Body Gamma Irradiation Research Articles

The role of melatonin and carnosine in prevention of oxidative intestinal injury induced by gamma irradiation in rats

AbstractExposure of biological materials to ionizing irradiation causes accumulation of reactive oxygen species. The current study aimed to investigate whether melatonin or carnosine could provide protection against irradiation-induced small intestinal damage. Forty Wistar albino rats were divided into five groups. Melatonin, carnosine, and combination of carnosine and melatonin were injected into rats in the third, fourth, and fifth groups, respectively. Rats were injected three times every 48 hours. All groups, excluding the control group, were exposed to a dose of 8 Gray whole body gamma irradiation one hour after the second injection. It was determined that irradiation caused degenerative changes in the intestinal tissues, reduced PCNA (proliferating cell nuclear antigen) -positive cell number, and increased caspase-3- and TNF-

Noninvasive assessment of cutaneous alterations in mice exposed to whole body gamma irradiation using optical imaging techniques.

We report the results of a study carried out to investigate the potential of optical techniques such as optical coherence tomography, Mueller matrix spectroscopy, and cross-polarization imaging for noninvasive monitoring of the ionizing radiation exposure-induced alterations in cutaneous tissue of mice. Radiation dose-dependent changes were observed in tissue microvasculature and tissue optical parameters like retardance and depolarization as early as 1h post radiation exposure. Results suggest that these optical techniques may allow early detection of radiation dose-dependent alterations which could help in screening of population exposed to radiation.

Methanolic Extracts of Cochorous olitorous (L.) and Adansonia digitata (L.) Leaves Against Irradiation-Induced Atherosclerosis in Male Wistar Rats

The present study investigated the anti-atherosclerotic and antioxidative effect of the methanolic extracts (MExt) of Cochorous olitorous (CO) and Adansonia digitata (AD) leaves on irradiation-induced atherosclerosis in male Wistar rats. Atherosclerosis was induced in male rats by a single dose of 6 gray whole body gamma radiation. MExt of C. olitorous and A. digitata leaves at 500 and 1,000 mg/kg bwt were administered as treatment for 7 days. Blood serum was analysed for lipid profile, MDA (malondialdehyde) and liver tissue for antioxidants enzymes, whereas the therapeutic potential was compared to the lipids-lowering drug lovastatin at 10 mg/kg/bwt. The phytochemical studies showed the presence of polyphenols, flavonoids, tannins and saponins. Treatment with MExt of CO and AD normalized the elevated MDA level, whereas the activities of superoxide dismutase, catalase and glutathione peroxidase in the treated rats increased. Pronounced changes were observed at 1,000 mg/kg bwt mixture of MExt of CO and AD for 1 weeks and it was more potent than the standard drug. The current study provided strong evidence that MExt of CO and AD might be important in the treatment of atherosclerosis and ROS without any side effects at the studied dosage and duration.

Potential Protective Effects of Ursolic Acid against Gamma Irradiation-Induced Damage Are Mediated through the Modulation of Diverse Inflammatory Mediators.

This study was aimed to evaluate the possible protective effects of ursolic acid (UA) against gamma radiation induced damage both in vitro as well as in vivo. It was observed that the exposure to gamma radiation dose- and time-dependently caused a significant decrease in the cell viability, while the treatment of UA attenuated this cytotoxicity. The production of free radicals including reactive oxygen species (ROS) and NO increased significantly post-irradiation and further induced lipid peroxidation and oxidative DNA damage in cells. These deleterious effects could also be effectively blocked by UA treatment. In addition, UA also reversed gamma irradiation induced inflammatory responses, as indicated by the decreased production of TNF-α, IL-6, and IL-1β. NF-κB signaling pathway has been reported to be a key mediator involved in gamma radiation-induced cellular damage. Our results further demonstrated that gamma radiation dose- and time-dependently enhanced NF-κB DNA binding activity, which was significantly attenuated upon UA treatment. The post-irradiation increase in the expression of both phospho-p65, and phospho-IκBα was also blocked by UA. Moreover, the treatment of UA was found to significantly prolong overall survival in mice exposed to whole body gamma irradiation, and reduce the excessive inflammatory responses. Given its radioprotective efficacy as described here, UA as an antioxidant and NF-κB pathway blocker, may function as an important pharmacological agent in protecting against gamma irradiation-induced injury.

