Effect Of Low-dose Gamma Radiation Research Articles

Exploring low-dose gamma radiation effects on monoterpene biosynthesis in Thymus vulgaris: insights into plant defense mechanisms.

Thymus vulgaris, commonly known as thyme, is a plant renowned for producing monoterpenes. This study aimed to understand the effects of low-dose gamma radiation, specifically in the range of 1-5Gy, on various traits of Thymus vulgaris, providing context on its importance in agricultural and medicinal applications. The research explored morpho-physiological, biochemical, and gene-expression responses in thyme plants under no gamma- and gamma-ray exposure conditions. The study revealed complex relationships between gamma-ray doses and plant characteristics. In particular, shoot and root lengths initially increased with low doses (1-3Gy) but decreased at higher doses (5Gy), suggesting a dose-dependent threshold effect. Similarly, shoot and root fresh weights displayed an initial increase followed by a decline with increasing doses. Biochemical parameters showed dose-dependent responses, with low to moderate doses (1-3Gy) stimulating enzyme activities and high doses (5Gy) inhibiting them. Gene expression analysis was focused on the following specific genes: thymol synthase, γ-terpinene synthase, and carvacrol synthase. Low to moderate doses increased the expression of these genes, resulting in increased production of bioactive compounds. However, higher doses had diminished effects or suppressed gene expression. Metabolite analysis demonstrated dose-dependent responses, with moderate doses enhancing secondary metabolite production, while higher doses provided limited benefits. These findings underscore the implications of using gamma radiation to enhance secondary metabolite production in plants and its potential applications in agriculture, medicine, and environmental science. The study emphasizes the potential of gamma radiation as an external stressor to influence plant responses and highlights the importance of understanding such effects in various fields.

Spirulina as a promising agent in rheumatoid arthritis with no observed hepatic injury

Aim of the workTo examine early mitigation and conservative effects of low-dose gamma radiation (LDR) or spirulina (SPR) algae on inflammation, oxidative stress and liver function in experimentally-induced arthritis in rats, and comparing such effects to conventionally used rheumatoid arthritis (RA) drugs; methotrexate (MTX) and hydroxychloroquine (HCQ) in an attempt to unleash a safer remedy/therapeutic modality for RA management. Materials and methodsMale Wister albino rats were rendered arthritic by sub-plantar injection of 0.1 ml Freund's complete adjuvant (FCA). Adjuvant-induced arthritis (AIA) rats were treated with each of LDR (0.5 Gy at day 0 of arthritis induction), MTX (1 mg/kg/week, intra-peritoneal), HCQ sulphate (15 mg/kg/day, orally), MTX + HCQ, and SPR (1 g/kg/day, orally) for 28 days. ResultsSub-plantar injection of FCA led to marked increase in paw volume accompanied with increased serum level of C-reactive protein (CRP) and oxidative stress markers including malondialdehyde (MDA) and nitric oxide (NO) levels. Exposure to LDR did not induce any significant alteration in the estimated parameters. Treatment with MTX and HCQ alone or combined induced deterioration in liver function (transaminases), insignificantly reduced paw edema, yet failed to attenuate CRP, MDA and NO levels. Instead, treatment with SPR significantly guarded against changes in nearly all measured parameters and kept liver function at normal level. ConclusionThis is a leading work showing the hepato-preservative impact of spirulina as a promising alternative therapy during the course management of RA. It could thus be considered as a potential option in the management armamentarium of RA.

Effects of Low-dose Gamma Radiation on Expression of Apoptotic Genes in Rat Peripheral Blood Lymphocyte.

