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1.
Exp Eye Res ; 209: 108642, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34058232

RESUMO

Excessive iron can be accumulated in the retina and lead to retinal iron overload. Salvianic acid A (SAA) has a variety of pharmacologic effects, but there is only a limited understanding of its benefits for retinal iron overload. The aim of this study was to examine the protective effects and latent mechanisms of SAA on retinal iron overload. SAA reduced iron in the serum and retina, attenuated pathophysiological changes, and reduced retinal iron deposition in the retinas of iron-overloaded mice. It also reduced intracellular iron in ARPE-19 cells by regulating iron-handling proteins and chelating with iron. It also significantly inhibited cellular oxidative and inflammatory damage by increasing the nuclear translocation of nuclear erythroid 2-related factor 2 (Nrf2) while decreasing nuclear factor-kappa B (NF-κB), protecting the ARPE-19 cells from apoptosis by suppressing the Bax/Bcl-2 ratio, cytochrome c release, caspase activation, and poly ADP-ribose polymerase cleavage. The ability of SAA to inhibit apoptosis, increase nuclear Nrf2 expression, and decrease nuclear NF-κB expression was further confirmed in the retinas of iron-overloaded mice. This study demonstrates that SAA shows significant protective effects against retinal iron overload; its mechanisms might be associated with iron chelation; regulation of iron-handling proteins; and inhibition of oxidative stress, inflammation and apoptosis.


Assuntos
Sobrecarga de Ferro/tratamento farmacológico , Ferro/metabolismo , Lactatos/farmacologia , Retina/metabolismo , Doenças Retinianas/tratamento farmacológico , Animais , Apoptose , Linhagem Celular , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas , Ensaio de Imunoadsorção Enzimática , Sobrecarga de Ferro/induzido quimicamente , Sobrecarga de Ferro/metabolismo , Complexo Ferro-Dextran/toxicidade , Masculino , Camundongos , Retina/efeitos dos fármacos , Retina/patologia , Doenças Retinianas/induzido quimicamente , Doenças Retinianas/metabolismo , Transdução de Sinais
2.
Cell Physiol Biochem ; 44(3): 870-883, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29176318

RESUMO

BACKGROUND/AIMS: Iron overload (IO) is accompanied by hepatic inflammation. The chemokine (C-C motif) ligand 2 (CCL2) mediates inflammation, and its overexpression is associated with IO. However, whether IO results in CCL2 overexpression in the liver and the underlying mechanisms are unclear. METHODS: We subjected mice to IO by administering intraperitoneal injections of dextran-iron or by feeding mice a 3% dextran-iron diet to observe the effects of IO on miR-122/CCL2 expression through real-time qPCR and Western blot analysis. We also used indicators, including the expression of the inflammatory cytokine, the inflammation score based on H&E staining and the serum content of ALT and AST to evaluate the effects of IO on hepatic inflammation. Meanwhile, we observed the effects of vitamin E on IO-induced hepatic inflammation. In cells, we used 100 µΜ FeSO4 or 30 µΜ Holo-Tf to produce IO and observed the roles of miR-122 in regulating CCL2 expression by using miR-122 mimics or inhibitors to overexpress or inhibit miR-122. Then, we used a dual-luciferase reporter assay to prove that miR-122 regulates CCL2 expression through direct binding to its complementary sequence in the CCL2 mRNA 3'UTR. RESULTS: IO induces the downregulation of miR-122 and the upregulation of CCL2, as well as inflammatory responses both in vitro and in vivo. Although IO-induced oxidative stress is eliminated by the antioxidant vitamin E, IO-induced hepatic inflammation still exists, which probably can be explained by the fact that vitamin E has no effects on the miR-122/CCL2 pathway. In in vitro experiments, the overexpression and inhibition of miR-122 significantly reduced and increased CCL2 expression, respectively. The dual-luciferase reporter assay indicates that miR-122 binds CCL2 mRNA 3'UTR. CONCLUSION: We propose the roles of miR-122/CCL2 in IO-induced hepatic inflammation. Our studies should provide a new clue for developing clinical strategies for patients with IO.


