Radioprotective Effect Research Articles

The effect of melatonin and probiotics on radiation-induced enteritis in experimental rat models

Radiotherapy plays an important role in the treatment of tumors, and enteritis is a common side effect of this therapy. The aim of present study was to evaluate the protective effect of melatonin and probiotics on radiation-induced intestinal tissue damage in rats. Histopathological, biochemical and microbiological samples were examined. Thirty-two Wistar Albino rats were randomly distributed into four groups: the control group, only radiotherapy (RT) group, radiotherapy plus melatonin (RT + MEL) groups and radiotherapy plus probiotics (RT + PROB) groups. The abdominal-pelvic region of the experimental rat was irradiated with in a single dose of 16 Gy. The melatonin was administered at a single dose of 50 mg/kg through intraperitoneal injection, 15 min before radiation exposure. The probiotic was administered orally every day to the rats for 5 days starting before radiotherapy. There was a statistically significant changes in histopathological (villus atrophy, mitotic activity, apoptotic index, goblet cell swelling, degenerative changes, atypia) and biochemical (oxidant and antioxidant status, IL-1β, IL-6 and TNF- α levels) parameters in the small intestine in the radiotherapy group G2 compared to the G1 control group (p < 0.05). However, a significant decrease was observed with the administration of probiotics and melatonin (p < 0.05). In addition, although positive bacterial growth was detected in the mesenteric lymph node of all rats in the radiotherapy group, there was no statistically significant difference between all groups (p > 0.05). Melatonin and probiotics were found to have a potent radioprotective effect against radiotherapy-induced acute small intestinal tissue damage. However, their superiority over each other was not observed.

Transient HR enhancement by RAD51-stimulatory compound confers protection on intestinal rather than hematopoietic tissue against irradiation in mice

DNA double-strand breaks (DSBs) are cytotoxic lesions that compromise genomic integrity and trigger cell death. Homologous recombination (HR) is a major pathway for repairing DSBs in cycling cells. However, it remains unclear whether transient modulation of HR could confer protection to adult stem cells against lethal irradiation exposure. In this study, we investigated the radio-protective effect of the RAD51-stimulatory compound RS-1 on adult stem cells and progenitor cells with varying cycling rates in intestinal and hematopoietic tissues. Treatment with RS-1 even at high doses did not induce noticeable cell death or proliferation of intestinal crypt cells in vivo. Pretreatment with RS-1 before irradiation significantly decreased mitotic death, promoted DNA repair and enhanced the survival of intestinal stem cells and progenitor cells and increased the number of regenerative crypt colonies thereby mitigating IR-induced gastrointestinal syndrome. Moreover, RS1 pretreatment could increase the survival and regeneration of irradiated intestinal organoid in vitro, which can be rescued by RAD51 inhibitor. However, pretreatment with RS-1 in vivo did not elevate nucleated cell count or HSPCs in bone marrow after 6Gy irradiation. Additionally, there was no impact on mouse survival due to drug treatment observed. Thus, our data suggest that targeting HR as a strategy to prevent tissue damage from acute irradiation exposure may depend on cell cycling rates and intrinsic DNA repair mechanisms.

Zinc Influences the Efficacy of Betulinic Acid Treatment and Radiotherapy in Breast Cancer Cells

The trace element zinc influences a number of biological reactions, including cell growth, apoptosis, and DNA damage, which affect tumor therapy. The natural compound betulinic acid (BA) and its derivatives are known for their antiviral, antibacterial, and antitumor effects. Previous studies show that BA and 3-acetyl-28-sulfamoyloxybetulin (CAI3) have high cytotoxicity and induce radiosensitization in breast cancer cells. This study investigates the effects of zinc supplementation on treatment with BA or CAI3 and radiotherapy of breast cancer cell lines MDA-MB-231 and HS578T. Expression analysis shows that BA and CAI3 lead to altered expression of genes involved in zinc metabolism. Zinc supplementation affects cell survival and cell death alone and in combination with BA or CAI3 in both breast cancer cell lines. In MDA-MB-231 cells, zinc excess protects against ROS formation by BA or CAI3 and exhibits radioprotective effects compared to the single agent treatment. In contrast, in HS578T cells, zinc induces ROS formation but does not affect radiosensitivity. The variable effects of zinc on radiosensitivity highlight the importance of individualized treatment approaches. Although zinc has cytotoxic, pro-apoptotic, and anti-clonogenic effects, it seems worthwhile to consider its radioprotective properties when making treatment decisions in the case of adjuvant radiotherapy of breast cancer.

