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

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: Apigenin can provide effective protection for spermatogenesis, minimize the adverse effects of ionizing radiation, and safeguard normal tissues.

[Research progress of irradiation injuries anti-agents].

Irradiation injuries anti-agents refer to drugs that can inhibit the initial stage of radiation injuries, or reduce the development of radiation injuries and promote the recovery of injuries when used early after irradiation exposure. According to the mechanism of action and the time of intervention, the irradiation injuries anti-agents are divided into four categories: radioprotectors, radiomitigators, radiation therapeutics for external radiation exposure, and anti-agents for internalized radionuclides. In this paper, the research progress of irradiation injuries anti-agents in recent years is reviewed.

Radioprotective effect of Malva sylvestris L. against radiation-induced liver, kidney and intestine damages in rat: A histopathological study.

Background: Ionizing radiation (IR) is widely used in the treatment of cancer in radiotherapy. One of the main concerns of patients with gastrointestinal cancers undergoing radiotherapy is the harmful side effects of IR on normal tissues. The liver, kidney, and duodenum are usually exposed to high doses of radiation in the treatment of some cancers in abdominal region radiotherapy. We aimed to assess the radioprotective effects of Malva sylvestris L. against IR damages to the abdominal region. Materials and methods: This current study was conducted on 45 rats divided randomly into nine groups of five: A) negative control group, B) sham group, C) irradiation group, D) mallow treatment-1(200gr/kg), E) mallow treatment-2(400gr/kg), F) mallow treatment-3(600gr/kg), G) mallow treatment-4(200gr/kg) plus irradiation, H) mallow treatment-5(400gr/kg) plus irradiation, I) mallow treatment-6(600gr/kg) plus irradiation. Irradiation was performed with a 6Gy x-ray. Histopathological evaluations were performed 10 days after irradiation. Results: The histopathological examination results confirmed that preventive therapy with the effective dose of mallow reduced the liver, kidney, and intestine damage induced by radiation. The dose of 400 mg/kg was more effective than other selected dose in improving the damage caused by irradiation in the studied tissues. Conclusion: This study concludes that Malva sylvestris L. contributed to significant improvements in radiation-induced histological parameters of the liver and kidney and, to a lesser extent, in the intestine. These results collectively indicate that mallow is an effective radioprotective agent.

Research progress of irradiation injuries anti-agents / 中华劳动卫生职业病杂志

Irradiation injuries anti-agents refer to drugs that can inhibit the initial stage of radiation injuries, or reduce the development of radiation injuries and promote the recovery of injuries when used early after irradiation exposure. According to the mechanism of action and the time of intervention, the irradiation injuries anti-agents are divided into four categories: radioprotectors, radiomitigators, radiation therapeutics for external radiation exposure, and anti-agents for internalized radionuclides. In this paper, the research progress of irradiation injuries anti-agents in recent years is reviewed.

Modern Dressings in Prevention and Therapy of Acute and Chronic Radiation Dermatitis-A Literature Review.

Radiotherapy is an integral part of modern oncology, applied to more than half of all patients diagnosed with cancer. It can be used alone or in combination with surgery or chemotherapy. However, despite the high precision of radiation delivery, irradiation may affect surrounding healthy tissues leading to the development of toxicity. The most common and clinically significant toxicity of radiotherapy is acute and chronic radiation dermatitis, which could result in desquamation, wounds, nonhealing ulcers, and radionecrosis. Moreover, preoperative radiotherapy impairs wound healing after surgery and may lead to severe wound complications. In this review, we comprehensively discuss available types of dressings used in the management of acute and chronic radiation dermatitis and address their efficacy. The most effective ways of preventing acute radiation dermatitis are film dressings, whereas foam dressings were found effective in its treatment. Data regarding dressings in chronic radiation dermatitis are scarce. This manuscript also contains authors' consensus.

Does the administration of meloxicam before head and neck radiotherapy reduce the risk of mandibular osteoradionecrosis? An animal model study.