Assuntos
Quimiocina CCL2/metabolismo , Complexo Ferro-Dextran/toxicidade , Fígado/patologia , MicroRNAs/metabolismo , Regulação para Cima/efeitos dos fármacos , Regiões 3' não Traduzidas , Animais , Antagomirs/metabolismo , Sequência de Bases , Linhagem Celular , Quimiocina CCL2/antagonistas & inibidores , Quimiocina CCL2/genética , Compostos Ferrosos/toxicidade , Humanos , Inflamação , Interleucina-6/sangue , Ferro/análise , Ferro/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Estresse Oxidativo/efeitos dos fármacos , Alinhamento de Sequência , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Transferrina/farmacologia , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Vitamina E/farmacologia
3.
Pharm Biol ; 53(7): 1066-74, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25609151

RESUMO

CONTEXT: Nerium indicum Mill. (Apocynaceae) was reported for its efficient in vitro antioxidant and iron-chelating properties. OBJECTIVE: This study demonstrates the effect of 70% methanol extract of N. indicum leaf (NIME) towards in vitro DNA protection and ameliorating iron-overload-induced liver damage in mice. MATERIALS AND METHODS: Phytochemical and HPLC analyses were carried out to standardize the extract and the effect of Fe(2+)-mediated pUC18 DNA cessation was studied. Thirty-six Swiss Albino mice were divided into six groups of blank, negative control (iron overload only), and iron-overloaded mice receiving 50, 100, and 200 mg/kg b.w. doses of NIME and desirox (20 mg/kg b.w.). The biochemical markers of hepatic damage, various liver and serum parameters, and reductive release of ferritin iron were studied. RESULTS AND DISCUSSION: The presence of different phytocomponents was revealed from phytochemical and HPLC analyses. A substantial supercoiled DNA protection, with [P]50 of 70.33 ± 0.32 µg, was observed. NIME (200 mg/kg b.w.) significantly normalized the levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and bilirubin by 126.27, 125.25, 188.48, and 45.47%, respectively. NIME (200 mg/kg b.w.) was shown to alleviate the reduced levels of superoxide dismutase, catalase, glutathione-S-transferase, and non-enzymatic-reduced glutathione, by 48.95, 35.9, 35.42, and 13.22%, respectively. NIME also lowered raised levels of lipid peroxidation, protein carbonyl, hydroxyproline, and liver iron by 32.28, 64.58, 136.81, and 83.55%, respectively. CONCLUSION: These findings suggest that the active substances present in NIME may be capable of lessening iron overload-induced toxicity, and possibly be a useful drug for iron-overloaded diseases.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Complexo Ferro-Dextran/toxicidade , Nerium , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/uso terapêutico , Folhas de Planta , Animais , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Masculino , Camundongos , Estresse Oxidativo/fisiologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia
4.
Biometals ; 27(2): 349-61, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24549594

RESUMO

Although iron is a first-line pro-oxidant that modulates clinical manifestations of various systemic diseases, including diabetes, the individual tissue damage generated by active oxidant insults has not been demonstrated in current animal models of diabetes. We tested the hypothesis that oxidative stress is involved in the severity of the tissues injury when iron supplementation is administered in a model of type 1 diabetes. Streptozotocin (Stz)-induced diabetic and non-diabetic Fischer rats were maintained with or without a treatment consisting of iron dextran ip at 0.1 mL day(-1) doses administered for 4 days at intervals of 5 days. After 3 weeks, an extensive increase (p < 0.001) in the production of reactive oxygen species (ROS) in neutrophils of the diabetic animals on iron overload was observed. Histological analysis revealed that this treatment also resulted in higher (p < 0.05) tissue iron deposits, a higher (p < 0.001) number of inflammatory cells in the pancreas, and apparent cardiac fibrosis, as shown by an increase (p < 0.05) in type III collagen levels, which result in dysfunctional myocardial. Carbonyl protein modification, a marker of oxidative stress, was consistently higher (p < 0.01) in the tissues of the iron-treated rats with diabetes. Moreover, a significant positive correlation was found between ROS production and iron pancreas stores (r = 0.42, p < 0.04), iron heart stores (r = 0.54, p < 0.04), and change of the carbonyl protein content in pancreas (r = 0.49, p < 0.009), and heart (r = 0.48, p < 0.02). A negative correlation was still found between ROS production and total glutathione content in pancreas (r = -0.50, p < 0.03) and heart (r = -0.45, p < 0.04). In conclusion, our results suggest that amplified toxicity in pancreatic and cardiac tissues in rats with diabetes on iron overload might be attributed to increased oxidative stress.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Modelos Animais de Doenças , Complexo Ferro-Dextran/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Animais , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 1/induzido quimicamente , Sobrecarga de Ferro/induzido quimicamente , Sobrecarga de Ferro/complicações , Sobrecarga de Ferro/metabolismo , Complexo Ferro-Dextran/administração & dosagem , Complexo Ferro-Dextran/farmacocinética , Masculino , Ratos , Ratos Endogâmicos F344 , Espécies Reativas de Oxigênio/metabolismo , Estreptozocina , Distribuição Tecidual
5.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 35(5): 547-52, 2013 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-24183045

