Antiradiation Agents Research Articles

Development of a Therapeutic Agent Based on Escherichia coli, Assessment of Harmlessness and Anti-Radiation Activity

The paper presents the development, assessment of the safety and antiradiation activity of a therapeutic agent based on the culture of Escherichia coli strains “PL-6” and “KV-1”. To obtain the antiradiation agent, the causative agent of colibacillosis was grown in meat-peptone broth in a thermostat at a temperature of 37°C for 3 days. The grown suspension was centrifuged at 3000 rpm for 50 min, the supernatant was decanted. The sediment was brought to 1 billion cm3 with distilled water. Smears were prepared from the grown cultures and stained according to Gram to determine the purity and species of the grown culture. The prepared suspension was poured into sterile vials of 10, 50 or 100 cm3, sealed with rubber stoppers and rolled with aluminum caps, labeling with an indication of the strain, radiation dose and date. Irradiation of the microbial material was carried out on the γ-installation “Issledovatel”, source 60Co, absorbed dose rate of 1.028 Gy/sec, in the ranges of absorbed doses from 7.5 to 30.0 kGy with interdose intervals of 2.5 and 5.0 kGy. The degree of inactivation of γ-irradiated E. coli cultures was determined by seeding them on meat-peptone agar and thermostatting for 168 hours, recording the presence or absence of microorganism growth. The studies have established that the timing and degree of growth of irradiated E. coli cultures of the “PL-6” and “KV-1” strains are directly dependent on the radiation dose, their complete inactivation occurs with irradiation at a dose of 25.0 kGy. Further studies have shown that the developed biopreparation obtained on the basis of E. coli is sterile, areactogenic, non-toxic and harmless. The mechanism of formation of radioresistance of the organism against the background of application of antiradiation agents based on E. coli strains “PL-6” and “KV-1” consisted in restoration of hematological, biochemical and immune parameters, which contributed to preservation of 66.7 to 83.3٪ of lethally irradiated animals.

Multifunctional carbomer based ferulic acid hydrogel promotes wound healing in radiation-induced skin injury by inactivating NLRP3 inflammasome

BackgroundRadiation-induced skin injury is a significant adverse reaction to radiotherapy. However, there is a lack of effective prevention and treatment methods for this complication. Ferulic acid (FA) has been identified as an effective anti-radiation agent. Conventional administrations of FA limit the reaching of it on skin. We aimed to develop a novel FA hydrogel to facilitate the use of FA in radiation-induced skin injury.MethodsWe cross-linked carbomer 940, a commonly used adjuvant, with FA at concentrations of 5%, 10%, and 15%. Sweep source optical coherence tomography system, a novel skin structure evaluation method, was applied to investigate the influence of FA on radiation-induced skin injury. Calcein-AM/PI staining, CCK8 assay, hemolysis test and scratch test were performed to investigate the biocompatibility of FA hydrogel. The reducibility of DPPH and ABTS radicals by FA hydrogel was also performed. HE staining, Masson staining, laser Doppler blood flow monitor, and OCT imaging system are used to evaluate the degree of skin tissue damage. Potential differentially expressed genes were screened via transcriptome analysis.ResultsGood biocompatibility and in vitro antioxidant ability of the FA hydrogels were observed. 10% FA hydrogel presented a better mechanical stability than 5% and 15% FA hydrogel. All three concentrations of FA remarkably promoted the recovery of radiation-induced skin injury by reducing inflammation, oxidative conidiation, skin blood flow, and accelerating skin tissue reconstruction, collagen deposition. FA hydrogel greatly inhibiting the levels of NLRP3, caspase-1, IL-18, pro-IL-1β and IL-1β in vivo and vitro levels through restraining the activation of NLRP3 inflammasome. Transcriptome analysis indicated that FA might regulate wound healing via targeting immune response, inflammatory response, cell migration, angiogenesis, hypoxia response, and cell matrix adhesion.ConclusionsThese findings suggest that the novel FA hydrogel is a promising therapeutic method for the prevention and treatment of radiation-induced skin injury patients.Graphical

Cytogenetic changes in irradiated rats under influence of guaninium-zinc chloride complex

