Radioprotective effects of citrus extract against gamma-irradiation in mouse bone marrow cells

Fruits and their phytochemicals in mitigating the ill effects of ionizing radiation: review on the existing scientific evidence and way forward

Although helpful in treating cancer, exposure to ionizing radiation can sometimes cause severe side effects, negating its benefit. In addition to its use in clinics, a nontoxic radioprotective agent can also be beneficial in occupational settings where humans are occupationally exposed for prolonged periods to low doses of radiation. Scientific studies using laboratory animals have shown that the fruits Aegle marmelos, Capsicum annuum, Citrus aurantium, Citrullus lanatus, Crataegus microphylla, Eugenia jambolana, Emblica officinalis, Garcinia kola, Grewia asiatica, Hippophae rhamnoides, Malus baccata, Malpighia glabra or Malpighia emarginata, Mangifera indica, Prunus domestica, Prunus avium, Prunus armeniaca, Psoralea corylifolia, Punica granatum, Solanum lycopersicum, Terminalia chebula, Vaccinium macrocarpon, Vitis vinifera and Xylopia aethiopica, and the phytochemicals gallic acid, ellagic acid, quercetin, geraniin, corilagin, ascorbic acid, hesperetin, ursolic acid, lycopene, naringin, hesperidin, rutin, resveratrol, β-sitosterol, apigenin, luteolin, chlorogenic acid, caffeic acid, mangiferin, diosmin, ferulic acid, and kaempferol are effective in preventing radiation-induced ill effects. Clinical studies with Emblica officinalis and Punica granatum have also shown that fruits help mitigate radiation-induced mucositis, dermatitis, and cystitis. For the first time, the current review summarizes the beneficial effects of fruits and phytochemicals in mitigating radiation-induced damage, the underlying mechanisms and the existing lacunae for future studies to be undertaken for the benefit of humans and the nutraceutical and agri-based industries.

In-vivo and in vitro assessments of the radioprotective potential natural and chemical compounds: a review

PURPOSE

The study of the radioactive role of natural and chemical substances on human and animal studies has been the subject of research by some researchers. Therefore, the review of some of the past and current studies conducted in this field, can provide helpful information to elucidate of the importance of radioprotective components in reducing radiation exposure side effects.

METHODS

The authors search for keywords including In vitro, In vivo, Radioprotective, Ionizing radiation, and Vitamin in ScienceDirect, Scopus, Pubmed, and Google Scholar databases to access previously published articles and search for more reference articles on the role of radioprotective materials from natural and chemical compounds.

RESULTS

Radiation exposure can produce reactive oxygen species (ROS) in the body, however most of which are eliminated by the body's natural mechanisms, but when the body's antioxidant systems do not have enough ability to neutralize free radicals, oxidative stress occurs, which causes damage to DNA and body tissues. Therefore, it is necessary use of alternative substances that reduce and inhibit free radicals.

CONCLUSION

In general, recommended that antioxidant component(s) can be protect tissue damages in humans or animals, due to the their ability to scavenge free radicals generated by ionizing radiation.

The protective effects of Xuebijing injection on intestinal injuries of mice exposed to irradiation

BACKGROUND

Gastrointestinal (GI) injury is one of the most common side effects of radiotherapy. However, there is no ideal therapy method except for symptomatic treatment in the clinic. Xuebijing (XBJ) is a traditional Chinese medicine, used to treat sepsis by injection. In this study, the protective effects of XBJ on radiation-induced intestinal injury (RIII) and its mechanism were explored.

METHODS

The effect of XBJ on survival of irradiated C57BL/6 mice was monitored. Histological changes including the number of crypts and the length of villi were evaluated by H&E. The expression of Lgr5+ intestinal stem cells (ISCs), Ki67+ cells, villin and lysozymes were examined by immunohistochemistry. The expression of cytokines in the intestinal crypt was detected by RT-PCR. DNA damage and apoptosis rates in the small intestine were also evaluated by immunofluorescence.

RESULTS

In the present study, XBJ improved the survival rate of the mice after 8.0 and 9.0 Gy total body irradiation (TBI). XBJ attenuated structural damage of the small intestine, maintained regenerative ability and promoted proliferation and differentiation of crypt cells, decreased apoptosis rate and reduced DNA damage in the intestine. Elevation of IL-6 and TNF-α was limited, but IL-1, TNF-𝛽 and IL-10 levels were increased in XBJ-treated group after irradiation. The expression of Bax and p53 were decreased after XBJ treatment.

CONCLUSIONS

Taken together, XBJ provides a protective effect on RIII by inhibiting inflammation and blocking p53-related apoptosis pathway.

Aloe vera modulates X-ray induced hematological and splenic tissue damage in mice

The present study was premeditated to examine the radioprotective effects of aqueous Aloe vera gel extract against whole-body X-ray irradiation-induced hematological alterations and splenic tissue injury in mice. Healthy male balb/c mice were divided into four groups: group 1, control; group 2, A. vera (50 mg/kg body weight) administered per oral on alternate days for 30 days (15 times); group 3, X-ray exposure of 2 Gy (0.25 Gy twice a day for four consecutive days in the last week of the experimental protocol); and group 4, A. vera + X-ray. X-ray exposure caused alterations in histoarchitecture of spleen along with enhanced clastogenic damage as assessed by micronucleus formation and apoptotic index. Irradiation caused an elevation in proinflammatory cytokines like tumor necrosis factor and interleukin-6, total leucocyte counts, neutrophil counts and decreased platelet counts along with unaltered red blood cell counts and hemoglobin. Irradiation also caused an elevation in reactive oxygen species (ROS), lipid peroxidation (LPO) levels, lactate dehydrogenase activity and alterations in enzymatic and nonenzymatic antioxidant defense mechanism in plasma and spleen. However, administration of A. vera gel extract ameliorated X-ray irradiation-induced elevation in ROS/LPO levels, histopathological and clastogenic damage. It also modulated biochemical indices, inflammatory markers, and hematological parameters. These results collectively indicated that the A. vera gel extract offers protection against whole-body X-ray exposure by virtue of its antioxidant, anti-inflammatory and anti-apoptotic potential.