RESUMO

OBJECTIVE: To establish a mouse model of iron overload by intraperitoneal injection of iron dextran and investigate the impact of iron overload on bone marrow hematopoiesis. METHODS: A total of 40 C57BL/6 mice were divided into control group, low-dose iron group (12.5 mg/ml), middle-dose iron group (25 mg/ml), and high-dose iron group (50 mg/ml). The control group received normal saline (0.2 ml), and the rest were injected with intraperitoneal iron dextran every three days for six weeks. Iron overload was confirmed by observing the bone marrow, hepatic, and splenic iron deposits and the bone marrow labile iron pool. In addition, peripheral blood and bone marrow mononuclear cells were counted and the hematopoietic function was assessed. RESULTS: Iron deposits in bone marrow, liver, and spleen were markedly increased in the mouse models. Bone marrow iron was deposited mostly within the matrix with no significant difference in expression of labile iron pool.Compared with control group, the ability of hematopoietic colony-forming in three interventional groups were decreased significantly (P<0.05). Bone marrow mononuclear cells counts showed no significant difference. The amounts of peripheral blood cells (white blood cells, red blood cells, platelets, and hemoglobin) in different iron groups showed no significant difference among these groups;although the platelets were decreased slightly in low-dose iron group [(780.7±39.60)×10(9)/L], middle dose iron group [(676.2±21.43)×10(9)/L], and high-dose iron group [(587.3±19.67)×10(9)/L] when compared with the control group [(926.0±28.23)×10(9)/L], there was no significant difference(P>0.05). CONCLUSIONS: The iron-overloaded mouse model was successfully established by intraperitoneal administration of iron dextran. Iron overload can damage the hepatic, splenic, and bone marrow hematopoietic function, although no significant difference was observed in peripheral blood count.


Assuntos
Medula Óssea/efeitos dos fármacos , Modelos Animais de Doenças , Hematopoese/efeitos dos fármacos , Sobrecarga de Ferro/fisiopatologia , Complexo Ferro-Dextran/toxicidade , Animais , Medula Óssea/fisiopatologia , Sobrecarga de Ferro/induzido quimicamente , Complexo Ferro-Dextran/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Baço/efeitos dos fármacos
6.
Radiology ; 253(2): 390-8, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19789237

RESUMO

PURPOSE: To use a rat model for nephrogenic systemic fibrosis (NSF) that was administered high-dose gadodiamide to determine whether the co-administration of erythropoietin (Epo) and intravenous iron potentiated development of skin lesions that are thought to be a marker for the development of NSF. MATERIALS AND METHODS: The local committee for animal research approved this study. High-dose gadodiamide was administered, 2.5 mmol per kilogram of body weight for 20 days, or 500 times the U.S. Food and Drug Administration-approved dose, to four groups of Hannover-Wistar rats: group A, gadodiamide only; B, gadodiamide and Epo; C, gadodiamide and intravenous iron; and D, gadodiamide, Epo, and intravenous iron. The animals were sacrificed 7 days after final injection, and the authors examined dermal histologic findings from each animal and measured metal deposition by using inductively coupled plasma mass spectrometry. To compare the effect of metal deposition and cellularity, a linear mixed effects model was used to fit the data within PROC MIXED modeled with rat-specific random effects, and subsequently a Dunnett adjustment was performed. RESULTS: Rats treated with gadodiamide and both Epo and intravenous iron (group D) had significantly worse skin lesions at gross and histologic analysis (P = .004) compared with the rate treated with gadodiamide only (group A). Group D also had increased levels of deposited gadolinium as measured by means of mass spectrometry (P = .012). CONCLUSION: With a rat model similar to those already existing in the literature, skin changes were more marked in animals exposed to gadodiamide, Epo, and intravenous iron, as opposed to those animals exposed to gadodiamide alone; this experiment suggests that great caution may be warranted when prescribing gadolinium-based contrast agents to patients receiving Epo and intravenous iron.


Assuntos
Meios de Contraste/toxicidade , Eritropoetina/toxicidade , Gadolínio DTPA/toxicidade , Complexo Ferro-Dextran/toxicidade , Dermopatia Fibrosante Nefrogênica/induzido quimicamente , Animais , Cálcio/metabolismo , Meios de Contraste/administração & dosagem , Sinergismo Farmacológico , Epoetina alfa , Gadolínio DTPA/administração & dosagem , Injeções Intravenosas , Complexo Ferro-Dextran/administração & dosagem , Masculino , Dermopatia Fibrosante Nefrogênica/metabolismo , Dermopatia Fibrosante Nefrogênica/patologia , Ratos , Ratos Wistar , Proteínas Recombinantes , Pele/metabolismo , Pele/patologia
7.
Acta Haematol ; 118(4): 193-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17940334