Aim. The main goal of this study was to study the anti-radiation effect of guaninium-zinc chloride complex on cytogenetic changes in irradiated rats. Methods. White rats of the Wistar line with an average weight of 110-125 grams served as the material for the detection of the anti-radiation effect of guaninium-zinc chloride complex. Animals were injected intraperitoneally with solutions of guaninium-zinc chloride complex at a concentration of 40 mg/kg 2 hours before irradiation and were subjected to general uniform gamma irradiation from a 60Co source in the Rukhund-20000 irradiation unit at a dose of 3 and 5 Gy. Results. Cytogenetic analysis of animals showed that with a single injection of guaninium-zinc chloride complex solutions before irradiation, the proportion of chromosomal abnormalities decreased markedly, and reached 2.93 %, and the amount of abnormal spermatozoa markedly decreased. Guaninium-zinc chloride complex softened the damaging effects of ionizing radiation. There was no suppression of cell division. Conclusions. It was found for the first time that, with the introduction of a solution of guaninium-zinc chloride complex in white Wistar rats before irradiation, it reduces the damaging effect of gamma irradiation. The obtained data gives grounds to assume that the guaninium-zinc chloride complex tested by us can be recommended as a promising anti-radiation agent.

Issues of Organization of the Development of Antiradiation Agents in Russia for Drug Safety during Radiation Incidents

Issues of Organization of the Development of Antiradiation Agents in Russia for Drug Safety during Radiation Incidents

К ВОПРОСУ О ФАРМАКОЛОГИЧЕСКОЙ ЗАЩИТЕ ПРИ ОБЛУЧЕНИИ В НЕПОРАЖАЮЩИХ ДОЗАХ: ВОЗМОЖНО, НЕОБХОДИМО? СООБЩЕНИЕ 2. ОБЗОР ПАТОГЕНЕТИЧЕСКИХ НАПРАВЛЕНИЙ ПРИМЕНЕНИЯ ПРОТИВОЛУЧЕВЫХ СРЕДСТВ В ЭКСПЕРИМЕНТЕ

Purpose: Review and systematization of modern ideas about the mechanisms of the development of the effects of ionizing radiation in medium doses on a living organism in order to assess the need and possibility of using pharmaceutical agents suitable for modification purposes, about research methods in experiment; stimulation of discussion on the issue under consideration. Results: the current understanding of the genesis of radiation effects from irradiation at medium doses in the range of 0.2-1 Gy as a subject of modification with antiradiation agents is considered. Conclusions: The systematic nature of modern knowledge about the genesis of radiation effects from low-power irradiation in medium doses of the range 0.2-1 Gy, heterogeneity and mixing of mechanisms can be considered as a basis for the use of antiradiation agents with different properties and aimed at target (direct) and non-target (indirect) ) the effect of radiation. One of the problems of using and predicting the radioprotective efficiency of the PLC is the poor development of methods for establishing correlations between the indicators of increased radioresistance (without irradiation) with the actual antiradiation effect.

RADIOPROTECTIVE PROPERTIES OF PHYTOMEDICINES: A LITERATURE REVIEW

Relevance: Till today, antiradiation agents have been mainly found among radioprotectors synthesized from sulfur-containing
 compounds. The search for radioprotectors in other classes of compounds appeared to be less successful.
 The study aimed to analyze the pharmacodynamics of phytopreparations used to correct disorders of the immune and antioxidant
 systems and purine metabolism of the body induced by radiation.
 Methods: The review included publications indexed in PubMed, Medline, E-library, and CyberLeninka databases. The search was
 made using the Google Scholar scientific search engine. The search filters included: experimental studies performed on mice and rats over
 the past decade (2012 to 2022).
 Results: The literary search returned an insufficient number of publications on the qualities of the action of phytopreparations, such as
 integrity and complexity, the versatility of action, selectivity, and organotropism. The lack of publications on side effects (except for allergic
 intolerance to any components of plants) requires a profound study of this topic.
 Conclusion: Radiobiology should search for new non-drug means of treatment and make experiments to study the effect of
 phytocompositions on biochemical processes in an irradiated organism.

Acanthopanax senticosus Polysaccharide Enhances the Pathogen Resistance of Radiation-Damaged Caenorhabditis elegans through Intestinal p38 MAPK-SKN-1/ATF-7 Pathway and Stress Response.