Blueberry extract attenuates γ-radiation-induced hepatocyte damage by modulating oxidative stress and suppressing NF-κB in male rats

Radiation exposure is known to produce many harmful effects in biological systems, and these effects are often mediated by oxygen free radicals. Because blueberries are rich in antioxidant compounds such as anthocyanins and phenolic acids, we divided forty adult rats into four treatment groups of 10 (G1-4) as follows: G1 rats were used as a control, G2 rats were irradiated with 8 Gy at 2 Gy/week at a dose rate of 0.5 Gy/min, G3 rats were administered blueberry extract (200 mg/kg) and G4 rats were administered blueberry extract during the same irradiation period. In subsequent determinations, γ-irradiated rats had increased levels of cholesterol, triglyceride, high density lipoprotein (HDL) and low density lipoprotein (LDL), and significantly elevated liver enzyme activities, including alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), and total bilirubin. In contrast, significant reductions in albumin, total protein and globulin were observed, whereas gamma irradiation decreased activities of the antioxidant enzymes glutathione (GSH), catalase (CAT), xanthine dehydrogenase (XDH) and superoxide dismutase (SOD). We also observed incremental increases in DNA fragmentation percentages and histopathological changes in liver tissues. Serum pro-inflammatory cytokine levels (IL-6, IL-10 and TNF-α) were significantly elevated and hepatic NF-кB was upregulated. In G4 rats, treatments with blueberry extract restored liver pro-oxidant status, reduced cytokine levels, ameliorated histopathological parameters and reduced DNA damage. In conclusion, γ-radiation exerts toxic effects in the rat livers, and blueberry extract is protective against these.

Medicinally important aromatic plants with radioprotective activity

Aromatic plants are often used as natural medicines because of their remedial and inherent pharmacological properties. Looking into natural resources, particularly products of plant origin, has become an exciting area of research in drug discovery and development. Aromatic plants are mainly exploited for essential oil extraction for applications in industries, for example, in cosmetics, flavoring and fragrance, spices, pesticides, repellents and herbal beverages. Although several medicinal plants have been studied to treat various conventional ailments only a handful studies are available on aromatic plants, especially for radioprotection. Many plant extracts have been reported to contain antioxidants that scavenge free radicals produced due to radiation exposure, thus imparting radioprotective efficacy. The present review focuses on a subset of medicinally important aromatic plants with radioprotective activity.

Rescue effects of ginger extract on dose dependent radiation-induced histological and biochemical changes in the kidneys of male Wistar rats

Radiation is an essential modality in the management of cancer therapy, but its acute and chronic side effects on the normal organs limit the helpfulness of radiotherapy. The deleterious effects of radiation begin with oxidative stress and inflammatory reaction to radiolytic hydrolysis and formation of free radicals. The aim of the current study was to investigate the effect of dose dependent whole body radiation exposure on histological and biochemical alterations in rat kidney. It was also planned to find out whether ginger extract mitigated the deleterious effects of different doses of radiation in rat kidney. Male Wistar rats were exposed to three doses (2, 4, and 8Gy) of γ- ray with or without a 10day pretreatment with ginger extract. After 10days of whole body γ- ray exposure, the results revealed proliferation of glomerular and tubular cells, fibrosis in glomerular and peritubular and a significant increase in 8-OHdG, CRP, cystatin C (in 8Gy), plasma urea and creatinine levels, as well as a significant decrease in total antioxidant capacity of radiation groups compared to those of the control group. Ginger extract administration once daily for 10 consecutive days before exposure to 2-4-8Gy radiotherapy, which ameliorated histological and biochemical alterations in kidneys of the rats entirely or partially compared to those in the ethanol group rats. These findings indicate that whole body exposure to radiation induces kidney damage through oxidative DNA damage and inflammatory reactions, and that these effects can be alleviated using ginger pretreatment as an antioxidant and anti-inflammatory agent.

Oral Administration of Vitamin C, Cimetidine and Famotidine on Micronuclei Induced by Low Dose Radiation in Mouse Bone Marrow Cells

BACKGROUND

In many studies, chemicals and natural materials were tested to reduce the harmful effects of radiation. It is known that Famotidine and vitamin C reduce DNA damage.

OBJECTIVE

The aim of this study was to evaluate the radioprotective effect of vitamin C, Cimetidine and Famotidine on gamma-radiation-induced damage on mouse bone marrow.

METHODS

Six-to-seven week male NMRI mice (28 g ±3) were randomly divided into fourteen groups: control, 2Gy irradiation, six group drugs without irradition (Famotidine, Cimetidine, vitaminC, Fam-Cim, Fam-Vit, Cim-Vit), six groups received drugs and 2Gy radiation with a 60Co |γ|-ray source at room temperature 22 ± 2 °C. The mice were killed 48 hours after irradiation by cervical dislocation. Slides were prepared from bone marrow cells and stained in May-Granwald and Giemsa. Finally, the cells were counted with microscope, frequencies of polychromatic erythrocyte (PCE), normochoromatic erythrocyte (NCE) and their micronuclated cell were recorded. PCE / PCE + NCE were calculated.

RESULTS

There were significant differences of MNPCE/1000PCE, MNNCE/1000NCE and PCE/PCE+NCE among different groups with similar radiation doses (p≤0.01). Moreover, there were significant differences of MNPCE/1000PCE and PCE/PCE+NCE among different doses of radiation (p≤0.01). While considering MNNCE/1000NCE, there were no significant differences among silimar groups with radiation dose (p˃0.05).

