Induction of TGF-ß by Irradiation or Chemotherapy in Fanconi Anemia (FA) Mouse Bone Marrow Is Modulated by Small Molecule Radiation Mitigators JP4-039 and MMS350.

BACKGROUND/AIM: Total-body irradiation and/or administration of chemotherapy drugs in bone marrow transplantation induce cytokines that can suppress engraftment. Fanconi Anemia (FA) patients have a hyperactive responsiveness to the inhibitory cytokine, transforming growth factor-beta (TGF-ß). Small molecule radiation mitigator drugs, JP4-039 and MMS350, were evaluated for suppression of irradiation or drug-induced TGF-ß. MATERIALS AND METHODS: In vivo induction of TGF-ß by total-body ionizing irradiation (TBI), L-phenylalanine mustard (L-PAM), busulfan or fludarabine, was quantified. In parallel, mitigator drug amelioration of TGF-ß induction in FA D2-/- (FANCD2-/-) mouse bone marrow, was studied in vitro. Tissue culture medium, cell lysates, and mouse plasma were analyzed for TGF-ß levels. RESULTS: Induction of TGF-ß levels in FANCD2-/- and FANCD2+/+ mice and in mouse bone marrow were modulated by both JP4-039 and MMS350. CONCLUSION: Bone marrow transplantation in FA recipients may benefit from administration of small molecule agents that suppress TGF-ß induction.

Intraoral Mitochondrial-Targeted GS-Nitroxide, JP4-039, Radioprotects Normal Tissue in Tumor-Bearing Radiosensitive Fancd2(-/-) (C57BL/6) Mice.

We evaluated normal tissue specific radioprotection of the oral cavity in radiosensitive Fanconi Anemia (FA) Fancd2(-/-) mice with orally established tumors using mitochondrial-targeted GS-nitroxide (JP4-039). Adult (10-12 weeks old) Fancd2(+/+), Fancd2(+/-) and Fancd2(-/-) mice (C57BL/6 background) and subgroups with orally established TC-1 epithelial cell tumors received a single fraction of 28 Gy or four daily fractions of 8 Gy to the head and neck. Subgroups received JP4-039 in F15 emulsion (F15/JP4-039; 0.4 mg/mouse), 4-amino-Tempo in F15 emulsion (F15/4-amino-Tempo; 0.2 mg/mouse) or F15 emulsion alone prior to each irradiation. Oral mucosa of Fancd2(-/-) mice showed baseline elevated RNA transcripts for Sod2, p53, p21 and Rad51 (all P < 0.0012) and suppressed levels of Nfkb and Tgfb, (all P < 0.0020) compared with Fancd2(+/+) mice. The oral mucosa in tumor-bearing mice of all genotypes showed decreased levels of p53 and elevated Tgfb and Gadd45a (P ≤ 0.0001 for all three genotypes). Intraoral F15/JP4-039, but not F15/4-amino-Tempo, modulated radiation-induced normal tissue transcript elevation, ameliorated mucosal ulceration and reduced the depletion of antioxidant stores in oral cavity tissue of all genotypes, but did not radioprotect tumors. Mitochondrial targeting makes F15/JP4-039 an effective normal tissue radioprotector for Fancd2(-/-) mice, as well as wild-type mice.

Organ-specific responses of total body irradiated doxycycline-inducible manganese superoxide dismutase Tet/Tet mice.