OBJECTIVE: To assess whether the administration of meloxicam before head and neck radiotherapy reduces the risk of mandibular osteoradionecrosis in rats. MATERIAL AND METHODS: Sixty male Wistar rats were randomly divided into 6 groups (n = 10) according to the meloxicam administration and radiation therapy: control (C), irradiated (I), single dose of meloxicam (M1), single dose of meloxicam and irradiated (M1I), triple dose of meloxicam (M3), triple dose of meloxicam and irradiated (M3I). Meloxicam was administrated (20 mg/kg per dose) 1 h before the radiation therapy (single dose of 20 Gy) and 24 h and 48 h after the radiation therapy for groups with two additional doses. Ten days after the radiation therapy, the three right mandibular molars were extracted from all rats, who were euthanatized after 21 or 35 days (n = 5 per group). The mandibles were assessed by macroscopic evaluation and micro-CT analysis. RESULTS: The right hemimandibles of the irradiated groups revealed macroscopic signs of osteoradionecrosis, and those of the non-irradiated groups revealed complete gingival healing. A significant delay in alveolar socket healing in all irradiated groups was observed in the micro-CT assessment regardless meloxicam treatment. CONCLUSION: The administration of meloxicam before head and neck radiotherapy does not reduce the risk of mandibular osteoradionecrosis when associated to dental extractions. CLINICAL RELEVANCE: Since meloxicam has been shown to be a potential radiation-protective agent, and osteoradionecrosis physiopathology is believed to be related to an inflammatory process, possible interactions are relevant to be investigated.

[Radiation-protective agent and anti-aging agents: random and predictable matches.]

Radiation-protective and anti-aging properties are often combined. Combination of this properties is linked to the common mechanisms of action such as direct and indirect antioxidant activities, inhibition of free radicals formation, increase resistance to stress impacts at the cellular level, acceleration of DNA reparation, prevention of chronic diseases linked to abnormalities in regeneration processes, activation of immune inflammatory processes and carcinogenesis. Regulation of cell cycle and apoptosis can often be considered as an implementing driver of radiation-protective and anti-aging activities. On the one hand, against the background of stopping the cell cycle and blockade of apoptosis increases the time required to repair the defects of a DNA. Antiapoptotic effects enhances survival chances at the early stage after irradiation in a particular range of doses. On the other hand, activation of apoptosis of altered cells can be seen as one of the mechanisms to delay aging processes and prevention of isolated effects of exposure to ionizing radiation. Formation of radiation-induced and age-related alterations are characterized by multiple factors and a variety of manifestations. Nevertheless, similarity of individual links of the pathogenesis of disease related to radiation exposure and aging of the body is striking. It could be stated that radiation-protective property defines an increase in life expectancy by short-term exposure in sub-lethal and lethal doses. However anti-aging activities prevent the development of remote effects of ionizing radiation by prolonged low doses or fractionated exposure to radiation.

Substituted Piperazines as Novel Potential Radioprotective Agents.

The increasing risk of radiation exposure underlines the need for novel radioprotective agents. Hence, a series of novel 1-(2-hydroxyethyl)piperazine derivatives were designed and synthesized. Some of the compounds protected human cells against radiation-induced apoptosis and exhibited low cytotoxicity. Compared to the previous series of piperazine derivatives, compound 8 exhibited a radioprotective effect on cell survival in vitro and low toxicity in vivo. It also enhanced the survival of mice 30 days after whole-body irradiation (although this increase was not statistically significant). Taken together, our in vitro and in vivo data indicate that some of our compounds are valuable for further research as potential radioprotectors.

Radioprotective effect of sodium selenite on mandible of irradiated rats

Abstract The purpose of this study was to test the radioprotective effect of selenium in the bone microarchitecture of irradiated rats mandibles. Forty rats were separated into 4 groups with 10 animals: control group (CG), irradiated group (IG), sodium selenite group (SSG) and sodium selenite irradiated group (SSIG). A single dose of 0.8 mg/kg sodium selenite was administered intraperitoneally in the SSG and SSIG groups. One hour later, animals of IG and SSIG groups were irradiated with 15 Gy of x-rays. Forty days after radiation a bilateral extraction of the mandibular first molars was performed. After the extraction procedure, five rats were killed after fifteen days and others five after thirty days. Micro- computed tomography was used to evaluate cortical and trabecular bone of each rat. The mean and standard deviation of each bone microarchitecture parameter were analyzed using the statistical test of two-way Analysis of Variance (ANOVA). At 15 days, the bone volume presented higher values in the CG and SSG groups (p=0.001). The same groups presented statistically significant higher values when bone volume fraction (p<0.001) and trabecular thickness (p<0.001) were analyzed. At 30 days, it was observed that in relation to the bone volume fraction, SSG group presented the highest value while SSIG group had the lowest value, with statistically significant difference (p=0.016). Sodium selenite demonstrated a median radioprotective effect in the bone microarchitecture of irradiated mandibles, which indicates the substance may be a potential radioprotective agent against chronic effects of high doses of ionizing radiation.

