Low-dose Gamma Irradiation Research Articles

Enhancement of lead (Pb) biosorption by Gamma irradiated Aspergillus japonicus

Among the different types of microorganisms; the fungal biomass is considered as an effective mediator for bioremediation of heavy metals, due to its higher surface area and extensive hyphal density in the soil. About seven fungal spp. were isolated from the soil garden of the Middle Eastern Regional Radioisotope Center for Arab Countries (MERRCAC); however, a single isolate of Aspergillus japonicus with high potential of metals biosorption was selected for further research during this work. Soil analysis revealed that lead concentration was 5.25 mg/ l. The aims of the present study were to gamma irradiate A. japonicus with low doses of 50 to 250Gy, in order to enhance its heavy metal tolerance ability, and to increase its efficacy for removal of lead (Pb) from the soil. Results indicated that combined treatments of A. japonicus with lead and gamma irradiation doses displayed more enhancements of its biosorption capacity and gain in dry biomass than single treatment. Treatment with Pb (1950 mg/ l) in combination with gamma irradiation (100 Gy) proved to be optimum for increasing the biosorption capacity of this isolate. However, Pb at 650 mg/ l combined with gamma irradiation at 100 Gy was the optimum for gain in dry biomass. Fourier Transform Infrared Spectroscopic (FTIR) analysis showed that the fungal biomass includes in its surface hydroxyl, carboxyl and amine groups. On the other hand, Transmission electron microscope (TEM) examination of the irradiated A. japonicus cells demonstrated accumulation of electron dense Pb on the cell wall and within the fungal cells, this indicate that Pb2+ accumulation by fungi occurs by two methods absorption inside the cell and adsorption on the cell wall. The current study expressed a potential new method for enhancing microbial biosorption using low doses of gamma radiation.

Evaluation of irradiation quarantine dose – induced DNA damage in Rhyzopertha dominica and its effect on wheat grains using comet assay

Irradiation is a quarantine treatment option for stored product pests. In the present studies, we try to investigate the effect of low gamma irradiation doses in the range of 20–300 Gy on the different developmental stages of Rhyzopertha dominica in wheat grains. It was found that no adults emerged after irradiation of eggs, larvae, and pupae at 140, 240, and 260 Gy, respectively. Treatment of adult weevils at the radiation dose of 180 Gy resulted in 71.33% mortality after 14 days post-treatment and there was no adult emergence in the F1 generation. When the adult emergence of the F1 generation was used for the measuring effective irradiation dose and phytosanitary efficacy, 280 Gy was required for quarantine security of wheat weevils. The comet assay serves to verify the DNA damage induced by the phytosanitary irradiation dose, 280 Gy on the R. dominica, and wheat grains. DNA damage was measured as the percentage of comet tail DNA. A significant linear increase in DNA damage was observed in the irradiated adult stage of R. dominica but there is no DNA damage in the wheat grains. Also, the wheat grains viability (in terms of wheat germination) was not affected by the dose level, 280 Gy. Thus, an irradiation dose of 280 Gy is recommended as an effective phytosanitary irradiation dose for quarantine security to control lesser grain borer.

Enhancement of Electrical Parameters of Ni/n-GaN SBDs under Remote and not In-flux Gamma Irradiation

Remote and not in-flux gamma irradiation effects have been examined on the cumulative dose ranges from 250 Gy to 1 kGy by current-voltage (I–V) and capacitance-voltage (C-V) characteristics for Ni/n-GaN Schottky barrier diodes (SBDs). The interface and charge transport properties of Ni/n-GaN SBDs are significantly changed after gamma irradiation. In addition, the reverse current conduction mechanism indicates that the emission of Poole-Frenkel is dominant in lower voltages and Schottky emission for different doses at the higher voltage. The electrical parameters, such as barrier height and series resistance, decreases significantly at 500 Gy. Due to the internal irradiation of Compton electrons caused by primary gamma photons, low-dose gamma irradiation reveals the enhancement of device characteristics. Nonetheless, for higher doses of gamma irradiation above 500 Gy, degradation of Ni/n-GaN characteristics was observed.

Boswellic Acid Synergizes With Low-Level Ionizing Radiation to Modulate Bisphenol Induced-Lung Toxicity in Rats by Inhibiting JNK/ERK/c-Fos Pathway.