Erratum to: Synergistic effect of aluminum and ionizing radiation upon ultrastructure, oxidative stress and apoptotic alterations in Paneth cells of rat intestine

Environmental and occupational exposure to aluminum along with ionizing radiation results in serious health problems. This study was planned to investigate the impact of oxidative stress provoked by exposure to ionizing radiation with aluminum administration upon cellular ultra structure and apoptotic changes in Paneth cells of rat small intestine . Animals received daily aluminum chloride by gastric gavage at a dose 0.5 mg/Kg BW for 4 weeks. Whole body gamma irradiation was applied at a dose 2 Gy/week up to 8 Gy. Ileum malondialdehyde, advanced oxidation protein products, and protein carbonyl were assessed as biomarkers of lipid peroxidation along with superoxide dismutase, catalase, and glutathione peroxidase activities as enzyme antioxidants. Moreover, analyses of cell cycle division and apoptotic changes were evaluated by flow cytometry. Intestinal cellular ultra structure was investigated using transmission electron microscope. Oxidative stress assessment in the ileum of rats revealed that aluminum and ionizing radiation exposure either alone or in combination exhibits a significant effect upon the increase in biomarkers of lipid peroxidation along with tumor necrosis factor-α with concomitant significant decrease of the antioxidant enzyme activities. Flow cytometric analyses showed significant alterations in the percentage of cells during cell cycle division phases along with significant increase in apoptotic cells. Ultra structurally, intestinal cellular alterations with marked injury in Paneth cells at the sites of bacterial translocation in the crypt of lumens were recorded. The results of this study have clearly suggested that aluminum exposure and ionizing either alone or in combination induced apoptosis and oxidative stress in the Paneth cells of rat intestine, which appeared to play a major role in the pathogenesis of cellular damage. Furthermore, the interaction of these two intestinal toxic routes was found to be synergistic.

Synergistic effect of aluminum and ionizing radiation upon ultrastructure, oxidative stress and apoptotic alterations in Paneth cells of rat intestine.

Environmental and occupational exposure to aluminum along with ionizing radiation results in serious health problems. This study was planned to investigate the impact of oxidative stress provoked by exposure to ionizing radiation with aluminum administration upon cellular ultra structure and apoptotic changes in Paneth cells of rat small intestine . Animals received daily aluminum chloride by gastric gavage at a dose 0.5mg/Kg BW for 4weeks. Whole body gamma irradiation was applied at a dose 2Gy/week up to 8Gy. Ileum malondialdehyde, advanced oxidative protein products, protein carbonyl and tumor necrosis factor-alpha were assessed as biomarkers of lipid peroxidation, protein oxidation and inflammation respectively along with superoxide dismutase, catalase, and glutathione peroxidase activities as enzymatic antioxidants. Moreover, analyses of cell cycle division and apoptotic changes were evaluated by flow cytometry. Intestinal cellular ultra structure was investigated using transmission electron microscope.Oxidative and inflammatory stresses assessment in the ileum of rats revealed that aluminum and ionizing radiation exposures exhibited a significant effect upon the increase in oxidative stress biomarkers along with the inflammatory marker tumor necrosis factor-α accompanied by a significant decreases in the antioxidant enzyme activities. Flow cytometric analyses showed significant alterations in the percentage of cells during cell cycle division phases along with significant increase in apoptotic cells. Ultra structurally, intestinal cellular alterations with marked injury in Paneth cells at the sites of bacterial translocation in the crypt of lumens were recorded. The results of this study have clearly showed that aluminum and ionizing radiation exposures induced apoptosis with oxidative and inflammatory disturbance in the Paneth cells of rat intestine, which appeared to play a major role in the pathogenesis of cellular damage. Furthermore, the interaction of these two intestinal toxic routes was found to be synergistic.

Development of Orally Administered γ-Tocotrienol (GT3) Nanoemulsion for Radioprotection.

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.