With the advancement of science and technology, humans are chronically exposed to ionizing radiation. It is crucial to look for efficient and low-toxic anti-radiation agents. Through preliminary screening, we found that Acanthopanax senticosus polysaccharide (ASPS) played a major role in regulating immune damage caused by radiation. The objective of this study was to apply the Caenorhabditis elegans—P. aeruginosa (PA14) infection model to illuminate the mechanism of ASPS increasing the pathogen resistance of radiation-damaged nematodes. Results indicated that ASPS (1 mg/mL) significantly enhanced the pathogen resistance of radiation-damaged nematodes by directly elevating the immune response of nematodes rather than by affecting the bacterial activity. Through further research on the p38 MAPK signaling pathway and related mutants, we found that ASPS functioned by the p38 MAPK pathway in the intestine, and SKN-1, ATF-7 as the downstream targets of PMK-1 participated the regulation of ASPS. In addition, ASPS markedly alleviated the stress status of damaged nematodes by regulating oxidative stress. Collectively, our findings suggest that ASPS enhances the pathogen resistance of radiation-damaged nematodes through the intestinal p38MAPK-SKN-1/ATF-7 pathway and stress response.

CLASSIFICATION OF MEDICAL EQUIPMENT FOR ANTI-RADIATION PROTECTION.

Any collection of objects of study needs some arrangement, i. e. classification. The existing numerous classifications of antiradiation agents are built on the basis of their antiradiation effects of an integrated or differentiated nature. The work presents the chronology of the main classifications of chemical compounds that are able to protect against the shortterm and longterm effects of ionizing radiation when they are introduced into the body both before and after exposure. The change of views, trends and paradigms regarding radioprotective compounds is shown. These classifications of antiradiation medicines include radioprotectors, means of stimulating the radioresistance of the body, means of prevention and suppression of the primary reaction to irradiation, means of prevention and treatment of lesions from exposure to incorporated radionuclides, means of treatment of acute bone marrow syndrome, means of treatment of local radiation lesions. It is shown that modern concepts of radiation protection are based on fundamentally different «points of application» of groups of radioprotective agents and depend on the stage of radiation damage.

К ВОПРОСУ О ФАРМАКОЛОГИЧЕСКОЙ ЗАЩИТЕ ПРИ ОБЛУЧЕНИИ В НЕПОРАЖАЮЩИХ ДОЗАХ: ВОЗМОЖНО, НЕОБХОДИМО? СООБЩЕНИЕ 1. ОБЩИЙ ОБЗОР МЕДИКО-ТАКТИЧЕСКИХ И ФЕНОМЕНОЛОГИЧЕСКИХ АСПЕКТОВ

Purpose: Review of modern concepts of the biological effect of ionizing radiation in medium doses on a living organism and the consequences of radiation in order to assess the need for the use of drugs suitable for the purpose of modifying the effects; stimulation of discussion on the issue under consideration. Results: The conditions of origin and the list of possible radiation effects from irradiation at medium doses of the 0.1–1 Gy range were assessed, the scale and phenomenology of the consequences were assessed as a subject of modification by antiradiation agents. Conclusions: Pharmacological support (use of PLC) under conditions of short-term and prolonged irradiation with a low dose rate and in the dose range of 0.2–1 Gy seems to be necessary due to the reality of deterministic effects when the dose limits are exceeded (partly at the premorbid or preclinical level, with pronounced psychogenic reactions – components of the final state), as well as with the possibility of stochastic effects in excess of spontaneous ones, although, according to approximate estimates, with an insignificant frequency.

Evaluation of the Efficiency of Various Antiradiation Preparations according to Phosphorylated Histone H2AX and the Micronucleus Test

In experiments on R-irradiated female F1 mice (CBA × C57Bl), the possibility of using rapid tests for the number of double-stranded DNA breaks (γH2AX) in the spleen and micronuclei in polychromatophilic erythrocytes (MN-PCE) of the bone marrow for an approximate evaluation of the effectiveness of antiradiation agents was investigated. Cytokine betaleukin, α-adrenomimetic indraline, and nucleoside riboxin were tested. By the DRF criterion, γH2AX showed a higher sensitivity compared to MN-PCE. Between the two indicators, a significant degree of correlation was revealed.