Radioprotective effects of melatonin therapy against testicular oxidative stress: a systematic review and meta-analysis of rodent models

Background: Radiation exposure is a concern in today’s world, given the widespread use of electronic devices and medical procedures involving ionizing and non-ionizing radiation. Radiations may cause male infertility by inducing oxidative stress in testicular tissue. Melatonin has antioxidant properties. Methods: We systematically reviewed the literature for the studies that have investigated the effects of melatonin therapy on radiation-induced oxidative stress in rodents’ testicular tissue. PubMed, Scopus, and Web of Science were searched for relevant animal trials. Standardized mean difference and 95% confidence intervals were used to pool the data. Subgroup and sensitivity analyses were done. The risk of bias was assessed using SYRCLE tool. Results: Outcomes: histopathology and sperm analyses (testicular apoptotic cells, Johnsen’s testicular biopsy score, seminiferous epithelial height, tubular diameter, sperm motility, viability, count, and morphology, concentration of spermatid, spermatocyte, and spermatogonia), body and testes weights (absolute and relative body and testicular weights), reproductive hormones (serum prolactin, FSH, and testosterone), and oxidative stress tissue markers (TBARS, CAT, GSH, GSH-Px, MDA, SOD, and XO, and total antioxidant capacity). Rats and mice were exposed to electromagnetic radiations (gamma, roentgen, microwave, radiofrequency, and high-power line energy) and particle waves (radioiodine and carbon-ion). Melatonin therapy was significantly associated with improved male reproduction. Conclusion: Radiation exposure harms male fertility, but melatonin, as an antioxidant, is potentially associated with improved male reproductive function in rodents. Inconsistencies in research require further investigations.

Radioprotective potential of pomegranate peel extract against gamma irradiation-induced hazards

BackgroundWhile gamma irradiation’s damaging biological effects are well-established, the natural radioprotective agents from agricultural waste remain an underexplored area of significant potential.Aim of studyThis study was to investigate the novel use of pomegranate peel ethanol extract (PE) as a radioprotective agent against gamma radiation damage.MethodsWe pretreated Wistar rats with PE (100 mg/kg) for 14 days prior to 6 Gy gamma irradiation. We analyzed blood biochemicals, oxidative stress, and inflammatory markers. These included tests of red cell membrane integrity, lipid and protein oxidation, antioxidant enzyme levels, and cytokine profiles.ResultsThe study showed that PE demonstrated remarkable radioprotective effects across multiple parameters. Antioxidants were significantly enhanced, as evidenced by increased glutathione peroxidase activity (87.00 ± 6.11 mg/ml in PE-treated irradiated rats compared to 26.40 ± 1.21 mg/ml in irradiated controls). Oxidative damage was markedly reduced, with MDA levels dropping from 9.59 ± 0.24 nmol/ml in irradiated controls to near-control levels in PE-treated rats. Notably, PE treatment resulted in unprecedented maintenance of red blood cell membrane integrity post-irradiation. Furthermore, PE exhibited novel modulation of inflammatory cytokines, effectively reducing pro-inflammatory markers IL-6 and TNF-α while simultaneously boosting anti-inflammatory IL-4 and IL-10 levels. These multifaceted protective effects highlight PE’s potential as a comprehensive radioprotective agent.ConclusionThis study presents PE as an effective new natural radioprotective agent. Its protective effect is due to its high polyphenol content, which enhances antioxidant defenses, reduces oxidative damage, and prevents inflammation. The findings open new avenues for sustainable, cost-effective radioprotection strategies and demonstrate the potential for repurposing agricultural byproducts for critical health applications.

