WorldWideScience

Sample records for antioxidant iron chelating

  1. Flavonoids function as antioxidants: By scavenging reactive oxygen species or by chelating iron?

    Science.gov (United States)

    Wuguo, Deng; Xingwang, Fang; Jilan, Wu

    1997-09-01

    Flavonoids have been reported to exhibit strong antioxidative activity. In the present work, a systematic mechanistic study has been performed on five flavonoids (baicalin, hesperidin, naringin, quercetin and rutin) selected according to their structural characteristics. The experimental results reveal that flavonoids function as antioxidant mainly by chelating iron ions and by scavenging peroxyl radicals whereas their OH radical scavenging effect is much less important.

  2. Flavonoids function as antioxidants: by scavenging reactive oxygen species or by chelating iron?

    International Nuclear Information System (INIS)

    Flavonoids have been reported to exhibit strong antioxidative activity. In the present work, a systematic mechanistic study has been performed on five flavonoids (baicalin, hesperidin, naringin, quercetin and rutin) selected according to their structural characteristics. The experimental results reveal that flavonoids function as antioxidant mainly by chelating iron ions and by scavenging peroxyl radicals whereas their OH radical scavenging effect is much less important. (author)

  3. Flavonoids function as antioxidants: by scavenging reactive oxygen species or by chelating iron?

    Energy Technology Data Exchange (ETDEWEB)

    Wuguo Deng; Xingwang Fang; Jilan Wu [Peking Univ., Technical Physics Dept., Beijing (China)

    1997-09-01

    Flavonoids have been reported to exhibit strong antioxidative activity. In the present work, a systematic mechanistic study has been performed on five flavonoids (baicalin, hesperidin, naringin, quercetin and rutin) selected according to their structural characteristics. The experimental results reveal that flavonoids function as antioxidant mainly by chelating iron ions and by scavenging peroxyl radicals whereas their OH radical scavenging effect is much less important. (author).

  4. Combined Iron Chelator and Antioxidant Exerted Greater Efficacy on Cardioprotection Than Monotherapy in Iron-Overloaded Rats

    Science.gov (United States)

    Wongjaikam, Suwakon; Kumfu, Sirinart; Khamseekaew, Juthamas; Sripetchwandee, Jirapas; Srichairatanakool, Somdet; Fucharoen, Suthat; Chattipakorn, Siriporn C.; Chattipakorn, Nipon

    2016-01-01

    Background Iron chelators are used to treat iron overload cardiomyopathy patients. However, a direct comparison of the benefits of three common iron chelators (deferoxamine (DFO), deferiprone (DFP) and deferasirox (DFX)) or an antioxidant (N-acetyl cysteine (NAC)) with a combined DFP and NAC treatments on left ventricular (LV) function with iron overload has not been investigated. Methods and Findings Male Wistar rats were fed with either a normal diet or a high iron diet (HFe group) for 4 months. After 2 months, the HFe-fed rats were divided into 6 groups to receive either: a vehicle, DFO (25 mg/kg/day), DFP (75 mg/kg/day), DFX (20 mg/kg/day), NAC (100 mg/kg/day) or the combined DFP and NAC for 2 months. Our results demonstrated that HFe rats had increased plasma non-transferrin bound iron (NTBI), malondialdehyde (MDA), cardiac iron and MDA levels and cardiac mitochondrial dysfunction, leading to LV dysfunction. Although DFO, DFP, DFX or NAC improved these parameters, leading to improved LV function, the combined DFP and NAC therapy caused greater improvement, leading to more extensively improved LV function. Conclusions The combined DFP and NAC treatment had greater efficacy than monotherapy in cardioprotection through the reduction of cardiac iron deposition and improved cardiac mitochondrial function in iron-overloaded rats. PMID:27428732

  5. Aroylhydrazone iron chelators: Tuning antioxidant and antiproliferative properties by hydrazide modifications.

    Science.gov (United States)

    Hrušková, Kateřina; Potůčková, Eliška; Hergeselová, Tereza; Liptáková, Lucie; Hašková, Pavlína; Mingas, Panagiotis; Kovaříková, Petra; Šimůnek, Tomáš; Vávrová, Kateřina

    2016-09-14

    Aroylhydrazones such as salicylaldehyde isonicotinoyl hydrazone (SIH) are tridentate iron chelators that may possess antioxidant and/or antineoplastic activities. Their main drawback, their low stability in plasma, has recently been partially overcome by exchanging the aldimine hydrogen for an unbranched alkyl group. In this study, ten analogs of methyl- and ethyl-substituted SIH derivatives with modified hydrazide scaffolds were synthesized to further explore their structure-activity relationships. Their iron-chelation efficiencies, anti- or pro-oxidant potentials, abilities to induce protection against model oxidative injury on the H9c2 cell line derived from rat embryonic cardiac tissue, cytotoxicities on the same H9c2 cells and antiproliferative activities on MCF-7 human breast adenocarcinoma and HL-60 human promyelotic leukemia cell lines were evaluated. Compounds derived from lipophilic naphthyl and biphenyl hydrazides displayed highly selective antiproliferative activities against both MCF-7 and HL-60 cell lines, and they showed markedly improved stabilities in plasma compared to SIH. Of particular interest is a hydrazone prepared from 2-hydroxypropiophenone and pyridazin-4-carbohydrazide that showed a considerable antiproliferative effect and protected cardiomyoblasts against oxidative stress with a five-fold higher selectivity compared to the parent compound SIH. Thus, this work highlighted new structure-activity relationships among antiproliferative and antioxidant aroylhydrazones and identified new lead compounds for further development. PMID:27187862

  6. Iron Chelators and Antioxidants Regenerate Neuritic Tree and Nigrostriatal Fibers of MPP+/MPTP-Lesioned Dopaminergic Neurons

    Science.gov (United States)

    Aguirre, Pabla; Mena, Natalia P.; Carrasco, Carlos M.; Muñoz, Yorka; Pérez-Henríquez, Patricio; Morales, Rodrigo A.; Cassels, Bruce K.; Méndez-Gálvez, Carolina; García-Beltrán, Olimpo; González-Billault, Christian; Núñez, Marco T.