Bisphenol A (BPA) is a low molecular weight chemical compound that has a deleterious effect on the endocrine system. It was used in plastics manufacturing with injurious effects on different body systems. Occupational exposure to low-level ionizing radiation (<1 Gy) is shown to attenuate an established inflammatory process and therefore enhance cell protection. Therefore, the objective of this study was to investigate the protective effect of boswellic acid (BA) accompanied by whole-body low-dose gamma radiation (γ-R) against BPA-induced lung toxicity in male albino rats. BPA intoxication induced with 500 mg/kg BW. Rats received 50 mg BA/kg BW by gastric gavage concomitant with 0.5 Gy γ-R over 4 weeks. The immunoblotting and biochemical results revealed that BA and/or γ-R inhibited BPA-induced lung toxicity by reducing oxidative damage biomolecules; (MDA and NADPH oxidase gene expression), inflammatory indices (MPO, TNF-α, IL-6, and gene expression of CXCR-4). Moreover, BA and or/γ-R ameliorated the lung inflammation via regulation of the JNK/ERK/c-Fos and Nrf2/ HO-1 signaling pathways. Interestingly, our data demonstrated that BA in synergistic interaction with γ-R is efficacious control against BPA-induced lung injury via anti-oxidant mediated anti-inflammatory activities.

The temporal dynamics of antioxidants and lipid peroxidation in chick embryo livers after low-dose gamma irradiation

The temporal dynamics of antioxidants and lipid peroxidation in chick embryo livers after low-dose gamma irradiation

Effect of gamma irradiation and subsequent cold storage on the development and predatory potential of seven spotted ladybird beetle Coccinella septempunctata Linnaeus (Coleoptera; Coccinellidae) larvae

Seven spot ladybird beetle, (Coccinella septempunctata) is a widely distributed natural enemy of soft-bodied insect pests especially aphids worldwide. Both the adult and larvae of this coccinellid beetle are voracious feeders and serve as a commercially available biological control agent around the globe. Different techniques are adopted to enhance the mass rearing and storage of this natural enemy by taking advantage of its natural ability to withstand under extremely low temperatures and entering diapause under unfavorable low temperature conditions. The key objective of this study was to develop a cost effective technique for enhancing the storage life and predatory potential of the larvae of C. septempunctata through cold storage in conjunction with the use of nuclear techniques, gamma radiations. Results showed that the host eating potential of larvae was enhanced as the cold storage duration was increased. Gamma irradiation further enhanced the feeding potential of larvae that were kept under cold storage. Different irradiation doses also affected the development time of C. septempuntata larvae significantly. Without cold storage, the lower radiation doses (10 and 25 GY) prolonged the developmental time as compared to un-irradiated larvae. Furthermore, the higher dose of radiation (50GY) increased the developmental time after removal from cold storage. This study first time paves the way to use radiation in conjunction with cold storage as an effective technique in implementation of different biological control approaches as a part of any IPM programs

Effect of edible composite film based on chitosan and cumin essential oil-loaded nanoemulsion combined with low-dose gamma irradiation on microbiological safety and quality of beef loins during refrigerated storage

This research was conducted to assess the combined effect of chitosan (Ch) film containing cumin essential oil nanoemulsion (CNE) and low-dose gamma irradiation (GI) at 2.5 kGy on microbiological safety and quality of beef loins during 21 days of chilled storage. The growth of mesophilic and psychrophilic bacteria, Enterobacteriaceae, and lactic acid bacteria were retarded in all treated groups (Ch, GI, Ch + CNE, Ch + GI, and Ch + CNE + GI groups) compared to control group during storage time. The treatments also slowed down the increasing level of total volatile basic nitrogen and pH during storage, while irradiation increased the levels of thiobarbituric acid reactive substances and protein carbonyls in beef loins. All treatments except Ch were effective to control the growth of inoculated pathogenic bacteria, including Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium, in loin samples. The combination of Ch + CNE + GI was the most effective treatment to control the population of microbial flora and inoculated pathogens, slow down some physicochemical changes, and enhance the storage life of beef loins. As a result, the combination of active chitosan film and low-dose gamma irradiation can ensure microbiological safety and is suggested for long time preservation of beef during chilled storage.