A new insight on the effects of Schiff Base Iron (III) complexes in breast cancer cells for clinical radiotherapy

PurposeBreast cancer is a significant global health concern, and researchers strive to enhance radiotherapy outcomes while minimizing the side effects. Schiff Base Iron (III) Complexes are one of the prospective elements that can be used as radiosensitizer or radioprotective agents in cancer radiotherapy. This study investigates the potential effects of Schiff base (ligand 2; L2) with Fe(III) in MCF-7 breast cancer cells under clinical radiotherapy treatment. MethodsThe effects of the Schiff Base Iron (III) Complexes were measured using clonogenic assay with MCF-7 breast cancer cells. The cells were irradiated with megavoltage 6 MV photon, 6 MeV electron and high dose rate (HDR) brachytherapy with 192Ir source at different doses. Intercellular localization of Fe(III)-L2 complexes and antioxidant activities were also investigated. ResultsThe Fe(III)-L2 complexes were observed to be internalized by cellular nuclei without any effects on the cells. Interestingly, the Fe(III)-L2 complexes indicate radioprotective effects which provide intriguing insight towards application of metal ions complexes as radioprotector in cancer radiotherapy. The Fe(III)-L2 complexes also exhibit scavenging activities of free radical which further proved the antioxidative properties and radioprotective effects. ConclusionThe Fe(III)-L2 complexes show the radioprotective effects and antioxidant properties in MCF-7 cells, particularly for HDR brachytherapy. The findings suggest potential applications of the Fe(III)-L2 complexes as radioprotector agents in clinical radiotherapy.

Study on the protective effect of flavonoids extracted from Jatropha curcas leaves against radiation damage in mice

The primary objective of this study was to evaluate the radioprotective effects of Flavonoids Extracted from Jatropha curcas Leaves (FEL) and to elucidate the underlying protective mechanisms against radiation damage. Six monomers of the FEL were analyzed using Ultra Performance Liquid Chromatography (UPLC). The results indicate that FEL increases the survival rate of mice and promotes the recovery of organs damaged by 60Co γ-rays to their normal appearance, through mechanisms that include the enhancement of immune and hematopoietic functions in vivo. In vitro studies suggest that the molecular mechanism by which FEL mitigates radiation damage involves the reduction of DNA damage and mutations. These findings indicate that FEL could be effective in alleviating radiation-induced injuries.

Metal-organic framework-edaravone nanoparticles for radiotherapy-induced brain injury treatment

Cranial radiotherapy may cause damage to normal brain tissues and induce cognitive dysfunction, so developing an effective strategy to prevent radiotherapy-induced brain injury is essential. Metal-organic frameworks (MOFs) can be used as vectors for the delivery of neuroprotective drugs due to their high drug loading capacity and low toxicity. In this study, we synthesized MIL-53(Cr) nanoparticles, which were used to deliver edaravone, and modified the surface of the nanoparticles with polyethylene glycol and Angiopep-2 (EDA@MIL-53(Cr)–P/A) to improve their oral bioavailability and ability to cross the blood–brain barrier (BBB). We confirmed that MIL-53(Cr)–P/A nanoparticles could achieve the sustained release of edaravone and enhance its ability to cross the BBB. The results of in vitro experiments showed that EDA@MIL-53(Cr)–P/A could exert radioprotective effects on HT22 and BV2 cells. We also demonstrated that EDA@MIL-53(Cr)–P/A could alleviate brain injury and cognitive dysfunction in mice receiving whole-brain irradiation. Mechanistically, EDA@MIL-53(Cr)–P/A alleviated irradiation-induced brain damage by inhibiting oxidative stress, DNA damage, apoptosis and inflammatory reactions. This study provides a new strategy for the protection against radiotherapy-induced brain injury.

Targeting Oxidative Stress: The Potential of Vitamin C in Protecting against Liver Damage after Electron Beam Therapy.