    2015-01-01

    Neuronal death in Parkinson’s disease (PD) is often preceded by axodendritic tree retraction and loss of neuronal functionality. The presence of non-functional but live neurons opens therapeutic possibilities to recover functionality before clinical symptoms develop. Considering that iron accumulation and oxidative damage are conditions commonly found in PD, we tested the possible neuritogenic effects of iron chelators and antioxidant agents. We used three commercial chelators: DFO, deferiprone and 2.2’-dypyridyl, and three 8-hydroxyquinoline-based iron chelators: M30, 7MH and 7DH, and we evaluated their effects in vitro using a mesencephalic cell culture treated with the Parkinsonian toxin MPP+ and in vivo using the MPTP mouse model. All chelators tested promoted the emergence of new tyrosine hydroxylase (TH)-positive processes, increased axodendritic tree length and protected cells against lipoperoxidation. Chelator treatment resulted in the generation of processes containing the presynaptic marker synaptophysin. The antioxidants N-acetylcysteine and dymetylthiourea also enhanced axodendritic tree recovery in vitro, an indication that reducing oxidative tone fosters neuritogenesis in MPP+-damaged neurons. Oral administration to mice of the M30 chelator for 14 days after MPTP treatment resulted in increased TH- and GIRK2-positive nigra cells and nigrostriatal fibers. Our results support a role for oral iron chelators as good candidates for the early treatment of PD, at stages of the disease where there is axodendritic tree retraction without neuronal death. PMID:26658949

  7. Ferritin iron minerals are chelator targets, antioxidants, and coated, dietary iron

    OpenAIRE

    Theil, Elizabeth C.

    2010-01-01

    Cellular ferritin is central for iron balance during transfusions therapies; serum ferritin is a small fraction of body ferritin, albeit a convenient reporter. Iron overload induces extra ferritin protein synthesis but the protein is overfilled with the extra iron that damages ferritin, with conversion to toxic hemosiderin. Three new approaches that manipulate ferritin to address excess iron, hemosiderin, and associated oxidative damage in Cooley’s Anemia and other iron overload conditions, a...

  8. Structure-activity relationships of novel salicylaldehyde isonicotinoyl hydrazone (SIH analogs: iron chelation, anti-oxidant and cytotoxic properties.

    Directory of Open Access Journals (Sweden)

    Eliška Potůčková

    Full Text Available Salicylaldehyde isonicotinoyl hydrazone (SIH is a lipophilic, tridentate iron chelator with marked anti-oxidant and modest cytotoxic activity against neoplastic cells. However, it has poor stability in an aqueous environment due to the rapid hydrolysis of its hydrazone bond. In this study, we synthesized a series of new SIH analogs (based on previously described aromatic ketones with improved hydrolytic stability. Their structure-activity relationships were assessed with respect to their stability in plasma, iron chelation efficacy, redox effects and cytotoxic activity against MCF-7 breast adenocarcinoma cells. Furthermore, studies assessed the cytotoxicity of these chelators and their ability to afford protection against hydrogen peroxide-induced oxidative injury in H9c2 cardiomyoblasts. The ligands with a reduced hydrazone bond, or the presence of bulky alkyl substituents near the hydrazone bond, showed severely limited biological activity. The introduction of a bromine substituent increased ligand-induced cytotoxicity to both cancer cells and H9c2 cardiomyoblasts. A similar effect was observed when the phenolic ring was exchanged with pyridine (i.e., changing the ligating site from O, N, O to N, N, O, which led to pro-oxidative effects. In contrast, compounds with long, flexible alkyl chains adjacent to the hydrazone bond exhibited specific cytotoxic effects against MCF-7 breast adenocarcinoma cells and low toxicity against H9c2 cardiomyoblasts. Hence, this study highlights important structure-activity relationships and provides insight into the further development of aroylhydrazone iron chelators with more potent and selective anti-neoplastic effects.

  9. Acute toxicity test of a natural iron chelator and an antioxidant, extracted from Triticum aestivum Linn. (wheat grass).

    Science.gov (United States)

    Das, Priyabrata; Mukhopadhyay, Soma; Mandal, Suvra; Chakraborty, Abhijit; Pal, Amartya; Sarkar, Nirmal Kumar; Mukhopadhyay, Ashis

    2014-01-01

    Triticum aestivum (wheat grass) is widely used in traditional medicine to treat various diseases. Previously the purified compounds and crude extract of T. aestivum were established to have iron chelation potency and antioxidant activity. So it is necessary to evaluate the toxic properties of any compound isolated from plant extract to prevent any untoward side effects. The aim of this study was to determine the acute oral toxicity level of our purified compounds, i.e. mugineic acids and methylpheophorbide a., and crude extract of T. aestivum, on Swiss albino mice at dosage of 2000 mg/kg for a period of 14 days using the organisation for economic co-operation and development guidelines 423. There was no mortality. No change in behavioural pattern, clinical signs, body weight and blood biochemistry profile were observed. Kidney and liver showed normal histo-pathological architecture. Hence, the oral administration of compounds and extract of T. aestivum did not produce any significant toxic effect on mice. Thus we may conclude that the extract can be utilised for pharmaceutical formulations as iron chelator and antioxidant agent for various diseases. PMID:24697628

  10. Synthesis, antioxidant activities of the nickel(II), iron(III) and oxovanadium(IV) complexes with N2O2 chelating thiosemicarbazones

    Science.gov (United States)

    Bal-Demirci, Tülay; Şahin, Musa; Özyürek, Mustafa; Kondakçı, Esin; Ülküseven, Bahri

    The nickel(II), iron(III) and oxovanadium(IV) complexes of the N2O2 chelating thiosemicarbazones were synthesized using 4-hydroxysalicyladehyde-S-methylthiosemicarbazone and R1-substitute-salicylaldehyde (R1: 4-OH, H) in the presence of Ni(II), Fe(III), VO(IV) ions by the template reaction. The structures of the thiosemicarbazone complexes were characterized by FT-IR, 1H NMR, elemental, ESI-MS and APCI-MS analysis. The synthesized compounds were screened for their antioxidant capacity by using the cupric reducing antioxidant capacity (CUPRAC) method. Trolox equivalent antioxidant capacity (TEAC) of iron(III) complex, 1c, was measured to be higher than that of the other complexes. Other parameters of antioxidant activity (scavenging effects on rad OH, O2rad - and H2O2) of these compounds were also determined. All the compounds have shown encouraging ROS scavenging activities.