CONCLUSION

Oral administration of Famotidine, vitamin C and Cimetidine demonstrate reliable and similar radioprotective effects. Additionally, the protective effect of single use of these drugs was similar to the combination form. Thus, the oral use of combination, 48 hours after irradiation cannot induce more radioprotective effect.

Radioprotective effect of Zamzam (alkaline) water: A cytogenetic study

BACKGROUND

Radioprotectors are useful compounds to reduce radiation toxicity of normal cells. Many natural radioprotectors have antioxidant power and display fewer toxicity and side effects than the chemical ones. Alkaline waters such as Zamzam have antioxidant power potentially. This study aimed to investigate the radioprotective effect of Zamzam water in mice bone marrow exposed to gamma radiation by micronuclei test.

METHOD

Five study groups including control group which was fed by ordinary water, the second group was fed by Zamzam water, and radiation groups were received 2Gy gamma with ordinary and Zamzam water for 10 days and another for 20 days. The frequency of micronuclei and polychromatic erythrocytes to normochromatic erythrocytes ratio were calculated by micronuclei test.

RESULT

In the absence of radiation, no significant difference was found between Zamzam group and control in the number of micronuclei in normochromatic erythrocytes, micronuclei in polychromatic erythrocytes, and the polychromatic erythrocyte to polychromatic erythrocyte plus normochromatic erythrocyte ratio. But all of these indices were significantly different between irradiated and non-irradiated groups. The frequency of micronuclei in polychromatic erythrocytes was not significantly different between 10 and 20 days Zamzam irradiated groups, but the reduction in micronuclei in normochromatic erythrocytes and an increase in the polychromatic erythrocyte to polychromatic erythrocyte plus normochromatic erythrocyte ratio compared to ordinary water were seen in 20 days Zamzam group. Dose reduction factor was 1.36 and 2 for Zamzam water groups of 10 days and 20 days, respectively.

CONCLUSION

The results demonstrated that Zamzam alkaline water could reduce clastogenic and cytotoxic effects of gamma irradiation.

Protective role of Aloe vera against X-ray induced testicular dysfunction

The present investigation was carried out to evaluate the possible radioprotective potential of an Aloe vera extract against whole-body X-ray irradiation-induced testicular alterations in mice. Male balb/c mice were divided into four groups: control, A. vera, X-ray and A. vera pre-treated + X-ray irradiated. Histopathological examination revealed significant structural alterations in testes after X-ray exposure, which was also associated with the presence of apoptotic cells as assessed by TUNEL assay. X-ray irradiation resulted in elevation in the levels of reactive oxygen species, lipid peroxidation, a reduction in glutathione concentration and enhanced activities of antioxidant enzymes such as glutathione reductase, glutathione peroxidase, catalase, superoxide dismutase and glutathione-S-transferase. Sperm count/motility and testosterone levels were significantly decreased in the irradiated group. Irradiated animals pre-treated with A. vera extract revealed an improvement in antioxidant status, inhibition of lipid peroxides, apoptotic cell formation and enhanced testicular parameters when compared to the X-ray-exposed group. These findings suggest that A. vera extract could ameliorate X-ray-induced damage due to its free radical scavenging properties and its potential to boost cellular antioxidant defence machinery.

Radioprotective Agents: Strategies and Translational Advances

Radioprotectors are agents required to protect biological system exposed to radiation, either naturally or through radiation leakage, and they protect normal cells from radiation injury in cancer patients undergoing radiotherapy. It is imperative to study radioprotectors and their mechanism of action comprehensively, looking at their potential therapeutic applications. This review intimately chronicles the rich intellectual, pharmacological story of natural and synthetic radioprotectors. A continuous effort is going on by researchers to develop clinically promising radioprotective agents. In this article, for the first time we have discussed the impact of radioprotectors on different signaling pathways in cells, which will create a basis for scientific community working in this area to develop novel molecules with better therapeutic efficacy. The bright future of exceptionally noncytotoxic derivatives of bisbenzimidazoles is also described as radiomodulators. Amifostine, an effective radioprotectant, has been approved by the FDA for limited clinical use. However, due to its adverse side effects, it is not routinely used clinically. Recently, CBLB502 and several analog of a peptide are under clinical trial and showed high success against radiotherapy in cancer. This article reviews the different types of radioprotective agents with emphasis on the strategies for the development of novel radioprotectors for drug development. In addition, direction for future strategies relevant to the development of radioprotectors is also addressed.

Utilization of cytogenetic biomarkers as a tool for assessment of radiation injury and evaluation of radiomodulatory effects of various medicinal plants - a review

Systematic biological measurement of “cytogenetic endpoints” has helped phenomenally in assessment of risks associated with radiation exposure. There has been a surge in recent times for the usage of radioactive materials in health care, agriculture, industrial, and nuclear power sectors. The likelihood of radiation exposure from accidental or occupational means is always higher in an overburdened ecosystem that is continuously challenged to meet the population demands. Risks associated with radiation exposure in this era of modern industrial growth are minimal as international regulations for maintaining the safety standards are stringent and strictly adhered to, however, a recent disaster like “Fukushima” impels us to think beyond. The major objective of radiobiology is the development of an orally effective radio-modifier that provides protection from radiation exposure. Once available for mass usage, these compounds will not only be useful for providing selective protection against accidental and occupational radiation exposure but also help to permit use of higher doses of radiation during treatment of various malignancies curtailing unwarranted adverse effects imposed on normal tissues. Bio-active compounds isolated from natural sources enriched with antioxidants possess unique immune-modulating properties, thus providing a double edged benefit over synthetic radioprotectors. We aim to provide here a comprehensive overview of the various agents originating from plant sources that portrayed promising radioprotection in various experimental models with special emphasis on studies that used cytogenetic biomarkers. The agents will include crude extracts of various medicinal plants, purified fractions, and herbal preparations.