Background: Exposure to high-dose ionizing radiation is known as a human carcinogen factor, but our information about the effects of low-dose ionizing radiation such as occupational exposures is limited. The main concern of scientific community is biological consequences due to low-dose radiations.Objective: This study aims to evaluate the effects of low-dose γ-radiation on expression changes of apoptotic genes (bax and bcl-2) in the rat peripheral blood lymphocytes.Material and Methods: In this experimental study, 42 adult male rats were classified into 6 groups, which was exposed to various doses values ranged from 20 mGy to 1000 mGy by γ-rays from a Co-60 source. Blood samples were provided for analysis of gene expression 24 h after gamma radiation by relative quantitative Reverse Transcription - Polymerase Chain Reaction (RT-PCR). Radiation sensitivity of rat lymphocytes was measured by the bax/bcl-2 ratio as a predictive marker for radio-sensitivity. Results: The results of this study showed that low dose of gamma radiation can induce down-regulation of bax in rat peripheral blood lymphocytes. Despite other mechanisms of cellular radio-protection, changes in expression of these apoptotic genes can be the primary pathway in responses of the lymphocytes radio-protection to the exposure. Our study revealed a significant decrease in the bax/bcl-2 ratio at 50 mGy dose compare to control and the other irradiated groups (p < 0.05).Conclusion: These results suggest that changes in the bax/bcl-2 ratio especially in radiation workers, as a key factor in apoptosis, can be considered as a biological marker in low-dose gamma radiation.

Effect of Low-Dose Gamma Radiation and Lipoic Acid on High- Radiation-Dose Induced Rat Brain Injuries

AimThis work aims to investigate the possible radio-adaptive mechanisms induced by low-dose (LD) whole-body γ-irradiation alone or combined with alpha-lipoic acid (ALA) administration in modulating high-dose (HD) head irradiation–induced brain injury in rats.Materials and MethodsRats were irradiated with LD (.25 Gy) 24 hours prior HD (20 Gy), and subjected to ALA (100 mg/kg/day) 5 minutes after HD and continued for 10 days. At the end of the experiment, animals were sacrificed and brain samples were dissected for biochemical and histopathological examinations.ResultsHD irradiation-induced brain injury as manifested by elevation of oxidative stress, DNA damage, apoptotic, and inflammatory markers in brain tissue. Histological examination of brain sections showed marked alterations. However, LD alone or combined with ALA ameliorated the changes induced by HD.ConclusionUnder the present experimental conditions, LD whole-body irradiation exhibited neuroprotective activity against detrimental effects of a subsequent HD head irradiation. This effect might be due to the adaptive response induced by LD that activated the anti-oxidative, anti-apoptotic, and anti-inflammatory mechanisms in the affected animals making them able to cope with the subsequent high-dose exposure. However, the combined LD exposure and ALA supplementation produced a further modulating effect in the HD-irradiated rats.

Hormetic effects of low-dose gamma rays in soybean seeds and seedlings: A detection technique using optical sensors

The use of radiation technology in agriculture has increased remarkably in recent years. The stimulating effect of low-dose gamma rays, known as hormesis, improves the adaptive response of living organisms to more severe challenges. Different areas of agriculture such as plant physiology, crop breeding and seed biology demand accurate methods for real-time diagnosis of the ionizing radiation effect on biological systems. However, traditional measures are still calculated from slow, laborious and destructive techniques, which depend on human vision. Here, we present two robust optical sensors based on multispectral and fluorescence imaging approaches for rapid and non-destructive detection of the hormetic effects of low-dose gamma radiation in soybean seeds and seedings. Multispectral images were acquired from seeds treated with gamma radiation (0, 12, 16 and 20 Gy), and the reflectance, autofluorescence, texture and color features were extracted from images. Next, a chlorophyll fluorescence-based technique was applied to measure the minimal level of fluorescence (F0), maximum fluorescence (FM), average chlorophyll a fluorescence and quantum yield of photosystem II (FV/FM) in seedlings grown from irradiated and non-irradiated seeds. Using a reflectance technology, the seedlings were also evaluated for anthocyanin, chlorophyll a and normalized difference vegetation index (NDVI). Results showed that multispectral and fluorescence-based techniques provide useful information on the hormetic effects of gamma rays in soybean seeds and seedlings, which are invisible to the naked eye. Our findings provide a better understanding of the link between spectral and fluorescence parameters and the hormetic effect of low-dose gamma rays. From a practical point of view, such optical sensors can provide markers for fast, non-destructive and reliable identification of the best gamma-ray doses to stimulate soybean growth parameters. However, we strongly support in-depth studies of the dose–response relationship in seeds with different initial physiological potential from different soybean genotypes.