  11. Antioxidant, Iron Chelating and Tyrosinase Inhibitory Activities of Extracts from Talinum triangulare Leach Stem

    OpenAIRE

    Ana Paula Oliveira Amorim; Márcia Cristina Campos de Oliveira; Thiago de Azevedo Amorim; Aurea Echevarria

    2013-01-01

    The aim of this work is to evaluate the antioxidant activity against the radical species DPPH, the reducing capacity against Fe II ions, and the inhibitory activity on the tyrosinase enzyme of the T. triangulare. Hydromethanolic crude extract provided two fractions after the liquid/liquid partition with chloroform. The Folin-Ciocalteu method determined the total phenolic content of the crude extract (CE) and the hydromethanolic fraction (Fraction 1), resulting in a concentration of 0.5853 g/1...

  12. Iron chelation and multiple sclerosis

    OpenAIRE

    Kelsey J. Weigel; Sharon G. Lynch; Steven M. LeVine

    2014-01-01

    Histochemical and MRI studies have demonstrated that MS (multiple sclerosis) patients have abnormal deposition of iron in both gray and white matter structures. Data is emerging indicating that this iron could partake in pathogenesis by various mechanisms, e.g., promoting the production of reactive oxygen species and enhancing the production of proinflammatory cytokines. Iron chelation therapy could be a viable strategy to block iron-related pathological events or it can confer cellular prote...

  13. Antioxidant, Iron Chelating and Tyrosinase Inhibitory Activities of Extracts from Talinum triangulare Leach Stem

    Science.gov (United States)

    Oliveira Amorim, Ana Paula; Campos de Oliveira, Márcia Cristina; de Azevedo Amorim, Thiago; Echevarria, Aurea

    2013-01-01

    The aim of this work is to evaluate the antioxidant activity against the radical species DPPH, the reducing capacity against Fe II ions, and the inhibitory activity on the tyrosinase enzyme of the T. triangulare. Hydromethanolic crude extract provided two fractions after the liquid/liquid partition with chloroform. The Folin-Ciocalteu method determined the total phenolic content of the crude extract (CE) and the hydromethanolic fraction (Fraction 1), resulting in a concentration of 0.5853 g/100 g for Fraction 1, and 0.1400 g/100 g for the CE. Taking into account the results of the DPPH, the free radical scavenging capacity was confirmed. The formation of complexes with Fe II ions was evaluated by UV/visible spectrometry; results showed that CE has complexing power similar to the positive control (Gingko biloba extract).The inhibitory capacity of samples against the tyrosinase enzyme was determined by the oxidation of L-DOPA, providing IC50 values of 13.3 μg·mL−1 (CE) and 6.6 μg·mL−1 (Fraction 1). The values indicate that Fraction 1 was more active and showed a higher inhibitory power on the tyrosinase enzyme than the ascorbic acid, used as positive control. The hydromethanolic extract of T. triangulare proved to have powerful antioxidant activity and to inhibit the tyrosinase enzyme; its potential is increased after the partition with chloroform. PMID:26784338

  14. Antioxidant, Iron Chelating and Tyrosinase Inhibitory Activities of Extracts from Talinum triangulare Leach Stem

    Directory of Open Access Journals (Sweden)

    Ana Paula Oliveira Amorim

    2013-07-01

    Full Text Available The aim of this work is to evaluate the antioxidant activity against the radical species DPPH, the reducing capacity against Fe II ions, and the inhibitory activity on the tyrosinase enzyme of the T. triangulare. Hydromethanolic crude extract provided two fractions after the liquid/liquid partition with chloroform. The Folin-Ciocalteu method determined the total phenolic content of the crude extract (CE and the hydromethanolic fraction (Fraction 1, resulting in a concentration of 0.5853 g/100 g for Fraction 1, and 0.1400 g/100 g for the CE. Taking into account the results of the DPPH, the free radical scavenging capacity was confirmed. The formation of complexes with Fe II ions was evaluated by UV/visible spectrometry; results showed that CE has complexing power similar to the positive control (Gingko biloba extract.The inhibitory capacity of samples against the tyrosinase enzyme was determined by the oxidation of L-DOPA, providing IC50 values of 13.3 μg·mL−1 (CE and 6.6 μg·mL−1 (Fraction 1. The values indicate that Fraction 1 was more active and showed a higher inhibitory power on the tyrosinase enzyme than the ascorbic acid, used as positive control. The hydromethanolic extract of T. triangulare proved to have powerful antioxidant activity and to inhibit the tyrosinase enzyme; its potential is increased after the partition with chloroform.

  15. Antioxidant, Iron Chelating and Tyrosinase Inhibitory Activities of Extracts from Talinum triangulare Leach Stem.

    Science.gov (United States)

    Oliveira Amorim, Ana Paula; Campos de Oliveira, Márcia Cristina; de Azevedo Amorim, Thiago; Echevarria, Aurea

    2013-01-01

    The aim of this work is to evaluate the antioxidant activity against the radical species DPPH, the reducing capacity against Fe II ions, and the inhibitory activity on the tyrosinase enzyme of the T. triangulare. Hydromethanolic crude extract provided two fractions after the liquid/liquid partition with chloroform. The Folin-Ciocalteu method determined the total phenolic content of the crude extract (CE) and the hydromethanolic fraction (Fraction 1), resulting in a concentration of 0.5853 g/100 g for Fraction 1, and 0.1400 g/100 g for the CE. Taking into account the results of the DPPH, the free radical scavenging capacity was confirmed. The formation of complexes with Fe II ions was evaluated by UV/visible spectrometry; results showed that CE has complexing power similar to the positive control (Gingko biloba extract).The inhibitory capacity of samples against the tyrosinase enzyme was determined by the oxidation of L-DOPA, providing IC50 values of 13.3 μg·mL(-1) (CE) and 6.6 μg·mL(-1) (Fraction 1). The values indicate that Fraction 1 was more active and showed a higher inhibitory power on the tyrosinase enzyme than the ascorbic acid, used as positive control. The hydromethanolic extract of T. triangulare proved to have powerful antioxidant activity and to inhibit the tyrosinase enzyme; its potential is increased after the partition with chloroform. PMID:26784338