Effects of lethal dose of γ-radiation and partial body hyperthermia on Wistar rats

PURPOSE

The radioprotectors currently available are generally poorly tolerated in human beings; thus, their use has been restricted due to their side effects and their limited clinical tolerance. In a search for fewerand/or without side effects agents, the radioprotective effects of partial body hyperthermia (PBH) were tested on Wistar rats of both sexes at different ages.

MATERIALS AND METHODS

PBH (43 °C, 1 h) was carried out by immersion of each animal's lower parts and legs in a thermostatically controlled water bath 20 h prior to irradiation with a lethal single exposure dose of 9 Gy of gamma irradiation. Irradiated PBH pretreated animals were monitored for 30 days post-irradiation and survival percentages were calculated.

RESULTS

The data obtained provide evidence that PBH treatment prolonged the irradiated rats' lifespans and the mortality rates varied significantly with animal age and sex. In addition, PBH treatment significantly enhanced bone marrow recovery of irradiated rats of both genders.

CONCLUSIONS

Partial body hyperthermia prior to radiation proved to have beneficial effects on gamma irradiated rats.

Kojic acid protects C57BL/6 mice from gamma-irradiation induced damage

The radioprotective effects of a single administration of kojic acid (KA) against ionizing radiation were evaluated via assessment of 30-day survival and alterations of peripheral blood parameters of adult C57BL/6 male mice. The 30-day survival rate of mice pretreated with KA (75 or 300 mg/kg body weight, KA75 or KA300) subcutaneously 27 h prior to a lethal dose (8 Gy, 153.52 cGy/min) of gamma irradiation was higher than that of mice irradiated alone (40% or 60% vs 0%). It was observed that the white blood cell (WBC) count/the red blood cell (RBC) count, haemoglobin content, haematocrit and platelet count of mice with or without KA pretreatment as exposed to a sub-lethal dose (4 Gy, 148.14 cGy/min) of gamma irradiation decreased maximally at day 4/day 8 post-irradiation. Although the initial WBC values were low in KA300 or WR-2721 (amifostine) groups, they significantly recovered to normal at day 19, whereas in the control group they did not. The results from the cytotoxicity and cell viability assays demonstrated that KA could highly protect Chinese hamster ovary (CHO) cells against ionizing radiation with low toxicity. In summary, KA provides marked radioprotective effects both in vivo and in vitro.

An evidence-based systematic review of bitter orange (Citrus aurantium) by the Natural Standard Research Collaboration

An evidence-based systematic review of bitter orange (Citrus aurantium) by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Mitigating the effects of Xuebijing injection on hematopoietic cell injury induced by total body irradiation with γ rays by decreasing reactive oxygen species levels

Hematopoietic injury is the most common side effect of radiotherapy. However, the methods available for the mitigating of radiation injury remain limited. Xuebijing injection (XBJ) is a traditional Chinese medicine used to treat sepsis in the clinic. In this study, we investigated the effects of XBJ on the survival rate in mice with hematopoietic injury induced by γ ray ionizing radiation (IR). Mice were intraperitoneally injected with XBJ daily for seven days after total body irradiation (TBI). Our results showed that XBJ (0.4 mL/kg) significantly increased 30-day survival rates in mice exposed to 7.5 Gy TBI. This effect may be attributable to improved preservation of white blood cells (WBCs) and hematopoietic cells, given that bone marrow (BM) cells from XBJ-treated mice produced more granulocyte-macrophage colony forming units (CFU-GM) than that in the 2 Gy/TBI group. XBJ also decreased the levels of reactive oxygen species (ROS) by increasing glutathione (GSH) and superoxide dismutase (SOD) levels in serum and attenuated the increased BM cell apoptosis caused by 2 Gy/TBI. In conclusion, these findings suggest that XBJ enhances the survival rate of irradiated mice and attenuates the effects of radiation on hematopoietic injury by decreasing ROS production in BM cells, indicating that XBJ may be a promising therapeutic candidate for reducing hematopoietic radiation injury.

Radioprotectors - the evergreen topic

To protect organisms from ionizing radiation (IR), and to reduce morbidity or mortality, various agents, called radioprotectors, have been utilized. Because radiation-induced cellular damage is attributed primarily to the harmful effects of free radicals, molecules with radical-scavenging properties are particularly promising as radioprotectors. Early development of such agents focused on thiol synthetic compounds, known as WR protectors, but only amifostine (WR-2721) has been used in clinical trials as an officially approved radioprotector. Besides thiol compounds, various compounds with different chemical structure were investigated, but an ideal radioprotector has not been found yet. Plants and natural products have been evaluated as promising sources of radioprotectors because of their low toxicity, although they exhibit an inferior protection level compared to synthetic thiol compounds. Active plant constituents seem to exert the radioprotection through antioxidant and free radical-scavenging activities. Our research established that plants containing polyphenolic compounds (raspberry, blueberry, strawberry, grape, etc.) exhibit antioxidative activities and protect genetic material from IR.

Radio-protective role of antioxidant agents

Ionizing radiation interacts with biological systems to produce reactive oxygen species and reactive nitrogen species which attack various cellular components. Radio-protectors act as prophylactic agents to shield healthy cells and tissues from the harmful effects of radiation. Past research on synthetic radio-protectors has brought little success, primarily due to the various toxicity-related problems. Results of experimental research show that antioxidant nutrients, such as vitamin E and herbal products and melatonin, are protective against the damaging effects of radiation, with less toxicity and side effects. Therefore, we propose that in the future, antioxidant radio-protective agents may improve the therapeutic index in radiation oncology treatments.