RESUMO

INTRODUCTION: Iron cardiomyopathy is a lethal complication of transfusion therapy in thalassemia major. Nutritional supplements decreasing cardiac iron uptake or toxicity would have clinical significance. Murine studies suggest taurine may prevent oxidative damage and inhibit Ca2+-channel-mediated iron transport. We hypothesized that taurine supplementation would decrease cardiac iron-overloaded toxicity by decreasing cardiac iron. Vitamin E and selenium served as antioxidant control. METHODS: Animals were divided into control, iron, taurine, and vitamin E/selenium groups. Following sacrifice, iron and selenium measurements, histology, and biochemical analyses were performed. RESULTS: No significant differences were found in heart and liver iron content between treatment groups, except for higher hepatic dry-weight iron concentrations in taurine-treated animals (p < 0.03). Serum iron increased with iron loading (751 +/- 66 vs. 251 +/- 54 microg/dl, p < 0.001) and with taurine (903 +/- 136 microg/dl, p = 0.03). CONCLUSION: Consistent with oxidative stress, iron overload increased cardiac malondialdehyde levels, decreased heart glutathione peroxidase (GPx) activity, and increased serum aspartate aminotransferase. Taurine ameliorated these changes, but only significantly for liver GPx activity. Selenium and vitamin E supplementation did not improve oxidative markers and worsened cardiac GPx activity. These results suggest that taurine acts primarily as an antioxidant rather than inhibiting iron uptake. Future studies should illuminate the complexity of these results.


Assuntos
Antioxidantes/uso terapêutico , Cardiomiopatias/prevenção & controle , Sobrecarga de Ferro/tratamento farmacológico , Miocárdio/metabolismo , Taurina/uso terapêutico , Alanina Transaminase/sangue , Animais , Antioxidantes/administração & dosagem , Aspartato Aminotransferases/sangue , Cardiomiopatias/etiologia , Avaliação Pré-Clínica de Medicamentos , Feminino , Gerbillinae , Glutationa Peroxidase/análise , Coração/efeitos dos fármacos , Sobrecarga de Ferro/complicações , Complexo Ferro-Dextran/farmacocinética , Complexo Ferro-Dextran/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/química , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/patologia , Malondialdeído/análise , Modelos Animais , Miocárdio/química , Miocárdio/patologia , Tamanho do Órgão/efeitos dos fármacos , Estresse Oxidativo , Ácido Selênico , Compostos de Selênio/administração & dosagem , Compostos de Selênio/uso terapêutico , Taurina/administração & dosagem , Vitamina E/administração & dosagem , Vitamina E/uso terapêutico
8.
Eur J Pharmacol ; 535(1-3): 263-9, 2006 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-16527270

RESUMO

The introduction of new iron chelating drugs may ultimately improve iron-chelation therapy for patients with iron overload diseases such as thalassaemia and other disorders. In this paper, the in vivo effects of baicalin and quercetin on iron overload induced liver injury were studied on mice. It was found that when iron-dextran induced iron overload mice were fed baicalin or quercetin containing diet (1% w/w) for 45 days, both flavonoids significantly inhibited iron overload induced lipid peroxidation and protein oxidation of liver, decreased hepatic iron and hepatic collagen content, increased the serum non-heme iron level but not serum ferritin level. Flavonoids supplementation also increased the excretion of iron through feces. In vitro study demonstrated that both flavonoids could release iron from ferritin. These results indicate that besides acting as antioxidants, both flavonoids can also release iron from liver and finally excrete it through feces. The present study provides further support for flavonoids to be medicines for iron overload diseases.


Assuntos
Suplementos Nutricionais , Flavonoides/farmacologia , Sobrecarga de Ferro/complicações , Hepatopatias/prevenção & controle , Quercetina/farmacologia , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Colágeno/metabolismo , Ferritinas/sangue , Ferritinas/metabolismo , Flavonoides/administração & dosagem , Flavonoides/uso terapêutico , Ferro/sangue , Ferro/metabolismo , Ferro/urina , Sobrecarga de Ferro/induzido quimicamente , Complexo Ferro-Dextran/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/lesões , Fígado/metabolismo , Hepatopatias/etiologia , Hepatopatias/metabolismo , Masculino , Camundongos , Oxirredução/efeitos dos fármacos , Proteínas/metabolismo , Quercetina/administração & dosagem
9.
Clin J Am Soc Nephrol ; 1 Suppl 1: S24-31, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17699373