  16. Iron chelation and multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Kelsey J. Weigel

    2014-01-01

    Full Text Available Histochemical and MRI studies have demonstrated that MS (multiple sclerosis patients have abnormal deposition of iron in both gray and white matter structures. Data is emerging indicating that this iron could partake in pathogenesis by various mechanisms, e.g., promoting the production of reactive oxygen species and enhancing the production of proinflammatory cytokines. Iron chelation therapy could be a viable strategy to block iron-related pathological events or it can confer cellular protection by stabilizing hypoxia inducible factor 1α, a transcription factor that normally responds to hypoxic conditions. Iron chelation has been shown to protect against disease progression and/or limit iron accumulation in some neurological disorders or their experimental models. Data from studies that administered a chelator to animals with experimental autoimmune encephalomyelitis, a model of MS, support the rationale for examining this treatment approach in MS. Preliminary clinical studies have been performed in MS patients using deferoxamine. Although some side effects were observed, the large majority of patients were able to tolerate the arduous administration regimen, i.e., 6–8 h of subcutaneous infusion, and all side effects resolved upon discontinuation of treatment. Importantly, these preliminary studies did not identify a disqualifying event for this experimental approach. More recently developed chelators, deferasirox and deferiprone, are more desirable for possible use in MS given their oral administration, and importantly, deferiprone can cross the blood–brain barrier. However, experiences from other conditions indicate that the potential for adverse events during chelation therapy necessitates close patient monitoring and a carefully considered administration regimen.

  17. Antioxidant properties of modified rutin esters by DPPH, reducing power, iron chelation and human low density lipoprotein assays

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Nielsen, Nina Skall; Jacobsen, Charlotte;

    2010-01-01

    moieties. Herein, two derivatives of rutin (possessing C12:0 or C16:0 acyl groups) were assessed for their antioxidant properties, and compared with their parent compound, rutin and with butylated hydroxytoluene (BHT). While all compounds exhibited relatively strong radical scavenging abilities, modified...... rutin compounds exhibited decreased reducing power and metal chelating abilities as compared to rutin. Conversely, investigations on the oxidation of human low density lipoprotein (LDL) revealed that rutin laurate was most effective in inhibiting oxidation by prolonging LDL lag time for an in vitro...... system. With regards to in vivo considerations, a pre-treatment step confirmed that the ester bond linking rutin and acyl moieties was most susceptible to hydrolysis by digestive enzymes, while rutin itself was not degraded. Thus, acylation of rutin with medium or long chain fatty acids may result in...

  18. Iron Chelation Therapy in Myelodysplastic Syndromes

    OpenAIRE

    Giuseppe Saglio; Daniela Cilloni; Emanuela Messa

    2010-01-01

    Myelodysplastic syndromes (MDS) are a heterogeneous disorder of the hematopoietic stem cells, frequently characterized by anemia and transfusion dependency. In low-risk patients, transfusion dependency can be long lasting, leading to iron overload. Iron chelation therapy may be a therapeutic option for these patients, especially since the approval of oral iron chelators, which are easier to use and better accepted by the patients. The usefulness of iron chelation in MDS patients is still unde...

  19. Importance of iron chelation therapy

    OpenAIRE

    A. Varoğlu

    2011-01-01

    It is necessary to remember that today patients have different options of chelation treatment, as desferrioxamine, deferiprone and deferasirox are available. However, a patient has to be compliant with treatments. They have always to remember that too much iron causes different complications and could be a barrier for a definitive cure from thalassemia. 由于出现了去铁胺、去铁酮和去铁斯若等药物,病人现在可以选择不同的螯合治疗方式。 然而,病人必须适应这几种治疗方式。 他们必须时刻记住太多的铁元素会引发多种并发症,并对地中海贫血的彻底治疗造成阻碍。...

  20. Trypanotoxic activity of thiosemicarbazone iron chelators.

    Science.gov (United States)

    Ellis, Samuel; Sexton, Darren W; Steverding, Dietmar

    2015-03-01

    Only a few drugs are available for treating sleeping sickness and nagana disease; parasitic infections caused by protozoans of the genus Trypanosoma in sub-Saharan Africa. There is an urgent need for the development of new medicines for chemotherapy of these devastating diseases. In this study, three newly designed thiosemicarbazone iron chelators, TSC24, Dp44mT and 3-AP, were tested for in vitro activity against bloodstream forms of Trypanosoma brucei and human leukaemia HL-60 cells. In addition to their iron chelating properties, TSC24 and Dp44mT inhibit topoisomerase IIα while 3-AP inactivates ribonucleotide reductase. All three compounds exhibited anti-trypanosomal activity, with minimum inhibitory concentration (MIC) values ranging between 1 and 100 µM and 50% growth inhibition (GI50) values of around 250 nM. Although the compounds did not kill HL-60 cells (MIC values >100 µM), TSC24 and Dp44mT displayed considerable cytotoxicity based on their GI50 values. Iron supplementation partly reversed the trypanotoxic and cytotoxic activity of TSC24 and Dp44mT but not of 3-AP. This finding suggests possible synergy between the iron chelating and topoisomerase IIα inhibiting activity of the compounds. However, further investigation using separate agents, the iron chelator deferoxamine and the topoisomerase II inhibitor epirubicin, did not support any synergy for the interaction of iron chelation and topoisomerase II inhibition. Furthermore, TSC24 was shown to induce DNA degradation in bloodstream forms of T. brucei indicating that the mechanism of trypanotoxic activity of the compound is topoisomerase II independent. In conclusion, the data support further investigation of thiosemicarbazone iron chelators with dual activity as lead compounds for anti-trypanosomal drug development. PMID:25595343

  1. IRON CHELATION THERAPY IN THALASSEMIA SYNDROMES

    Directory of Open Access Journals (Sweden)

    Paolo Cianciulli

    2009-06-01

    Full Text Available Transfusional hemosiderosis is a frequent complication in patients with transfusion dependent chronic diseases such as  thalassemias and severe type of sickle cell diseases. As there are no physiological mechanisms to excrete the iron contained in transfused red cells (1 unit of blood contains approximately 200 mg of iron the excess of iron is stored in various organs. Cardiomyopathy is the most severe complication covering more than 70% of the causes of death of thalassemic patients. Although the current reference standard iron chelator deferoxamine (DFO has been used clinically for over four decades, its effectiveness is limited by a demanding therapeutic regimen that leads to poor compliance. Despite poor compliance, because of the inconvenience of subcutaneous infusion, DFO improved considerably the survival and quality of life of patients with thalassemia. Deferiprone since 1998 and Deferasirox since 2005 were licensed for clinical use. The oral chelators have a better compliance because of oral use, a comparable efficacy to DFO in iron excretion and probably a better penetration to myocardial cells. Considerable increase in iron excretion was documented with combination therapy of DFO and Deferiprone. The proper use of the three chelators will improve the prevention and treatment of iron overload, it will reduce  complications, and improve survival and quality of life of transfused patients

  2. Recent developments centered on orally active iron chelators

    Directory of Open Access Journals (Sweden)

    Robert Hider

    2014-09-01

    Full Text Available Over the past twenty years there has been a growing interest in the orally active iron chelators, deferiprone and deferasirox, both have been extensively studied. The ability of these compounds to mobilize iron from the heart and endocrine tissue has presented the clinician with some advantages over desferrioxamine, the first therapeutic iron chelator. Other orally active iron chelators are currently under development. The critical features necessary for the design of therapeutically useful orally active iron chelators are presented in this review, together with recent studies devoted to the design of such chelators. This newly emerging range of iron chelators will enable clinicians to apply iron chelation methodology to other disease states and to begin to design personalized chelation regimes.