Resumo O propósito deste estudo foi testar o efeito radioprotetor do selênio na microarquitetura óssea de mandíbulas de ratos irradiados. Quarenta ratos foram separados em 4 grupos com 10 animais: grupo controle (GC), grupo irradiado (GI), grupo selenito de sódio (SSG) e grupo selenito de sódio irradiado (SSIG). Uma dose única de 0,8 mg/kg de selenito de sódio foi administrada intraperitonealmente nos grupos SSG e SSIG. Uma hora depois, os animais dos grupos IG e SSIG foram irradiados com 15 Gy de raios-x. Quarenta dias após a irradiação foi realizada extração bilateral dos primeiros molares inferiores. Após o procedimento de extração, cinco ratos foram mortos após quinze dias e outros cinco após trinta dias. A microtomografia computadorizada foi utilizada para avaliar o osso cortical e trabecular de cada rato. A média e o desvio padrão de cada parâmetro da microarquitetura óssea foi analisada pelo teste estatístico de Análise de Variância dois fatores (ANOVA), seguido por comparações post hoc com o teste de Tukey. Após 15 dias, o volume ósseo apresentou valores mais elevados nos grupos GC e GNS (p=0,001). Os mesmos grupos apresentaram valores estatisticamente significantes maiores quando se analisou fração de volume ósseo (p<0,001) e espessura trabecular (p<0,001). Após 30 dias, observou-se que, em relação à fração de volume ósseo, o grupo SSG apresentou o maior valor enquanto o grupo SSIG apresentou o menor valor, com diferença estatisticamente significante (p=0,016). O selenito de sódio demonstrou um efeito radioprotetor mediano na microarquitetura óssea das mandíbulas irradiadas, o que indica que a substância pode ser um potencial agente radioprotetor contra os efeitos crônicos da radioterapia.

Meloxicam as a Radiation-Protective Agent on Mandibles of Irradiated Rats

Abstract This study evaluated the action of ionizing radiation and the possible radioprotective effect of the non-steroidal anti-inflammatory drug meloxicam on the bone physiology of rat mandibles by assessing the alveolar socket healing and bone strength. Forty male Wistar rats were divided in 4 groups (n=10): control (CG), irradiated (IG), meloxicam (MG), meloxicam irradiated (MIG). A dose of 0.2 mg/kg meloxicam was administered to MG and MIG. After this, IG and MIG were irradiated with 15 Gy radiation dose in the mandible. Forty days after the above procedures, the mandibular first molars were extracted and the animals were killed after 15 or 30 days (n=5). Micro-computed tomography and bending test were used to evaluate alveolar socket healing and bone strength, respectively. At 15 days, bone volume, bone volume fraction and trabecular thickness were higher in the CG and MG than in the IG and MIG; and trabecular separation was higher in the IG compared with the others. At 30 days, there was a difference only in trabecular separation, which was higher in IG than in CG and MG, and MIG did not differ from the others. Bone strength was lower in IG compared with CG and MG, and MIG did not differ from the others. In conclusion, the ionizing radiation affected the bone physiology of rat mandibles, delaying the alveolar socket healing and reducing the bone strength. Moreover, the meloxicam had a positive effect on the trabecular separation in alveolar socket healing and on the bone strength.