RESUMO

Ferric iron (Fe)-carbohydrate complexes are widely used for treating Fe deficiency in patients who are unable to meet their Fe requirements with oral supplements. Intravenous Fe generally is well tolerated and effective in correcting Fe-deficient states. However, the complexing of Fe to carbohydrate polymers does not block its potent pro-oxidant effects; systemic free radical generation and, possibly, tissue damage may result. The purpose of this review is to (1) underscore the capacity of currently used parenteral Fe formulations to induce oxidative stress, (2) compare the severity of these oxidant reactions with those that result from unshielded Fe salts and with each other, and (3) speculate as to the potential of these agents to induce acute renal cell injury and augment systemic inflammatory responses. The experimental data that are reviewed should not be extrapolated to the clinical setting or be used for clinical decision making. Rather, it is hoped that the information provided herein may have utility for clinical hypothesis generation and, hence, future clinical studies. By so doing, a better understanding of Fe's potential protean effects on patients with renal disease may result.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Anemia Ferropriva/tratamento farmacológico , Hematínicos/toxicidade , Inflamação/induzido quimicamente , Compostos de Ferro/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Diálise Renal , Insuficiência Renal Crônica/complicações , Injúria Renal Aguda/metabolismo , Trifosfato de Adenosina/metabolismo , Anemia Ferropriva/etiologia , Anemia Ferropriva/metabolismo , Animais , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Compostos Férricos/toxicidade , Óxido de Ferro Sacarado , Ácido Glucárico , Hematínicos/administração & dosagem , Humanos , Inflamação/metabolismo , Infusões Intravenosas , Compostos de Ferro/administração & dosagem , Complexo Ferro-Dextran/toxicidade , Córtex Renal/efeitos dos fármacos , Córtex Renal/metabolismo , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/terapia , Fator de Necrose Tumoral alfa/metabolismo
10.
Hum Exp Toxicol ; 20(9): 471-6, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11776409

RESUMO

Skin chemical carcinogenesis has been divided into the process of initiation, promotion and progression. Earlier, we showed the role of iron overload in the promotion stage of skin carcinogenesis. In this communication, we report that iron overload does not augment croton oil-mediated tumor promotion in 7,12-dimethylbenz(a)anthracene (DMBA)-initiated pregnant mice skin tumorigenesis. Virgin female Swiss mice were given 1 mg iron/mouse/day parenterally for 2 weeks to induce iron overload. After the last injection, a group of mice was left with male mice for 10 days. These animals showed an increase in cutaneous iron concentration as compared to normal mice. Papillomas were induced in mice skin by a single topical application of DMBA as initiator. A week after the initiation, promoting agent, croton oil was applied twice per week for 20 weeks. The appearance of the first tumor (papilloma), number of tumors/mouse and percentage incidence were recorded. When compared to the iron unloaded control and iron overload pregnant groups, the iron overload virgin animals showed an increased incidence of tumors. In iron overload virgin animals, tumors appeared earlier and also the numbers of tumors/mouse were significantly higher. However, in iron overload pregnant animals, diminished tumor incidence was observed and the numbers of tumors matched the result of normal pregnant animals. Our results show that iron overload in pregnant mice does not participate in the augmentation of DMBA- and croton oil-induced skin tumorigenesis.


Assuntos
9,10-Dimetil-1,2-benzantraceno/toxicidade , Carcinógenos/toxicidade , Carcinoma de Células Escamosas/induzido quimicamente , Óleo de Cróton/toxicidade , Complexo Ferro-Dextran/toxicidade , Complicações Neoplásicas na Gravidez/induzido quimicamente , Neoplasias Cutâneas/induzido quimicamente , Animais , Carcinoma de Células Escamosas/metabolismo , Feminino , Sobrecarga de Ferro/metabolismo , Masculino , Camundongos , Papiloma/induzido quimicamente , Papiloma/metabolismo , Gravidez , Complicações Neoplásicas na Gravidez/metabolismo , Pele/metabolismo , Neoplasias Cutâneas/metabolismo
11.
Carcinogenesis ; 20(9): 1801-8, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10469627

RESUMO

The aim of this study is to establish a good animal model for esophageal adenocarcinoma (EAC) and to test the hypothesis that iron over-nutrition enhances EAC formation. With rats, esophagogastroduodenal anastomosis (EGDA) was accomplished by anastomosing the duodenum to the gastroesophageal junction. Iron supplementation was given by i.p. injection of iron dextran (4 mg Fe/kg/week). This model mimics the development of human EAC by introducing mixed reflux of gastric and duodenal contents. At 40 weeks after surgery, the body weight, food intake, hemoglobin, total serum iron, transferrin saturation, serum albumin, and plasma levels of alpha-tocopherol, gamma-tocopherol and retinol of the EGDA rats were not significantly different from those of the non-operated controls. The animals generally had only mild esophagitis, except that the area surrounding the anastomosis opening had more severe esophagitis. Columnar-lined esophagus (CLE), CLE with dysplasia, and EAC were diagnosed in 53.5, 34.9 and 25.6%, respectively, of the 43 rats. Intraperitoneal iron supplementation significantly enhanced esophageal lesions with CLE, CLE with dysplasia, and EAC to 78.0, 53. 7 and 53.7%, respectively, of the 41 rats. All the tumors were well-differentiated mucinous adenocarcinomas at the squamocolumnar junction area, where most iron deposition was observed. EGDA avoids nutritional problems seen in other animal models for EAC. We believe that direct anastomosis of squamous epithelium to columnar epithelium and mixed reflux of gastric and duodenal contents lead to the formation of CLE and EAC. With this model, we demonstrated that iron supplementation significantly enhanced EAC formation, suggesting that iron over-nutrition could also be a risk factor for human EAC.