  3. New developments and controversies in iron metabolism and iron chelation therapy

    Science.gov (United States)

    Kontoghiorghe, Christina N; Kontoghiorghes, George J

    2016-01-01

    Iron is essential for all organisms including microbial, cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients’ therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic

  4. New developments and controversies in iron metabolism and iron chelation therapy.

    Science.gov (United States)

    Kontoghiorghe, Christina N; Kontoghiorghes, George J

    2016-03-26

    Iron is essential for all organisms including microbial, cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients' therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic

  5. REGIONAL SIDEROSIS: A NEW CHALLENGE FOR IRON CHELATION THERAPY

    OpenAIRE

    ZviIoavCabantchik; ArnoldMunnich; MoussaB.Youdim; DavidDevos

    2013-01-01

    The traditional role of iron chelation therapy has been to reduce body iron burden via chelation of excess metal from organs and fluids and its excretion via biliary-fecal and/or urinary routes. In their present use for hemosiderosis, chelation regimens might not be suitable for treating disorders of iron maldistribution, as those are characterized by toxic islands of siderosis appearing in a background of normal or subnormal iron levels (e.g. sideroblastic anemias, neuro- and cardio-siderosi...

  6. Metal regeneration of iron chelates in nitric oxide scrubbing

    Science.gov (United States)

    Chang, S.G.; Littlejohn, D.; Shi, Y.

    1997-08-19

    The present invention relates to a process of using metal particles to reduce NO to NH{sub 3}. More specifically, the invention concerns an improved process to regenerate iron (II) (CHELATE) by reduction of iron (II) (CHELATE) (NO) complex, which process comprises: (a) contacting an aqueous solution containing iron (II) (CHELATE) (NO) with metal particles at between about 20 and 90 C to reduce NO present, produce ammonia or an ammonium ion, and produce free iron (II) (CHELATE) at a pH of between about 3 and 8. The process is useful to remove NO from flue gas and reduce pollution. 34 figs.

  7. Trypanotoxic activity of thiosemicarbazone iron chelators

    OpenAIRE

    Ellis, Samuel; Sexton, Darren; Steverding, Dietmar

    2015-01-01

    Only a few drugs are available for treating sleeping sickness and nagana disease; parasitic infections caused by protozoans of the genus Trypanosoma in sub-Saharan Africa. There is an urgent need for the development of new medicines for chemotherapy of these devastating diseases. In this study, three newly designed thiosemicarbazone iron chelators, TSC24, Dp44mT and 3-AP, were tested for in vitro activity against bloodstream forms of T. brucei and human leukaemia HL-60 cells. In addition to t...

  8. Antioxidant, Free Radical Scavenging and Metal Chelating Characteristics of Propolis

    Directory of Open Access Journals (Sweden)

    Hikmet Geckil

    2005-01-01

    Full Text Available This study was undertaken to determine the reducing characteristics, metal chelating capability, anti-lipid peroxidative and antiradical properties of propolis compared to two widely used artificial antioxidants, Butylated Hydroxyanisole (BHA and Butylated Hydroxytoluene (BHT. The water and ethanol extracts of propolis showed significantly a different degree of metal chelating, radical scavenging activity and reducing power. In general, ethanol extracts of propolis showed higher activity regarding these parameters. Synthetic antioxidants showed better activities than both propolis extracts for antioxidant properties, utilizing a -carotene bleaching method. At higher concentrations, the reducing power of ethanol extract of propolis was similar to that of artificial antioxidants. The metal chelating activity of both water and ethanol extracts of propolis was comparable to that of EDTA and significantly higher than both BHA and BHT.

  9. Μethods of iron chelation therapy: a bibliographic review

    OpenAIRE

    Maria Agapiou; Elpida Georgiadi

    2012-01-01

    "Iron Chelation Therapy" is a term used to describe the procedure of removing excess iron from the body, which is applied after a total of approximately 20 blood transfusions or when serum ferritin levels rise above 1000 ng/ml. Aim: The purpose of the present paper is a retrospective search in bibliography, concerning the methods of iron chelation treatment for patients with hemochromatosis owing to their undergoing multiple blood transfusions. Method: The methology followed, included the sea...

  10. Pathophysiological and clinical aspects of iron chelation therapy in MDS.

    Science.gov (United States)

    Gattermann, Norbert

    2012-01-01

    The majority of patients with myelodysplastic syndromes (MDS) become transfusion-dependent during the course of disease and may thus develop transfusional iron overload. As a further contributor to iron overload there is increased absorption of dietary iron from the gut, as a consequence of ineffective erythropoiesis. Compared with thalassemia, it is less clear how frequent patients with MDS develop clinical complications of iron overload, and whether the accumulation of iron shortens their survival. This review aims to summarize our current knowledge of the detrimental effects of transfusional iron overload in MDS, point out the risks associated with iron-induced oxidative stress, describe the tools available for diagnosing iron overload, indicate the treatment options with currently available iron chelators, and discuss the measurement of labile plasma iron (LPI) as a tool to monitor the efficacy of iron chelation therapy. PMID:22571702

  11. Antioxidant, Free Radical Scavenging and Metal Chelating Characteristics of Propolis

    OpenAIRE

    Hikmet Geckil; Burhan Ates; Gokhan Durmaz; Selim Erdogan; Ismet Yilmaz

    2005-01-01

    This study was undertaken to determine the reducing characteristics, metal chelating capability, anti-lipid peroxidative and antiradical properties of propolis compared to two widely used artificial antioxidants, Butylated Hydroxyanisole (BHA) and Butylated Hydroxytoluene (BHT). The water and ethanol extracts of propolis showed significantly a different degree of metal chelating, radical scavenging activity and reducing power. In general, ethanol extracts of propolis showed higher activity re...