BACKGROUND/AIM: We evaluated doxycycline-inducible manganese superoxide dismutase (MnSOD(tet/tet)) mice after 9.25 Gy total-body irradiation (TBI) or 20 Gy thoracic irradiation. MATERIALS AND METHODS: Six-week-old MnSOD(tet/tet) or control C57BL/6NHsd mice on or off doxycycline (doxy) in food received 9.25 Gy TBI, were sacrificed at day 19 and bone marrow, brain, esophagus, heart, intestine, kidney, liver, lung, spleen and tongue harvested, total RNAs extracted and transcripts for irradiation response genes quantitated by real time-polymerase chain reaction (RT-PCR). RESULTS: MnSOD(tet/tet) mice only survived with daily injections of doxy beginning 5 days after birth until weaning, at which time they were placed on food containing doxy. Manganese superoxide dismutase (MnSOD) transcript levels were reduced in all tissues except the lung. Adult mice survived with low MnSOD levels, but induced by doxy or TBI. Thoracic-irradiated MnSOD(tet/tet) mice survived past day 120. CONCLUSION: MnSOD(tet/tet) mice should be valuable for elucidating the role of MnSOD in growth and irradiation response.

Amelioration of radiation-induced oral cavity mucositis and distant bone marrow suppression in fanconi anemia Fancd2-/- (FVB/N) mice by intraoral GS-nitroxide JP4-039.

The altered DNA damage response pathway in patients with Fanconi anemia (FA) may increase the toxicity of clinical radiotherapy. We quantitated oral cavity mucositis in irradiated Fanconi anemia Fancd2(-/-) mice, comparing this to Fancd2(+/-) and Fancd2(+/+) mice, and we measured distant bone marrow suppression and quantitated the effect of the intraoral radioprotector GS-nitroxide, JP4-039 in F15 emulsion. We found that FA mice were more susceptible to radiation injury and that protection from radiation injury by JP4-039/F15 was observed at all radiation doses. Adult 10-12-week-old mice, of FVB/N background Fancd2(-/-), Fancd2(+/-) and Fancd2(+/+) were head and neck irradiated with 24, 26, 28 or 30 Gy (large fraction sizes typical of stereotactic radiosurgery treatments) and subgroups received intraoral JP4-039 (0.4 mg/mouse in 100 µL F15 liposome emulsion) preirradiation. On day 2 or 5 postirradiation, mice were sacrificed, tongue tissue and femur marrow were excised for quantitation of radiation-induced stress response, inflammatory and antioxidant gene transcripts, histopathology and assay for femur marrow colony-forming hematopoietic progenitor cells. Fancd2(-/-) mice had a significantly higher percentage of oral mucosal ulceration at day 5 after 26 Gy irradiation (59.4 ± 8.2%) compared to control Fancd2(+/+) mice (21.7 ± 2.9%, P = 0.0063). After 24 Gy irradiation, Fancd2(-/-) mice had a higher oral cavity percentage of tongue ulceration compared to Fancd2(+/+) mice irradiated with higher doses of 26 Gy (P = 0.0123). Baseline and postirradiation oral cavity gene transcripts were altered in Fancd2(-/-) mice compared to Fancd2(+/+) controls. Fancd2(-/-) mice had decreased baseline femur marrow CFU-GM, BFUe and CFU-GEMM, which further decreased after 24 or 26 Gy head and neck irradiation. These changes were not seen in head- and neck-irradiated Fancd2(+/+) mice. In radiosensitive Fancd2(-/-) mice, biomarkers of both local oral cavity and distant marrow radiation toxicity were ameliorated by intraoral JP4-039/F15. We propose that Fancd2(-/-) mice are a valuable radiosensitive animal model system, which can be used to evaluate potential radioprotective agents.

Differences in irradiated lung gene transcription between fibrosis-prone C57BL/6NHsd and fibrosis-resistant C3H/HeNHsd mice.

