamma irradiation in mouse bone marrow cells. Phys Med 2013; 30:427-31. [PMID: 24360838 DOI: 10.1016/j.ejmp.2013.12.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 11/19/2013] [Accepted: 12/04/2013] [Indexed: 01/25/2023] Open
Abstract
PURPOSE The radioprotective effects of Dragon's blood (DB) and its extracts (DBE) were investigated using the chromosomal aberrant test, micronucleus and oxidative stress assay for anti-clastogenic and anti-oxidative activity. MATERIALS AND METHODS Adult BALB/C mice were exposed to the whole body irradiation with 4 Gy (60)Co γ-rays. DB and DBE were administered orally once a day from 5 days prior to irradiation treatment to 1 day after irradiation. The mice were sacrificed on 24 h after irradiation. The cells of bone marrow were measured by counting different types of chromosomal aberrations and the frequency of micronuclei. Oxidative stress response was carried out by analysis of serum from blood. RESULTS DB and DBE significantly decreased the number of bone marrow cells with chromosome aberrations after irradiation with respect to irradiated alone group. The administration of DB and DBE also significantly reduced the frequencies of micronucleated polychromatic erythrocytes (MPCE) and micronucleated normochromatic erythrocytes (MNCE). In addition, DB and DBE markedly increased the activity of antioxidant enzymes and the level of antioxidant molecular. Malondialdehyde (MDA) and nitric oxide (NO) levels in serum were significantly reduced by DB and DBE treatment. CONCLUSIONS Our data suggested that DB and DBE have potential radioprotective properties in mouse bone marrow after (60)Co γ-ray exposure, which support their candidature as a potential radioprotective agent.
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Affiliation(s)
- Yuanyuan Ran
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Ran Wang
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Fankai Lin
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Murtaza Hasan
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Qiutian Jia
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Bo Tang
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Yu Xia
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Shuangquan Shan
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China
| | - Xiao Wang
- China Institute of Atomic Energy, Beijing 102413, PR China
| | - Qiang Li
- Lanzhou Institute of Modern Physics, Lanzhou 730000, PR China
| | - Yulin Deng
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China.
| | - Hong Qing
- School of Life Science, Beijing Institute of Technology, Beijing 100081, PR China.
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87
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Singh VK, Beattie LA, Seed TM. Vitamin E: tocopherols and tocotrienols as potential radiation countermeasures. JOURNAL OF RADIATION RESEARCH 2013; 54:973-88. [PMID: 23658414 PMCID: PMC3823775 DOI: 10.1093/jrr/rrt048] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Despite the potential devastating health consequences of intense total-body irradiation, and the decades of research, there still remains a dearth of safe and effective radiation countermeasures for emergency, radiological/nuclear contingencies that have been fully approved and sanctioned for use by the US FDA. Vitamin E is a well-known antioxidant, effective in scavenging free radicals generated by radiation exposure. Vitamin E analogs, collectively known as tocols, have been subject to active investigation for a long time as radioprotectors in patients undergoing radiotherapy and in the context of possible radiation accidents or terrorism scenarios. Eight major isoforms comprise the tocol group: four tocopherols and four tocotrienols. A number of these agents and their derivatives are being investigated actively as radiation countermeasures using animal models, and several appear promising. Although the tocols are well recognized as potent antioxidants and are generally thought to mediate radioprotection through 'free radical quenching', recent studies have suggested several alternative mechanisms: most notably, an 'indirect effect' of tocols in eliciting specific species of radioprotective growth factors/cytokines such as granulocyte colony-stimulating factor (G-CSF). The radioprotective efficacy of at least two tocols has been abrogated using a neutralizing antibody of G-CSF. Based on encouraging results of radioprotective efficacy, laboratory testing of γ-tocotrienol has moved from a small rodent model to a large nonhuman primate model for preclinical evaluation. In this brief review we identify and discuss selected tocols and their derivatives currently under development as radiation countermeasures, and attempt to describe in some detail their in vivo efficacy.
