RESUMEN
The identification of substances that prevent or minimize the detrimental effects of ionizing radiation is an essential undertaking. The aim of this paper was to evaluate and compare the radioprotective potential of chlorophyllin, protoporphyrin and bilirubin, with amifostine®, an US Food & Drug Administration approved radioprotector Using the somatic mutation and recombination assay in the Drosophila melanogaster wing, it was found that pretreatment (1-9â¯h) with any of the porphyrins or amifostine® alone, did not affect the larva-adult viability or the basal frequency of mutation. However, they were associated with significant reductions in frequency of somatic mutation and recombination compared with the gamma-irradiated (20â¯Gy) control as follows: bilirubin (69.3 %)> chlorophyllin (40.0 %)> protoporphyrin (39.0 %)> amifostine® (19.7 %). Bilirubin also caused a 16 % increase in larva-adult viability with 3â¯h of pretreatment respect to percentage induced in 20â¯Gy control group. Whilst amifostine® was associated with lower genetic damage after pre-treatment of 1 and 3â¯h, this did not attain significance. These findings suggest that the tested porphyrins may have some potential as radioprotectant agents.
Asunto(s)
Amifostina/farmacología , Bilirrubina/farmacología , Clorofilidas/farmacología , Drosophila melanogaster/efectos de los fármacos , Drosophila melanogaster/efectos de la radiación , Protoporfirinas/farmacología , Protectores contra Radiación/farmacología , Animales , Drosophila melanogaster/genética , Femenino , Masculino , Pruebas de Mutagenicidad , Mutación/efectos de los fármacos , Recombinación Genética/efectos de los fármacos , Alas de Animales/efectos de los fármacos , Alas de Animales/efectos de la radiaciónRESUMEN
PURPOSE: To investigate the effects of amifostine on bacterial translocation and overgrowth in colonic flora after acute radiation enteritis in a rat model. METHODS: Thirty-two female Wistar albino rats were divided into four groups: Group-1 (n=8): only normal saline was administered intraperitoneally. Group-2 (n=8): first serum saline was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. Group-3 (n=8): only amifostine 200 ml/kg was administered intraperitoneally and radiation was not applied. Group-4 (n=8): first amifostine 200 ml/kg was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. On the 5th day after radiation, samples of mesenteric lymph tissues and cecal contents were taken by laparotomy for microbiological culture. RESULTS: Intraperitoneal amifostine administration significantly decreased the bacterial overgrowth related to radiation in colon but did not significantly decrease the bacterial translocation. CONCLUSION: Although not providing a full protection on the damaged mucosal barrier, amifostine significantly decreased the bacterial overgrowth in the cecal content after high dose radiation. There is a need to find out appropriate amifostine dose under different radiation applications avoiding bacterial translocation in gastrointestinal system.
Asunto(s)
Amifostina/farmacología , Traslocación Bacteriana/efectos de los fármacos , Enteritis/inducido químicamente , Enterobacteriaceae/efectos de la radiación , Traumatismos Experimentales por Radiación/microbiología , Protectores contra Radiación/farmacología , Animales , Ciego/microbiología , Ciego/efectos de la radiación , Enteritis/microbiología , Enteritis/prevención & control , Enterobacteriaceae/fisiología , Femenino , Linfa/microbiología , Dosis de Radiación , Traumatismos Experimentales por Radiación/prevención & control , Ratas WistarRESUMEN
ABSTRACT PURPOSE: To investigate the effects of amifostine on bacterial translocation and overgrowth in colonic flora after acute radiation enteritis in a rat model. METHODS: Thirty-two female Wistar albino rats were divided into four groups: Group-1 (n=8): only normal saline was administered intraperitoneally. Group-2 (n=8): first serum saline was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. Group-3 (n=8): only amifostine 200 ml/kg was administered intraperitoneally and radiation was not applied. Group-4 (n=8): first amifostine 200 ml/kg was administered intraperitoneally and 30 minutes later 20 Gy radiation was applied to abdominopelvic region. On the 5th day after radiation, samples of mesenteric lymph tissues and cecal contents were taken by laparotomy for microbiological culture. RESULTS: Intraperitoneal amifostine administration significantly decreased the bacterial overgrowth related to radiation in colon but did not significantly decrease the bacterial translocation. CONCLUSİON: Although not providing a full protection on the damaged mucosal barrier, amifostine significantly decreased the bacterial overgrowth in the cecal content after high dose radiation. There is a need to find out appropriate amifostine dose under different radiation applications avoiding bacterial translocation in gastrointestinal system.