BACKGROUND/AIM: We compared pulmonary irradiation-induced whole-lung, gene transcripts over 200 days after 20 Gy thoracic irradiation in female fibrosis-prone C57BL/6NHsd mice with fibrosis-resistant C3H/HeNHsd mice. MATERIALS AND METHODS: Lung specimens were analyzed by real time polymerase chain reaction (rt-PCR) and changes over time in representative gene transcript levels were correlated with protein levels using western blot. RESULTS: C3H/HeNHsd mice showed a significantly longer duration of elevation of gene transcripts for stress-response genes nuclear factor kappa-light-chain-enhancer of activated B cells (Nfkb), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), transcription factor SP1 (SP1), activator protein 1 (AP1), radioprotection gene manganese superoxide dismutase (Sod2), and endothelial cell-associated genes von Willebrand factor (Vwf) and vascular endothelial growth factor (Vegf). C57BL/6NHsd mice showed acute elevation then down-regulation and a second elevation in gene transcripts for Nfkb, connective tissue growth factor (Ctgf), insulin-like growth factor-binding protein 7 (Igfbp7), tumor necrosis factor-alpha (Tnfa) Ctgf, Igfbp7, Tnfa, collagen 1a, and toll like receptor 4 (Tlr4). There were reciprocal patterns of elevation and decrease in levels of transcripts for epigenetic reader proteins bromodomain coding protein 1 (Brd1)Brd2,-3, and -4 between mouse strains. CONCLUSION: Regulatory pathways linked to radiation pulmonary fibrosis may identify new targets for mitigators of radiation-induced fibrosis.

Effects of mouse genotype on bone wound healing and irradiation-induced delay of healing.

We tested the effects of mouse genotype (C57BL/6NHsd, NOD/SCID, SAMR1, and SAMP6) and ionizing irradiation on bone wound healing. Unicortical wounds were made in the proximal tibiae, and the time course of spontaneous healing and effects of irradiation were monitored radiographically and histologically. There was reproducible healing beginning with intramedullary osteogenesis, subsequent bone resorption by osteoclasts, gradual bridging of the cortical wound, and re-population of medullary hematopoietic cells. The most rapid wound closure was noted in SAMR1 mice, followed by SAMP6, C57BL/6NHsd, and NOD/SCID. Ionizing irradiation (20 Gy) to the leg significantly delayed bone wound healing in mice of all four genotypes. Mice with genetically-determined predisposition to early osteopenia (SAMP6) or with immune deficiency (NOD/SCID) had impairments in bone wound healing. These mouse models should be valuable for determining the effects of irradiation on bone healing and also for the design and testing of novel bone growth-enhancing drugs and mitigators of ionizing irradiation.

Improved survival of mice after total body irradiation with 10 MV photon, 2400 MU/min SRS beam.

BACKGROUND/AIM: We evaluated the radiobiological effects of stereotactic radiosurgery (SRS) photon beams on survival of C57BL/6NTac mice following total body irradiation. MATERIALS AND METHODS: Survival of Lewis lung carcinoma (3LL) cells was tested after irradiation using 6 MV: 300 MU/min or 1400 MU/min; or 10 MV: 300 MU/min or 2400 MU/min. Survival of C57BL/6NTac mice after a dose which is lethal to 50% of the mice in 30 days (LD50/30) (9.25 Gy) total body irradiation (TBI) and 21 Gy to orthotopic 3LL tumors was tested. We quantitated levels of organ-specific gene transcripts by Real Time Polymerase Chain Reaction (RT-PCR). RESULTS: While 3LL cell survival and inhibition of orthotopic tumor growth was uniform, 10 MV photons at 2400 MU/min TBI led to significantly greater survival (p=0.0218), with higher levels of intestinal (Sod2), (Gpx1), (Nrf2), and (NFκB) RNA transcripts. CONCLUSION: Clinical 10 MV-2400 cGy/min SRS beams led to unexpected protection of mice on TBI and increased radioprotective gene transcripts.

A pragmatic approach to embedding patient blood management in a tertiary hospital.