Resumo Este estudo avaliou a ação da radiação ionizante e o possível efeito radioprotetor do anti-inflamatório não esteroide meloxicam na fisiologia óssea de mandíbulas de rato por meio da análise da reparação alveolar e da resistência óssea. Quarenta ratos Wistar machos foram divididos em 4 grupos (n=10): controle (GC), irradiado (GI), meloxicam (GM), meloxicam irradiado (GMI). Administrou-se uma dose única de 0,2 mg/kg de meloxicam no GM e GMI. Posteriormente, o GI e GMI foram irradiados com dose de 15 Gy na região de mandíbula. Decorridos 40 dias dos procedimentos acima, extraiu-se os primeiros molares inferiores dos animais, que foram mortos após 15 e 30 dias (n=5). Utilizou-se a microtomografia computadorizada e o teste de flexão para avaliação da reparação alveolar e da resistência óssea, respectivamente. Aos 15 dias, o volume ósseo, a fração de volume ósseo e a espessura trabecular foram maiores no GC e GM comparados ao GI e GMI; já a separação trabecular foi maior no GI em relação aos demais. Aos 30 dias, houve diferença apenas na separação trabecular, que foi maior no GI em comparação ao GC e GM, não tendo o GMI diferido dos demais. A resistência óssea no GI foi menor em relação ao GC e GM, não tendo o GMI diferido dos demais. Concluiu-se que a radiação ionizante afetou a fisiologia óssea das mandíbulas de rato, promovendo atraso na reparação alveolar e redução da resistência óssea; além disso, o meloxicam, apresentou efeito positivo na separação trabecular da reparação alveolar e na resistência óssea.

Short- and long-term effects of zinc treatment on lacrimal gland histopathology and tear functions tests in radioiodine-administered rats / Efeitos de curto e longo prazo do tratamento com zinco na histopatologia da glândula lacrimal e funções lacrimais em ratos que receberam iodo radioativo

ABSTRACT Purpose: To investigate the short-term (1 week) and long-term (8 weeks) protective effects of zinc administration on radioiodine (RAI)-induced lacrimal gland damage of rats. Methods: A total of 40 rats were divided into two groups: an RAI group (n=20), which was administrated a single dose of 3 mCi of 131I and 1 mL physiologic saline for 7 days by gastric gavage, and a zinc group (n=20), which received a single dose of 3 mCi of 131I and 1 mL of physiologic saline containing zinc sulfate at a concentration of 10 mg/kg concentration for 7 days by gastric gavage. All rats underwent tear function tests before and 1 week after RAI administration. About 1 week after irradiation, half of the animals in each group were sacrificed and the extraorbital lacrimal glands were removed for histopathological examination. The remaining animals of the groups underwent the same procedures at 8 weeks after irradiation. Results: In the RAI and zinc groups, the mean tear production was 3.75 ± 1.55 and 3.65 ± 1.53 mm at baseline, 2.10 ± 1.07 and 3.30 ± 1.34 mm at week 1 (p=0.004), and 3.22 ± 1.48 and 3.50 ± 1.78 mm at week 8, respectively; further, the mean corneal fluorescein staining scores were 4.65 ± 2.16 and 4.80 ± 2.21 points at baseline, 7.85 ± 1.90 and 5.45 ± 2.06 points at week 1 (p=0.001), and 5.44 ± 2.13 and 4.90 ± 2.08 at week 8, respectively. The histopathological changes in rat lacrimal glands at weeks 1 and 8 were consistent with the tear function test results. Conclusions: Zinc treatment seems to be protective against RAI-induced lacrimal gland damage of rats, particularly in the acute period.