Asunto(s)
Animales , Femenino , Traumatismos Experimentales por Radiación/microbiología , Protectores contra Radiación/farmacología , Amifostina/farmacología , Traslocación Bacteriana/efectos de los fármacos , Enteritis/inducido químicamente , Enterobacteriaceae/efectos de la radiación , Dosis de Radiación , Traumatismos Experimentales por Radiación/prevención & control , Ciego/efectos de la radiación , Ciego/microbiología , Ratas Wistar , Enteritis/microbiología , Enteritis/prevención & control , Enterobacteriaceae/fisiología , Linfa/microbiologíaRESUMEN
Platinum-induced ovarian impairment is a consequence of treatment for malignant ovarian tumors. We compared the protective effects of Ginkgo flavonoids, amifostine, and leuprorelin on ovarian impairment in rats. Fifty rats were randomly divided into the A, B, C, D, and E groups, which were given saline, cisplatin, cisplatin plus Ginkgo flavonoids, cisplatin plus amifostine, and cisplatin plus leuprorelin, respectively. Ovarian weight was significantly greater in groups C and D compared with group B (83.5 ± 6.7 and 86.8 ± 10 vs 56.8 ± 5.4 mg). The total follicle numbers were higher in groups C, D, and E than in group B (60.5 ± 3.9, 63.8 ± 5.1, and 67.7 ± 3.5 vs 49.6 ± 4.5), and the apoptotic index was reduced in groups C, D, and E compared with group B (35.7 ± 2.0, 37.4 ± 1.6, and 30.5 ± 2.9 vs 65.3 ± 2.9%). The ovaries in groups B, C, and D had higher protein and mRNA expression levels of cytoplasmic Cytochrome c (Cyt-c) and apoptotic protease activating factor-1 (Apf-1) compared to group A; the Cyt-c mRNA expression was five-fold higher. The mRNA expression of Cyt-c and Apf-1 were significantly lower in groups C, D, and E compared with group B. Administration of leuprorelin, flavonoids, or amifostine protected rats against the ovarian impairment induced by prior intraperitoneal injection of cisplatin. The efficacy of leuprorelin was superior to that of Ginkgo flavonoids and amifostine, but there was no difference between the effects of Ginkgo flavonoids and amifostine.
Asunto(s)
Amifostina/farmacología , Cisplatino/antagonistas & inhibidores , Flavonoides/farmacología , Ginkgo biloba/química , Leuprolida/farmacología , Sustancias Protectoras/farmacología , Administración Oral , Animales , Antineoplásicos/toxicidad , Apoptosis/efectos de los fármacos , Factor Apoptótico 1 Activador de Proteasas/genética , Factor Apoptótico 1 Activador de Proteasas/metabolismo , Cisplatino/toxicidad , Citocromos c/genética , Citocromos c/metabolismo , Femenino , Expresión Génica/efectos de los fármacos , Tamaño de los Órganos/efectos de los fármacos , Ovario/efectos de los fármacos , Ovario/metabolismo , Extractos Vegetales/química , Sustancias Protectoras/aislamiento & purificación , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
BACKGROUND: Amifostine has been widely tested as a cytoprotective agent against a number of aggressors in different organs. Recently, a gastroprotective effect was observed for this drug in a model of indomethacin-induced gastric injury. Our objective was to investigate the effect of amifostine on ethanol-induced gastric injury and the role played in this mechanism by afferent sensory neurons, non-protein sulfhydryl groups, nitric oxide, ATP-sensitive potassium channels, and cyclooxygenase-2. METHODS: Rats were treated with amifostine (22.5, 45, 90, or 180 mg/kg, PO or SC). After 30 min, the rats received absolute ethanol (5 ml kg(-1), PO). One hour later, gastric damage was quantified with a planimeter. Samples from the stomach were also taken for histopathological assessment and for assays of non-protein sulfhydryl groups. The other groups were pretreated with L-NAME (10 mg kg(-1), IP), glibenclamide (10 mg kg(-1), PO), or celecoxib (10 mg kg(-1), PO). After 30 min, the animals were given amifostine (90 mg kg(-1), PO or SC), followed 30 min later by gavage with absolute ethanol (5 ml kg(-1)). Other rats were desensitized with capsaicin (125 mg kg(-1), SC) 8 days prior to amifostine treatment. RESULTS: Amifostine administration PO and SC significantly and dose-dependently reduced ethanol-induced macroscopic and microscopic gastric damage by restoring glutathione levels in the stomach mucosa. Amifostine-promoted gastroprotection against ethanol-induced stomach injury was reversed by pretreatment with neurotoxic doses of capsaicin, but not by L-NAME, glibenclamide, or celecoxib. CONCLUSIONS: Amifostine protects against ethanol-induced gastric injury by increasing glutathione levels and stimulating the afferent sensory neurons in the stomach.