Survival and Histamine Production by Histamine-Forming Bacteria Exposed to Low Doses of Gamma Irradiation

Histamine poisoning occurs when fish containing high amount of histamine are consumed. Because histamine is thermally stable, control of histamine-forming bacteria in seafood is an appropriate strategy for preventing the formation of histamine. One prevention method is the use of gamma irradiation on the histamine formers. To understand the effect of gamma irradiation on the histamine-forming bacteria, laboratory isolates of the prolific histamine formers Morganella morganii, Klebsiella variicola, and Proteus vulgaris were exposed to various doses of gamma radiation in nutrient broth and tuna muscle spiked with histamine formers. None of the test bacteria survived in tuna muscle irradiated at 2.0 kGy. K. variicola was highly sensitive to gamma irradiation and was eliminated at a dose of 1.5 kGy. Histamine production also was reduced significantly as the radiation dose increased. These results suggest that gamma irradiation can effectively eliminate histamine-forming bacteria and reduce the threat of histamine poisoning from seafood.

Radio Sensitivity of the winter and spring barley varieties according to the morphological efect of low-dose gamma irradiation on the original seeds.

Barley is the main forage crop in the Russian Federation. Barley grain is also used for food and brewery (Filippov, 2013). It is common knowledge that low doses of gamma irradiation can have a stimulating effect on the growth and development of plants, in particular barley. However, there is a lack of knowledge about the molecular pathways responsible for the formation of the stimulation effect after low-dose seed irradiation. The use of varieties with different radio sensitivity to low-dose gamma irradiation will allow studying specific molecular mechanisms to form a stimulating irradiation effect. Such knowledge could further help in the development of varieties with a large stable productivity over the years and with high resistance to biotic and abiotic stressors. In 2019 there was conducted a gamma irradiation of the original seeds of nine winter and spring barley varieties developed in the FSBSI “Agricultural Research Center “Donskoy” in order to assess intensity of the response on low-dose ionizing irradiation based on changes in the morphological parameters of irradiated and unirradiated plants. The original seeds of each barley variety were irradiated at the FSBSI “All-Russian Research Institute of Radiology and Agroecology” by the gamma device “GUR-120” with 60Со radiation sources at a dose of 20 Gy (dose rate of 60 Gy/hour). The statistical data processing was performed by the Microsoft Office Excel 2019. The morphological analysis of the length and weight of roots and sprouts made it possible to establish the presence or absence of the stimulating irradiation effect on the studied indicators of the varieties and to conduct their subsequent ranking according to the value of the radiobiological effect. There have been identified the winter and spring barley varieties with different sensitivity to a dose of 20 Gy. The stimulating irradiation effect was established in such varieties as “Foks 1”, “Ratnik”, “Yerema” and “Master”. The variety “Leon” had an inhibitory irradiation effect.

Pathogen reduction by predatory bacteria and survival of Bdellovibrio bacteriovorus and Escherichia coli on produce and buffer treated with low-dose gamma radiation

Bdellovibrio bacteriovorus is a predator of Gram-negative bacteria and there is limited research on its utility for decontamination of post-harvest produce. The objective of this research was to determine reduction of E. coli O157:H7 and Salmonella on lettuce and carrot by B. bacteriovorus 109 (Bb109) and evaluate its survival and E. coli in buffer and on lettuce following gamma radiation exposure. Bb109 was cultured on ML35, filtered, and predator cells were suspended in buffer. Produce and buffer were co-inoculated with E. coli and Salmonella, separately; and Bb109 applied. In a separate experiment, Bb109 were inoculated on lettuce and suspended in buffer, then irradiated at 0.25–1.0 kGy treatments. E. coli and Salmonella in buffer were reduced by Bb109 0.4–3.9 and 0.9–2.6 logs, respectively. The predation of E. coli by Bb109 on carrot and lettuce resulted in 0.3–1.8 log reductions, and for Salmonella on the same produce, they were 0.9 and 1.2 logs, respectively. In radiation sensitivity assays, Bb109 populations in buffer and lettuce were inactivated by 3–5 logs (0.5 kGy). Bdellovibrio could aid the mortality of pathogenic bacteria during post-harvest treatment or in hurdle interventions of post-harvest produce. No previous data on Bdellovibrio exposure to radiation is available.