  12. Synthesis, characterization and in vitro anticancer evaluations of two novel derivatives of deferasirox iron chelator.

    Science.gov (United States)

    Salehi, Samie; Saljooghi, Amir Sh; Shiri, Ali

    2016-06-15

    Iron (Fe) chelation therapy was initially designed to alleviate the toxic effects of excess Fe evident in Fe-overload diseases. However, the novel toxicological properties of some Fe chelator-metal complexes have shifted significant attention to their application in cancer chemotherapy. The present study investigates the new role of deferasirox as an anticancer agent due to its ability to chelate with iron. Because of aminoacids antioxidant effect, deferasirox and its two novel amino acid derivatives have been synthesized through the treatment of deferasirox with DCC as well as glycine or phenylalanine methyl ester. All new compounds have been characterized by elemental analysis, FT-IR NMR and mass spectrometry. Therefore, the cytotoxicity of these compounds was screened for antitumor activity against some cell lines using cisplatin as a comparative standard by MTT assay and Flow cytometry. The impact of iron in the intracellular generation of reactive oxygen species was assessed on HT29 and MDA-MB-231 cells. The potential of the synthesized iron chelators for their efficacy to protect cells against model oxidative injury induced was compared. The reactive oxygen species intracellular fluorescence intensity were measured and the result showed that the reactive oxygen species intensity after iron incubation increased while after chelators incubation the reactive oxygen species intensity were decreased significantly. Besides, the effect of the synthesized compounds on mouse fibroblast cell line (L929) was simultaneously evaluated as control. The pharmacological results showed that deferasirox and its two novel aminoacid derivatives were potent anticancer agents. PMID:27090924

  13. Iron chelators ICL670 and 311 inhibit HIV-1 transcription

    International Nuclear Information System (INIS)

    HIV-1 replication is induced by an excess of iron and iron chelation by desferrioxamine (DFO) inhibits viral replication by reducing proliferation of infected cells. Treatment of cells with DFO and 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311) inhibit expression of proteins that regulate cell-cycle progression, including cycle-dependent kinase 2 (CDK2). Our recent studies showed that CDK2 participates in HIV-1 transcription and viral replication suggesting that inhibition of CDK2 by iron chelators might also affect HIV-1 transcription. Here we evaluated the effect of a clinically approved orally effective iron chelator, 4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid (ICL670) and 311 on HIV-1 transcription. Both ICL670 and 311 inhibited Tat-induced HIV-1 transcription in CEM-T cells, 293T and HeLa cells. Neither ICL670 nor 311 induced cytotoxicity at concentrations that inhibited HIV-1 transcription. The chelators decreased cellular activity of CDK2 and reduced HIV-1 Tat phosphorylation by CDK2. Neither ICL670A or 311 decreased CDK9 protein level but significantly reduced association of CDK9 with cyclin T1 and reduced phosphorylation of Ser-2 residues of RNA polymerase II C-terminal domain. In conclusion, our findings add to the evidence that iron chelators can inhibit HIV-1 transcription by deregulating CDK2 and CDK9. Further consideration should be given to the development of iron chelators for future anti-retroviral therapeutics

  14. Korean Guideline for Iron Chelation Therapy in Transfusion-Induced Iron Overload

    OpenAIRE

    Jang, Jun Ho; Lee, Je-Hwan; Yoon, Sung-Soo; Jo, Deog-Yeon; Kim, Hyeoung-Joon; Chung, Jooseop; Lee, Jong Wook

    2013-01-01

    Many Korean patients with transfusion-induced iron overload experience serious clinical sequelae, including organ damage, and require lifelong chelation therapy. However, due to a lack of compliance and/or unavailability of an appropriate chelator, most patients have not been treated effectively. Deferasirox (DFX), a once-daily oral iron chelator for both adult and pediatric patients with transfusion-induced iron overload, is now available in Korea. The effectiveness of deferasirox in reducin...

  15. Guidelines on iron chelation therapy in patients with myelodysplastic syndromes and transfusional iron overload.

    Science.gov (United States)

    Gattermann, Norbert

    2007-12-01

    Experts believe that iron overload is an important problem which could be avoided with suitable treatment. Guidelines on treating myelodysplastic syndromes (MDS) include sections on using iron chelation therapy to prevent or ameliorate transfusional iron overload. The proportion of MDS patients who may benefit from iron chelation therapy is 35-55%, depending on the length of survival necessary for iron to accumulate to a detrimental level. Candidates for iron chelation are mainly patients with dyserythropoietic and cytopenic subtypes of disease, which fall into the International Prognostic Scoring System (IPSS) Low-risk or Intermediate-1-risk categories, with median survival of 3-6 years. PMID:18037413

  16. Hydroxyurea could be a good clinically relevant iron chelator.

    Directory of Open Access Journals (Sweden)

    Khushnooma Italia

    Full Text Available Our previous study showed a reduction in serum ferritin of β-thalassemia patients on hydroxyurea therapy. Here we aimed to evaluate the efficacy of hydroxyurea alone and in combination with most widely used iron chelators like deferiprone and deferasirox for reducing iron from experimentally iron overloaded mice. 70 BALB/c mice received intraperitonial injections of iron-sucrose. The mice were then divided into 8 groups and were orally given hydroxyurea, deferiprone or deferasirox alone and their combinations for 4 months. CBC, serum-ferritin, TBARS, sTfr and hepcidin were evaluated before and after iron overload and subsequently after 4 months of drug therapy. All animals were then killed. Iron staining of the heart and liver tissue was done using Perl's Prussian Blue stain. Dry weight of iron in the heart and liver was determined by atomic absorption spectrometry. Increased serum-ferritin, TBARS, hepcidin and dry weight of iron in the liver and heart showed a significant reduction in groups treated with iron chelators with maximum reduction in the group treated with a combination of deferiprone, deferasirox and hydroxyurea. Thus hydroxyurea proves its role in reducing iron from iron overloaded mice. The iron chelating effect of these drugs can also be increased if given in combination.