Asunto(s)
Amifostina/farmacología , Capsaicina/farmacología , Etanol/toxicidad , Neuronas Aferentes/efectos de los fármacos , Gastropatías/inducido químicamente , Compuestos de Sulfhidrilo/metabolismo , Amifostina/administración & dosificación , Animales , Relación Dosis-Respuesta a Droga , Vías de Administración de Medicamentos , Mucosa Gástrica/efectos de los fármacos , Masculino , Protectores contra Radiación/farmacología , Ratas , Ratas Wistar , Gastropatías/prevención & controlRESUMEN
We studied p38 phosphorylation and its intracellular localization during p53 and Puma (a p53 upregulated modulator of apoptosis) apoptotic signaling pathway in bone marrow granulocytes in mice irradiated in vivo and the role of the radioprotector amifostine in ameliorating these responses. Sixty-four C57BL mice were randomly assigned in two non-irradiated (Ami-/rad- and Ami+/rad-) and two irradiated (Ami-/rad+ and Ami+/rad+) groups. Animals received 400mg/kg of amifostine i.p. 30 min prior to a single whole body radiation dose of 7Gy. The experiments were performed using immunohistochemistry for caspase-3, cleaved caspase-3, p53, p-p53 (Ser 15), Puma, p38 and p-p38 (Thr 180/Tyr 182) protein expression. In addition transmission electron microscopy was used for ultrastructural characterization of apoptosis. Data showed that: (i) amifostine significantly reduced the number of apoptotic cells, (ii) p-p53 and Puma proteins were strongly immunostained in granulocytes after irradiation (Ami-/rad+), (iii) amifostine decreased the immunostaining of the proteins (Ami+/rad+), (iv) p38 was immunolocalized in physiological conditions in the nucleus and cytoplasm of granulocytes and neither radiation nor amifostine changed the protein immunostaining or its subcellular distribution, but influenced its activation, (v) radiation-induced p38 phosphorylation and its cytoplasmic accumulation during apoptosis signaling in granulocytes after whole body high radiation dose and amifostine markedly reduced these effects.
Asunto(s)
Amifostina/farmacología , Apoptosis/fisiología , Granulocitos/efectos de los fármacos , Granulocitos/metabolismo , Protectores contra Radiación/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Apoptosis/efectos de los fármacos , Granulocitos/citología , Granulocitos/efectos de la radiación , Inmunohistoquímica , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Transmisión , Fosforilación/efectos de los fármacos , Transporte de Proteínas/efectos de los fármacos , Transducción de Señal/efectos de los fármacosRESUMEN
OBJECTIVES: Microsatellite instability (MSI) induction by alkylating agent-based chemotherapy (ACHT) may underlie both tumor resistance to chemotherapy and secondary leukaemias in cancer patients. We investigated if ACHT could induce MSI in tumor-derived plasma-circulating DNA (pfDNA) and in normal peripheral blood mononuclear (PBMN) cells. We also evaluated if amifostine could interfere with this process in an in-vitro model. METHODS: MSI was determined in pfDNA, PBMN cells and urine cell-free DNA (ufDNA) of 33 breast cancer patients before and after ACHT. MCF-7 cells and PBMN from normal donors were exposed in vitro to melphalan, with or without amifostine. RESULTS: We observed at least one MSI event in PBMN cells, pfDNA or ufDNA of 87, 80 and 80% of patients, respectively. In vitro, melphalan induced MSI in both MCF-7 and normal PBMN cells. In PBMN cells, ACHT-induced MSI occurred together with a significant decrease in the expression of the DNA mismatch repair gene hMSH2. Amifostine decreased hMSH2 expression and also prevented MSI induction only in normal PBMN cells. CONCLUSIONS: ACHT induced MSI in PBMN cells and in tumour-derived pfDNA. Because of its protective effect against ACHT induction of MSI in normal PBMN cells in vitro, amifostine may be a potential agent for preventing secondary leukaemias in patients exposed to ACHT.