Protecting HaCaT cells from ionizing radiation using persimmon tannin-Aloe gel composite

Context Persimmon tannin (extract of Diospyros kaki L.f [Ebenaceae]) and Aloe gel (extract of Aloe vera (L.) Burm.f. [Asphodelaceae]) are known as anti-radiation agents. However, radiation resistance of the persimmon tannin-Aloe gel composite remains inconclusive. Objective To investigate the capacity of the persimmon tannin-Aloe gel composite to protect against ionising radiation at the cellular level. Materials and methods HaCaT (human epidermal keratinocytes) cells were pre-treated with PT-A-1 (the mass ratio of persimmon tannin and Aloe gel was 2:1) or the single component (persimmon tannin or Aloe gel) at various concentrations (0, 50, 100, 200, 400, 800 μg/mL. Control group: medium with no HaCaT cells), and then radiated with X-rays (radiation dose: 4, 8, 12, 16, and 20 Gy). Cell viability, cell apoptosis, and radiation-induced intracellular reactive oxygen species (ROS) generation were analysed by CCK-8, Hoechst 33258 staining/flow cytometry, and 2′,7′-dichlorfluorescein diacetate (DCFH-DA) assay, respectively, for 12 or 24 h incubation after radiation. Results The optimal radiation dose and post-radiation incubation period were determined to be 8 Gy and 12 h. CCK-8 activity detection showed that the cell activity was 77.85% (p < 0.05, IC50 = 55.67 μg/mL). The apoptotic rate was the lowest (4.32%) at 200 μg/mL of PT-A-1 towards HaCaT cells. ROS production was the most effectively suppressed by 200 μg/mL PT-A-1 towards HaCaT cells. Discussion and conclusions The persimmon tannin-Aloe gel composite has good radioprotective effect, and which will facilitate its clinic application as a potential natural anti-radiation agent in future.

Study of the Prooxidant and Antioxidant Activity of Anti-Radiation Agents with LUX-Biosensors

The effects of 29 substances, including known antioxidants, anti-radiation agents, amino acids, and vitamins, on the luminescence intensity of E. coli K12 MG1655 (pSoxS-lux) and MG1655 (pKatG-lux) bacterial cells induced by paraquat and peroxide, respectively, were studied. The luminescence of biosensors occurs as a result of activation of the soxS and katA gene promoters in response to an increase in the concentration of superoxide radicals and H2O2 in the cell. In the case of an antioxidant effect exerted by a substance under study, the intensity of the induced luminescence decreases, and in the case of a prooxidant effect, the luminescence intensity increases. Antioxidant activity was exhibited by 23 of 29 substances (79%) on the pKatG-lux biosensor and 22 of 29 substances (76%) on the pSoxS-lux biosensor. The studied anti-radiation agents (ten substances) showed different degrees of pro- and antioxidant activity. Lithium salt of glutathione disulfide, glutoxim, ginestein, and indraline significantly reduced the level of induced luminescence in both biosensors; magnesium salt of glutathione disulfide, zinc salt of reduced glutathione, and molixane, only in the pSoxS-lux biosensor; and cistamine and 5-AED, only in the pKatG-lux biosensor. Among the anti-radiation agents, a high prooxidant activity on the pKatG-lux biosensor at low concentrations was shown by lithium and magnesium salts of glutathione disulfide, zinc salt of reduced glutathione, molixane, and indralin (B-190); and on the pSoxS-lux biosensor, by genistein, cystamine, and 5-АED. The applicability of lux-biosensors for primary evaluation of the potential antioxidant and radioprotective activity of chemicals is discussed.

Antiradiation properties of extracts from Hypericum perforatum L.

Aim. Considering the high biological activity of the components of the St. John’s wort, we conducted studies to identify its radioprotective effect. Methods. Studies were conducted on adult Vistar rats with an average weight of 100-120 grams.3 hours before irradiation, the extract from St. John’s wort was intraperitoneally administered to animals at a concentration of 50 mg/kg. Irradiation was carried out once with doses of 5 and 7 Gy on the “Rhund-20000” facility with an average radiation dose rate MD = 0.3069 Gr/s. The frequency of chromosomal abnormalities was recorded on the mitotic cells of the bone marrow. Results. Acute irradiation with a dose of 5 Gy led to cell division inhibition. The number of chromosomal aberrations increased due to structural disorders (deletions, fragments, inversions) up to 6.8%.In animals that received a dose of 7 Gy after a single irradiation, the frequency of chromosomal abnormalities increased to 11.02%. The introduction of the Hypericum perforatum L. extract softened the effect of ionizing radiation, reducing the mutational effect of radiation. It not only contributed to the restoration of the cell division, but also reduced the proportion of structural disorders. Conclusions. Hypericum extract can be considered to be promising as an anti-radiation agent of plant origin.&#x0D; Keywords: rats, chromosomal abnormalities, marrow, irradiation, extract.