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Affiliation(s)
- Vijay K. Singh
- Radiation Countermeasures Program, Scientific Research Department, Armed Forces Radiobiology Research Institute, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA
- Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- Corresponding author. Radiation Countermeasures Program, Armed Forces Radiobiology Research Institute, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA. Tel: +1-301-295-2347; Fax: +1-301-295-6503;
| | - Lindsay A. Beattie
- Radiation Countermeasures Program, Scientific Research Department, Armed Forces Radiobiology Research Institute, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA
| | - Thomas M. Seed
- Tech Micro Services, 4417 Maple Avenue, Bethesda, MD, USA
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Gamma tocotrienol, a potent radioprotector, preferentially upregulates expression of anti-apoptotic genes to promote intestinal cell survival. Food Chem Toxicol 2013; 60:488-96. [PMID: 23941772 DOI: 10.1016/j.fct.2013.08.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 08/02/2013] [Accepted: 08/04/2013] [Indexed: 01/03/2023]
Abstract
Gamma tocotrienol (GT3) has been reported as a potent ameliorator of radiation-induced gastrointestinal (GI) toxicity when administered prophylactically. This study aimed to evaluate the role of GT3 mediated pro- and anti-apoptotic gene regulation in protecting mice from radiation-induced GI damage. Male 10- to 12-weeks-old CD2F1 mice were administered with a single dose of 200 mg/kg of GT3 or equal volume of vehicle (5% Tween-80) 24 h before exposure to 11 Gy of whole-body γ-radiation. Mouse jejunum was surgically removed 4 and 24h after radiation exposure, and was used for PCR array, histology, immunohistochemistry, and immunoblot analysis. Results were compared among vehicle pre-treated no radiation, vehicle pre-treated irradiated, and GT3 pre-treated irradiated groups. GT3 pretreated irradiated groups, both 4h and 24h after radiation, showed greater upregulation of anti-apoptotic gene expression than vehicle pretreated irradiated groups. TUNEL staining and intestinal crypt analysis showed protection of jejunum after GT3 pre-treatment and immunoblot results were supportive of PCR data. Our study demonstrated that GT3-mediated protection of intestinal cells from a GI-toxic dose of radiation occurred via upregulation of antiapoptotic and downregulation of pro-apoptotic factors, both at the transcript as well as at the protein levels.
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89
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Kulkarni S, Chakraborty K, Kumar KS, Kao TC, Hauer-Jensen M, Ghosh SP. Synergistic radioprotection by gamma-tocotrienol and pentoxifylline: role of cAMP signaling. ISRN RADIOLOGY 2013; 2013:390379. [PMID: 24959559 PMCID: PMC4045513 DOI: 10.5402/2013/390379] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 05/30/2013] [Indexed: 11/23/2022]
Abstract
Purpose. This study was designed to determine the efficacy and mechanisms of radioprotection by the combination of gamma-tocotrienol (GT3) and pentoxifylline (PTX) against acute radiation injury. Materials and Methods. Post-irradiation survival was monitored to determine the most efficacious dose and time of administration of PTX. Dose reduction factor (DRF) was calculated to compare the radioprotective efficacy of the combination. To determine the mechanism of synergistic radioprotection by the combination, mevalonate or calmodulin were coadministered with the GT3-PTX combination. Mevalonate was used to reverse the inhibitory effect of GT3 on 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR), and calmodulin was used to reverse the inhibition of phosphodiesterase (PDE) by PTX. Results. The combination was most effective when 200 mg/kg of PTX was administered 15 min before irradiation along with 200 mg/kg of GT3 (-24 h) and resulted in a DRF of 1.5. White blood cells and neutrophil counts showed accelerated recovery in GT3-PTX-treated groups compared to GT3. Mevalonate had no effect on the radioprotection of GT3-PTX; calmodulin abrogated the synergistic radioprotection by GT3-PTX. Conclusion. The mechanism of radioprotection by GT3-PTX may involve PDE inhibition.