Asunto(s)
Amifostina/farmacología , Antimutagênicos/farmacología , Antineoplásicos Alquilantes/efectos adversos , Neoplasias de la Mama/genética , Reparación de la Incompatibilidad de ADN/efectos de los fármacos , Leucocitos Mononucleares/efectos de los fármacos , Inestabilidad de Microsatélites/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Reparación de la Incompatibilidad de ADN/genética , Femenino , Humanos , Leucemia/inducido químicamente , Leucemia/prevención & control , Leucocitos Mononucleares/metabolismo , Melfalán/efectos adversos , Repeticiones de Microsatélite/efectos de los fármacos , Persona de Mediana Edad , Proteína 2 Homóloga a MutS/genética , Proteína 2 Homóloga a MutS/metabolismo , Valores de ReferenciaRESUMEN
BACKGROUND: Amifostine is an efficient cytoprotector against toxicity caused by some chemotherapeutic drugs. Doxorubicin, a potent anticancer anthracycline, is known to produce spermatogenic damage even in low doses. Although some studies have suggested that amifostine does not confer protection to doxorubicin-induced testicular damage, schedules and age of treatment have different approach depending on the protocol. Thus, we proposed to investigate the potential cytoprotective action of amifostine against the damage provoked by doxorubicin to prepubertal rat testes (30-day-old) by assessing some macro and microscopic morphometric parameters 15, 30 and 60 days after the treatment; for fertility evaluation, quantitative analyses of sperm parameters and reproductive competence in the adult phase were also carried out. METHODS: Thirty-day-old male rats were distributed into four groups: Doxorubicin (5 mg/kg), Amifostine (400 mg/kg), Amifostine/Doxorubicin (amifostine 15 minutes before doxorubicin) and Sham Control (0.9% saline solution). "Standard One Way Anova" parametric and "Anova on Ranks" non-parametric tests were applied according to the behavior of the obtained data; significant differences were considered when p < 0.05. RESULTS: The rats killed 30 and 60 days after doxorubicin treatment showed diminution of seminiferous epithelium height and reduction on the frequency of tubular sections containing at least one type of differentiated spermatogonia; reduction of sperm concentration and motility and an increase of sperm anomalous forms where observed in doxorubicin-treated animals. All these parameters were improved in the Amifostine/Doxorubicin group only when compared to Doxorubicin group. Such reduction, however, still remained below the values obtained from the Sham Control group. Nevertheless, the reproductive competence of doxorubicin-treated rats was not improved by amifostine pre-administration. CONCLUSIONS: These results suggest that amifostine promotes a significant reduction of the doxorubicin long-term side effects on the seminiferous epithelium of prepubertal rats, which is reflected in the epidydimal fluid parameters in the adult phase. However, fertility status results suggest that such protection may not be effective against sperm DNA content damage. Further investigation of sperm DNA integrity must be carried out using amifostine and doxorubicin-treated experimental models.
Asunto(s)
Amifostina/farmacología , Doxorrubicina/efectos adversos , Fertilidad/efectos de los fármacos , Epitelio Seminífero/efectos de los fármacos , Enfermedades Testiculares/inducido químicamente , Enfermedades Testiculares/prevención & control , Animales , Antibióticos Antineoplásicos/efectos adversos , Citoprotección/efectos de los fármacos , Regulación hacia Abajo/efectos de los fármacos , Femenino , Fertilidad/fisiología , Estado de Salud , Masculino , Embarazo , Protectores contra Radiación/farmacología , Ratas , Ratas Wistar , Análisis de Semen , Epitelio Seminífero/patología , Maduración Sexual/efectos de los fármacos , Enfermedades Testiculares/patologíaRESUMEN
Amifostine is the most effective radioprotector known and the only one accepted for clinical use in cancer radiotherapy. In this work, the antigenotoxic effect of amifostine against gamma-rays was studied in Escherichia coli cells deficient in DNA damage repair activities. Assays of irradiated cells treated with amifostine showed that the drug reduced the genotoxicity induced by radiation in E. coli wild-type genotypes and in uvr, recF, recB, recB-recC-recF mutant strains, but not in recN defective cells. Thus, the mechanism of DNA protection by amifostine against gamma-radiation-induced genotoxicity appears to involve participation of the RecN protein that facilitates repair of DNA double-strand breaks. The results are discussed in relation to amifostine's chemopreventive potential.