Polyphenolic fraction of Pilea microphylla (L.) protects Chinese hamster lung fibroblasts against γ-radiation-induced cytotoxicity and genotoxicity

Present study was designed to compare cytoprotective and antigenotoxic activity of the polyphenolic fraction of Pilea microphylla (PM1) with that of its active polyphenolic constituents against γ-radiation in V79 cells. PM1 was standardized with respect to the polyphenols present by RP-HPLC. It was evaluated for its free radical scavenging potential using Fenton reaction-induced DNA damage and lipid peroxidation. Further, PM1 was subjected against γ-radiation-induced cytotoxicity and genotoxicity in V79 cells. PM1 significantly reduced free radical-mediated calf thymus DNA damage and lipid peroxidation. Among the concentrations tested (12.5, 25 and 50 μg/ml) for radioprotection, PM1 at 25 μg/ml exhibited maximum protection. Further, when compared with constituent polyphenols viz., rutin, quercetin and chlorogenic acid (concentrations equivalent to that present in PM1-25 μg/ml), a combination of polyphenols was found most effective in preventing γ-radiation-induced cytotoxicity and genotoxicity. To conclude, radioprotection is possibly a synergistic effect of the phytochemicals present in the herbal extract, rather than any single component.

The radioprotective effect of Zataria multiflora against genotoxicity induced by γ irradiation in human blood lymphocytes

The radioprotective effect of hydroalcholic Zataria multiflora (Avishan-e shirazi) extract was investigated against genotoxicity induced by γ irradiation in human lymphocytes. Peripheral blood samples were collected from human volunteers and incubated with Z. multiflora extract at different concentrations (5, 10, and 50 μg/mL) for 1 hour. At each dose point, the whole blood was exposed in vitro to 150 cGy of cobalt-60 γ irradiation, and then the lymphocytes were cultured with mitogenic stimulation to determine number of the micronuclei in cytokinesis-blocked binucleated cells. The treatment of lymphocytes with extract showed a significant decrease in the incidence of micronuclei binucleated cells, compared with similarly irradiated lymphocytes without extract against γ irradiation. The maximum protection and decrease in frequency of micronuclei was observed at 50 μg/mL of Zataria extract by 32% reduction. High-performance liquid chromatography analysis of extract showed that it contains high amounts of thymol. Zataria extract exhibited concentration-dependent radical-scavenging activity on 1,1-diphenyl-2-picryl hydrazyl free radicals. These data have an important application for the protection of human lymphocyte from the genetic damage and side-effects induced by γ irradiation in personnel exposed to radiation.

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.

Whole body radioprotective activity of an acetone-water extract from the seedpod of Nelumbo nucifera Gaertn. seedpod

Procyanidins extracted with acetone-water from lotus (Nelumbo nucifera Gaertn.) seedpod (LSPCs) were evaluated for in vivo radioprotective activity against whole body gamma irradiation in Swiss albino mice. Pretreated with LSPCs 200 mg/kg by intragastric (i.g.) for 15 days was found to be the most effective dose in preventing radiation sickness, reducing radiation-induced mortality, increasing mean survival time and elevating radiation median lethal dose (LD(50)) from 8.9 to 10.5 Gy, indicating a dose modifying factor (DMF) of 1.18. Further, administered LSPCs at a dose of 200 mg/kg could effectively maintain spleen index close to normal, stimulate endogenous spleen colony forming units, promote the levels of red blood cells (RBC), white blood cells (WBC), platelets and hemoglobin in peripheral blood, and prevent spleen and skin damage in irradiated mice, reduce the level of radiation-induced micronucleated polychromatic erythrocytes in bone marrow, maintain the polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) ratio (P/N ratio) and significantly decrease bone marrow chromosomal damage. Alternatively, pretreated with LSPCs (200 mg/kg) significantly decreased the lipid peroxidation (LPO) level, and elevated the activities of endogenous antioxidant enzymes in liver after irradiation. Thus LSPCs possess a strong whole body radioprotective activity, and it may be used as a radioprotector.

Citrus extract modulates genotoxicity induced by cyclophosphamide in mice bone marrow cells

The protective effect of citrus extract was investigated by using the micronucleus assay for anticlastogenic activity in mouse bone marrow cells; liver glutathione (GSH) content was determined against toxicity induced by cyclophosphamide. Mice were orally (gavage) pretreated with solutions of citrus peel extract (Citrus aurantium var. amara) prepared at three different doses (100, 200 and 400 mg kg−1 body weight) for 7 consecutive days. Then mice were injected intraperitoneally on the seventh day with cyclophosphamide (50 mg kg−1) and after 24 h killed for the evaluation of micronucleated polychromatic erythrocytes (MnPCEs) in bone marrow cells. Non-protein thiol levels in liver were estimated in mice injected with citrus extract with or without cyclophosphamide treatment. Administration of citrus extract before cyclophosphamide treatment significantly reduced the frequency of MnPCEs in mice bone marrow compared with the group treated with cyclophosphamide alone (P<0.0001–0.05). Citrus extract at a dose of 400 mg kg−1 reduced MnPCEs 2.8 fold against genotoxicity induced by cyclophosphamide. Administration of cyclophosphamide depleted the GSH level in liver. Citrus extract showed excellent scavenging effects on 1,1-diphenyl-2-picryl hydrazyl radical (DPPH) at a concentration of 1.6 mg mL−1. Application of citrus extract 1 h before cyclophosphamide treatment allowed GSH content to reach the normal level. It appeared that citrus extract, particularly flavonoids constituents with antioxidative activity, may return the GSH level to normal in stress conditions and reduces genotoxicity induced by cyclophosphamide in bone marrow cells.

Protection of DNA and membranes from gamma-radiation induced damages by Centella asiatica

Objectives

The objective of the present study was to examine the ability of Centella asiatica extract to offer protection to DNA and membranes against the deleterious effects of ionizing radiation exposure.