Low dose gamma irradiation attenuates cyclophosphamide-induced cardiotoxicity in rats: role of NF-κB signaling pathway

Purpose Cyclophosphamide (Cyp) is one of the most commonly used, wide spectrum chemotherapeutic agents. Cyp has multi-organ toxicities that are dose limiting, thus it’s mostly used in chemotherapeutic combinations. Radiation is well known as a hazardous sort of energy, recent studies are interested in studying the beneficial therapeutic effects of low-dose gamma radiation. This study examined the protective effect of two different doses/dose-rates of irradiation either alone or combined with telmisartan against Cyp-induced cardiotoxicity. Materials and methods Rats were divided into seven groups; (1): Control, (2): Cyp, (3–4): 0.05 Gy low dose rate (LDR) irradiation, 0.25 Gy high dose rate (HDR) irradiation, respectively, prior to Cyp dose, (5–7): telmisartan either alone or with 0.05 Gy LDR-irradiation or 0.25 Gy HDR-irradiation, respectively, prior to Cyp dose. The current investigation studied the effect of Cyp alone or combined with different treatment regimens on serum cTn-I and LDH, nuclear factor-κB (NF-κB) pathway (p65/IκB/IKK-α/IKK-ß) in the myocardium. Pro-inflammatory cytokines IL-1ß, IL-6 and TNF-α were assessed in addition to histopathological examination of the heart. Results Low-dose irradiation attenuated cardiac enzymes, pro-inflammatory cytokines, NF-κB content, and histology, in both low and HDRs. Furthermore, the combination of low-dose irradiation with telmisartan (an angiotensin-II receptor type-1 blocker and a known cardio-protective drug) offered the best histological results. Conclusions Low-dose irradiation-induced amelioration is partially but not completely through canonical activation of NF-κB, and may have another atypical pathway. While telmisartan probably ameliorates NF-κB totally through canonical pathway.

Exposure of luminous marine bacteria to low-dose gamma-radiation

The study addresses biological effects of low-dose gamma-radiation. Radioactive 137Cs-containing particles were used as model sources of gamma-radiation. Luminous marine bacterium Photobacterium phosphoreum was used as a bioassay with the bioluminescent intensity as the physiological parameter tested. To investigate the sensitivity of the bacteria to the low-dose gamma-radiation exposure (≤250 mGy), the irradiation conditions were varied as follows: bioluminescence intensity was measured at 5, 10, and 20°С for 175, 100, and 47 h, respectively, at different dose rates (up to 4100 μGy/h). There was no noticeable effect of gamma-radiation at 5 and 10°С, while the 20°С exposure revealed authentic bioluminescence inhibition. The 20°С results of gamma-radiation exposure were compared to those for low-dose alpha- and beta-radiation exposures studied previously under comparable experimental conditions. In contrast to ionizing radiation of alpha and beta types, gamma-emission did not initiate bacterial bioluminescence activation (adaptive response). As with alpha- and beta-radiation, gamma-emission did not demonstrate monotonic dose-effect dependencies; the bioluminescence inhibition efficiency was found to be related to the exposure time, while no dose rate dependence was found. The sequence analysis of 16S ribosomal RNA gene did not reveal a mutagenic effect of low-dose gamma radiation. The exposure time that caused 50% bioluminescence inhibition was suggested as a test parameter for radiotoxicity evaluation under conditions of chronic low-dose gamma irradiation.