Assuntos
Adenocarcinoma Mucinoso/etiologia , Cocarcinogênese , Neoplasias Esofágicas/etiologia , Refluxo Gastroesofágico/complicações , Sobrecarga de Ferro/complicações , Complexo Ferro-Dextran/toxicidade , Anastomose Cirúrgica , Animais , Esôfago de Barrett/complicações , Modelos Animais de Doenças , Duodeno/cirurgia , Epitélio/patologia , Esôfago/cirurgia , Conteúdo Gastrointestinal , Injeções Intraperitoneais , Ferro/sangue , Complexo Ferro-Dextran/administração & dosagem , Masculino , Metaplasia , Ratos , Ratos Sprague-Dawley , Albumina Sérica/análise , Estômago/cirurgia , Transferrina/análise , Vitamina A/sangue , Vitamina E/sangue
12.
Environ Mol Mutagen ; 33(1): 28-41, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10037321

RESUMO

The mutagenic activity of elemental and salt forms of iron (Fe), including compounds currently being used in dietary supplements and for food fortification, were evaluated for mutagenicity in Salmonella typhimurium and L5178Y mouse lymphoma cells. Except for the weak response obtained with ferrous fumarate, none of the compounds induced a mutagenic response in Salmonella. In the mouse lymphoma assay, responses were related to the Fe compound and/or reduction of ferric (Fe+3) to ferrous (Fe+2). Responses with the elemental forms of Fe were divergent. Electrolytic Fe with a relatively larger particle size and irregular shape was negative. The smaller-sized carbonyl Fe, which after 4 hr attached to and was taken up by the cells, induced mutagenic responses both with and without S9. With ferric chloride (FeCl3) and ferric phosphate (FePO4), there was an increase in mutant frequency only with S9. With the Fe+2 compounds, ferrous sulfate (FeSO4) and ferrous fumarate (FeC4H2O4), positive responses were observed without S9. The Fe chelate, sodium Fe(III)EDTA was positive in both the presence and absence of S9. The lowest effective doses (LED) for induction of mutagenicity were identified for these compounds and an LED ratio calculated. The LED ratio ranges from 1 for FeSO4 to 30 for carbonyl Fe, which are similar to oral LD50 values obtained in animal studies.


Assuntos
Ferro/toxicidade , Leucemia L5178/genética , Mutagênicos/toxicidade , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Animais , Relação Dose-Resposta a Droga , Complexo Ferro-Dextran/toxicidade , Leucemia L5178/patologia , Camundongos , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley , Células Tumorais Cultivadas
13.
Blood ; 93(1): 370-5, 1999 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9864183

RESUMO

To further examine the potential clinical usefulness of the hexadentate phenolic aminocarboxylate iron chelator N, N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) for the chronic treatment of transfusional iron overload, we performed a subchronic toxicity study of the HBED monosodium salt in rodents and have evaluated the iron excretion in primates induced by HBED. The HBED-induced iron excretion was determined for the monohydrochloride dihydrate that was first dissolved in a 0.1-mmol/L sodium phosphate buffer at pH 7.6 and administered to the primates either orally (PO) at a dose of 324 micromol/kg (149.3 mg/kg, n = 5), subcutaneously (sc) at a dose of 81 micromol/kg (37.3 mg/kg, n = 5), sc at 324 micromol/kg (n = 5), and sc at 162 micromol/kg (74.7 mg/kg) for 2 consecutive days for a total dose of 324 micromol/kg (n = 3). In addition, the monosodium salt of HBED in saline was administered to the monkeys sc at a single dose of 150 micromol/kg (64.9 mg/kg, n = 5) or at a dose of 75 micromol/kg every other day for three doses, for a total dose of 225 micromol/kg (n = 4). For comparative purposes, we have also administered deferoxamine (DFO) PO and sc in aqueous solution at a dose of 300 micromol/kg (200 mg/kg). In the iron-loaded Cebus apella monkey, whereas the PO administration of DFO or HBED even at a dose of 300 to 324 micromol/kg was ineffective, the sc injection of HBED in buffer or its monosodium salt, 75 to 324 micromol/kg, produced a net iron excretion that was nearly three times that observed after similar doses of sc DFO. In patients with transfusional iron overload, sc injections of HBED may provide a much needed alternative to the use of prolonged parenteral infusions of DFO. Note: After the publication of our previous paper (Blood, 91:1446, 1998) and the completion of the studies described here, it was discovered that the HBED obtained from Strem Chemical Co (Newburyport, MA) that was labeled and sold as a dihydrochloride dihydrate was in fact the monohydrochloride dihydrate. Therefore, the actual administered doses were 81, 162, or 324 micromol/kg; not 75, 150, or 300 micromol/kg as was previously reported. The new data have been recalculated accordingly, and the data from our earlier study, corrected where applicable, are shown in parentheses.