Serum protein concentration in low-dose total body irradiation of normal and malnourished rats

Among the radiotherapeutics' modalities, total body irradiation (TBI) is used as treatment for certain hematological, oncological and immunological diseases. The aim of this study was to evaluate the long-term effects of low-dose TBI on plasma concentration of total protein and albumin using prematurely and undernourished rats as animal model. For this, four groups with 9 animals each were formed: Normal nourished (N); Malnourished (M); Irradiated Normal nourished (IN); Irradiated Malnourished (IM). At the age of 28 days, rats of the IN and IM groups underwent total body gamma irradiation with a source of cobalt-60. Total protein and Albumin in the blood serum was quantified by colorimetry. This research indicates that procedures involving low-dose total body irradiation in children have repercussions in the reduction in body-mass as well as in the plasma levels of total protein and albumin. Our findings reinforce the periodic monitoring of total serum protein and albumin levels as an important tool in long-term follow-up of pediatric patients in treatments associated to total body irradiation.

The Protective Role of Transplanted Bone Marrow Cells against Injuries Induced by a Chemical Carcinogen and / or γ-Rays in Kidney Tissue of Rats

Aim of the work:this work aimed to study the biochemical and histopathological changes in the kidney of male albino rats post exposure to 6Gy of gamma radiation and the protective role of transplanted bone marrow cellsagainst damage induced in rat's kidney by a chemical carcinogen. Materials and Methods: in this study, forty eight healthy and active male albino rats about 120 grams in body weight were used. The animals were housed in plastic cages under normal temperature, pressure, humidity and good ventilation conditions during the whole period of experimentation. The animals were fed on a standard pellet diet and water. Results:exposure of rats to γ-radiation caused a significant increase in kidney function tests, decreased significantly the antioxidants with numerous histopathological changes in the rat kidney tissue. These changes were ameliorated by bone marrow transplantation either after whole body gamma-irradiation and/or Fe-NTA treatment. Conclusion: bone marrow transplantation either after whole body gamma-irradiation and/or Fe-NTA treatment restored the kidney functions and ameliorated the oxidative stress and antioxidants markers. The histopathological observations showed amelioration in the structure of the kidney cortex. So, BM transplantation exerts some curative effects on the function and histological structure of kidney cortex of rats exposed to gamma-irradiation and/or Fe-NTA treatment.

The Protective Effect of BM Transplantation on Liver Tissue by a Chemical Carcinogen or γ-Radiation in Rats

Aim of work: this work aimed to study the biochemical and histopathological changes in the liver of male albino rats post exposure to 6Gy of gamma radiation and the possible protective effect of bone marrow(BM) transplantation on the liver tissues by a chemical carcinogen ferric nitrilotriacetate (Fe-NTA) or γ- radiation in rats. Materials and methods:in this study, thirty six healthy and active male albino rats about 120 grams in body weight were used. The animals were housed in plastic cages under normal temperature, pressure, humidity and good ventilation conditions during the whole period of the experiment . The animals were fed on a standard pellet diet and water.Animals were categorized into six groups and served as the following groups: control, gamma irradiated(R), Fe-NTA, BM+R, BM + Fe-NTA and BM.+Fe-NTA+R. Results: the present results suggested that exposure to γ-radiation or Fe-NTA induced a significantly disturbance in the liver functions and structure. They increased significantly the oxidative stress and decreased significantly the antioxidants tissues and they also increased necrotic and apoptotic cells in rat’s liver tissue. Bone marrow transplantation either after whole body gamma-irradiation or Fe-NTA treatment restored the liver functions and structure.BT also ameliorated the oxidative stress and antioxidative markers. The histopathological observations recorded some amelioration in the apoptotic and necrotic evaluation in liver tissue.

Radioprotective Role of Some Bacteria Belonging to Actinomycetales against Gamma Irradiation-Induced Oxidative Stress in Male Albino Rats

