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.

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.

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.

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.

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.

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.

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.

Avaliação do Conhecimento dos usuários da Faculdade de odontologia da UFJF quanto às medidas de radioproteção / The knowledge's evaluation of UFJF dentistry school's users in terms of radioprotection measures

Proposição: Avaliar o conhecimento dos usuários da Faculdade de Odontologia da UFJF em relação às medidas de radioproteção que devem ser adotadas durante a obtenção de radiografias. Métodos: Cem pacientes responderam a um questionário sobre a experiência como usuários de serviços de Radiologia bem como sobre o conhecimento em relação às medidas de radioproteção. Resultados: Oitenta e cinco por cento dos participantes já realizaram radiografias odontológicas, sendo que para 61,2%, sempre foi oferecido avental de chumbo. Por outro lado, em relação ao protetor de tireoide, em apenas 24,7% dos participantes este aparato foi utilizado rotineiramente. Durante a realização de radiografias intrabucais, 43,5% relataram que foram utilizados posicionadores para manutenção do filme na cavidade bucal. Sete participantes já haviam permanecido como acompanhantes, e apenas um afirmou sempre ter utilizado avental de chumbo durante essa função. Mais de 39% das participantes nunca havia sido questionada sobre a possibilidade de estar grávida. Do total de pacientes entrevistados, 53% consideram a radiação X perigosa, e 49% acham que, durante a exposição, correm algum risco. Conclusão: Apesar de ainda haver negligência em relação aos procedimentos de radioproteção durante a obtenção de radiografias odontológicas, a maioria dos pacientes reconhece os perigos associados à utilização da radiação X.

Purpose: To evaluate the users' knowledge of UFJF School of Odontology in terms of radiation protection measures to be adopted while taking X-rays. Methods: One hundred patients answered a questionnaire about their experience as users of Radiology services, as well as on knowledge about radiation protection measures. Results: Eighty-five percent of the participants had taken dental X-rays and a lead apron was offered to 61.2%. In relation to the thyroid shield, in only 24.7% of cases was this apparatus used routinely. For intraoral radiographs, 43.5% reported that positioners were used to keep the film in the oral cavity. Seven participants had already remained as companions, and only one said to have always used a lead apron for this function. More than 39% of the female participants had never been questioned about the possibility of being pregnant. Of the participants interviewed, 53% considered X-rays dangerous and 49% believed that exposure incurred some risk. Conclusion: Although there is still neglect of radiation protection procedures while obtaining dental radiographs, most patients recognize the dangers associated with the use of X-rays.

Effect of sodium selenite on bone repair in tibiae of irradiated rats

This study evaluated the radioprotective effect of sodium selenite on the bone repair process in tibiae of female rats. For such purpose, 100 female Wistar rats (Rattus norvegicus, albinus) were randomly assigned to 4 groups (n=25), according to the treatment received: administration of distilled water (control); administration of sodium selenite; gamma radiation; and administration of sodium selenite plus gamma radiation. A bone defect was prepared on both tibiae of all animals. Three days after surgery, the gamma radiation and selenium/gamma radiation groups received 8 Gy gamma rays on the lower limbs. Five animals per group were sacrificed 7, 14, 21, 28 days after surgery for evaluation of the repair process by bone volumetric density analysis. The 5 animals remaining in each group were sacrificed 45 days postoperatively for examination of the mature bone by scanning electron microscopy. Based on all analyzed parameters, the results of the present study suggest that sodium selenite exerted a radioprotective effect in the bone repair of tibia of irradiated rats.