Pharmacoprophylactic and Pharmacotherapeutic Approaches to Mitigating the Damaging Effects of Ionizing Radiation: Review of Information Sources

Метою статті є узагальнення наукових точок зору щодо сучасних підходів до фармакологічної корекції ушкоджень радіаційного генезу. Проведення лікувальних заходів, спрямованих на усунення негативних наслідків впливу іонізуючого опромінення та прискорення відновлювальних процесів в опроміненому організмі потребує обов’язкового застосування протипроменевих засобів. На сьогоднішній день є обґрунтованим поділ всіх протипроменевих препаратів на фармакопрофілактичні та фармакотерапевтичні лікарські засоби. До засобів профілактики радіаційних уражень належать три класи препаратів – радіопротектори, радіомодулятори та радіомодифікатори. Окреме місце посідають препарати ранньої патогенетичної терапії (радомітігатори) та засоби терапії відтермінованих наслідків дії радіаційного чинника. Зважаючи на доволі широкий спектр медикаментозних засобів з протипроменевими ефектами, що значно ускладнює цілісне сприйняття їх компартменталізації із врахуванням їх практичної значущості за конкретних сценаріїв радіаційного ураження, складено їх сучасну класифікацію.

Improved Synthesis of Dbibb as a New Anti-Radiation Agent

An excellent candidate in the fight against damage caused by nuclear radiation is 2-[4-(1,3-dioxo-1H,3Hbenzoisoquinolin-2-yl)butylsulfamoyl]benzoic acid (DBIBB), a lipid agonist of lysophospholipid acid receptor 2. In this study, a novel method that synthesizes DBIBB was developed. In this method, saccharin was replaced singly by 1,4-dibromobutane, reacted with 1,8-naphthalimide, hydrolyzed by sodium hydroxide, and finally acidified by hydrochloric acid to obtain DBIBB. The new synthesis route was shorter, milder, and simpler than previously reported approaches. The method also produced higher total yield than that of existing ones. Thus, it is applicable to the large-scale synthesis of DBIBB.

Ultrasmall Pt Clusters Reducing Radiation-Induced Injuries via Scavenging Free Radicals.

High energy ionizing radiation was widely used in medical diagnosis and cancer radiation therapy. The high dose of X ray or γ ray can cause the damage of cancerous tissue as well as healthy tissue during therapy. Therefore, it is urgent to develop chemical agents to protect the healthy tissue from high energy ray invasion. Here, the ultrasmall Pt clusters were employed as the anti-radiation agents for protecting healthy cells and improving survival rate of irradiated mice. It was found that Pt clusters can reduce the DNA damages in irradiated cells. In vivo experiments show that the Pt clusters treatment can improve the survival rate of irradiated mice up to 30%. As a contrast, only-irradiated mice without Pt clusters treatment completely died after 15 days. The detailed biological experiments showed that Pt clusters can recover the bone marrow DNA level and superoxide dismutase activities via scavenging free radicals. Importantly, the ultrasmall Pt clusters can be excreted rapidly by kidney and do not cause long-term toxicity.

Target/signalling pathways of natural plant-derived radioprotective agents from treatment to potential candidates: A reverse thought on anti-tumour drugs.

Radiation damage can occur in nuclear power plant workers when physical protections fail, which results in nuclear leakage through the protective layers. Alternatively, workers may be unable to use physical protection in time (in the case of a sudden nuclear weapons attack). In addition, patients who receive local radiotherapy and are not allowed to adopt local physical protection may experience radiation damage. Thus, protection against chemical radiation has become indispensable. In view of the side effects caused by synthetic radioprotective agents (such as amisfostine), searching for radioprotective agents from plant sources is an alternative strategy. Radiation damage can cause multiple signalling pathway disturbances, leading to multiple organ injuries. Changes in these signalling pathways can lead to apoptosis, necrosis, and autophagy, as well as organ fibrosis, atrophy, and inflammation. Through literature searches, we determined that most targets for treating radiation injury are mechanistically opposite those of anti-tumour agents. This is likely attributable to the idea that anti-tumour agents promote cell necrosis or apoptosis, whereas the goal of anti-radiation agents is to promote cell survival or autophagy. This observation has important theoretical and practical significance when searching and developing new radioprotective agents derived from plant extracts. Further, it has important guiding value for meeting military needs and serving the public.