Background: Radiation-induced liver disease (RILD) is a severe complication arising from radiotherapy, particularly when treating abdominal malignancies such as hepatocellular carcinoma. The liver's critical role in systemic metabolism and its proximity to other abdominal organs make it highly susceptible to radiation-induced damage. This vulnerability significantly limits the maximum safe therapeutic dose of radiation, thereby constraining the overall efficacy of radiotherapy. Among the various modalities, electron beam therapy has gained attention due to its ability to precisely target tumors while minimizing exposure to surrounding healthy tissues. However, despite its advantages, the long-term impacts of electron beam exposure on liver tissue remain inadequately understood, particularly concerning chronic injury and fibrosis driven by sustained oxidative stress. Objectives: to investigate the molecular and cellular mechanisms underlying the radioprotective effects of vitamin C in a model of radiation-induced liver disease. Methods: Male Wistar rats (n = 120) were randomly assigned to four groups: control, fractionated local electron irradiation (30 Gy), pre-treatment with vitamin C before irradiation, and vitamin C alone. The study evaluated the effects of electron beam radiation and vitamin C on liver tissue through a comprehensive approach, including biochemical analysis of serum enzymes (ALT, AST, ALP, and bilirubin), cytokine levels (IL-1β, IL-6, IL-10, and TNF-α), and oxidative stress markers (MDA and SOD). Histological and morphometric analyses were conducted on liver tissue samples collected at 7, 30, 60, and 90 days, which involved standard staining techniques and advanced imaging, including light and electron microscopy. Gene expression of Bax, Bcl-2, and caspase-3 was analyzed using real-time PCR. Results: The present study demonstrated that fractional local electron irradiation led to significant reductions in body weight and liver mass, as well as marked increases in biochemical markers of liver damage (ALT, AST, ALP, and bilirubin), inflammatory cytokines (IL-1β, IL-6, and TNF-α), and oxidative stress markers (MDA) in the irradiated group. These changes were accompanied by substantial histopathological alterations, including hepatocyte degeneration, fibrosis, and disrupted microvascular circulation. Pre-treatment with vitamin C partially mitigated these effects, reducing the severity of the liver damage, oxidative stress, and inflammation, and preserving a more favorable balance between hepatocyte proliferation and apoptosis. Overall, the results highlight the potential protective role of vitamin C in reducing radiation-induced liver injury, although the long-term benefits require further investigation. Conclusions: The present study highlights vitamin C's potential as a radioprotective agent against electron beam-induced liver damage. It effectively reduced oxidative stress, apoptosis, and inflammation, particularly in preventing the progression of radiation-induced liver fibrosis. These findings suggest that vitamin C could enhance radiotherapy outcomes by minimizing liver damage, warranting further exploration into its broader clinical applications.

Studying the composition and anti-radiation properties of sage (Salvia officinalis L.) in wheat seeds

Aim. The purpose of the research was to study the chemical composition, develop methods for obtaining an extract from the leaves of Salvia officinalis L. and study their anti-radiation properties of irradiated wheat seeds of the Guneshli variety. Methods. Using qualitative reactions and chromatography, the content of lipids, essential oils, diterpene acids, phenolic compounds, macro- and microelements in plants was determined. Wheat seeds were irradiated using a URI installation (K-25) at a dose rate of 13.4 rad/sec, at a dose of 200 Gy. The amount of chlorophyll pigments, carotenoids, and malondialdehyde was measured using a spectrophotometer. Chlorophyll fluorescence in leaves was determined using a MINI-PAM device. Results. According to the results of morphological and physiological-biochemical parameters of seedlings, 0.01 % and 0.001 % Salvia officinalis extract has a positive effect on growth and development, increases the maximum quantum yield of PS II and reduces the yield of lipid peroxidation product. Conclusions. It has been established that Salvia officinalis extract has a radioprotective effect and can be used as a radioprotector for some agricultural plants.

Novel Molecular Mechanisms Underlying the Ameliorative Effect of Platelet-Rich Plasma against Electron Radiation-Induced Premature Ovarian Failure.