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Affiliation(s)
- Shilpa Kulkarni
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889, USA
| | - Kushal Chakraborty
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889, USA
| | - K. Sree Kumar
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889, USA
| | - Tzu-Cheg Kao
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889, USA
| | - Martin Hauer-Jensen
- University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, AR 72205, USA
| | - Sanchita P. Ghosh
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889, USA
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90
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Granulocyte colony-stimulating factor antibody abrogates radioprotective efficacy of gamma-tocotrienol, a promising radiation countermeasure. Cytokine 2013; 62:278-85. [DOI: 10.1016/j.cyto.2013.03.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 01/10/2013] [Accepted: 03/08/2013] [Indexed: 12/11/2022]
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91
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Ray S, Kulkarni SS, Chakraborty K, Pessu R, Hauer-Jensen M, Kumar KS, Ghosh SP. Mobilization of progenitor cells into peripheral blood by gamma-tocotrienol: A promising radiation countermeasure. Int Immunopharmacol 2013; 15:557-64. [DOI: 10.1016/j.intimp.2012.12.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 11/27/2012] [Accepted: 12/18/2012] [Indexed: 12/22/2022]
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92
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Investigation of tocotrienol biosynthesis in rice (Oryza sativa L.). Food Chem 2013; 140:91-8. [PMID: 23578619 DOI: 10.1016/j.foodchem.2013.02.058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 02/04/2013] [Accepted: 02/13/2013] [Indexed: 11/23/2022]
Abstract
Rice tocotrienol (T3) has gained attention due to its physiological activities (e.g., antiangiogenesis). However, the biosynthetic pathway for T3 production in rice grain has not been well studied. We hypothesized that T3 biosynthesis enzymes and/or precursors play an important role in T3 production in whole grain. This proposal was evaluated in rice (Oryza sativa L.) by PCR and HPLC techniques. Grain tocopherol as well as flag leaf vitamin E levels were also investigated for comparison. For rice samples 14 days after flowering, grain was abundant in T3, but not in flag leaf. Expression of a gene encoding homogentisate geranylgeranyltransferase (HGGT, which has long been believed to be important for T3 production) differed significantly between grain and flag leaf. We then investigated rice samples during the grain maturation period, and found that grain T3 and HGGT levels increased in the early stage and then reached a plateau. T3 precursors such as homogentisate and geranylgeranyl pyrophosphate decreased during maturation. No increase in grain T3 from the middle to late stages of maturation and a decrease in T3 precursors during maturation suggest that HGGT would be an essential, but not limiting factor for T3 biosynthesis, and T3 precursors could regulate the T3 level in grain. The results of this study would be useful for nutraceutical purposes (e.g., development of T3-overproducing rice for the prevention of angiogenic disorders).
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93
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Kulkarni SS, Cary LH, Gambles K, Hauer-Jensen M, Kumar KS, Ghosh SP. Gamma-tocotrienol, a radiation prophylaxis agent, induces high levels of granulocyte colony-stimulating factor. Int Immunopharmacol 2012; 14:495-503. [PMID: 23000517 DOI: 10.1016/j.intimp.2012.09.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 08/07/2012] [Accepted: 09/07/2012] [Indexed: 01/22/2023]
Abstract
Gamma-tocotrienol (GT3), a promising radioprotectant, is shown to protect CD2F1 mice from radiation-induced neutropenia and thrombocytopenia when given 24h prior to total-body irradiation. GT3 also is shown to increase white blood cells (WBC) and absolute neutrophil counts (ANC) transiently in peripheral blood. We hypothesized that increases in WBC and ANC may involve stimulation of hematopoiesis possibly by cytokines and growth factors. To evaluate the effects of GT3 on hematopoietic system, we measured various cytokines, chemokines and growth factors by cytokine array and Bio-Plex assays. Both showed strong induction of various cytokines and chemokines. GT3 treatment resulted in significant increases in G-CSF, IL-1α, IL-1β, IL-6, IL-12p70, IL-17, MIP-1α, and KC levels. G-CSF levels increased markedly within 12-24h after administration (5441 pg/ml in GT3-treated groups compared to 17 pg/ml in vehicle control). Most of these cytokine levels were elevated in the presence or absence of radiation. Time-course analysis of G-CSF and IL-6 induction showed that both cytokines were induced transiently after GT3 administration, and returned to normal levels by 48 h post-administration. For G-CSF, the peak was observed between 12 and 24h post-administration of GT3; however, the highest levels of IL-6 were obtained between 6 and 12h. These results demonstrate that GT3 induced high levels of G-CSF and other inflammatory cytokines and chemokines within 24h after administration. Survival studies reported showed that the most efficacious time for administering GT3 was 24h prior to irradiation, possibly because it induced key hematopoietic cytokines in that time window. These results also suggest a possible role of GT3-induced G-CSF stimulation in protecting mice from radiation-induced neutropenia and thrombocytopenia.
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Affiliation(s)
- Shilpa S Kulkarni
- Armed Forces Radiobiology Research Institute, USUHS, Bethesda, MD 20889-5603, United States
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94
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Ghosh SP, Kulkarni S, Perkins MW, Hieber K, Pessu RL, Gambles K, Maniar M, Kao TC, Seed TM, Kumar KS. Amelioration of radiation-induced hematopoietic and gastrointestinal damage by Ex-RAD(R) in mice. JOURNAL OF RADIATION RESEARCH 2012; 53:526-36. [PMID: 22843617 PMCID: PMC3393340 DOI: 10.1093/jrr/rrs001] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The aim of the present study was to assess recovery from hematopoietic and gastrointestinal damage by Ex-RAD(®), also known as ON01210.Na (4-carboxystyryl-4-chlorobenzylsulfone, sodium salt), after total body radiation. In our previous study, we reported that Ex-RAD, a small-molecule radioprotectant, enhances survival of mice exposed to gamma radiation, and prevents radiation-induced apoptosis as measured by the inhibition of radiation-induced protein 53 (p53) expression in cultured cells. We have expanded this study to determine best effective dose, dose-reduction factor (DRF), hematological and gastrointestinal protection, and in vivo inhibition of p53 signaling. A total of 500 mg/kg of Ex-RAD administered at 24 h and 15 min before radiation resulted in a DRF of 1.16. Ex-RAD ameliorated radiation-induced hematopoietic damage as monitored by the accelerated recovery of peripheral blood cells, and protection of granulocyte macrophage colony-forming units (GM-CFU) in bone marrow. Western blot analysis on spleen indicated that Ex-RAD treatment inhibited p53 phosphorylation. Ex-RAD treatment reduces terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay (TUNEL)-positive cells in jejunum compared with vehicle-treated mice after radiation injury. Finally, Ex-RAD preserved intestinal crypt cells compared with the vehicle control at 13 and 14 Gy. The results demonstrated that Ex-RAD ameliorates radiation-induced peripheral blood cell depletion, promotes bone marrow recovery, reduces p53 signaling in spleen and protects intestine from radiation injury.