Background: radiation protection concepts and philosophy have been evolving over the past several decades. The inadvertent exposure of human from various source of radiation causes ionization of molecules, setting off potentially damaging reactions via free radicals production. Development of radioprotectants and mitigators is the therapeutic approach to ameliorate the negative health impact of radiation exposure. The majority of substances with biological activity used in medicine are produced by actinomycetes and fungi. Aim: the aim of the present study is to evaluate the radioprotective role of the antimicrobial active metabolite of Streptomyces atrovirens Rahman as antioxidant against gamma irradiation that induced some biochemical alterations in rats. Material and Methods: animals were pretreated with antimicrobial active metabolite of Streptomyces atrovirens Ab1 using suitable stomach tube for two weeks prior to radiation exposure. The levels of malondialdhyde (MDA), glutathione content (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutamic oxaloacetic transaminase (ALT), glutamic aspartate transaminase (AST), alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT) activities, also total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), and low density lipoprotein cholesterol (LDL- C) were estimated. Results: the results revealed that exposure to ionizing radiation resulted in significant elevation in the levels of MDA content, ALT, AST, ALP and GGT activities and concentration of TC, TG and LDL-C, meanwhile, showed significant depletion in GSH content and SOD, CAT and GPx activities and HDL-C concentration. Conclusion: it could be concluded that, the administration of the antimicrobial active metabolite of Streptomyces atrovirens Ab1 pre-whole body gamma irradiation resulted in sufficient amelioration against radiation effects on the biochemical aspects examined in the present study.

Multiple parametric approaches to assess acute radiation lung injury of rats radiation lung injury of rats.

The effect of whole body gamma irradiation (WBI) in single fraction was studied, as well as its influence on the secretion of various biochemical markers and cellular component that could be used as acute radiation lung injury marker. Sprague dawley rats were treated with WBI (60Co) of radiation dose from 1 Gy to 5 Gy (dose rate - 0.95 Gy/min). Bronchoalveolar lavage fluid was retrieved from all animals in control and radiation treated groups up to 72 h post radiation. Bronchoalveolar lavage fluid (BALF) was analyzed for lactate dehydrogenase (LDH ), acid phosphatase (AP ), alkaline phosphatase (ALP ), cell count and total protein. Intragroup and intergroup comparison of BALF parameters at different radiation doses showed significant difference. LDH was significantly increased as the dose increased from 1Gy to 5Gy (P = 0.00) after 2 h with effect size of difference (r > 0.3). ALP was significantly altered after 3Gy and 4Gy (P < 0.05). AP was significantly altered at 2Gy-5Gy (p < 0.05). Total protein level changed significantly from 1Gy to 5Gy (P < 0.00). Cellular content of BALF showed significant changes after radiation exposure. BALF parameters like LDH, AP, ALP, neutrophils, lymphocytes, total leukocyte count and total protein were sensitive to radiation exposure and their levels vary significantly up to 72 h after single whole body radiation exposure in Sprague dawley rats. It can be concluded that the biochemical indices in BALF have more wide application in evaluation of acute radiation induced lung injury.

Acute whole-body low dose gamma irradiation does not affect humoral immunity in chicken

Summary It has been documented that low-dose ionising irradiation enhance the immune response on both cellular and humoral immunity in mammals. In the present study three experiments were conducted to compare antibody titre against a vaccinal strain of Newcastle disease virus after low-dose total body gamma irradiation in chickens. In all experiments, male Leghorn chicks were irradiated, on day 1 or 3 of life, with the dose of 0.05, 0.15, 0.30, 0.50 and 0.80 Gy gamma radiation. In two experiments, after irradiation, chicks were vaccinated with the commercial Newcastle disease vaccine by the nebulisation method. Blood samples were collected for serological analyses from day one or 7 up to day 28 in weekly intervals, depending on experimental design. Specific serum anti-Newcastle disease virus antibodies were quantitated by haemagglutination inhibition assay. No significant effect on the level of haemagglutination inhibition of maternal antibody titre and antibody titre against vaccinal Newcastle disease virus as well as on the rate of antibody catabolism was found. The ionising radiation used in the present experiment did not influence the humoral immune response in this light strain of chickens.