BACKGROUND: We describe the implementation and impact of a patient blood management program (PBMP) in an Australian teaching hospital. STUDY DESIGN AND METHODS: A PBMP was introduced at a single tertiary care hospital in 2009 as a pilot for the Western Australian Health Department statewide PBMP. The first 3 years of interventions aimed to make effective use of preoperative clinics, manage perioperative anemia, improve perioperative hemostasis, reduce blood sample volumes, and implement restrictive transfusion triggers and a single-unit transfusion policy. RESULTS: Between 2008 and 2011, admissions to Fremantle Hospital and Health Services increased by 22%. Using 2008 as a reference year, the mean number of red blood cell (RBC) units per admission declined 26% by 2011. Use of fresh-frozen plasma and platelets showed 38 and 16% declines, respectively. Cryoprecipitate increased 7% over the 4-year period. For elective admissions between 2008 and 2011, the leading decline in RBC transfusion rate was seen in cardiothoracic surgery (27.5% to 12.8%). The proportion of single RBC unit use increased from 13% to 28% (p < 0.001), and the proportion of double units decreased from 48% to 37% (p < 0.001). CONCLUSION: This is the first tertiary hospital in Australia to establish a multidisciplinary multimodal PBMP. Interventions across disciplines resulted in decreased use of RBC units especially in orthopedic and cardiothoracic surgery. Continuing education and feedback to specialties will maintain the program, improve patient outcomes, and decrease the transfusion rate.

Amelioration of radiation-induced pulmonary fibrosis by a water-soluble bifunctional sulfoxide radiation mitigator (MMS350).

A water-soluble ionizing radiation mitigator would have considerable advantages for the management of acute and chronic effects of ionizing radiation. We report that a novel oxetanyl sulfoxide (MMS350) is effective both as a protector and a mitigator of clonal mouse bone marrow stromal cell lines in vitro, and is an effective in vivo mitigator when administered 24 h after 9.5 Gy (LD100/30) total-body irradiation of C57BL/6NHsd mice, significantly improving survival (P = 0.0097). Furthermore, MMS350 (400 µM) added weekly to drinking water after 20 Gy thoracic irradiation significantly decreased: expression of pulmonary inflammatory and profibrotic gene transcripts and proteins; migration into the lungs of bone marrow origin luciferase+/GFP+ (luc+/GFP+) fibroblast progenitors (in both luc+ marrow chimeric and luc+ stromal cell line injected mouse models) and decreased radiation-induced pulmonary fibrosis (P < 0.0001). This nontoxic and orally administered small molecule may be an effective therapeutic in clinical radiotherapy and as a counter measure against the acute and chronic effects of ionizing radiation.

Conditional radioresistance of Tet-inducible manganese superoxide dismutase bone marrow stromal cell lines.

Mitochondrial targeted manganese superoxide dismutase is a major antioxidant enzyme, the levels of which modulate the response of cells, tissues and organs to ionizing irradiation. We developed a Tet-regulated MnSOD mouse (MnSOD(tet)) to examine the detailed relationship between cellular MnSOD concentration and radioresistance and carried out in vitro studies using bone marrow culture derived stromal cell lines (mesenchymal stem cells). Homozygous MnSOD(tet/tet) cells had low levels of MnSOD, reduced viability and proliferation, increased radiosensitivity, elevated overall antioxidant stores, and defects in cell proliferation and DNA strand-break repair. Doxycycline (doxy) treatment of MnSOD(tet/tet) cells increased MnSOD levels and radioresistance from ñ of 2.79 ± 1.04 to 8.69 ± 1.09 (P = 0.0060) and normalized other biologic parameters. In contrast, MnSOD(tet/tet) cells showed minimal difference in baseline and radiation induced mRNA and protein levels of TGF-ß, Nrf2 and NF-κB and radiation induced cell cycle arrest was not dependent upon MnSOD level. These novel MnSOD(tet/tet) mouse derived cells should be valuable for elucidating several parameters of the oxidative stress response to ionizing radiation.

Effects of thoracic irradiation on pulmonary endothelial compared to alveolar type-II cells in fibrosis-prone C57BL/6NTac mice.