Radiotherapy is one of the risk factors for radiation-induced premature ovarian failure and infertility in cancer patients. The development of methods for ovarian radioprotection remains relevant. Moreover, electrons are a little-studied and promising method of radiation with the least toxic effect on normal tissues. The assessment of intracellular mechanisms regulating the protective effects of leukocyte-poor platelet-rich plasma in a model of radiation-induced premature ovarian failure caused by electron irradiation. Wistar rats were divided into four groups, namely a control group, irradiation group (electron exposure), irradiation + leukocyte-poor platelet-rich plasma group, and only leukocyte-poor platelet-rich plasma group. Fragments of ovaries were removed and hormonal, oxidant, histological, and morphometric studies were carried out. The cell cycle of ovarian follicles and the inflammatory and vascular response were assessed using immunohistochemistry. The activity of MAPK, ERK, and PI3K pathways was also assessed using the RT-qPCR. We found that electron irradiation causes a decrease in the functional activity of the ovaries and the death of follicular cells through apoptosis. The administration of LP-PRP led to a partial restoration of the cytokine balance. In addition, minor ovarian damage and mild inflammation were observed in this group. Leukocyte-poor platelet-rich plasma components have anti-inflammatory, angiogenetic, and radioprotective effects, reducing the activation of the NOX4, caspase and cytokine cascades, and inflammatory response severity through the MAPK/p38/JNK signaling pathway. This leads to the induction of endogenous antioxidant protection, the repair of post-radiation follicular damage, and slowing down the development of radiation-induced premature ovarian failure after electron irradiation.

Effects of Ionizing Radiation on Intestinal Bile Acid Metabolism: Mechanism of the Radioprotective Effect of Glycoursodeoxycholic Acid

Radioactive intestinal injury is a common complication during radiotherapy of tumors. The aim of this study is to observe the effect of ionizing radiation on short-term changes in intestinal bile acids and to investigate the radioprotective effect of bile acids on intestinal cells. A rat model of small intestinal injury was constructed by exposing the abdomen of the rats to daily irradiation at 2 Gy for 4 d in succession. The bile acids were quantified using metabolomics analysis. IEC-6 cells, a small intestinal epithelial cell line, were divided into a dimethyl sulfoxide (DMSO) control group receiving DMSO and 0 Gy irradiation, a glycoursodeoxycholic acid (GUDCA) experimental group receiving GUDCA and 0 Gy irradiation, a DMSO irradiation group receiving DMSO and 10 Gy irradiation, and a GUDCA irradiation group receiving GUDCA and 10 Gy irradiation. Cell viability and cytotoxicity was assessed by CCK-8 assay test. The apoptosis rate of cells was determined by flow cytometry. The colony formation rate and the radiosensitivity of the cells were determined by colony formation assay on solid media. The expression levels of proteins associated with cell death were determined using Western blot. After exposure to irradiation, the small intestine tissues of the rats showed typical radioactive intestinal injury. In addition, various bile acids showed fluctuation before and after irradiation. Among the bile acids, GUDCA increased significantly at 3 d after irradiation, but returned to the pre-irradiation level at 7 d after irradiation. Compared with the control group, after GUDCA treatment at 20 μmol/L for 24 h, the cell viability rate after irradiation was significantly higher than that of the DMSO group (P<0.05); the expression levels of the proteins, including PARP, caspase-3, RIP, and GSDMD, were significantly lower than those in the control group (P<0.05). After GUDCA treatment at 20 μmol/L for 24 h and 48 h, the cell apoptosis rate of the cells after irradiation was lower than that of the DMSO group (P<0.05). Compared with the DMSO control group, the colony formation ability of the GUDCA experimental group was stronger than that of the DMSO group after irradiation at 0, 2, 4, and 6 Gy (P<0.05). D0, or the mean lethal dose, of the GUDCA group was 6.374, while that of the DMSO group was 4.572. Compared with the DMSO control group, the D0 value of the GUDCA treatment group increased, and the sensitization enhancement ratio (SER) was 0.717. After exposing the abdomen of rats to irradiation, the intestinal bile acid metabolism of the rats will change significantly, and GUDCA can produce radioprotective effects on intestinal cells to a certain extent.