Improvement of 6-gingerol production in ginger rhizomes (Zingiber officinale Roscoe) plants by mutation breeding using gamma irradiation

Ginger (Zingiber officinale Roscoe) is a valuable culinary and medicinal plant. The compound 6-gingerol is the main gingerol in ginger rhizomes and it possesses interesting pharmacological and physiological properties. Mutation breeding involved using low doses of gamma radiation (5–30 Gy) to increase the genetic variability in ginger rhizomes (M1 generation). Ginger plants selected from the next generation (M2) were characterized and subjected to quantitative analysis for 6-gingerol content using HPLC of ginger extracts. M2 offspring from a parent ginger rhizome irradiated with 20 Gy was found to have a high 6-gingerol content (38.4 ± 0.01 mg/g methanol extract in comparison to 22.1 ± 0.03 mg/g methanol extract in non-irradiated control samples). Radiation induced genetic variability was also probed and confirmed using RAPD-PCR analysis. This research demonstrates the potential for ginger improvement and to our knowledge is the first to report the use of gamma radiation in breeding ginger plants with enhanced 6-gingerol content.

Amelioration of adjuvant-induced arthritis by exposure to low dose gamma radiation and resveratrol administration in rats

Purpose: Low dose radiation has been reported as an effective treatment for rheumatoid arthritis via multiple dose exposures. The present study was designed to increase the therapeutic efficacy of low dose radiation with the minimum exposure level in arthritic rats by concurrent administration of resveratrol (RSV) as an adjunctive therapy with anti-inflammatory properties.Materials and methods: Rats were rendered arthritic by sub-plantar injection of Freund’s complete adjuvant (FCA) and exposed to low dose radiation at a total exposure level of 0.5 Gy (2 × 0.25). During the exposure course, RSV (50 mg/kg) was orally administered once daily for two weeks. Diclofenac (3 mg/kg) was administered as a standard anti-inflammatory drug. Paw volume was measured every 4 days. After 28 days of induction, rats were sacrificed and serum was collected for estimation of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), thiobarbituric acid reactive substances (TBARS), and total nitrate/nitrite (NOx). Furthermore, paws were dissected for histopathological examinations and immuno-histochemical estimation of nuclear factor-kappa B p65 (NF-κB p65) expression.Results: Administration of RSV during the low dose radiation exposure course produced a significant decrease in the paw swelling and a potentiated inhibition in the serum levels of TNF-α, IL-1β, TBARs, and NOx. The dual treatment strategy alleviated the histopathological damage to a greater extent than that produced by each treatment. Moreover, a pronounced suppression of NF-κB p65 expression in the synovial tissue was observed in the combination group. The combination treatment showed a nearly similar potency to that observed in the diclofenac treated group.Conclusion: Administration of RSV augmented the modulatory activity of low dose radiation with minimum exposure level on the disease progression.

Delineation of gamma irradiation (60Co) induced oxidative stress by decrypting antioxidants and biochemical responses of microalga, Chlorella sp.

The use of different radiation technologies are becoming more popular in health care (radiotherapy) and food processing. On the other hand, gamma (γ) radiation is a potential ionizing radiation that can generate huge amount of free radicals and Reactive Oxygen Species (ROS) cause a potential damage to important macromolecules in the cell. Therefore, information on biochemical components significantly need attention for their potential usefulness in counteracting gamma radiation-induced oxidative damage. Chlorella is an unicellular microalga enrich with high protein contents and other potential nutritional supplements. However, the information about the change of active biochemical attributes by the effects of gamma radiation on Chlorella is scanty. Hence, this is highly significant to assess the impacts of gamma radiation on microalga Chlorella sp. (BUACC06). The main objectives of this study is to unlock the information of the change of phytochemicals and antioxidants content in response to γ-irradiation on Chlorella sp. (BUACC06). This strain was treated with acute doses of γ-irradiation (0.01 kGy, 0.05 kGy, 0.075 kGy of 60 Co). The effect of higher dose γ-irradiation resulted in a decline in growth, total phenolic, total flavonoid, antioxidant activity, free radical scavenging and alternation of pigmentation; these could be due to the accumulation of radiation-induced ROS in the cell. Further, protein content and antioxidant enzyme activities were increased as increasing of dose and the effective dose was 0.075 kGy. It was concluded that the administration of Chlorella sp. showed radio resistance response to low dose of gamma radiation by synthesize more proteins, carotenoids, and active antioxidant compounds as radio-protective phytochemicals. This gamma radiation could be used as novel effective method to activate biosynthesis of certain bioactive compounds in algal cells to establish improved varieties of microalgae.