BACKGROUND/AIM: Thoracic irradiation results in an acute inflammatory response, latent period, and late fibrosis. Little is known about the mechanisms involved in triggering late radiation fibrosis. MATERIALS AND METHODS: Thoracic irradiated fibrosis prone C57BL/6NTac mice were followed for detectable mRNA transcripts in isolated lung cells and micro-RNA in whole-tissues, and the effect of administration of water-soluble oxetanyl sulfoxide MMS350 was studied. Marrow stromal cell motility in medium from fibrotic-phase explanted pulmonary endothelial and alveolar type-II cells was measured. RESULTS: RNA and micro-RNA expression in lung correlated with fibrosis. MMS350 reduced pro-fibrotic gene expression in both endothelial and alveolar type-II cells in irradiated mice. Conditioned medium from irradiated cells did not alter cell motility in vitro. CONCLUSION: These studies should facilitate identification of potential new drug targets for ameliorating irradiation-induced pulmonary fibrosis.

Declining incidence of osteoporotic hip fracture in Australia.

UNLABELLED: Between 1997-1998 and 2006-2007 in Australia, the age-standardised incidence rates of hip fractures declined by 20 and 13 %, in females and males, respectively. Although this may be related to the rollout of public health campaigns and strategies addressing osteoporosis, absolute numbers of hip fractures continued to increase. BACKGROUND: Previous reports described an increasing trend in osteoporotic hip fracture incidence in Australia in the 1980s with a stabilisation over the 1990s. AIM: The aim of this study was to describe national trends in the incidence of osteoporotic hip fracture in Australia between 1997-1998 and 2006-2007. METHODS: Data on low-trauma hip fractures in persons aged 50 years and over were obtained from the National Hospital Morbidity Database. Cases where the patient was transferred in from another hospital were excluded. Age-standardised incidence rates were calculated and a linear test for trend applied. RESULTS: Although the absolute number of hip fracture cases has continued to increase, from 14,769 in 1997-1998 to 16,412 in 2006-2007, these numbers are lower than previous predictions based on population ageing. Over the 10-year period, the age-standardised incidence rates in females declined by 20 %, from 370 to 295 per 100,000, while the age-standardised incidence rates in males declined by 13 %, from 200 to 174 per 100,000. Both declines were statistically significant. The sex difference in incidence rates narrowed between 1997-1998 (females 85 % higher) and 2006-2007 (females 70 % higher). CONCLUSIONS: The age-standardised incidence of osteoporotic hip fracture in Australia is falling. This may be related to the uptake of bisphosphonates as well as the rollout of public health campaigns and strategies addressing osteoporosis.

Ionizing irradiation protection and mitigation of murine cells by carbamazepine is p53 and autophagy independent.

BACKGROUND: Carbamazepine, a sodium channel blocker and pro-autophagy agent used in the treatment of epilepsy and trigeminal neuralgia, is also an ionizing radiation mitigator and protector. MATERIALS AND METHODS: We measured the effect of carbamazepine, compared to other pro-autophagy drugs (i.e. lithium and valproic acid), on irradiation of autophagy incompetent (Atg5(-/-)) and competent (Atg5(+/+)) mouse embryonic fibroblasts, p53(-/-) and p53(+/+) bone marrow stromal cells, and human IB3, KM101, HeLa, and umbilical cord blood cell and in total body-irradiated or orthotopic tumor-bearing mice. RESULTS: Carbamazepine, but not other pro-autophagy drugs, was a radiation protector and mitigator for mouse cell lines, independent of apoptosis, autophagy, p53, antioxidant store depletion, and class I phosphatidylinositol 3-kinase, but was ineffective with human cells. Carbamazepine was effective when delivered 24 hours before or 12 hours after total body irradiation of C57BL/6HNsd mice and did not protect orthotopic Lewis lung tumors. CONCLUSION: Carbamazepine is a murine radiation protector and mitigator.

Dysregulated in vitro hematopoiesis, radiosensitivity, proliferation, and osteoblastogenesis with marrow from SAMP6 mice.