Radiation protection of sodium alginate and its regulatory effect on intestinal microflora in mice

Prolonged or high-dose exposure to ionizing radiation (IR) can cause damage to normal tissues of the body. Therefore, it is imperative to find effective radiation protective agents to mitigate IR-induced damage. This study evaluated the effects of sodium alginate (SA) on the radiation protection and modulatory effects of gut microorganisms using a 60Coγ-induced damage model in mice. Results showed that SA could reduce the damage of hematopoietic system; and alleviate the oxidative damage in irradiated mice by inhibiting the content of malondialdehyde (MDA) and increasing the activities of superoxide dismutase (SOD) and glutathione (GSH) in serum, spleen, jejunum and liver. Moreover, SA treatment ameliorated IR-induced small intestine lesions and alleviated liver injury. This was consistent with decreased levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and tumor necrosis factor-α (TNF-α), and increased levels of interferon-γ (IFN-γ) and interleukin-2 (IL-2) after SA treatment. Furthermore, SA treatment reversed IR-induced gut dysbiosis, elevated the Firmicutes/Bacteroidetes ratio, increased the beneficial bacteria and reduced the pathogenic bacteria in the small intestine. In conclusion, the present study demonstrated that SA exerted good radioprotective effect by improving hematopoietic system, alleviating oxidative stress, attenuating liver injury and inflammatory response, and modulating the intestinal microbiota in irradiated mice.

Protective effect of propolis in protecting against radiation-induced oxidative stress in the liver as a distant organ

Stresses caused by ionizing radiation can also damage tissues and organs through the circulatory system. In this study, we aimed to determine the radioprotective effect of propolis, a natural and powerful antioxidant product, against oxidative liver damage caused by cranial irradiation. Thirty-two male albino Sprague–Dawley rats, divided into four groups, were designed as sham group, irradiation (IR) group, propolis plus IR, control group of propolis. Biochemical parameters were measured in liver tissue of rats. While Total enzymatic superoxide scavenging activity (TSSA) and non-enzymatic superoxide scavenging activity (NSSA), glutathione peroxidase (GSH-Px) activities of all groups were statistically significantly higher than rats receiving only-irradiation, Glutathione-S-transferase (GST) activity in the IR group was significantly lower than in the sham control group and IR + propolis group. Superoxide dismutase (SOD) activity in the IR group was found to be significantly higher than both the sham control group and the propolis control group, but lower than the IR + propolis group. Malondialdehyde level and xanthine oxidase activity were higher in the IR group than in the other groups. Compared to the sham control group, in the group treated with propolis, a significant elevation in antioxidant parameters, specifically TSSA, NSSA, SOD, and GST activities, was noted, with corresponding increases of 32.3%, 23.2%, 47.6%, and 22.6%, respectively. Our findings show that propolis can be a radioprotective agent against ionized radiation damage by increasing antioxidant activity and reducing oxidant stress in liver tissue.

Experimental study of radioprotective properties of lithium pyruvate in vitro

Radiotoxicity is a serious problem for patients undergoing radiotherapy, so the search for new radioprotective drugs to mitigate its effects is highly relevant. Radioprotectors should have a number of properties, including direct antioxidant action, reduction of oxidative stress, ability to induce DNA repair or inhibit apoptosis, and at the same time not cause their own side effects. Antioxidants based on lithium salts look promising in terms of their properties. The aim of study was to study the radioprotective properties of lithium pyruvate in vitro. Material and Methods. Relatively radiosensitive blood mononuclear cells and relatively radioresistant fibroblasts of 3T3L1 line were used as biomodels for x-ray exposure. Cells were incubated and irradiated in 96-well plates. Lithium pyruvate was used at a final concentration of 1.2 mM. Cells were irradiated at a dose rate of 15 mGy/s in the absorbed-dose range from 0 to 5 Gy using an x-ray unit (anode voltage: 160 kV, average current: 3.5 mA). Cell viability was assessed by MTT test and resazurin test. The evaluation of cell death variants and the level of oxidative stress were determined by cytofluorimetric method. Results. The cytoprotective effect of lithium pyruvate was established. Cytoprotection was manifested in the increased cell survival and decreased oxidative stress level under lithium pyruvate after x-ray in a wide range of absorbed doses. Relatively high efficiency was shown in relation to blood mononuclear cells with an increase in the viable fraction by 5–7 % and a decrease in oxidative stress level during irradiation in the range of 1.0–3.0 Gy. Apoptosis was found to be the main mechanism of cell death after irradiation. Lithium pyruvate reduced the level of apoptosis in cell population under irradiation and chemically induced oxidative stress. Conclusion. Radioprotective effect of lithium pyruvate under x-ray irradiation in vitro has been shown. Reduction of oxidative stress under the action of pyruvate provides a pathogenetic basis for the potential use of this compound as a radioprotector, which requires further studies on in vivo models.