Asunto(s)
Amifostina/farmacología , Daño del ADN/efectos de los fármacos , Proteínas de Escherichia coli/metabolismo , Escherichia coli/efectos de los fármacos , Rayos gamma , Protectores contra Radiación/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Daño del ADN/efectos de la radiación , Reparación del ADN/efectos de los fármacos , Reparación del ADN/efectos de la radiación , Enzimas de Restricción del ADN/genética , Enzimas de Restricción del ADN/metabolismo , Escherichia coli/genética , Escherichia coli/efectos de la radiación , Proteínas de Escherichia coli/genéticaRESUMEN
Fanconi anaemia (FA) is a rare genetic chromosomal instability syndrome caused by impairment of DNA repair and reactive oxygen species (ROS) imbalance. This disease is also related to bone marrow failure and cancer. Treatment of these complications with radiation and alkylating agents may enhance chromosomal breakage. We have evaluated the effect of amifostine (AMF) on basal and mitomycin C (MMC)-induced chromosomal breakage in FA blood cells using the micronucleus assay. The basal micronuclei count was higher among FA patients than healthy subjects. Pre-treatment with AMF significantly inhibited micronucleation induced by MMC in healthy subjects (23.4 +/- 4.0 - MMC vs 12.3 2.9 - AMF --> MMC) MN/1000CB, p < 0.01, one way ANOVA) as well as in FA patients (80.0 +/- 5.8 - MMC vs 40.1 +/- 5.8 - AMF --> MMC) MN/1000CB, p < 0.01, ANOVA). Release of ROS by peripheral blood mononuclear cells treated with AMF -> MMC and measured by chemoluminometry showed that AMF-protection was statistically higher among FA patients than in healthy individuals. Based on these results we suggest that AMF prevents chromosomal breakage induced by MMC, probably by its antioxidant effect.
Asunto(s)
Amifostina/farmacología , Rotura Cromosómica/efectos de los fármacos , Anemia de Fanconi/tratamiento farmacológico , Linfocitos/efectos de los fármacos , Mitomicina/efectos adversos , Adolescente , Adulto , Células Sanguíneas , Estudios de Casos y Controles , Niño , Anemia de Fanconi/genética , Femenino , Humanos , Masculino , Micronúcleos con Defecto Cromosómico/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Cisplatin is a potent drug used in clinical oncology but causes spermatogenesis damage. Amifostine is a drug used against toxicity caused by ionizing irradiation and chemotherapeutic drugs. Since cisplatin provokes fertility and induces germ cell apoptosis and necrosis, we proposed to evaluate the amifostine cytoprotective action on testes of cisplatin-treated rats. Thirty-day-old prepubertal Wistar rats received a single cisplatin dose of 5 mg/kg and were killed after 3, 6, and 12 hr. The hematoxylin-eosin stained testicular sections were submitted to histological, morphometric, and stereological analysis. The terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling (TUNEL) method was used to label apoptotic cells. TUNEL-positive and TUNEL-negative germ cells with abnormal nuclear morphology (ANM) were scored. Significant alterations of greater part of the parameters occurred in the cisplatin-treated group (CE) compared to the group that received amifostine before the cisplatin-treatment (ACE); however, testicular weight and volume did not vary between these groups. Tubular diameter was reduced in CE in comparison to ACE rats, while interstitial tissue and lymphatic space volume and volume density were significantly higher in CE rats; interstitial testicular edema probably occurred in cisplatin-treated rats. CE rats showed important histological alterations, which were more accentuated than in ACE rats. The numerical densities of apoptotic germ cells and TUNEL-negative cells with ANM were lower in ACE than in CE rats. In conclusion, the amifostine previously administered to prepubertal rats reduced the testicular damage caused by cisplatin. We conclude that amifostine partially protected the rat seminiferous epithelium against cisplatin toxicity.