Assuntos
Desferroxamina/toxicidade , Ácido Edético/análogos & derivados , Quelantes de Ferro/toxicidade , Administração Oral , Animais , Cebus , Desferroxamina/farmacocinética , Ácido Edético/farmacocinética , Ácido Edético/toxicidade , Injeções Intravenosas , Injeções Subcutâneas , Ferro/metabolismo , Ferro/urina , Quelantes de Ferro/farmacocinética , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/metabolismo , Complexo Ferro-Dextran/farmacocinética , Complexo Ferro-Dextran/toxicidade , Masculino , Ratos , Ratos Sprague-Dawley
14.
Anticancer Res ; 9(6): 1477-82, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2560618

RESUMO

The effect of parenteral and oral iron was examined in the rat 1,2 dimethylhydrazine (DMH) colorectal carcinogenesis model in a series of experiments. Parenteral supplementation of iron was found to augment tumor yield (p = 0.012) and oral iron was found to augment tumor incidence (p = 0.03, when control groups were combined). In addition, phytic acid, a significant component of dietary fiber was found to reverse the augmenting effect of oral iron on tumor yield and incidence (p = 0.09 for both). Furthermore, in a short term DMH nuclear toxicity assay, analysis of the karyorrhectic index (KI), there was no difference in the KI between oral iron and phytate dietary groups (p = 0.53 for the left colon and p = 0.2 for the right colon), implying that iron's effect on colorectal tumor induction takes place during the promotional phase of carcinogenesis and not during initiation. These experiments support the epidemiologic observation that dietary iron may augment colorectal cancer risk and that the mechanism by which dietary fiber diminishes colorectal cancer risk may be the chelation of dietary iron by the phytic acid component of dietary fiber.


Assuntos
Carcinógenos , Colo/patologia , Neoplasias do Colo/patologia , Fibras na Dieta/uso terapêutico , Complexo Ferro-Dextran/toxicidade , Neoplasias Retais/patologia , 1,2-Dimetilidrazina , Animais , Colo/efeitos dos fármacos , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/prevenção & controle , Dimetilidrazinas , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Cariotipagem , Ratos , Ratos Endogâmicos , Neoplasias Retais/induzido quimicamente , Neoplasias Retais/prevenção & controle
15.
Vet Med Nauki ; 23(9): 35-44, 1986.
Artigo em Búlgaro | MEDLINE | ID: mdl-3811219

RESUMO

Investigated were the Bulgarian preparation dextrofer-100 (Pharmachim) and miofer-100 (Farbwerke, Hoechst, West Germany)--iron-dextran preparations with 100 mg Fe3+/cm3 each. Use was made of 62 domestic cats, 8 guinea pigs, and 18 albino rats. tI was found that the venous introduction of iron-dextran complexes into uretane-treated cats at rates of 100 to 500 mg Fe3+/kg body mass lowered the blood pressure by 10 to 65 per cent; the depressive effect was more strongly manifested with the use of miofer-100. At 100 mg Fe3+/kg and higher doses led to alfa-adrenolytic manifestations (an inverse effect of noradrenaline), and did not change the action of acetyl-choline, histamine, and serotonin. At venous injection the iron-dextran complexes diminished the amplitudes of the heart contractions (with cats in situ). With regard to the nervous-and-muscle condition these preparations were found to manifest an action that resembled that of curare (the effect produced by miofer was stronger). Dextrofer-100 in a five-fold application to guinea pigs at the rate of 0.2 cm3+ (= 20 mg Fe3+) blocked the sensibilizing action of horse serum--it gave protection from an aphylactic shock in about 70 per cent of the animals. In muscular application to albino rats with experimentally induced dextran edema this preparation manifested an antiedema action. The iron-dextran complexes lowered the contraction capacity of ileum sections (taken from guinea pigs) that was manifested under the action of serotonin and histamine.