Melanins: functional properties and application possibilities in medical practice

Introduction. The article provides information on the functional properties of various melanins and their biosynthesis, as well as natural sources of their production, the use of medicines and dietary supplements containing melanin in medical practice. To do this, a systematic search was conducted in the databases: CyberLeninka, eLibrary, PubMed, SAGE Premier, Springer, Wiley Journals, over the past 10 years (2013–2023). As a result of the review, it was revealed that melanins are widespread in living organisms and are an important natural biomaterial. Melanins of microbial, fungal, animal and plant origin are known, they are divided into five types, of which the most studied are eumelanin, pheomelanin and neuromelanin. A number of studies are presented that prove that melanins are characterized by a wide range of biological activity. They have photoprotective, radioprotective, antimutagenic, immunomodulatory stress-protective, geroprotective, antioxidant, detoxification and anti-inflammatory effects. Information is provided on the possible use of melanin in the complex therapy of melanoma, Parkinson's disease and neurodegenerative diseases, to protect the skin and eyes from radiation damage, correct stress conditions and prevent infectious diseases during the epidemic season. It has been shown that melanin chaga is widely used in domestic medicine in the form of medicines (Befungin) and dietary supplements. An important difference between them is the concentration of melanin, the method of its isolation and purification, as well as the manufacturing technology, which is demonstrated in the article. A biologically active additive with an additional source of β-glucans and polyphenols Amelan is considered, the main active component of which is melanin of fungal origin obtained by a method that increases the yield of melanin and improves its quality by increasing the concentration of its paramagnetic centers compared with melanin obtained without the specified pretreatment of fruit bodies. Conclusion. The information presented in the article on melanins and their functional properties indicates the prospects of using melanins as a source for the production of medicines and biologically active additives.

Radiation-induced Testicular Damage in Mice: Protective Effects of Apigenin Revealed by Histopathological Evaluation.

Radiation exposure poses a significant threat to reproductive health, particularly the male reproductive system. The testes, being highly sensitive to radiation, are susceptible to damage that can impair fertility and overall reproductive function. The study aims to investigate the radioprotective effects of apigenin on the testis through histopathological evaluation. This research involved utilizing a total of 40 mice, which were randomly divided into eight groups of five mice each. The groups were categorized as follows: A) negative control group, B, C, and D) administration of apigenin at three different doses (0.3 mg/kg, 0.6 mg/kg, and 1.2 mg/kg) respectively, E) irradiation group, and F, H, and I) administration of apigenin at three different doses (0.3 mg/kg, 0.6 mg/kg, and 1.2 mg/kg) in combination with irradiation. The irradiation procedure involved exposing the mice to a 2Gy X-ray throughout their entire bodies. Subsequently, histopathological assessments were conducted seven days after the irradiation process. The findings indicated that radiation exposure significantly impacted the spermatogenesis system. This research provides evidence that administering apigenin to mice before ionizing radiation effectively mitigated the harmful effects on the testes. Apigenin demonstrated radioprotective properties, positively influencing various parameters, including the spermatogenesis process and the presence of inflammatory cells within the tubular spaces. Apigenin can provide effective protection for spermatogenesis, minimize the adverse effects of ionizing radiation, and safeguard normal tissues.

The Radioprotective Effect of LBP on Neurogenesis and Cognition after Acute Radiation Exposure.

Radiation exposure has been linked to the development of brain damage and cognitive impairment, but the protective effect and mechanism of Lycium barbarum pills (LBP) on radiation-induced neurological damage remains to be clarified. Behavioral tests and immunohistochemical studies were conducted to evaluate the protective effects of LBP extract (10 g/kg orally daily for 4 weeks) against radiation-induced damage on neurogenesis and cognitive function in Balb/c mice exposed to 5.5 Gy X-ray acute radiation. The results showed that the LBP extract significantly improved body weight loss, locomotor activity and spatial learning and memory. Immunohistochemical tests revealed that the LBP extract prevented the loss of proliferating cells, newly generated neurons and interneurons, especially in the subgranular area of the dentate gyrus. The findings suggest that LBP is a potential neuroprotective drug for mitigating radiation-induced neuropsychological disorders.