Asunto(s)
Amifostina/farmacología , Antineoplásicos/antagonistas & inhibidores , Antineoplásicos/toxicidad , Cisplatino/antagonistas & inhibidores , Cisplatino/toxicidad , Testículo/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Etiquetado Corte-Fin in Situ , Masculino , Sustancias Protectoras/farmacología , Ratas , Ratas Wistar , Epitelio Seminífero/efectos de los fármacos , Epitelio Seminífero/patología , Espermatogénesis/efectos de los fármacos , Testículo/patologíaRESUMEN
PURPOSE: To study the apoptotic effect of the 2-phenylaminopyrimidine derivative STI571 in combination with antioxidant agents on K-562 cell line derived from a Philadelphia chromosome-positive chronic myeloid leukemia patient. MATERIALS AND METHODS: K-562 (BCR/ABL+), U-937, and HL60 (BCR/ABL-) leukemic cell lines were incubated with STI571 and the antioxidant agents catalase, glutathione, superoxide dismutase, and amifostine (AMI). Apoptotic effect was analyzed by morphological and flow cytometric criteria. RESULTS: STI571 at concentrations higher than 0.25 mumol L(-1) produced apoptosis (P<0.05) in K-562 cells only after treatment for 72 h. At the mentioned concentrations, STI571 also induced an increase in the loss of mitochondrial transmembrane potential from 24.6 to 40%. Combination of STI571 (0.5 micromol L(-1)) with antioxidant agents showed that the cytoprotective agent AMI (0.75 mg mL(-1)) produced an additive effect in the proapoptotic activity of STI571 in K-562 cells at nuclear (58.8%+/-2.0 vs. 28.9%+/-3.3) and mitochondrial (53.3%+/-3.6 vs. 29.5%+/-1.2) levels. CONCLUSIONS: Our results show that only AMI in combination with STI571, at submicromolar concentration, has an additive effect in K-562 cell line, and it does not have severe toxic effects on Philadelphia chromosome negative cells.
Asunto(s)
Amifostina/farmacología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Pirimidinas/farmacología , Antioxidantes/farmacología , Benzamidas , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ensayo Cometa , Citoprotección , Ensayos de Selección de Medicamentos Antitumorales , Sinergismo Farmacológico , Células HL-60 , Humanos , Mesilato de Imatinib , Células K562 , Potenciales de la Membrana/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/fisiología , PiperazinasRESUMEN
In patients undergoing bone marrow transplant (BMT), reactive oxygen species (ROS) are released as a consequence of the events related to the preparative regimen. Total body irradiation (TBI), which is known to generate ROS, is a routine preconditioning procedure prior to BMT. Several studies have demonstrated that amifostine protects normal tissues. In the present report, we investigated the oxidative state of plasma and erythrocytes in 21 patients with hematological malignancies undergoing TBI. The dose fraction was 160 cGy, twice daily (eight sessions). For ROS detection, we used electron spin resonance spectroscopy and spin-trapping technique. In all, 15 patients received amifostine prior to the irradiation and six did not. No free radical signal was detected in the plasma samples spectrum of 15 amifostine-treated patients, and five of six samples of nontreated patients showed ROS signal. Only two of 15 treated patients had mucositis degree higher than 2, whereas five of six nontreated patients suffered this complication. The average hospitalization days in treated and nontreated patients were 23.5 and 29.7, respectively. This work represents an original observation; we found by direct measurements of free radicals that ROS are released during TBI, and confirmed the amifostine radical scavenger activity.
Asunto(s)
Amifostina/farmacología , Protectores contra Radiación/farmacología , Especies Reactivas de Oxígeno/efectos de la radiación , Acondicionamiento Pretrasplante/efectos adversos , Irradiación Corporal Total/efectos adversos , Adolescente , Adulto , Antioxidantes/metabolismo , Trasplante de Médula Ósea , Niño , Eritrocitos/metabolismo , Eritrocitos/efectos de la radiación , Femenino , Humanos , Leucemia/terapia , Masculino , Persona de Mediana Edad , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismoRESUMEN
Experiments were undertaken to assess the role of amifostine in the activation of latent TGFbeta1 and in the smad proteins cascade (smad 2/3, smad4, smad7), focusing on megakaryocytes, in the bone marrow irradiated in vivo. Non-irradiated megakaryocytes were negative for active TGFbeta1. Immunopositivity to active TGFbeta1 was detected in megakaryocytes 10 days after irradiation in amifostine- treated and untreated marrows. Smad 2/3 and smad 4 were strongly positive in the nucleus of megakaryocytes 10 days after irradiation. At the same time, a predominant hypocellular bone marrow with foci of hematopoiesis was observed with few megakaryocytes. An increase in the number of reticulin fibers was also seen. In amifostine-treated marrows, smad 2/3 and smad4 were not detected in the nucleus but were positive in the cytoplasm of megakaryocytes 10 days after irradiation. Coincidentally, bone marrows were cellular with megakaryocytes. Smad7 immunoexpression was detected in the cytoplasm of megakaryocytes in the non-irradiated, amifostine-treated and in the irradiated, amifostine-treated marrows. Data indicate that amifostine does not prevent latent TGFbeta1 activation in irradiated megakaryocytes. While TGFbeta1 signal transduction occurs in megakaryocytes in untreated bone marrows, it is inhibited in megakaryocytes in amifostine-treated marrows due to the induction of smad 7 activation. This is the first report showing smad 7 activation by amifostine. Our results also suggest a role for TGFbeta1 as an inhibitor of megakaryocytes in vivo.