Assuntos
Complexo Ferro-Dextran/farmacologia , Anafilaxia/induzido quimicamente , Animais , Sistema Nervoso Autônomo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Gatos , Avaliação Pré-Clínica de Medicamentos , Edema/tratamento farmacológico , Cobaias , Imunização , Complexo Ferro-Dextran/uso terapêutico , Complexo Ferro-Dextran/toxicidade , Tono Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Ratos , Respiração/efeitos dos fármacos
16.
Vet Med Nauki ; 20(5-6): 87-98, 1983.
Artigo em Búlgaro | MEDLINE | ID: mdl-6197805

RESUMO

A combined preparation, biofer, was studied, defining its clinical and pharmacological capacity. Featuring in its composition are: normal bovine gammaglobulin, 8.0 g; ferridextran (dextrofer-100), 32 cm2 (= 3.2 g Fe); cuprum sulfuricum, 0.32 g (= 0.08 Cu); Co chloride, 0.18 g (= 0.08 Co); cyancobalamin, 0.0032 g; and protein hydrolysate up to 100 cm3, at pH = 7.0-7.2. The local and total tolerance of animals for biofer was studied along with the acute toxicity, absorption, and retention in the body of test animals and calves as well as the antianemic action in albino mice and calves. It was found that at 4 degrees C to 8 degrees C the shelf life of biofer was 2 years. Its LD50 at subcutaneous injection to albino rats was 11.7 cm3/kg body mass. At the rate of 0.6 cm3/kg (i/m) rabbits did not manifest local and total intolerance; at 1.8 cm3/kg there was no local inflammation, however, a transient drop of appetite was seen; at 3 cm3/kg rabbits manifested intoxication with exitus. At i/m introduction to rabbits and calves biofer was more slowly absorbed than dextrofer-100. The liver and spleen of animals injected with biofer showed higher values for copper. In i/m application to anemic albino rats biofer showed a better antianemic effect than dextrofer-100. In calves it activated to a better extent both erythropoiesis and leukopoiesis.


Assuntos
Anemia/veterinária , Doenças dos Bovinos/tratamento farmacológico , Cobalto/farmacologia , Cobre/farmacologia , Complexo Ferro-Dextran/farmacologia , Hidrolisados de Proteína/farmacologia , Vitamina B 12/farmacologia , gama-Globulinas/farmacologia , Absorção , Anemia/tratamento farmacológico , Animais , Bovinos , Cobalto/uso terapêutico , Cobalto/toxicidade , Cobre/uso terapêutico , Cobre/toxicidade , Sulfato de Cobre , Combinação de Medicamentos/farmacologia , Combinação de Medicamentos/uso terapêutico , Combinação de Medicamentos/toxicidade , Avaliação de Medicamentos/veterinária , Avaliação Pré-Clínica de Medicamentos/veterinária , Tolerância a Medicamentos , Compostos Ferrosos , Complexo Ferro-Dextran/uso terapêutico , Complexo Ferro-Dextran/toxicidade , Masculino , Camundongos , Hidrolisados de Proteína/uso terapêutico , Hidrolisados de Proteína/toxicidade , Ratos , Ratos Endogâmicos , Vitamina B 12/uso terapêutico , Vitamina B 12/toxicidade , gama-Globulinas/uso terapêutico , gama-Globulinas/toxicidade
18.
Scand J Haematol Suppl ; 32: 87-98, 1977.
Artigo em Inglês | MEDLINE | ID: mdl-272039

RESUMO

Four groups of Sprague-Dawley rats were given Ferastral, an iron-poly(sorbitol-gluconic acid) complex (IPSG) or Imferon, an iron-dextran complex, intramuscularly twice a week for 17 weeks. The experiment lasted for 95 weeks. Each compound was given to two groups, one low dose group and one high dose group. Depending on the body mass, the dose levels varied between 2.5 and 10 mg (25-50 mg/kg body mass) and between 5 and 20 mg (50-100 mg/kg body mass) of iron per rat, respectively. The mean total dose of iron per rat was calculated to be 235 and 495 mg, respectively. Another group of animals served as a control. From about the 30th experimental week onwards tumours developed at the intramuscular injection sites in the groups given Ferastral and Imferon. The tumours appeared to be sarcomas. In almost all the treated animals that lived longer than 30 weeks after the start of the experiment, sarcomas were present at the intramuscular injection sites. The sarcomas appeared earlier in the high dose groups than in the low dose groups and slightly earlier in the rats given Ferastral than in those given Imferon. No other pathological changes, including neoplasms, were considered to be related to the treatment.


Assuntos
Carcinógenos , Ferro/administração & dosagem , Sarcoma/induzido quimicamente , Neoplasias de Tecidos Moles/induzido quimicamente , Animais , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Feminino , Gluconatos/administração & dosagem , Gluconatos/toxicidade , Injeções Intramusculares , Ferro/toxicidade , Complexo Ferro-Dextran/toxicidade , Masculino , Camundongos , Músculos/patologia , Metástase Neoplásica , Sarcoma Experimental/induzido quimicamente , Sarcoma Experimental/patologia , Neoplasias de Tecidos Moles/patologia , Sorbitol/administração & dosagem , Sorbitol/toxicidade
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