Methods

Protection of DNA under in-vitro conditions of irradiation was estimated using plasmid relaxation assay. For in-vivo studies the extract was administered orally to mice exposed to whole-body γ-radiation. The ability of the extract to offer protection against whole-body γ-radiation exposure was analysed by performing an alkaline comet assay on mouse bone marrow cells. The extent of lipid peroxidation was estimated using the TBARS (thio-barbituric acid reacting substances) method, in order to monitor membrane damage. Radiation-induced mortality of the animals following a lethal dose of γ-radiation was also examined.

Key findings

Centella asiatica extract significantly reduced radiation-induced damage to DNA. The extent of radiation-induced mortality and lipid peroxidation was also found to be considerably reduced in animals administered with the extract.

Conclusions

Centella asiatica rendered radioprotection to DNA and membranes against radiation exposure, both in vitro and in vivo. We have earlier reported that administration of the extract can prevent a radiation-induced decline in antioxidant enzyme levels. This suggests that radioprotection by Centella asiatica extract could be mediated by mechanisms that act in a synergistic manner, especially involving antioxidant activity.

Radioprotective effects of quercetin and ethanolic extract of propolis in gamma-irradiated mice

The aim of this study was to assess radioprotective effects of quercetin and the ethanolic extract of propolis (EEP) in CBA mice exposed to a single radiation dose 4 Gy (60Co). The mice were treated with 100 mg kg(-1) quercetin or EEP a day for three consecutive days either before (pre-treatment) or after gamma-irradiation (therapy). Leukocyte count was determined in blood drawn from the tail vein, and DNA damage in leukocytes was assessed using the alkaline comet assay. Genotoxic effects of the test compounds were also evaluated in non-irradiated mice. The levels of radioprotection provided by both test compounds were compared with those established in mice that were given chemical radioprotector S-(2-aminoethy1)isothiouronium bromide hydrobromide (AET). Mice that received pre-treatment were less sensitive to irradiation. Mice given the post-irradiation therapy showed a slight but not significant increase in total leukocyte count over irradiated negative control. Quercetin showed better protective properties than EEP in both pre-treatment and therapy, and activated a higher number of leukocytes in non-irradiated mice. The alkaline comet assay suggests that both natural compounds, especially when given as pre-treatment, protect against primary leukocyte DNA damage in mice. At tested concentrations, EEP and quercetin were not genotoxic to non-irradiated mice. AET, however, caused a slight but not significant increase in DNA damage. Although the results of this study show the radioprotective potential of the test compounds, further investigation is needed to clarify the underlying protection mechanisms.

Treatment of mice with stem bark extract ofAphanamixis polystachyareduces radiation-induced chromosome damage

PURPOSE

Normal tissue radiosensitivity is the major limiting factor in radiotherapy of cancer. The use of phytochemicals may reduce the adverse effects of radiation in normal tissue. The effect of ethyl acetate fraction of Aphanamixis polystachya (EAP) was investigated on the radiation-induced chromosome damage in the bone marrow cells of Swiss albino mice exposed to various doses of gamma-radiation.

MATERIALS AND METHODS

The mice were divided into two groups, one group was exposed to 0, 1, 2, 3, 4 or 5 Gy of gamma-radiation, while another group received 7.5 mg/kg body weight (BW) of EAP 1 h before exposure to 0, 1, 2, 3, 4 or 5 Gy of gamma-radiation. Various asymmetrical chromosome aberrations were studied in the bone marrow cells of mice at 12, 24 or 48 h post-irradiation. To understand the mechanism of action of the free radical scavenging activity of 0, 5, 10, 20, 30, 40, 50, 60 or 70 microg/ml EAP, assays were carried out in vitro.

RESULTS

Irradiation of mice to different doses of gamma radiation caused a dose dependent elevation in the frequency of aberrant cells and chromosome aberrations like chromatid breaks, chromosome breaks, dicentrics, acentric fragments and total aberrations at all the post-irradiation times studied. The maximum asymmetrical aberrations were scored at 24 h post-irradiation except chromatid breaks that were highest at 12 h post-irradiation. A maximum number of polyploid and severely damaged cells (SDC) were recorded at 24 h post-irradiation in the SPS+irradiation group. Treatment of mice with 7.5 mg/kg BW of EAP before exposure to 1-5 Gy of whole body gamma-radiation significantly reduced the frequencies of aberrant cells and chromosomal aberrations like acentric fragments, chromatid and chromosome breaks, centric rings, dicentrics and total aberrations at all post-irradiation scoring times (p<0.01). The EAP showed a concentration dependent scavenging of hydroxyl, superoxide, 2,2'-diphenyl-1-picryl hydrazyl (DPPH) radicals and the 2,2-azino-bis-3-ethyl benzothiazoline-6-sulphonic acid (ABTS) cation radicals in vitro. EAP treatment also reduced lipid peroxidation in bone marrow cells in a concentration dependent manner.

CONCLUSION

Our study demonstrates that EAP protects mouse bone marrow cells against radiation-induced chromosomal aberrations and this reduction in radiation-induced chromosome damage may be due to free radical scavenging and reduction in lipid peroxidation. The radioprotection by EAP is best comparable to that of protection demonstrated by the grape fruit flavonone, naringin, in our earlier studies in mouse bone marrow cells.

Radioprotective effects of Hawthorn against genotoxicity induced by gamma irradiation in human blood lymphocytes

The radioprotective effect of hawthorn (Crataegus microphylla) fruit extract was investigated in cultured blood lymphocytes from human volunteers. Peripheral blood samples were collected from five human volunteers 10 min before and 1, 2 and 3 h after a single oral ingestion of 500 mg hawthorn powder extract. At each time point, the whole blood was exposed in vitro to 150 cGy of cobalt-60 gamma irradiation, and then the lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis-blocked binucleated cell. The lymphocytes in the blood samples collected after extract ingestion exhibited a significant decrease in the incidence of binucleated cells containing micronuclei as compared to similarly irradiated lymphocytes collected prior to extract ingestion. The maximum decrease in the frequency of micronuclei-containing cells was observed at 1 h after ingestion of Hawthorn extract (on average a 44% decrease). These data suggest that it may be possible to use Hawthorn extracts in personnel exposed to radiation in order to protect lymphocytes from radiation effects.