Este estudo avaliou o efeito radioprotetor de selenito de sódio no processo de reparação óssea em tíbias de ratas. Para isto, 100 ratas Wistar (Rattus norvegicus, albinus) foram aleatoriamente divididas em 4 grupos (n=25), de acordo com o tratamento recebido: administração de água destilada (controle); administração de selenito de sódio; irradiação gama; e administração de selenito de sódio mais irradiação gama. Um defeito ósseo foi realizado em ambas as tíbias de todos os animais. Três dias após a cirurgia, apenas os animais dos grupos irradiado e selênio/irradiado receberam 8 Gy de radiação gama na região dos membros inferiores. Cinco animais por grupo foram sacrificados 7, 14, 21 e 28 dias após a cirurgia para avaliação do processo de reparo ósseo pela análise da densidade óssea volumétrica. Os cinco animais remanescentes em cada grupo foram sacrificados aos 45 dias do pós-operatório para avaliação da maturação óssea por meio da microscopia eletrônica de varredura. Baseado em todos os parâmetros analisados, os resultados do presente estudo sugerem que o selenito de sódio exerceu efeito radioprotetor no reparo ósseo de tíbias de ratas irradiados.

Clinical study on the effect of Yangyinjiandu decoction on acute raditation esophagitis / 中华放射肿瘤学杂志

Objective To investigate the effect of Yangyinjiandu decoction for acute radiation esophagitis.Methods Lung cancer and mediastinal tumor treated by radiotherapy(portals including oesophagus to a radical tumoricidal dose≥40Gy, with≥10cm oesophagus include in radiotherapy).Patients were randomly divided according to the time of acceptance into the treatment group and the control group.All parameters of the two groups were basically similar and comparable.The treatment group was given Yangyinjiandu decoction(one dose daily,water decoction,200ml,twice a day) taken in the morning and in the evening before the end of radiotherapy.The control group was given oral vitamin C tablet 100mg once a day before the end of radiotherapy.Five days after radiotherapy,the control group took oral prednisone 5mg three times a day and amoxicillin 5g three times a day.All the above medicines were continued for 7 days.Results The commencement of complication was 14.86?0.34 days in the treatment group and 13.55?0.26 days in the control group(P

Protective effect of anisodaminum on light-induced rat retinopathy/ / 眼科

Acute intermittent visible fluorescent light was used as an experimental light source (18175?300lux, 1 hour dark: 1 hour light, 3 cycles). After light exposure, the myeloperoxidase activity (MDA) levels increased in rat retina, and the retinal structure and blood-retinal barrier were damaged. When 2 doses of anisodaminum (10 mg/Kg) were given 12 hours and just before light exposure, MDA levels lowered and the retinal structure was protected.

The protective effect of Tanshinone ⅡA in radiation-induced pulmonary fibrosis / 中华放射肿瘤学杂志

Objective To investigate the protective effect and it's possible mechanism of Tanshinone ⅡA in radiation-induced pulmonary fibrosis.Methods Having the right hemithorax of female Wistar rats irradiated(30?Gy) in 10 fractions within 14 days by 6 ?MV photons,the radiation-induced pulmonary fibrosis animal model was established.In the treatment group,sodium Tanshinone ⅡA sulfonate(15?mg/kg) was given by intraperitoneal injection 1 hour before each fraction of irradiation.Five months after irradiation,the difference of the histopathological changes,the hydroxyproline content and expression of TGF-?1 between the radiation alone group,tanshinone plus radiation and control group were analyzed by HE stain,Massion stain,immunohistochemical methor and reverse transcriptase polymerase chain reaction(RT-PCR) method.Results The histopathological comparison revealed the protective effect of Tanshinone ⅡA.The content of hydroxyproline was(21.99?3.96),((38.25?)(7.18)),(28.94?4.29)??g/g in the control group,radiation alone group and radiation plus Tanshinone ⅡA.The expression of TGF-?1(mRNA and protein) was reduced by Tanshinone ⅡA.Pathological changes of the pulmonary fibrosis was reduced by Tanshinone ⅡA yet.Conclusions Our study shows that Tanshinone ⅡA can inhibit radiation-induced pulmonary fibrosis,and the possible mechanism of its may be made possible through down-regulating the expression of TGF-?1 in the irritated lung tissue.