  17. Chelating Properties of Peptides from Red Seaweed Pyropia columbina and Its Effect on Iron Bio-Accessibility.

    Science.gov (United States)

    Cian, Raúl E; Garzón, Antonela G; Ancona, David Betancur; Guerrero, Luis Chel; Drago, Silvina R

    2016-03-01

    The aim of this work was to evaluate copper-chelating, iron-chelating and anticariogenic activity of peptides obtained by enzymatic hydrolysis of P. columbina protein concentrate and to study the effects of chelating peptides on iron bio-accessibility. Two hydrolyzates were obtained from P. columbina protein concentrate (PC) using two hydrolysis systems: alkaline protease (A) and alkaline protease + Flavourzyme (AF). FPLC gel filtration profile of PC shows a peak having molecular weight (MW) higher than 7000 Da (proteins). A and AF hydrolyzates had peptides with medium and low MW (1013 and 270 Da), respectively. Additionally, AF presented free amino acids with MW around 82 Da and higher content of His and Ser. Peptides from AF showed the highest chelating properties measured as copper-chelating activity (the lowest β-carotene oxidation rate: R o ; 0.7 min(-1)), iron-chelating activity (33 %), and phosphorous and Ca(2+) release inhibition (87 and 81 %, respectively). These properties could indicate antioxidant properties, promotion of iron absorption and anticariogenic activity, respectively. In fact, hydrolyzates promoted iron dialyzability (≈16 %), values being higher than that found for P. columbina seaweed. Chelating peptides from both hydrolyzates can maintain the iron in a soluble and bio-accessible form after gastrointestinal digestion. PMID:26860526

  18. CHELATION THERAPY FOR IRON OVERLOAD: NURSING PRACTICE IMPLICATIONS

    OpenAIRE

    Eckes, Ellen J.

    2011-01-01

    Many diseases of the blood are treated with blood transfusion therapy. Chronic transfusions can cause iron overload, and, if untreated, can cause end-organ damage. Chelation therapy provides a way of treating iron overload and minimizing its adverse effects. Nurses need to understand that iron overload is a consequence of chronic blood transfusion, and they need to know what effects it has on end-organs and what treatment options are available.

  19. Mixed ligand complexes of cobalt(III) and iron(III) containing N2O2-chelating Schiff base: Synthesis, characterisation, antimicrobial activity, antioxidant and DFT study

    Science.gov (United States)

    Pramanik, Harun A. R.; Paul, Pradip C.; Mondal, Paritosh; Bhattacharjee, Chira R.

    2015-11-01

    Six mixed ligand complexes, namely, [Co(acac)L1] (1), [Fe(acac)L1] (2), [Co(acac)L2] (3), [Fe(acac)L2] (4), [Co(acac)L3] (5), and [Fe(acac)L3] (6) (H2L1 = NN/-bis(salicylidene)-trans 1,2 diaminocyclohexane, H2L2 = NN/-bis(salicylidene)-1,2 phenylenediamine, H2L3 = NN/-bis(salicylidene)-4-methyl-1,2-phenylenediamine) were synthesised and characterized using elemental analysis, IR spectra, UV-Vis spectra, mass spectra, magnetic susceptibility measurements, 1H and 13C NMR spectroscopy, thermogravimetric analysis. The molar conductance measurement confirmed the non-electrolytic nature of the complexes in DMF solution. Antioxidant activity of the complexes was studied using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. Biological studies of the complexes have been carried out in vitro for antimicrobial activity against some selected gram-positive and gram-negative bacteria. DFT calculations were performed using GAUSSIAN 09 program to ascertain the stable electronic structure, HOMO-LUMO energy gap, chemical hardness and dipole moment of the complexes.

  20. Iron mobilization using chelation and phlebotomy

    DEFF Research Database (Denmark)

    Flaten, T. P.; Aaseth, J.; Andersen, Ole;

    2012-01-01

    . Iron overload has many different causes, both genetic and environmental. The two most common iron overload disorders are hereditary haemochromatosis and transfusional siderosis, which occurs in thalassaemias and other refractory anaemias. The two most important treatment options for iron overload are...

  1. Overview of guidelines on iron chelation therapy in patients with myelodysplastic syndromes and transfusional iron overload.

    Science.gov (United States)

    Gattermann, Norbert

    2008-07-01

    Between 2002 and 2008, a number of consensus statements and guidelines were developed by various groups around the world to educate healthcare professionals on the treatment of myelodysplastic syndromes (MDS), including the management of transfusional iron overload with iron chelation therapy. Guidelines have been developed by The Italian Society of Hematology, The UK MDS Guidelines Group, The Nagasaki Group, The National Comprehensive Cancer Network, and The MDS Foundation. These guidelines show that the approaches to managing iron overload in patients with MDS are region specific, differing in their recommendations for when iron chelation therapy should be initiated and strategies for the ongoing management of iron overload. The guidelines all agree that red blood cell transfusions are clinically beneficial to treat the symptomatic anemia in MDS, and that patients with low-risk MDS receiving transfusions are the most likely to benefit from iron chelation therapy. PMID:18581200

  2. Ascorbate status modulates reticuloendothelial iron stores and response to deferasirox iron chelation in ascorbate-deficient rats

    DEFF Research Database (Denmark)

    Brewer, Casey; Otto-Duessel, Maya; Lykkesfeldt, Jens; Nick, Hanspeter; Wood, John C

    2012-01-01

    Iron chelation is essential to patients on chronic blood transfusions to prevent toxicity from iron overload and remove excess iron. Deferasirox (DFX) is the most commonly used iron chelator in the United States; however, some patients are relatively refractory to DFX therapy. We postulated that ...

  3. Screening wheat genotypes in response to ordinary chelate and nano-iron chelate fertilizers in nutrient solution

    OpenAIRE

    S. Omidi Nargesi; Zahedi, M; H.R. Eshghizadeh; A.H. Khoshgoftarmanesh

    2015-01-01

    Recently, attentions have been taken on the investigations regarding the use of nano-sized compounds in different fields including agricultural sector. Due to the importance of evaluating the fate and operation of nano-particles in plant systems, in this survey, responses of 13 wheat genotypes to the effect of nano-iron chelate fertilizer in the Hoagland solution under the conditions of ordinary iron chelate and nano-iron chelate, with concentration of 22.5 mg/L, was studied. This experiment ...

  4. Meta-analysis of the safety of iron chelating agents

    OpenAIRE

    Li, Niya; 李妮婭

    2014-01-01

    Background: Thalassaemia is a genetic disorder disease, one of the most clinically relevant haemoglobinopathies in paediatric population. It interferes with the synthesis of haemoglobin chain. For the sake of maintaining the serum haemoglobin at a normal level, regular blood cell transfusion is required to the patients with thalassaemia. In general, patients with thalassaemia are often diagnosed at an early age and need to take a life-long iron chelating therapy to prevent the multi-organ...