Evaluation of radioprotective effects of propolis and quercetin on human white blood cells in vitro

This in vitro study aimed at investigating the possible radioprotective effects of natural substances propolis and quercetin on gamma-irradiated human white blood cells. The levels of primary DNA damage were studied by the alkaline comet assay, while the cytogenetic damage was evaluated using the analysis of structural chromosome aberration and cytokinesis-block micronucleus assay. The results obtained by all endpoints indicate acceptable toxicity profiles of propolis and quercetin in vitro, and also confirmed their radioprotective abilities. Propolis was found to be more effective in diminishing the levels of primary and more complex cytogenetic DNA damage in gamma-irradiated white blood cells. Data gathered in present study support the use of propolis and quercetin as non-toxic protective substances. However, to clarify the underlying mechanisms of their cyto/radioprotective activities, additional studies are necessary at both in vitro and in vivo levels.

Chemoprotective effects of hesperidin against genotoxicity induced by cyclophosphamide in mice bone marrow cells

The preventive effect of hesperidin as a flavonoid was investigated in mouse bone marrow cells against genotoxicity induced by cyclophosphamide. Mice were orally (gavages) pretreated with solutions of hesperidin at four different doses (50, 100, 200, and 400 mg/kg b.w.) for five consecutive days. Mice were injected intraperitoneally on the fifth day with cyclophosphamide (50 mg/kg b.w.) and killed after 24 h for the evaluation of micronucleated polychromatic erythrocytes (MnPCEs) and the ratio of PCE/(PCE+NCE) (polychromatic erythrocyte/ polychromatic erythrocyte + normochromatic erythrocyte). Three last doses of hesperidin significantly reduced frequency of MnPCEs induced by cyclophosphamide (p<0.0001). Hesperdin at dose 200 mg/kg b.w. reduced MnPCEs 2.37 time and also completely normalized PCE/ (PCE+NCE) ratio. Histological examination of bone marrow showed that hesperidin affected on proliferation and hyper cellularity of immature myeloid elements in bone marrow that reduced by cyclophosphamide. It is obvious that hesperidin, may with antioxidative activity, reduced the oxidative stress and genotoxicity induced by cyclophosphamide in mouse bone marrow cells.

Protective effect of hawthorn extract against genotoxicity induced by cyclophosphamide in mouse bone marrow cells

The preventive effect of hawthorn (Crataegus microphylla) fruit extract was investigated in mouse bone marrow cells against genotoxicity induced by cyclophosphamide. Mice were orally (gavages) pretreated with solutions of hawthorn extract which was prepared at five different doses (25, 50, 100, 200 and 400mg/kg b.w.) for seven consecutive days. Mice were injected intraperitoneally on the seventh day with cyclophosphamide (50mg/kg b.w.) and killed after 24h for the evaluation of micronucleated polychromatic erythrocytes (MnPCEs) and the ratio of PCE/(PCE+NCE) (polychromatic erythrocyte/polychromatic erythrocyte+normochromatic erythrocyte). All of five doses of extract significantly reduced MnPCEs induced by cyclophosphamide (P<0.0001). Hawthorn extract at dose 100mg/kg b.w. reduced MnPCEs 2.5 time and also completely normalized PCE/(PCE+NCE) ratio. Hawthorn extract exhibited concentration-dependent antioxidant activity on 1,1-diphenyl-2-picryl hydrazyl free radical. Hawthorn contains high amounts of phenolic compounds; the HPLC analysis showed that it contained chlorogenic acid, epicatechin and hyperoside. It is obvious that hawthorn, particularly flavonoids constituents with antioxidative activity, reduced the oxidative stress and genotoxicity induced by cyclophosphamide in mouse bone marrow cells.

Protective effect of N-acetylcysteine against radiation induced DNA damage and hepatic toxicity in rats

The present study was designed to evaluate the radioprotective effect of N- acetylcysteine (NAC) on gamma-radiation induced toxicity in hepatic tissue in rat. The cellular changes were estimated using malondialdehyde (MDA, an index of lipid peroxidation), superoxide dismutase (SOD), glutathione peroxidase (GSHPx), reduced glutathione (GSH), and total nitrate/nitrite (NO(x)) as markers of hepatic oxidative stress in rats following gamma-irradiation. The DNA damage was determined by agarose gel electrophoresis. To achieve the ultimate goal of this study, 40 adult rats were randomly divided into 4 groups of 10 animals each. Group I was injected intraperitoneally with saline solution for 7 consecutive days and served as control group. Group II was irradiated with a single dose of 6Gy gamma-radiation. Group III was daily injected with NAC (1g/kg, i.p.) for 7 consecutive days. Group IV received a daily i.p. injection of NAC (1g/kg, i.p.) for 7 consecutive days and 1h after the last dose, rats were irradiated with a single dose (6Gy) gamma-radiation. The animals were sacrificed after 24h. DNA damage was observed in tissue after total body irradiation with a single dose of 6Gy. Malondialdehyde and total nitrate/nitrite were increased significantly whereas the levels of GSH and antioxidant enzymes were significantly decreased in gamma-irradiated group. Pretreatment with NAC showed a significant decrease in the levels of MDA, NO(x) and DNA damage. The antioxidant enzymes increased significantly along with the levels of GSH. Moreover, histopathological examination of liver tissues confirmed the biochemical data. Thus, our results show that pretreatment with N-acetylcysteine offers protection against gamma-radiation induced cellular damage.