Biochemical Changes Induced by Gamma Irradiation in the Ground Beetle Blaps polycresta

The exposure to low-dose gamma radiation from natural sources is a continuing and inescapable feature and it is common in certain occupations. The present study was designed to investigate the effects of low-dose gamma radiation on some detoxification enzymes such as; AST, ALT, ACP, ALP, GSH, GPX, SOD and CAT, as well as, its effect on total protein and DNA content in the soft tissues homogenate of male’s ground beetle Blaps polycresta. Insects were divided into three groups (group A, B and C) of 10 beetles each. Two groups (group B and C) were irradiated with doses at a rate of 32 Gy and 64 Gy; group A was considered as the control group. The study revealed a dose-dependent effect on the tested parameters. Significant increase in the enzyme activity of AST, ALT, ACP and ALP were observed in group B and C respectively compared to the control group (group A). The findings also showed a significant inhibitions in the enzymatic activity of GSH, GST, GPX, SOD and CAT in the irradiated groups compared to the control group. Furthermore, their radiated groups reported a decrease in protein and DNA content compared to the control group. Our observations suggested that the genotoxic effects of gamma radiation induced damaging effects on enzyme molecules, protein and nucleic acid (DNA) and may explain the increase in health risk from high doses of ionizing radiation.

Effect of low-dose gamma radiation and active equilibrium modified atmosphere packaging on shelf life extension of fresh strawberry fruits

Abstract The effect of low-dose gamma irradiation (1 kGy) and active equilibrium modified atmosphere packaging (EMAP1: CO 2 10%: O 2 5%; N 2 85% and EMAP2: CO 2 5%: O 2 10%; N 2 85%) on quality of strawberry fruits stored at 4 °C was investigated. Several quality parameters were monitored during the storage period. Fruit firmness, fungal decay and sensory evaluation were analyzed on days 1, 7, 14 and 21. Strawberries kept in active EMAP1 maintained their texture and appearance better than those packaged under air and EMAP2. Strawberries stored in active EMAP were firmer than those stored in air during the storage time (21 days). The irradiated strawberry samples were not attacked by Botrytis cinerea during 7 days. Irradiation and EMAP1 increased the postharvest life of strawberries to 14 days, without any attack of fungus or any change in their external appearance. Low-dose gamma irradiation in combination with EMAP will enable food processors to deliver larger amounts of high quality strawberry with extended shelf life.

Effect of low-dose gamma-radiation on concrete during solidification

Concrete containers have been used worldwide for its low price and good shielding performance for transporting and storing radioactive wastes. For this purpose, concrete must satisfy a certain property like density in particular. A series of 12 specimens were carried in this study to examine the effect of gamma radiation on compressive strength of concrete during solidification. Two types of cementitious mixes with a water-to-cement ratio of 0.4 were used to mold 5 cm cubes with and without sand. The results s strength of gamma radiated concrete specimens have greatly been increased and confirmed by perceiving their microstructure using Scanning Electron Microscope (SEM). Key words: Radiation shielding, gamma ray, gamma effect, shielding material, nai detector, storing radioactive waste.

Effects of low-dose gamma radiation on DNA damage, chromosomal aberration and expression of repair genes in human blood cells

Exposure to low-dose gamma radiation is common in certain occupations but the biological and health effects from such exposure remain to be determined. The aim of this study was to investigate the effects of low-dose gamma radiation on DNA damage, chromosomal aberration and DNA repair gene expressions in whole blood and peripheral lymphocytes. The study revealed a dose-dependent effect of gamma radiation on DNA damage. Significant increases in DNA strand breaks and oxidative base damage, determined as formamidopyrimidine-DNA-glycosylase (FPG)-sensitive sites, were observed at absorbed doses of 5 and 10 cGy, respectively. However, gamma radiation at doses up to 500 cGy did not significantly increase the level of 8-oxo-7, 8-dihydro-2′-deoxyguanosine (8-oxodG) determined by HPLC with electrochemical detection (HPLC-ECD). Gamma radiation as low as 5 cGy caused chromosomal aberrations determined as dicentric and deletion frequencies. This finding is significant since the genotoxic effects of gamma radiation can be observed even at a low dose of 5 cGy. Furthermore, gamma radiation decreased the mRNA expression of both hOGG1 and XRCC1 repair genes determined by reverse transcriptase-polymerase chain reaction (RT-PCR), with a significant decrease of expression being observed at 20 cGy. The expression levels of hOGG1 and XRCC1 mRNA were inversely correlated with the levels of FPG-sensitive sites and DNA strand breaks. The finding of decreased expression levels for hOGG1 and XRCC1 in gamma-irradiated lymphocytes has not been reported elsewhere. Our observations suggest that the genotoxic effects of gamma radiation may be due to a combination of DNA-damaging effects and reduced DNA repair capacity, and may explain the significant increase in health risk from high doses of ionizing radiation.