Asunto(s)
Amifostina/farmacología , Proteínas de Unión al ADN/efectos de los fármacos , Proteínas de Unión al ADN/fisiología , Megacariocitos/metabolismo , Megacariocitos/efectos de la radiación , Protectores contra Radiación/farmacología , Transactivadores/efectos de los fármacos , Transactivadores/fisiología , Factor de Crecimiento Transformador beta/efectos de los fármacos , Irradiación Corporal Total , Animales , Proteínas de Unión al ADN/metabolismo , Inmunohistoquímica , Masculino , Megacariocitos/efectos de los fármacos , Megacariocitos/patología , Ratones , Ratones Endogámicos C57BL , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Transducción de Señal/efectos de la radiación , Proteína Smad2 , Proteína smad3 , Proteína Smad4 , Proteína smad7 , Factores de Tiempo , Transactivadores/metabolismo , Factor de Crecimiento Transformador beta/fisiología , Factor de Crecimiento Transformador beta1RESUMEN
In this study we evaluated the antigenotoxic and cytoprotective capabilities of WR-2721 [S-2-(3-aminopropylamino)-ethylphosphorothioic acid (amifostine)] in different normal tissues of BALB/c mice treated with idarubicin [4-demethoxydaunorubicin (IDA)]. The aminothiol WR-2721 is a pro-drug that requires dephosphorylation to its active metabolite WR-1065, to produce selectively cytoprotective activity in normal tissues exposed to radio- and chemotherapeutic agents, without protecting malignant tissues. IDA is an effective chemotherapeutic agent against hematological diseases, but produces a broad spectrum of toxicity in nontumoral cells. Animals were injected intravenously with WR-2721 (250 mg/kg) or IDA (6 mg/kg) and WR-2721/IDA. Micronuclei frequency in bone marrow was measured 24 and 48 hr after initiation of the treatments. The IDA-treated group showed increased levels of micronuclei. However, the WR-2721- and WR-2721/IDA-treated groups did not show differences from the controls. Genetic damage was evaluated by alkaline single-cell gel electrophoresis at 24-hr posttreatments. Important DNA damage was observed in liver, spleen, and peripheral blood cells of mice treated with IDA. The presence of WR-2721 diminished that damaging effect only in liver cells. The apoptotic index was measured in liver and spleen tissues by the TUNEL assay 14 and 24 hr after treatment. In liver we observed an increased percentage of apoptotic cells at 24 hr for the IDA-treated group, whereas the WR-2721 and WR-2721/IDA groups remained at low levels. Splenic cells treated with IDA and WR-2721/IDA showed increased DNA fragmentation levels at any time. In conclusion, WR-2721 has a tissue-specific antigenotoxic and cytoprotective effect in IDA-treated mice using these experimental conditions.