RESUMO Objetivo: Investigar se o tratamento com zinco tem efeito protetor, no curto prazo (1 semana) e longo prazo (8 semanas), sobre os danos induzidos na glândula lacrimal por iodo radiotativo (RAI) em ratos. Métodos: Quarenta ratos foram divididos em dois grupos. No grupo RAI (n=20) foi administrada uma única dose de 3 mCi 131I e 1 cc de solução salina fisiológica durante 7 dias, por gavagem gástrica. O grupo zinco (n=20) recebeu uma dose única de 3 mCi 131I e 1 cc de solução salina fisiológica contendo sulfato de zinco na concentração de 10 mg/kg durante 7 dias por gavagem gástrica. Os testes de função lacrimal foram realizadas para todos os animais antes e após uma semana da administração da RAI. Em seguida, após 1 semana da administração, metade dos animais de cada grupo foi sacrificada e as glândulas lacrimais extraorbitais foram removidas para exame histopatológico. Os animais remanescentes dos grupos foram submetidos aos mesmos procedimentos após 8 semanas a radiação. Resultados: As médias de produção lacrimal foram de 3,75 ± 1,55 e 3,65 ± 1,53 mm na linha de base, 2,10 ± 1,07 e 3,30 ± 1,34 mm na 1a semana (p=0,004), e 3,22 ± 1,48 e 3,50 ± 1,78 mm na 8a semana, para os grupos RAI e zinco, respectivamente. As pontuações médias de coloração fluoresceína foram 4,65 ± 2,16 e 4,80 ± 2,21 no início do estudo, 7,85 ± 1,90 e 5,45 ± 2,06 na primeira semana (p=0,001), 5,44 ± 2,13 e 4,90 ± 2,08 pontos na 8a semana, para os grupos RAI e zinco, respectivamente. As alterações histopatológicas das glândulas lacrimais em 1 e 8 semanas foram consistentes com os testes de função lacrimal resultados. Conclusões: O tratamento de zinco parece ser protetor sobre os danos glândula lacrimal induzidos por RAI em ratos, especialmente no período agudo.

L-carnitine has a protective effect on the colonic mucosa during abdominopelvic radiotherapy in rats

ABSTRACT PURPOSE: To evaluate histopathologically the radioprotective effect of L-carnitine on the colonic mucosa in rats undergoing abdominopelvic irradiation. METHODS: Thirty-two rats were randomly assigned to four experimental groups: intraperitoneal administration of normal saline (group 1) or L-carnitine (300 mL/kg; group 2), followed in groups 3 and 4, respectively, by one dose of abdominopelvic radiation (20 Gy) 30 min later. Rats were sacrificed 5 days after radiation, and their descending colons were resected for histopathological evaluation of the presence and severity of damage. RESULTS: Average damage scores did not differ significantly between groups 1 and 2 (0.13 ± 0.35 and 0.25 ± 0.46, respectively); the group 3 score was highest (10.25 ± 0.71), and the group 4 score (3.63 ± 1.41) was significantly lower than that of group 3 (both p = 0.0001). Pre-radiation L-carnitine administration significantly reduced mucosal thinning, crypt distortion, reactive atypia, inflammation, cryptitis, and reactive lymph-node hyperplasia (all p < 0.01). CONCLUSIONS: L-carnitine had a radioprotective effect on rat colonic mucosa. L-carnitine use should be explored for patients with gastrointestinal cancer, who have reduced serum L-carnitine levels.

Effects of Arbutin on Radiation-Induced Micronuclei in Mice Bone Marrow Cells and Its Definite Dose Reduction Factor.

BACKGROUND: Interactions of free radicals from ionizing radiation with DNA can induce DNA damage and lead to mutagenesis and carsinogenesis. With respect to radiation damage to human, it is important to protect humans from side effects induced by ionizing radiation. In the present study, the effects of arbutin were investigated by using the micronucleus test for anti-clastogenic activity, to calculate the ratio of polychromatic erythrocyte to polychromatic erythrocyte plus normochromatic erythrocyte (PCE/PCE+NCE) in order to show cell proliferation activity. METHODS: Arbutin (50, 100, and 200 mg/kg) was intraperitoneally (ip)administered to NMRI mice two hours before gamma radiation at 2 and 4 gray (Gy). The frequency of micronuclei in 1000 PCEs (MnPCEs) and the ratio of PCE/PCE+NCE were calculated for each sample. Data were statistically evaluated using one-way ANOVA, Tukey HSD test, and t-test. RESULTS: The findings indicated that gamma radiation at 2 and 4 Gy extremely increased the frequencies of MnPCE (P<0.001) while reducing PCE/PCE+NCE (P<0.001) compared to the control group. All three doses of arbutin before irradiation significantly reduced the frequencies of MnPCEs and increased the ratio of PCE/PCE+NCE in mice bone marrow compared to the non-drug-treated irradiated control (P<0.001). All three doses of arbutin had no toxicity effect on bone marrow cells. The calculated dose reduction factor (DRF) showed DRF=1.93 for 2Gy and DRF=2.22 for 4 Gy. CONCLUSION: Our results demonstrated that arbutin gives significant protection to rat bone against the clastogenic and cytotoxic effects of gamma irradiation.