The senescence accelerated-prone mouse variant 6 (SAMP6) shows normal growth followed by rapid aging, development of osteopenia, and shortened lifespan, compared with control R1 mice. Because oxidative stress is a fundamental mechanism of tissue aging, we tested whether cellular parameters that are associated with oxidative stress are impaired with marrow from SAMP6 mice. We compared in vitro hematopoiesis, irradiation sensitivity, proliferative potential, and osteoblastogenesis with marrow cells from SAMP6 and R1 mice. Marrow cells from SAMP6 mice showed shortened in vitro hematopoiesis; their stromal cells showed greater radiation sensitivity and decreased proliferation. Consistent with those properties, there was constitutive upregulation of transforming growth factor-ß(1), an inhibitor of hematopoiesis, and of cell cycle inhibitory genes, p16(INK4A) and p19(ARF). Paradoxically, there was constitutive expression of osteoblast genes in stromal cells from SAMP6 mice, but in vitro matrix mineralization was impaired. These studies and data included in other reports indicate that impaired proliferation of osteoblast progenitors in SAMP6 marrow may be a major factor contributing to accelerated loss of bone mass. In sum, marrow from SAMP6 mice had diminished capacity for long-term hematopoiesis, increased radiosensitivity, and reduced proliferative capacity.

Repopulation of the irradiation damaged lung with bone marrow-derived cells.

AIM: The effect of lung irradiation on reduction of lung stem cells and repopulation with bone marrow-derived cells was measured. MATERIALS AND METHODS: Expression of green fluorescent protein positive cells (GFP(+)) in the lungs of thoracic irradiated FVB/NHsd mice (Harlan Sprague Dawley, Indianapolis, IN, USA) was determined. This was compared to the repopulation of bone marrow-derived cells found in the lungs from naphthalene treated male FVB/NHsd mice and gangciclovir (GCV) treated FeVBN GFP(+) male marrow chimeric HSV-TK-CCSP. The level of mRNA for lung stem cell markers clara cell (CCSP), epithelium 1 (FOXJ1) and surfactant protein C (SP-C), and sorted single cells positive for marrow origin epithelial cells (GFP(+)CD45(-)) was measured. RESULTS: The expression of pulmonary stem cells as determined by PCR was reduced most by GCV, then naphthalene, and least by thoracic irradiation. Irradiation, like GCV, reduced mRNA expression of CCSP, CYP2F2, and FOXJ1, while naphthalene reduced that of CCSP and CYP2F2. Ultrastructural analysis showed GFP(+) pulmonary cells of bone marrow origin, with the highest frequency being found in GCV-treated groups. CONCLUSION: Bone marrow progenitor cells may not participate in the repopulation of the lung following irradiation.

Amelioration of radiation esophagitis by orally administered p53/Mdm2/Mdm4 inhibitor (BEB55) or GS-nitroxide.

BACKGROUND/AIM: Esophagitis is a significant toxicity of radiation therapy for lung cancer. In this study, reduction of irradiation esophagitis in mice, by orally administered p53/Mdm2/Mdm4 inhibitor, BEB55, or the GS-nitroxide, JP4-039, was evaluated. MATERIALS AND METHODS: BEB55 or JP4-039 in F15 (liposomal) formulation was administered intraesophageally to C57BL/6 mice prior to thoracic irradiation of 29 Gy × 1 or 11.5 Gy × 4 thoracic irradiation. Progenitor cells were sorted from excised esophagus, and nitroxide was quantified, by electron paramagnetic resonance (EPR). Mice with Lewis lung carcinoma (3LL) orthotopic lung tumors were treated with BEB55 or JP4-039 prior to 20 Gy to determine if the drugs would protect the tumor cells from radiation. RESULTS: Intraesophageal BEB55 and JP4-039 compared to formulation alone increased survival after single fraction (p=0.0209 and 0.0384, respectively) and four fraction thoracic irradiation (p=0.0241 and 0.0388, respectively). JP4-039 was detected in esophagus, liver, bone marrow, and orthotopic Lewis lung carcinoma (3LL) tumor. There was no significant radiation protection of lung tumors by BEB55 or JP4-039 compared to formulation only as assessed by survival (p=0.3021 and 0.3693, respectively). Thus, BEB55 and JP4-039 safely ameliorate radiation esophagitis in mice.