Kojic acid and its manganese and zinc complexes as potential radioprotective agents

The naturally occurring fungal metabolite kojic acid and its manganese and zinc complexes have been evaluated as potential radioprotectors in mice. Their toxicity and radioprotective activity (survival rate) have been determined and compared with that of WR-2721 (amifostine). The results of in vivo radioprotection showed that these compounds exhibited significant radioprotective effects against lethal dose of gamma-irradiation in mice.

Radioprotective effects of hawthorn fruit extract against gamma irradiation in mouse bone marrow cells

The radioprotective effect of hawthorn (Crataegus microphylla) fruit extract against genotoxicity induced by gamma irradiation has been investigated in mouse bone marrow cells. A single intraperitoneal (ip) administration of hawthorn extract at doses of 25, 50, 100 and 200 mg/kg 1h prior to gamma irradiation (2 Gy) reduced the frequencies of micronucleated polychromatic erythrocytes (MnPCEs). All four doses of hawthorn extract significantly reduced the frequencies of MnPCEs and increased the PCE/PCE+NCE ratio (polychromatic erythrocyte/ polychromatic erythrocyte + normochromatic erythrocyte) in mice bone marrow compared with the non drug-treated irradiated control (p < 0.02-0.00001). The maximum reduction in MnPCEs was observed in mice treated with extract at a dose of 200 mg/kg. Administration of amifostine at dose 100 mg/kg and hawthorn at dose 200 mg/kg reduced the frequency of MnPCE almost 4.8 and 5.7 fold; respectively, after being exposed to 2 Gy of gamma rays, compare with the irradiated control group. Crataegus extract exhibited concentration-dependent activity on 1,1-diphenyl 2-picrylhydrazyl free radical showing that Crataegus contained high amounts of phenolic compounds and the HPLC analysis determined that it contained chlorogenic acid, epicatechin and hyperoside. It appeared that hawthorn extract with antioxidant activity reduced the genotoxicity induced by gamma irradiation in bone marrow cells.

Captopril protects mice bone marrow cells against genotoxicity induced by gamma irradiation

The radioprotective effects of captopril were investigated by using the micronucleus test for anticlastogenic and cell proliferation activity. A single intraperitoneal administration of captopril at doses of 10, 25 and 50 mg/kg 1 h prior to gamma irradiation (2 Gy) reduced the frequencies of micronuleated polychromatic erythrocytes (MnPCEs). All three doses of captopril significantly reduced the frequencies of MnPCEs and increased polychromatic erythrocytes (PCE)/PCE+NCE (normochromatic erythrocyte) ratio in mice bone marrow compared to the non-drug-treated irradiated control (p < 0.001). The optimum dose for protection in mouse was 10 mg/kg to protect mice bone marrow 2.18-fold against the clastogenic effects of gamma-irradiation with respect to the non-drug-treated irradiated control. There was a drug dose-response effect of captopril in increasing the PCE/PCE+NCE ratio in bone marrow cells. The maximum protective effect of captopril was at a dose of 25 mg/kg for increasing the PCE/PCE + NCE ratio. Captopril exhibited concentration-dependent antioxidant activity, scavenging > 96% of the 1,1-diphenyl-2-picryl hydrazyl free radicals when used at a concentration of 0.2 mM. In this study captopril reduced lipid peroxidation induced by hydrogen peroxide in mice liver. It appears that captopril, due to its free radical scavenging properties, protects mice bone marrow cells from radiation-induced DNA damage and genotoxicity.

Radioprotective effects of hesperidin against gamma irradiation in mouse bone marrow cells

The radioprotective effects of hesperidin (HES), a flavonone glucoside, were investigated by using the micronucleus test for anticlastogenic and cell proliferation activity. A single intraperitoneal (ip) administration of hesperidin at doses of 10 mg kg(-1), 20 mg kg(-1), 40 mg kg(-1), 80 mg kg(-1) and 160 mg kg(-1) 45 min prior to gamma irradiation (2 Gy) reduced the frequencies of micronuleated polychromatic erythrocytes (MnPCEs). All five doses of HES significantly reduced the frequencies of MnPCEs and increased PCE/PCE+NCE ratio in mice bone marrow compared with non-drug-treated irradiated control (p<0.0001). There was a drug dose-response effect of HES in reducing MnPCE and increasing the PCE/PCE+NCE ratio in bone marrow cells. The maximum reduction in MnPCE was observed in mice treated with HES at a dose of 80 mg kg(-1). The total MnPCE values were 2.85 fold less in the 80 mg kg(-1) HES group after being exposed to 2 Gy of gamma-rays than those in the respective irradiated control. Our study demonstrates that hesperidin has powerful protective effects on the radiation-induced DNA damage and on the decline in cell proliferation in mouse bone marrow.

A rapid and simple procedure for the determination of synephrine in dietary supplements by gas chromatography-mass spectrometry

A simple and rapid procedure based on gas chromatography-mass spectrometry (GC-MS) is described for determination of synephrine, active principle of Citrus aurantium plant, in solid and liquid dietary supplements. After the addition of 3,4-methylenedioxypropylamphetamine as internal standard (I.S.), a liquid-liquid extraction procedure in alkaline conditions with chloroform/isopropanol (9:1, v/v) was applied to the samples prior to analysis. Chromatography was performed on a fused capillary column and synephrine and I.S., derivatized with pentafluoropropionic anhydride, were determined in the selected-ion-monitoring (SIM) mode. The method was validated in the range 0.1-50 microg/mg or microg/mL synephrine. Mean recovery ranged between 89.3% and 90.5% in both solid and liquid dietary supplements. The quantification limit was 0.1 microg/mg or microg/ml. The method was applied to analysis of various dietary supplements promoted for aiding weight control containing, among other constituents such as ephedrine alkaloids and methylxanthines, Citrus aurantium. Amount of synephrine present in such products ranged from 3.1 microg/mg solid product to 480.2 microg/mL liquid product.