AMELIORATIVE EFFECT OF BLUE BERRY AGAINST MULTIPLE ORGAN DAMAGE BY γ-IRRADIATION IN ADULT MALE ALBINO RATS

Background: Blue berry fruit are rich in bioactive constituents, including flavonoids, anthocyanins, phenolic acids, stilbenes, and tannins, as well as nutritive compounds such as sugars, essential oils, carotenoids, vitamins and minerals. Numerous scientific studies provide ample evidence that bioactive compounds have the potential to decrease the risk of cardiovascular and degenerative diseases. Whole body exposure to ionizing radiation induces oxidative stress through generation of free radicals which often trigger chain reactions mediated tissue damage. Objective: This work was done to study the potential protective effect of blue berry against injury of heart, liver and kidney caused by exposure to gamma irradiation . Material and Methods: Forty adult male albino rats were used and divided into four equal groups: Group 1 served as control group, group 2 received blue berry juice (BBJ) 1ml/100g body wt. by oral intubation gavage for 14 consecutive days , group 3 was exposed to single dose of 7Gy whole body gamma-irradiation, and group 4 received BBJ (1ml/100g body wt.) by oral gavage for 14 consecutive days before irradiation. All groups of rats were anesthetized and sacrificed on the last day after treatment and/or irradiation. Blood samples were taken from all groups to estimate lactate dehydrogenase (LDH), creatine phosphokinase (CPK), interleukin-6 (IL-6), total cholesterol (TC), triacylglycerol (TAG), high density lipoprotein cholesterol (HDL-C), malondialdehyde (MDA), alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), urea, creatinine, cystatin and lipocalin. Results: BBJ administration before exposure to g-irradiation significantly reduced serum LDH, CPK, IL-6, TC, TAG, and MDA versus a significant increase of serum HDL-C. Moreover, amelioration of liver and kidney function test was observed by significant decrease in ALT, AST, ALP, serum urea, creatinine, cyctatin-C and lipocalin-2 in comparison with irradiated group. Conclusion: The study pointed out to the promising positive role of blue berry supplementation as a natural product to reduce oxidative stress and protect body organs from gamma irradiation.

Therapeutic Effects of Olive Leaf Extract or Bone Marrow Mesenchymal Stem Cells against Lung Damage Induced in Male Albino Rats Exposed to Gamma Radiation

Aim of the work- This study aimed to investigate the histological and histochemical changes in the lung tissue of male albino rats post exposure to gamma radiation and the possible therapeutic effect of both olive leaf extract and bone marrow mesenchymal stem cells. Matrerial and methods-The current study was carried out on 40 adult male albino rats (Sprague dawely strain); they were divided equally into 5 groups (C group: control rats; O group : rats treated with olive leaves extract( 15 mg /kg body weight/daily) ; R group: rats exposed to a single dose of gamma-radiation(3 Gy); RO group: rats of this group treated with olive extract 15 mg /kg body weight/daily one week before and one week after irradiation; RS group: rats of this group irradiated with 3Gy then treated with bone marrow mesenchymal stem cells ( BMSCs) 3×106 cells/ml suspension through caudal vein about 5h post radiation exposure. Histopathological and histochemical changes were studied. Results-Rats exposed to gamma radiation showed numerous histological and histochemical changes, these changes were ameliorated by using either olive leaf extract or bone marrow mesenchymal stem cells. BMSCs showed more obvious therapeutic effect than olive leaf extract. Conclusion-The present work showed that olive leaf extract or bone marrow mesenchymal stem cells (BMSCs) have lung tissue radiotherapeutic effects against whole body gamma radiation in male albino rats.

Long-Lasting Impact of Neonatal Exposure to Total Body Gamma Radiation on Secondary Lymphoid Organ Structure and Function.