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Affiliation(s)
- Sanchita P Ghosh
- Armed Forces Radiobiology Research Institute, USUHS, Bethesda, MD 20889-5603, USA.
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Satyamitra M, Ney P, Graves J, Mullaney C, Srinivasan V. Mechanism of radioprotection by δ-tocotrienol: pharmacokinetics, pharmacodynamics and modulation of signalling pathways. Br J Radiol 2012; 85:e1093-103. [PMID: 22674714 DOI: 10.1259/bjr/63355844] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE The objective of this study was to investigate the correlation between in vivo δ-tocotrienol (DT3) pharmacokinetics, pharmacodynamics and radiation protection, and to evaluate the effect of DT3 pre-treatment on radiation-induced alterations in apoptotic and autophagic pathways. METHODS We evaluated pharmacokinetics (plasma, 0.5 to 12 h) and pharmacodynamics (peripheral blood indices; day 3, 7, 10 and 14) after a single subcutaneous injection of 300 mg kg(-1) DT3 in unirradiated CD2F1 mice. Next, we monitored 30-day post-irradiation survival (9.25 Gy) and haematopoietic recovery of DT3-treated mice (7 Gy) exposed to cobalt-60 γ-irradiation. The effects of DT3 on irradiated bone marrow apoptosis and autophagy were determined by analyses of key caspases (3, 7, 9 and 8), beclin-1 and light chain 3 conversion. RESULTS Plasma concentration of DT3 reached ∼195 µM (Cmax) 1 h after injection (Tmax), and DT3 was eliminated from plasma 12 h later. In unirradiated mice, DT3 significantly increased white blood cells (WBCs), neutrophils, lymphocytes (day 3 post DT3 injection) and platelets (day 7) by 1.5- to 2-fold, over vehicle-treated control. DT3 pre-treatment improved 30-day survival to 100% (∼15% in control) and accelerated recovery of reticulocytes, platelets, WBCs, neutrophils, lymphocytes and monocytes in peripheral blood. DT3 reduced activation of caspase-8, caspase-3 and caspase-7, inherent to apoptosis, while increasing autophagy-related beclin-1 expression in irradiated bone marrow. CONCLUSION These data indicate that DT3 stimulates multilineage haematopoiesis, protects against radiation-induced apoptosis downstream of the mitochondria and stimulates cytoprotective autophagy. Apart from a potent antioxidant activity, DT3 may elicit survival advantage following irradiation by enhancing haematopoiesis and modulating signalling pathways.
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Affiliation(s)
- M Satyamitra
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20889, USA.
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96
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Landes RD, Lensing SY, Kodell RL, Hauer-Jensen M. Statistical Analysis of Survival Data From Radiation Countermeasure Experiments. Radiat Res 2012; 177:546-54. [DOI: 10.1667/rr2872.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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97
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Berbée M, Hauer-Jensen M. Novel drugs to ameliorate gastrointestinal normal tissue radiation toxicity in clinical practice: what is emerging from the laboratory? Curr Opin Support Palliat Care 2012; 6:54-9. [PMID: 22228028 PMCID: PMC3677768 DOI: 10.1097/spc.0b013e32834e3bd7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE OF REVIEW To give an overview of promising novel agents under development for the prevention and reduction of gastrointestinal radiation injury. RECENT FINDINGS Currently, several novel agents are being tested as drugs to prevent or reduce gastrointestinal radiation injury. These drugs may not only prevent injury, but also mitigate toxicity, that is, reduce injury after radiation exposure has occurred. Promising novel agents include the somatostatin analogue SOM230, growth factors, agents acting on the toll-like receptor 5 pathway, endothelial protectants, and the vitamin E analogue γ-tocotrienol. SUMMARY Gastrointestinal radiation injury is the most important dose-limiting factor during radiotherapy of the abdomen or pelvis. It may severely affect the quality of life both during radiotherapy treatment and in cancer survivors. To date, there are no agents that can prevent or reduce intestinal radiation injury. Hence, there is an urgent need for the development of novel drugs to ameliorate intestinal toxicity during and after radiotherapy. This review summarizes the several agents that have been shown to reduce intestinal radiation injury in animals. Further research is needed to investigate their safety and efficacy in patients receiving radiotherapy for abdominal or pelvic tumours.