Piceatannol reduces radiation-induced DNA double-strand breaks by suppressing superoxide production and enhancing ATM-dependent repair efficiency

In contemporary society, humans are susceptible to various radiation-borne hazards, including exposure to therapeutic modalities using low-linear energy transfer (low-LET) radiations (X-rays and γ-rays), natural high-LET radiation sourced from cosmic rays, as well as nuclear accidents such as the Fukushima Daiichi Nuclear Power Plant incident. Therefore, this threat incites an imminent necessity to develop novel radioprotective agents against a wide range of LET radiation and elucidate the underlying molecular mechanisms. This study aimed at assessing the radioprotectivity of Piceatannol (PIC), a potent antioxidant polyphenol present in abundance in passion fruit, by investigating its effects on radiation-induced reactive oxygen species (ROS) production and the consequent DNA double-strand break (DSB) capacity and cellular senescence. Specifically, total ROS was evaluated by DCFDA staining, mitochondrial superoxide by MitoSOX staining, DSB by γ-H2AX immunostaining, and cellular senescence by Senescence-associated-β-galactosidase staining.The results demonstrated that PIC administration prior to exposure to both X-ray and high-LET radiation impeded radiation-induced DSB by suppressing ROS production. Interestingly, post-irradiation PIC treatment did not alter ROS levels but enhanced the efficiency of Ataxia Telangiectasia Mutated (ATM)-mediated DSB repair. Additionally, post-irradiation PIC treatment diminished senescence-associated beta-galactosidase levels, indicating that it hinders cellular senescence.Conclusively, PIC exerts radioprotective effects against a wide range of LET radiation. The study findings validate the potential application of PIC not only as a radical scavenger but also as a novel DSB repair-activating radioprotective agent.

Radioprotective Effects of Annona Muricata Leaf Extract in the Spinal Cord

Objective: The spinal cord is often involved in radiotherapy to treat malignancies and is considered as one of the most critical dose-limiting organs. Histopathological changes of radiation-induced spinal cord injury include gliosis, demyelination, and necrosis in the white matter, as well as vascular changes in both white and gray matter. All aerial parts of Annona muricata (AM) are used in traditional medicine practices, and previous studies revealed that AM leaf extract has radioprotective effect against gamma- irradiation. This study aimed to evaluate the possible protective effect of AM leaf extract against ionizing radiation spinal cord injury. Methods: A total of 37 adult female Wistar Albino rats were divided into 4 groups (1 control and 3 intervention groups): Group 1 (control) received 0.01 mL/kg of distilled water by oral gavage once a day for 7 days, group 2 (AM group) received 300 mg/kg of AM leaf extract by oral gavage once a day for 7 days, group 3 (IR group) received a single dose of spinal cord radiation (20 Gy) after a 7-day treatment with 0.01 mL/kg of physiologic serum (saline), and group 4 (AM + IR group) received 300 mg/kg of AM leaf extract by oral gavage once a day for 7 days, with spinal cord radiation (20 Gy) applied 1 hour after the last gavage. After the sacrificing, spinal cords were dissected out, embedded in paraffin, and stained with Hematoxylin-Eosin, and 11 parameters were microscopically examined and scored. Results: AM administration prior to irradiation (IR) lowered the histopathological scores for all parameters that were verified in the IR group at most severe levels: inflammatory cells infiltration, edema, neuron swelling, gliocytes hyperplasia, spinal cord cavitation (loosened tissue structure), pyknotic nuclei, vacuolar denaturation, and loss of Nissls substance. Necrosis was present in IR group and was higher compared to Control and AM treated groups. We noticed that necrosis was present in the AM group too and was higher compared to the control. Conclusion: The data of our study suggest that pretreatment with 300 mg/kg of AM leaf extract prior to IR reduce inflammatory cells infiltration, edema, and neuron swelling. This supports the fact that AM-proposed anti-inflammatory property may contribute to neuroprotection. Similarly, AM was documented to have efficient protection on neural cells from apoptosis or necrosis.