Risk assessment of space radiation during manned space flights

During a long-term exploration in space, astronauts will be constantly exposed to space radiation which contains various types of low dose-rate heavy particles. Although the fluxes of these heavy ions are very small, the heavy ions can cause severe biological effects including early effects and late effects. This short review will discuss the biological effects induced by space radiation and introduce a new anti-radiation agent we have developed. We synthesized a class of reactive oxygen species scavengers called GANRA-5 with lowly toxic but high radio-protective effect to both heavy ions and X-rays. GANRA-5 can protect cells from X-rays and carbon ions induced cell killing by significantly reducing the amount of free radical production therefor reduce double-strand breaks and genomic instability. In vivo, GANRA-5 can effectively protect the mice from the damage induced by X-rays irradiation by enhancing superoxide dismutase activities. In brief, GANRA-5 is potentially applicable in space flight.

ChemInform Abstract: S-(2-((2′-Carbamoylethyl)amino)ethyl) Phosphorothioate and Related Compounds as Potential Antiradiation Agents.

A reinvestigation of the radiation protection activity of S-(2-((2{prime}-carbamylethyl)amino)ethyl) lithium hydrogen phosphorothioate (4a) revealed that this compound possessed good (70% protection at a dose of 600 mg/kg) activity. The thione and imino bioisosteres of 4, S-(2-(2{prime}-thiocarbamylethylamino)ethyl) lithium hydrogen phosphorothioate (13a) and S-(2-(2{prime}-amidinoethylamino)ethyl) phosphorothioic acid (18b) showed 100% protection at doses of 300 and 150 mg/kg, respectively. The N-methyl (4b) and tert-butyl (4c) analogues of amide 4a, the N-methyl (13b) analogue of the thioamide 13a, the N-methyl (18a) analogue of amidine (18b), and the cyclic amidine S-(2-((2{prime}-(4,5-dihydroimidozoyl)ethyl)amino)ethyl) lithium hydrogen phosphorothioate (21) all showed 80% protection at the highest dose tested.

Radioprotection by Cu(II) Chelates of Nicotinyl-L-Aminoacidates

Essential metalloelement chelates presents a promising class of compounds for search and development of novel anti-radiation agents, study of which offers a new approach to overcome the pathological effects of ionizing radiation. In this study Cu(II) chelates of Nicotinyl-L-Tyrosinate and Nicotinyl-L-Tryptophanate Schiff Bases were synthesized and investigated as radioprotectors in animal experiments against injuries caused by ionizing irradiation. Based on the assessment of average life-span indices and 30-day animal survival after radiation exposure at LD50/30 (4.8 Gy) or LD100/30 (8.7 Gy) the radioprotective effects of 0 mg/kg (Vehicle), 10 mg/kg, 20 mg/kg, or 40 mg/kg Cu(II)(Nicotinyl-L-Tyrosinate)2 or Cu(II)(Nicotinyl-L-Tryptophanate)2 as well as their parents Schiff Bases were studied in case of single subcutaneous and oral administration to rats 1, 3, 6 and 24 hours prior to X-ray irradiation. The mixture of 4% propylene glycol and 1.4% polyvinyl alcohol in saline was used as a Vehicle for the administration of compounds to animal organism. According to the results obtained, administration of the metallochelates to the rat organism prior to X-ray irradiation provided strong radioprotective effects expressed upon application of all considered dose, mode and time treatment schedules: in groups of animals treated with Cu(II) chelates there was an remarkable increase in the indices of survival and average life-span in a 30-day period post exposure compared to the control Vehicle treated - irradiated rats. The appropriate parents Schiff Bases Nicotinyl-L-Tyrosinate and Nicotinyl-L-Tryptophanate also exerted the radioprotective action. However, these compounds were active as effective radioprotectors only in case X-ray irradiation at a dose level equal to or less than LD50/30. Data of analyses indicated that Cu(II) chelates as well as their initial amino acid Schiff Bases did not avert the development of disturbances of hematological indices of animals exposed at LD50/30. However, the findings of immunological studies have demonstrated the inhibiting effects of these compounds on circulating immune complexes (CICs) in blood plasma, which are the major mediators of immune response and are considered as indicators of the autoimmune and inflammatory components of radiation-induced up-regulated immune response. Unlike to Nicotinyl-L-Aminoacidate Schiff Bases their corresponding Cu(II) chelates diminished the harmful effects of radiation-induced CICs formation not only in case of irradiation at LD50/30, but also at much higher radiation dose levels. Thus, the single administration of Cu(II)(Nicotinyl-L-Tyrosinate)2 and Cu(II)(Nicotinyl-L-Tryptophanate)2 at non-toxic doses provides effective radiation protection and high level of survival of exposed animals. Research is performed in the frames of ISTC A-1321 Project.