Alterations in the photosynthetic pigments and antioxidant machineries of red pepper (Capsicum annuum L.) seedlings from gamma-irradiated seeds

To characterize the stimulatory effects of low-dose gamma radiation on early plant growth, we investigated alterations in the photosynthesis and antioxidant capacity of red pepper (Capsicum annuum L.) seedlings produced from gamma-irradiated seeds. For two cultivars (Yeomyung and Joheung), three irradiation groups (2, 4, and 8 Gy, but not 16 Gy) showed enhanced development, although Fv/Fm, the maximum photochemical efficiency of Photosystem II (PSII), did not differ significantly among any of the four groups. In contrast, values for 1/Fo — 1/Fm, i.e., a measure of functional PSII content, decreased in the irradiated groups of ‘Yeomyung’ but increased in those of ‘Joheung’. Pigment analyses and enzyme activity assays revealed that irradiation altered the compositions of photosynthetic pigments (chlorophylls and carotenoids) as well as the activities of antioxidant enzymes (superoxide dismutase and glutathione reductase). However, these shifts were not directly related to the increase in early growth, although they were cultivar-and developmental stage-dependent In addition, the effects of irradiation on the enzymatic activities measured here were at opposition between the two cultivars.

Effect of low-dose gamma radiation on nuclear RNA-polymerase activity and protein synthesis in liver cells of different-age chicks

The effect of low-dose (0.05 Gy) gamma irradiation of chicks in the preincubation period on subsequent liver cell RNA-polymerase activity and protein synthesis is studied at different ages. It is shown that irradiated chicks demonstrate an increased level of RNA-polymerase and increased incorporation of labeled amino acids into cytoplasmic proteins. Apparently, low-dose ionizing radiation induces activation of the liver cell genome, this being one of the main mechanisms of the general stimulatory effect of low doses.

Effect of low-dose irradiation on pregnant mouse haemopoiesis.

The effects of low-dose gamma radiation to haemopoietic progenitor cell compartments of the marrow and spleen of virgin female mice and pregnant mice were studied. Microplasma clot cultures were used to asses burst-forming unit-erythroid (BFU-E) and colony-forming unit-erythroid (CFU-E) activity, and double-layer agar cultures were established to evaluate granulocyte-macrophage colony-forming cell (GM-CFC) and macrophage colony-forming cell (M-CFC). The apparent shift in maternal erythropoiesis from the bone marrow to the enlarged spleen was reflected by an increase in the numbers of CFU-E and BFU-E per spleen and a concomitant decrease in CFU-E and BFU-E per femur. Whereas maternal GM-CFC values per femur increased 36%, maternal GM-CFC per spleen increased by 172% compared to virgin values. There was a greater decrease in M-CFC per spleen than per femur in the pregnant animal when values were compared to the virgin animal. Total-body irradiation to the day-10.5 pregnant mouse caused a further suppression of day-14.5 medullary erythropoiesis (i.e. decreased CFU-E values) compared to the response of the virgin female mouse. An ability of the maternal spleen to support further compensatory erythropoiesis following increasing doses of radiation was demonstrated. 4 d after 1.0 Gy exposure, maternal values for GM-CFC per femur or spleen decreased to nonirradiated virgin mice values. M-CFC per maternal femur decreased following 1.5 Gy, but M-CFC per spleen appeared to be unaffected with doses from 0.5 to 2.0 Gy.