Role of the esophageal vagus neural pathway in ionizing irradiation-induced seizures in nitric oxide synthase-1 homologous recombinant negative NOS1-/- mice.

AIM: We sought to define the mechanism of total body irradiation (TBI)-induced seizures in NOS1(-/-) mice and amelioration by intra-esophageal manganese superoxide dismutase-plasmid liposomes (MnSOD-PL). MATERIALS AND METHODS: We evaluated the role of vagus nerve pathways in irradiation-induced seizures using biochemical, physiologic, and histopathologic techniques. RESULTS: Heterozygous NOS1(+/-) mice demonstrated radioresistance similar to wild-type C57BL/6NHsd mice (p=0.9269). Irradiation-induced lipid peroxidation in fetal brain cultures from NOS1(-/-) or wild-type mice was reduced by MnSOD-PL. Right-sided vagotomy did not alter the TBI radiation response of wild-type or reverse the radiosensitivity of NOS1(-/-) mice. Excised esophagus from irradiated NOS1(-/-) mice demonstrated an increased histopathologic inflammatory response compared to C57BL/6NHsd mice. CONCLUSION: NOS1(-/-) mice represent a model system for dissecting the developmental abnormalities leading to esophageal-mediated TBI-induced seizures.

The Use of 3,5,4'-Tri-O-acetylresveratrol as a Potential Pro-drug for Resveratrol Protects Mice from γ-Irradiation-Induced Death.

Currently, no drugs are available to protect humans from γ-irradiation-induced death. Because reactive oxygen species are produced upon exposure to γ-irradiation and directly responsible for the resulting death, we hypothesized that antioxidants found in foodstuffs may provide a safe and potent means of antioxidant-dependent radioprotection. Here, we describe our studies investigating the radioprotective properties of resveratrol and 3,5,4'-tri-O-acetylresveratrol. Each of these natural antioxidants was found to protect live cells after γ-irradiation. In mice, the use of 3,5,4'-tri-O-acetylresveratrol with Cremophor EL was particularly effective, indicating that this natural antioxidant may be a leading candidate for radioprotective drug development.

The autophagy-inducing drug carbamazepine is a radiation protector and mitigator.

PURPOSE: To determine whether Carbamazepine (CBZ) is a radiation protector and/or mitigator. MATERIALS AND METHODS: Murine hematopoietic progenitor 32D cl 3 cells were incubated in 1, 10, or 100 µM CBZ 1 h before or immediately after 0-8 Gy irradiation and assayed for clonogenic survival. Autophagy was assayed by immunoblot for microtubule-associated protein light chain 3 (LC3). In vivo radioprotection and mitigation were determined with C57BL/6NTac mice. RESULTS: CBZ treatment at 1, 10 or 100 µM for 1 h prior to irradiation increased radioresistance (the dose for 37% survival or D(0)) from control 1.5 ± 0.1 Gy to 2.1 ± 0.2 Gy (P = 0.012), 2.3 ± 0.1 Gy (P = 0.010), and 3.6 ± 0.7 Gy (P = 0.003), respectively; after irradiation increased the extrapolation number (ñ) from 1.5 ± 0.3 to 10.1 ± 4.2 (P = 0.011), 5.5 ± 1.7 (P = 0.019), and 3.6 ± 0.8 (P = 0.014), respectively, and increased autophagy. CBZ treated mice 10 min or 24 h before or 10 min or 12 h after 9.25 Gy total body irradiation (TBI) showed increased survival (P = 0.012, 0.011, 0.0002, and 0.017, respectively). CONCLUSION: CBZ may be a useful radiation protector and mitigator.