The acute period after total body irradiation (TBI) is associated with an increased risk of infection, principally resulting from the loss of hematopoietic stem cells, as well as disruption of mucosal epithelial barriers. Although there is a return to baseline infection control coinciding with the apparent progressive recovery of hematopoietic cell populations, late susceptibility to infection in radiation-sensitive organs such as lung and kidney is known to occur. Indeed, pulmonary infections are particularly prevalent in hematopoietic cell transplant (HCT) survivors, in both adult and pediatric patient populations. Preclinical studies investigating late outcomes from localized thoracic irradiation have indicated that the mechanisms underlying pulmonary delayed effects are multifactorial, including exacerbated and persistent production of pro-inflammatory molecules and abnormal cross-talk among parenchymal and infiltrating immune and inflammatory cell populations. However, in the context of low-dose TBI, it is not clear whether the observed exacerbated response to infection remains contingent on these same mechanisms. It is possible instead, that after systemic radiation-induced injury, the susceptibility to infection may be independently related to defects in alternative organs that are revealed only through the challenge itself; indeed, we have hypothesized that this defect may be due to radiation-induced chronic effects in the structure and function of secondary lymphoid organs (SLO). In this study, we investigated the molecular and cellular alterations in SLO (i.e., spleen, mediastinal, inguinal and mesenteric lymph nodes) after TBI, and the time points when there appears to be immune competence. Furthermore, due to the high incidence of pulmonary infections in the late post-transplantation period of bone marrow transplant survivors, particularly in children, we focused on outcomes in mice irradiated as neonates, which served as a model for a pediatric population, and used the induction of adaptive immunity against influenza virus as a functional end point. We demonstrated that, in adult animals irradiated as neonates, high endothelial venule (HEV) expansion, generation of follicular helper T cells (TFH) and formation of splenic germinal centers (GC) were rapidly and, more importantly, persistently impaired in SLO, suggesting that the early-life exposure to sublethal radiation had long-lasting effects on the induction of humoral immunity. Although the neonatal TBI did not affect the overall outcome from influenza infection in the adults at the earlier time points assessed, we believe that they nonetheless contribute significantly to the increased mortality observed at subsequent late time points. Furthermore, we speculate that the detrimental and persistent impact on the induction of CD4 T- and B-cell responses in the mediastinal lymph nodes will decrease the animals' ability to respond to other aerial pathogens. Since many of these pathogens are normally cleared by antibodies, our findings provide an explanation for the susceptibility of survivors of childhood HCT to life-threatening respiratory tract infections. These findings have implications regarding the need for increased monitoring in pediatric hematopoietic cell transplant patients, since they indicate that there are ongoing and cumulative defects in SLO, which, importantly, develop during the immediate and early postirradiation period when patients may appear immunologically competent. The identification of changes in immune-related signals may offer bioindicators of progressive dysfunction, and of potential mechanisms that could be targeted so as to reduce the risk of infection from extracellular pathogens. Furthermore, these results support the potential susceptibility of the pediatric population to infection after sublethal irradiation in the context of a nuclear or radiological event.

Cochorous olitorous and Adasonia digitata leaves extracts protects against gamma radiation induced anaemia

This paper proposes that exposure to radiation could generate free radicals, which could lead to disorders such as heamolysis-induced anaemia. We evaluated the radioprotective potentials of Cochorous olitorious and Adasonia digitata methanol leaves extract in gamma radiation induced anaemia. Fifty four adult male Wistar rats were divided into nine groups of 6 animals. Except for the control group, the other the animals were treated with a single dose of whole body gamma radiation of 6Gy and received either 500 or 1000 mg/kg body weight (bwt) of A. digitata and C. olitorious either singly or combination and vitamin C was used as reference. A. digitata and C. olitorious were screened for phytochemical content and had saponin (16.59±1.85 and 22.12±0.24), tannins (311.98±0.01 and 287.07±0.16), polyphenols (170.90±0.68 and 330.07±0.32), alkaloids (81.56±0.56 and 68.65±2.05) and flavonoids (25.38±2.88 and 157.38±0.38) respectively. There was significant loss in body weight, depletion in red blood cells (RBC), packed cell volume (PCV), heamoglobin concentration (HBC) in untreated rats exposed to gamma radiation. Administration of the plant extract to rats exposed to radiation was able to attenuate and ameliorate loss in body weight and changes in blood cells (HBC, PCV, PLT and RBC) especially in radiated rats on combination therapy of both extracts at 1000 mg/kg bwt group. Hepatoprotective and safety evaluation was done by measuring the serum ALT, AST and ALP, these parameters were significantly (p<0.05) increased in untreated rats exposed to gamma radiation compared to normal control rats and these decreased in rats on plant extract.

Hesperidin, A Citrus Bioflavonoid Reduces the Oxidative Stress in the Skin of Mouse Exposed to Partial Body γ-Radiation