Effect of low dose gamma irradiation on the tensile and thermal properties of natural rubber-based blend

Natural rubber (NR) is a renewable natural resource that has been utilized in many applications. Due to its low tensile strength, NR is commonly blended with another polymer to improve the properties of NR. However, most of the blended NR has miscibility issue, leading to poor mechanical properties. Gamma irradiation (GR) is a safe and green alternative than conventional chemical method for inducing crosslinking in blended NR. This study was aimed at investigating the mechanical and thermal properties of NR/liquid natural rubber/polystyrene-block-polyisoprene block copolymer (NR/LNR/PS-b-PI) blend using GR method. The polymer blend is prepared according to the ratio of NR:LNR:PS-b-PI of 6:1:3 using an internal mixer. The NR/LNR/PS-b-PI blends are irradiated with gamma ray at doses of 0, 5, 6, 7, 8 and 9 kGy. Tensile and thermal tests are conducted to evaluate the properties of unirradiated and irradiated polymer blend. The tensile strength and modulus of the irradiated blend are increased with increasing irradiation dose before decrease at 9 kGy. Lower melting point of blend indicates that PS-b-PI are compatible in NR/LNR blend. The improvement in tensile properties of irradiated NR/LNR/PS-b-PI blend is related to the radiation-induced crosslinking.

Quantifying Biophoton Emissions From Human Cells Directly Exposed to Low-Dose Gamma Radiation.

Biophoton emission leading to bystander effects (BEs) was shown in beta-irradiated cells; however, technical challenges precluded the analysis of the biophoton role in gamma-induced BEs. The present work was to design an experimental approach to determine if, what type, and how many biophotons could be produced in gamma-irradiated cells. Photon emission was measured in HCT116 p53+/+ cells irradiated with a total dose of 22 mGy from a cesium-137 source at a dose rate of 45 mGy/min. A single-photon detection unit was used and shielded with lead to reduce counts from stray gammas reaching the detector. Higher quantities of photon emissions were observed when the cells in a tissue culture vessel were present and being irradiated compared to a cell-free vessel. Photon emissions were captured at either 340 nm (in the ultraviolet A [UVA] range) or 610 nm. At the same cell density, radiation exposure time, and radiation dose, HCT116 p53+/+ cells emitted 2.5 times more UVA biophotons than 610-nm biophotons. For the first time, gamma radiation was shown to induce biophoton emissions from biological cells. As cellular emissions of UVA biophotons following beta radiation lead to BEs, the involvement of cellular emissions of the same type of UVA biophotons in gamma radiation-induced BEs is highly likely.

Combination of organic acids and low-dose gamma irradiation as antimicrobial treatment to inactivate Shiga toxin-producing Escherichia coli inoculated in beef trimmings: Lack of benefits in relation to single treatments.

The aim of this study was to assess the efficacy of lactic acid (LA), caprylic acid (CA), high- (HDI) and low- (LDI) dose gamma irradiation and LDI combined with LA or CA on the inactivation of a pool of Shiga toxin-producing Escherichia coli (STEC) strains inoculated on beef trimmings. The three most efficacious treatments were selected to study their effect on meat quality parameters and sensory attributes. The inoculum included five native STEC serogroups (O26, O103, O111, O145 and O157). The treatments applied were 0.5% LA, 0.04% CA, 0.5 kGy LDI, 2 kGy HDI, LDI+LA and LDI+CA. Beef trimmings were divided into two groups; one was inoculated with high (7 log CFU/g) and the other with low (1 log CFU/g) level of inoculum. Efficacy was assessed by estimating log reduction and reduction of stx- and eae-positive samples after enrichment, respectively. Results showed that treatments with organic acids alone were not effective in reducing STEC populations. For high inoculum samples, the most effective treatment was HDI followed by LDI+LA and LDI alone or combined with CA. For low inoculum samples, the most effective treatment was HDI followed by LDI alone or combined with organic acids. Concerning meat quality parameters and sensory attributes, irradiation treatments (LDI and HDI) caused minimal changes, while LDI+LA modified them significantly compared with the control. Therefore, based on our results, no benefits were observed after combining organic acids with gamma irradiation.