Micro-CT evaluation of the radioprotective effect of resveratrol on the mandibular incisors of irradiated rats

Abstract The purpose of this study was to perform a microcomputed tomographic evaluation of the radioprotective effect of resveratrol on the volume of mandibular incisors of irradiated rats. A second aim was to make a quantitative assessment of the effect of x-ray exposure on these dental tissues. Twenty adult male rats were divided into four groups: control, irradiated control, resveratrol, and irradiated resveratrol. The resveratrol groups received 100 mg/kg of resveratrol, whereas the irradiated groups were exposed to 15 Gy of irradiation. The animals were sacrificed 30 days after the irradiation procedure, and their mandibles were removed and scanned in a microcomputed tomography unit. The images were loaded into Mimics software to allow segmentation of the mandibular incisor and assessment of its volume. The results were compared by One-way ANOVA and Tukey's post hoc test, considering a 5% significance level. The irradiated groups showed significantly diminished volumes of the evaluated teeth, as compared with the control group (p < 0.05). The resveratrol group presented higher values than those of the irradiated groups, and volumes similar to those of the control group. High radiation doses significantly affected tooth formation, resulting in alterations in the dental structure, and thus lower volumes. Moreover, resveratrol showed no effective radioprotective impact on dental tissues. Future studies are needed to evaluate different concentrations of this substance, in an endeavor to verify its potential as a radioprotector for these dental tissues.

Radioprotective effect of mefenamic acid against radiation-induced genotoxicity in human lymphocytes.

PURPOSE: Mefenamic acid (MEF) as a non-steroidal anti-inflammatory drug is used as a medication for relieving of pain and inflammation. Radiation-induced inflammation process is involved in DNA damage and cell death. In this study, the radioprotective effect of MEF was investigated against genotoxicity induced by ionizing radiation in human blood lymphocytes. MATERIALS AND METHODS: Peripheral blood samples were collected from human volunteers and incubated with MEF at different concentrations (5, 10, 50, or 100 µM) for two hours. The whole blood was exposed to ionizing radiation at a dose 1.5 Gy. Lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis blocked binucleated lymphocyte. RESULTS: A significant decreasing in the frequency of micronuclei was observed in human lymphocytes irradiated with MEF as compared to irradiated lymphocytes without MEF. The maximum decreasing in frequency of micronuclei was observed at 100 µM of MEF (38% decrease), providing maximal protection against ionizing radiation. CONCLUSION: The radioprotective effect of MEF is probably related to anti-inflammatory property of MEF on human lymphocytes.

Comparative study of the effects of rhKGF, CBLB502 and WR2721 on radiation-induced oral mucositis / 解放军医学杂志

Objective To compare the protective effect of rhKGF, CBLB502 and WR2721 on radiation-induced oral mucositis (ROM). Methods Fifty male 6-8-week-old C57BL/6J mice were randomly divided into normal group, irradiation control group, rhKGF group, CBLB502 group, and WR2721 group (n=10 each). The 30-day survival rate and change in body weight of mice that had received 17Gy irradiation of head and neck area were recorded. In another group of 20 mice, 1% toluidine blue staining and HE staining were used to observe oral ulcers and pathological changes in the tongue tissue. The proliferation of keratinocyte cells was assessed by Ki-67 immunohistochemistry. Results Compared with the irradiation control group, administration of rhKGF and WR2721 could significantly improve the 30-day survival rate, accelerate the recovery of body weight, and promote the proliferation of keratinized epithelial cells of mice after irradiation, without inducing obvious oral mucositis. However, There was no significant difference between CBLB502 group and irradiation control group in survival rate, body weight and pathological changes in tongue tissues of mice. Conclusion rhKGF and WR2721 could alleviate ROM and improve the survival of mice, while CBLB502 has no such effect.