Generation of reactive oxygen species (ROS) is one of the important and early events after exposure to ionizing radiations and this ROS production is responsible for the degenerative changes ensuing irradiation. An attempt has been made to modulate the radiation induced-ROS by hesperidin (hesperitin-7-rhamnoglucoside), a bioflavonoid in the wounded skin of irradiated mouse. The lower half of the animals was shaved and the animals were orally administered or not with 100 mg/kg body weight of hesperidin before exposure to 6 Gy of partial body gamma-radiation. The activities of glutathione peroxidase, superoxide dismutase and glutathione concentration as well as lipid peroxidation were estimated in the skin of mouse at 0, 1.5, 3, 6, 12, 24 and 48 h post-irradiation. Irradiation of mouse to 6 Gy caused a significant depletion in the activities of glutathione peroxidase, superoxide dismutase as well as glutathione concentration. Exposure of mouse to 6 Gy resulted in a significant elevation in lipid peroxidation when compared to the base line levels of lipid peroxidation. Administration of hesperidin before hemi- body exposure to 6 Gy γ-rays significantly raised the activities of glutathione peroxidase, superoxide dismutase and glutathione concentration, whereas hesperidin pretreatment caused a significant reduction in the radiation induced lipid peroxidation. The present study demonstrates that hesperidin pretreatment reduces the radiation induced oxidative stress in the irradiated wounds of mouse and may be useful paradigm to reduce the radiation-induced oxidative stress before or after surgery.

Evaluation of circulating endothelial cells in the rat after acute and fractionated whole-body gamma irradiation

Abstract Purpose: Damage to vascular endothelial cells is a well recognised complication of the irradiation. Our objective was to determine the gamma-irradiation effect on the rat circulating endothelial cells (CEC). Material and methods: Eight-week old rats were divided into four groups: group 1 - rats were exposed to acute whole- -body gamma irradiation with a wide range of single doses (0.5, 1, 2, 4 and 8 Gy), group 2 - rats were exposed to fractionated low doses of irradiation (0.1, 0.5 and 1 Gy) every three days for two months, group 3 as group 2, but followed by two months of rest, group 4 were control animals. CEC (CD146 positive cells) in group 1 were counted following CD146-based immuno-magnetic separation after one day and one week, as well as at the end of experiment in the other groups. Results: Quantified CEC showed that there was a dose-dependent reduction in CEC count in group 1 (one week after irradiation) and group 2. A partial re-population of CEC was observed at the end of experiment in both group 1 and group 2 compared to control group. Group 3 showed a significant increase in CEC levels as compared with group 2 without reaching the control level. Conclusion: The number of CEC (CD146 positive cells) in rats exposed to whole-body gamma irradiation was reduced in a dose-dependent manner and it partly recovered during the two-month interval after irradiation. We suggest that CEC count may be an indicator of the radiation-induced vascular damage.

The cognitive defects of neonatally irradiated mice are accompanied by changed synaptic plasticity, adult neurogenesis and neuroinflammation.

Background/purpose of the studyEpidemiological evidence suggests that low doses of ionising radiation (≤1.0 Gy) produce persistent alterations in cognition if the exposure occurs at a young age. The mechanisms underlying such alterations are unknown. We investigated the long-term effects of low doses of total body gamma radiation on neonatally exposed NMRI mice on the molecular and cellular level to elucidate neurodegeneration.ResultsSignificant alterations in spontaneous behaviour were observed at 2 and 4 months following a single 0.5 or 1.0 Gy exposure. Alterations in the brain proteome, transcriptome, and several miRNAs were analysed 6–7 months post-irradiation in the hippocampus, dentate gyrus (DG) and cortex. Signalling pathways related to synaptic actin remodelling such as the Rac1-Cofilin pathway were altered in the cortex and hippocampus. Further, synaptic proteins MAP-2 and PSD-95 were increased in the DG and hippocampus (1.0 Gy). The expression of synaptic plasticity genes Arc, c-Fos and CREB was persistently reduced at 1.0 Gy in the hippocampus and cortex. These changes were coupled to epigenetic modulation via increased levels of microRNAs (miR-132/miR-212, miR-134). Astrogliosis, activation of insulin-growth factor/insulin signalling and increased level of microglial cytokine TNFα indicated radiation-induced neuroinflammation. In addition, adult neurogenesis within the DG was persistently negatively affected after irradiation, particularly at 1.0 Gy.ConclusionThese data suggest that neurocognitive disorders may be induced in adults when exposed at a young age to low and moderate cranial doses of radiation. This raises concerns about radiation safety standards and regulatory practices.Electronic supplementary materialThe online version of this article (doi:10.1186/1750-1326-9-57) contains supplementary material, which is available to authorized users.