Low-dose gamma irradiation effect on structural and optical properties of PANI–ZnO composite thin films

The effects of different low doses of gamma irradiation on polyaniline-zinc oxide composite thin films were studied. The structural and optical properties of the sample were investigated using X-ray diffraction, ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy and photoluminescence spectroscopy. The variation in the structural and optical properties shown in this analysis will be helpful in correlating the properties with low-dose radiation dosimetry.

Assessment irradiation effects on different development stages of Callosobruchus maculatus and on chemical, physical and microbiological quality of cowpea seeds.

Irradiation is a physical, environmentally friendly treatment which does not leave any residues in the product. It is increasingly used as an alternative to methyl bromide and other chemical fumigants for disinfestation of insect pest in stored grains. In this research, we try to evaluate the effect of low gamma irradiation doses in the range of 50-1200 Gy on the different stages of Callosobruchus maculatus. It was found that no adults emerged after irradiation of eggs at 450 Gy. No emerging adults (F1 generation) have been shown when larvae or pupae were exposed to 650 Gy. Also, no emerging adult has been shown from the parental C. maculatus adults irradiated with 650 Gy. When suppression of F1 generation was used for the measuring effective irradiation dose and phytosanitary efficacy, 650 Gy was required for disinfestation of cowpea seed weevils. The irradiation dose level of 650 Gy was used for the large-scale confirmatory tests applied to 27,754 adults of C. maculatus in cowpea seeds resulting in non F1 adults' production with a confidence level of 93.77%. All the physical and chemical characteristics of cowpea seeds were non-significantly (P ≤ 0.05) affected by the irradiation dose of 650 Gy. Meanwhile, this irradiation dose very slightly reduced the microbial load of cowpea seeds. We recommend the generic dose 650 Gy as the phytosanitary irradiation dose for the cowpea seed weevil.

Effect of low dose gamma radiation on electric conductivity of LDPE and PMMA polymers

Effect of low dose gamma radiation on electric conductivity of LDPE and PMMA polymers

Integrative assessment of low-dose gamma radiation effects on Daphnia magna reproduction: Toxicity pathway assembly and AOP development

High energy gamma radiation is potentially hazardous to organisms, including aquatic invertebrates. Although extensively studied in a number of invertebrate species, knowledge on effects induced by gamma radiation is to a large extent limited to the induction of oxidative stress and DNA damage at the molecular/cellular level, or survival, growth and reproduction at the organismal level. As the knowledge of causal relationships between effects occurring at different levels of biological organization is scarce, the ability to provide mechanistic explanation for observed adverse effects is limited, and thus development of Adverse Outcome Pathways (AOPs) and larger scale implementation into next generation hazard and risk predictions is restricted. The present study was therefore conducted to assess the effects of high-energy gamma radiation from cobalt-60 across multiple levels of biological organization (i.e., molecular, cellular, tissue, organ and individual) and characterize the major toxicity pathways leading to impaired reproduction in the model freshwater crustacean Daphnia magna (water flea). Following gamma exposure, a number of bioassays were integrated to measure relevant toxicological endpoints such as gene expression, reactive oxygen species (ROS), lipid peroxidation (LPO), neutral lipid storage, adenosine triphosphate (ATP) content, apoptosis, ovary histology and reproduction. A non-monotonic pattern was consistently observed across the levels of biological organization, albeit with some variation at the lower end of the dose-rate scale, indicating a complex response to radiation doses. By integrating results from different bioassays, a novel pathway network describing the key toxicity pathways involved in the reproductive effects of gamma radiation were proposed, such as DNA damage-oocyte apoptosis pathway, LPO-ATP depletion pathway, calcium influx-endocrine disruption pathway and DNA hypermethylation pathway. Three novel AOPs were proposed for oxidative stressor-mediated excessive ROS formation leading to reproductive effect, and thus introducing the world's first AOPs for non-chemical stressors in aquatic invertebrates.