Radioprotective effects of CBLB502 on γ-radiated rhesus monkey / 解放军医学杂志

Objective A Rhesus monkey model was employed to study the radioprotective effects of a Toll-like receptor 5 agonist, CBLB502, against 7.0Gy whole-body irradiation of 60Co gamma-rays. Methods Thirty animals were assigned to a placebo treatment group, a WR-2721 positive control group, and three CBLB502 treatment groups (n=6 animals/group). Each animal was irradiated with 7.0Gy 60Co γ and given CBLB502 at 2.5, 10 and 40μg/kg, respectively in treatment groups, or WR-2721 at 30mg/kg, or physiological saline 0.3ml/kg for the placebo treatment group. The treatment was given once by intramuscular injection 30 min before irradiation. All irradiated animals received symptomatic treatment based on same guidelines. General observation, peripheral blood tests, hemopoietic progenitor cell colony-counting, and histopathological examination were performed. Results We found that 10 or 40μg/kg CBLB502 treatment resulted in 100% survival, while the survival rate was 33% in placebo treatment group. Hematopoietic recovery in the WR-2721 treatment group was marginally superior to the irradiation control group. Nadirs of peripheral white cell and platelet counts of animals treated with 40μg/kg of CBLB502 were significantly higher than those of the placebo treatment group (P60Co γ-rays would suffer from severe acute radiation sickness of hematopoietic system. CBLB502 at 40μg/kg is radioprotective in this model and a single intramuscular injection of CBLB502 in a dose of 40μg/kg 30min before irradiation gives better radioprotective effects than WR-2721.

Radioprotective effect of mefenamic acid against radiation-induced genotoxicity in human lymphocytes

PURPOSE: Mefenamic acid (MEF) as a non-steroidal anti-inflammatory drug is used as a medication for relieving of pain and inflammation. Radiation-induced inflammation process is involved in DNA damage and cell death. In this study, the radioprotective effect of MEF was investigated against genotoxicity induced by ionizing radiation in human blood lymphocytes. MATERIALS AND METHODS: Peripheral blood samples were collected from human volunteers and incubated with MEF at different concentrations (5, 10, 50, or 100 microM) for two hours. The whole blood was exposed to ionizing radiation at a dose 1.5 Gy. Lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis blocked binucleated lymphocyte. RESULTS: A significant decreasing in the frequency of micronuclei was observed in human lymphocytes irradiated with MEF as compared to irradiated lymphocytes without MEF. The maximum decreasing in frequency of micronuclei was observed at 100 microM of MEF (38% decrease), providing maximal protection against ionizing radiation. CONCLUSION: The radioprotective effect of MEF is probably related to anti-inflammatory property of MEF on human lymphocytes.

Advances in antiradiation drugs / 军事医学

Antiradiation drugs, also known as radioprotective agents, can prevent humans from radiation injury,reduce the clinical symptoms of radiation sickness,promote early recovery and reduce morbidity or mortality.Early developments of such agents focused on thiol synthetic compounds, such as amifostine (WR 2721).This compound reduced mortality, but its disadvantages, such as large use and high toxicity, limited its use in clinical practice.To find a suitable radioprotective agent is crucial to reducing side effects induced by ionizing radiation and increasing survival rate in patients during radiotherapy.In this paper, the classification and mechanism of radioprotective agents are reviewed and future developments in this field are predicted.

Evaluation of ray protective agent prevented radiation dermatitis in head carcinoma patients / 中国基层医药

Objective To evaluate the clinical effects of ray protective agent which prevented radiation dermatitis in head carcinoma patients.Methods 112 patients which prevented radiation dermatitis in head carcinoma patients were divided into the two groups by the single-blind random method.The treated group of 60 patients received the spray of ray protective agent on the radiated skin area 30 min prior and after the radiation exposure with health education,and the control group of 52 patients without any treatment for protection,except health education.The radiation-induced skin damage was observed and the incidence of skin damage was assessed.Results The incidence of 2 and 3 degree skin reaction of the treated group were 15 cases(25.0％) and 4 cases(6.7％),and the incidence of 2 and 3 degree skin reaction of the control group were 21 cases(40.4％) and 28 cases(53.8％),the difference between the two groups had statistical significance(x2 =48.902,24.113,all P ＜ 0.05).Conclusion Ray protective agent is an effective way in reducing the degree of radiation dermatitis,which can relieve pain and improve the quality of life.