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Affiliation(s)
- Maaike Berbée
- Department of Radiation Oncology (Maastro), GROW Research Institute, Maastricht University Medical Center, Maastricht, The Netherlands.
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98
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Singh VK, Ducey EJ, Brown DS, Whitnall MH. A review of radiation countermeasure work ongoing at the Armed Forces Radiobiology Research Institute. Int J Radiat Biol 2012; 88:296-310. [DOI: 10.3109/09553002.2012.652726] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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99
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Singh VK, Ducey EJ, Fatanmi OO, Singh PK, Brown DS, Purmal A, Shakhova VV, Gudkov AV, Feinstein E, Shakhov A. CBLB613: a TLR 2/6 agonist, natural lipopeptide of Mycoplasma arginini , as a novel radiation countermeasure. Radiat Res 2011; 177:628-42. [PMID: 22175300 DOI: 10.1667/rr2657.1] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
To date, there are no safe and effective drugs available for protection against ionizing radiation damage. Therefore, a great need exists to identify and develop non-toxic agents that will be useful as radioprotectors or postirradiation therapies under a variety of operational scenarios. We have developed a new pharmacological agent, CBLB613 (a naturally occurring Mycoplasma-derived lipopeptide ligand for Toll-like receptor 2/6), as a novel radiation countermeasure. Using CD2F1 mice, we investigated CBLB613 for toxicity, immunogenicity, radioprotection, radiomitigation and pharmacokinetics. We also evaluated CBLB613 for its effects on cytokine induction and radiation-induced cytopenia in unirradiated and irradiated mice. The no-observable-adverse-effect level of CBLB613 was 1.79 mg/kg and 1 mg/kg for single and repeated doses, respectively. CBLB613 significantly protected mice against a lethal dose of (60)Co γ radiation. The dose reduction factor of CBLB613 as a radioprotector was 1.25. CBLB613 also mitigated the effects of (60)Co γ radiation on survival in mice. In both irradiated and unirradiated mice, the drug stimulated induction of interleukin-1β (IL-1β), IL-6, IL-10, IL-12, keratinocyte-derived chemokine, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-1α. CBLB613 also reduced radiation-induced cytopenia and increased bone marrow cellularity in irradiated mice. Our immunogenicity study demonstrated that CBLB613 is not immunogenic in mice, indicating that it could be developed as a radioprotector and radiomitigator for humans against the potentially lethal effects of radiation exposure.
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Affiliation(s)
- Vijay K Singh
- Radiation Countermeasures Program, Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20889-5603, USA.
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Ling MT, Luk SU, Al-Ejeh F, Khanna KK. Tocotrienol as a potential anticancer agent. Carcinogenesis 2011; 33:233-9. [PMID: 22095072 DOI: 10.1093/carcin/bgr261] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Vitamin E is composed of two structurally similar compounds: tocopherols (TPs) and tocotrienols (T3). Despite being overshadowed by TP over the past few decades, T3 is now considered to be a promising anticancer agent due to its potent effects against a wide range of cancers. A growing body of evidence suggests that in addition to its antioxidative and pro-apoptotic functions, T3 possesses a number of anticancer properties that make it superior to TP. These include the inhibition of epithelial-to-mesenchymal transitions, the suppression of vascular endothelial growth factor tumor angiogenic pathway and the induction of antitumor immunity. More recently, T3, but not TP, has been shown to have chemosensitization and anti-cancer stem cell effects, further demonstrating the potential of T3 as an effective anticancer therapeutic agent. With most of the previous clinical studies on TP producing disappointing results, research has now focused on testing T3 as the next generation vitamin E for chemoprevention and cancer treatment. This review will summarize recent developments in the understanding of the anticancer effects of T3. We will also discuss current progress in clinical trials involving T3 as an adjuvant to conventional cancer therapy.
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Affiliation(s)
- Ming T Ling
- Australian Prostate Cancer Research Centre-Queensland, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Qld 4102, Australia.
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