Asunto(s)
Amifostina/farmacología , Antibióticos Antineoplásicos/efectos adversos , Antimutagênicos/farmacología , Idarrubicina/efectos adversos , Sustancias Protectoras/farmacología , Animales , Apoptosis/efectos de los fármacos , Sangre/efectos de los fármacos , Médula Ósea/efectos de los fármacos , Ensayo Cometa/métodos , Daño del ADN/efectos de los fármacos , Femenino , Hígado/efectos de los fármacos , Hígado/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Pruebas de Micronúcleos , Bazo/efectos de los fármacos , Bazo/patología , Pruebas de ToxicidadAsunto(s)
Amifostina/uso terapéutico , Citoprotección , Neoplasias/terapia , Protectores contra Radiación/uso terapéutico , Amifostina/farmacología , Animales , Neoplasias de la Mama/terapia , Femenino , Neoplasias de Cabeza y Cuello/terapia , Humanos , Neoplasias Pulmonares/terapia , Masculino , Traumatismos por Radiación/prevención & control , Protectores contra Radiación/farmacología , Neoplasias del Recto/terapia , Neoplasias del Cuello Uterino/terapiaRESUMEN
Clinical trials indicate that amifostine may confer protection on various normal tissues without attenuating anti-tumor response. When administered prior to chemotherapy or radiotherapy, it may provide a broad spectrum of cytoprotection including against alkylating drugs. The mechanism of protection resides in the metabolism at normal tissue site by membrane-bound alkaline phosphatase. Toxicity of this drug is moderate with hypotension, nausea and vomiting, and hypocalcemia being observed. We report a phase II study using amifostine as a protective drug against high-dose cyclophosphamide (HDCY) (7 g/m2), used to mobilize peripheral blood progenitor cells (PBPC) and to reduce tumor burden. We enrolled 29 patients, 22 (75. 9%) affected by aggressive and 7 (24.1%) by indolent non-Hodgkin's lymphoma (NHL), who were submitted to 58 infusions of amifostine and compared them with a historical group (33 patients) affected by aggressive NHL and treated with VACOP-B followed by HDCY. The most important results in favor of amifostine were the reduction of intensity of cardiac, pulmonary and hepatic toxicity, and a significant reduction of frequency and severity of mucositis (P = 0. 04). None of the 29 patients died in the protected group, while in the historical group 2/33 patients died because of cardiac or pulmonary toxicity and 2 patients stopped therapy due to toxicity. Amifostine did not prevent the aplastic phase following HDCY. PBPC collection and hematological recovery were adequate in both groups. The number of CFU-GM (colony-forming units-granulocyte/macrophage) colonies and mononuclear cells in the apheresis products was significantly higher in the amifostine group (P = 0.02 and 0.01, respectively). Side effects were mild and easily controlled. We conclude that amifostine protection should be useful in HDCY to protect normal tissues, with acceptable side effects.
Asunto(s)
Amifostina/farmacología , Antineoplásicos Alquilantes/administración & dosificación , Ciclofosfamida/administración & dosificación , Citoprotección , Linfoma no Hodgkin/tratamiento farmacológico , Protectores contra Radiación/uso terapéutico , Adolescente , Adulto , Amifostina/efectos adversos , Antineoplásicos Alquilantes/efectos adversos , Ciclofosfamida/efectos adversos , Citoprotección/efectos de los fármacos , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Protectores contra Radiación/efectos adversos , Estadísticas no Paramétricas , Resultado del TratamientoRESUMEN
Clinical trials indicate that amifostine may confer protection on various normal tissues without attenuating anti-tumor response. When administered prior to chemotherapy or radiotherapy, it may provide a broad spectrum of cytoprotection including against alkylating drugs. The mechanism of protection resides in the metabolism at normal tissue site by membrane-bound alkaline phosphatase. Toxicity of this drug is moderate with hypotension, nausea and vomiting, and hypocalcemia being observed. We report a phase II study using amifostine as a protective drug against high-dose cyclophosphamide (HDCY) (7 g/m2), used to mobilize peripheral blood progenitor cells (PBPC) and to reduce tumor burden. We enrolled 29 patients, 22 (75.9 percent) affected by aggressive and 7 (24.1 percent) by indolent non-Hodgkin's lymphoma (NHL), who were submitted to 58 infusions of amifostine and compared them with a historical group (33 patients) affected by aggressive NHL and treated with VACOP-B followed by HDCY. The most important results in favor of amifostine were the reduction of intensity of cardiac, pulmonary and hepatic toxicity, and a significant reduction of frequency and severity of mucositis (P = 0.04). None of the 29 patients died in the protected group, while in the historical group 2/33 patients died because of cardiac or pulmonary toxicity and 2 patients stopped therapy due to toxicity. Amifostine did not prevent the aplastic phase following HDCY. PBPC collection and hematological recovery were adequate in both groups. The number of CFU-GM (colony-forming units-granulocyte/macrophage) colonies and mononuclear cells in the apheresis products was significantly higher in the amifostine group (P = 0.02 and 0.01, respectively). Side effects were mild and easily controlled. We conclude that amifostine protection should be useful in HDCY to protect normal tissues, with acceptable side effects.