  5. Brazilian Thalassemia Association protocol for iron chelation therapy in patients under regular transfusion

    OpenAIRE

    Monica Pinheiro de Almeida Verissimo; Sandra Regina Loggetto; Antonio Fabron Junior; Giorgio Roberto Baldanzi; Nelson Hamerschlak; Juliano de Lara Fernandes; Aderson da Silva Araujo; Clarisse Lopes de Castro Lobo; Kleber Yotsumoto Fertrin; Vasilios Antonios Berdoukas; Renzo Galanello

    2013-01-01

    In the absence of an iron chelating agent, patients with beta-thalassemia on regular transfusions present complications of transfusion-related iron overload. Without iron chelation therapy, heart disease is the major cause of death; however, hepatic and endocrine complications also occur. Currently there are three iron chelating agents available for continuous use in patients with thalassemia on regular transfusions (desferrioxamine, deferiprone, and deferasirox) providing good results in red...

  6. Brazilian Thalassemia Association protocol for iron chelation therapy in patients under regular transfusion

    Directory of Open Access Journals (Sweden)

    Monica Pinheiro de Almeida Verissimo

    2013-01-01

    Full Text Available In the absence of an iron chelating agent, patients with beta-thalassemia on regular transfusions present complications of transfusion-related iron overload. Without iron chelation therapy, heart disease is the major cause of death; however, hepatic and endocrine complications also occur. Currently there are three iron chelating agents available for continuous use in patients with thalassemia on regular transfusions (desferrioxamine, deferiprone, and deferasirox providing good results in reducing cardiac, hepatic and endocrine toxicity. These practice guidelines, prepared by the Scientific Committee of Associação Brasileira de Thalassemia (ABRASTA, presents a review of the literature regarding iron overload assessment (by imaging and laboratory exams and the role of T2* magnetic resonance imaging (MRI to control iron overload and iron chelation therapy, with evidence-based recommendations for each clinical situation. Based on this review, the authors propose an iron chelation protocol for patients with thalassemia under regular transfusions.

  7. Development of Iron-Chelating Poly(ethylene terephthalate) Packaging for Inhibiting Lipid Oxidation in Oil-in-Water Emulsions.

    Science.gov (United States)

    Johnson, David R; Tian, Fang; Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2015-05-27

    Foods such as bulk oils, salad dressings, and nutritionally fortified beverages that are susceptible to oxidative degradation are often packaged in poly(ethylene terephthalate) (PET) bottles with metal chelators added to the food to maintain product quality. In the present work, a metal-chelating active packaging material is designed and characterized, in which poly(hydroxamic acid) (PHA) metal-chelating moieties were grafted from the surface of PET. Biomimetic PHA groups were grafted in a two-step UV-initiated process without the use of a photoinitiator. Surface characterization of the films by attenuated total reflective Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) suggested successful grafting and conversion of poly(hydroxyethyl acrylate) (PHEA) to PHA chelating moieties from the surface of PET. Colorimetric (ferrozine) and inductively coupled plasma mass spectroscopy (ICP-MS) assays demonstrated the ability of PET-g-PHA to chelate iron in a low-pH (3.0) environment containing a competitive metal chelator (citric acid). Lipid oxidation studies demonstrated the antioxidant activity of PET-g-PHA films in inhibiting iron-promoted oxidation in an acidified oil-in-water (O/W) emulsion model system (pH 3.0). Particle size and ζ-potential analysis indicated that the addition of PET-g-PHA films did not affect the physical stability of the emulsion system. This work suggests that biomimetic chelating moieties can be grafted from PET and effectively inhibit iron-promoted degradation reactions, enabling removal of metal-chelating additives from product formulations. PMID:25985711

  8. Overview of guidelines on iron chelation therapy in patients with myelodysplastic syndromes and transfusional iron overload

    OpenAIRE

    Gattermann, Norbert

    2008-01-01

    Between 2002 and 2008, a number of consensus statements and guidelines were developed by various groups around the world to educate healthcare professionals on the treatment of myelodysplastic syndromes (MDS), including the management of transfusional iron overload with iron chelation therapy. Guidelines have been developed by The Italian Society of Hematology, The UK MDS Guidelines Group, The Nagasaki Group, The National Comprehensive Cancer Network, and The MDS Foundation. These guidelines ...

  9. Natural iron chelators: Protective role in A549 cells of flavonoids-rich extracts of Citrus juices in Fe(3+)-induced oxidative stress.

    Science.gov (United States)

    Ferlazzo, Nadia; Visalli, Giuseppa; Cirmi, Santa; Lombardo, Giovanni Enrico; Laganà, Pasqualina; Di Pietro, Angela; Navarra, Michele

    2016-04-01

    Exogenous iron in particulate matter and imbalanced iron homeostasis cause deleterious effects on health. Natural and synthetic iron chelators may be of therapeutic benefit, therefore we evaluated the protective effect of Citrus flavonoids-rich extracts from bergamot and orange juices in iron overloaded human lung epithelial cells. Cytofluorimetric, biochemical and genotoxic analyses were performed in Fe2(SO4)3 exposed A549, pretreated with each extract whose chemical composition was previously detected. Chelating activity was assessed in cells by a calcein ester. Both extracts reduced the generation of reactive oxygen species and membrane lipid peroxidation, improved mitochondrial functionality, and prevented DNA-oxidative damage in iron-exposed cells. Antioxidant effects were attributed to the chelating property, blocking upstream the redox activity of iron. Flavonoid-rich extracts also induced antioxidant catalase. The bergamot and orange juice extracts had a broad-spectrum protective effect. Their use prevents iron oxidative injury and these natural iron chelators could be used as therapeutic agents. PMID:27037654

  10. Curcumin, a cancer chemopreventive and chemotherapeutic agent, is a biologically active iron chelator

    OpenAIRE

    Jiao, Yan; Wilkinson, John; Di, Xiumin; Wang, Wei; Hatcher, Heather; Kock, Nancy D.; D'Agostino, Ralph; Knovich, Mary Ann; Torti, Frank M; Suzy V Torti

    2009-01-01

    Curcumin is a natural product currently in human clinical trials for a variety of neoplastic, preneoplastic, and inflammatory conditions. We previously observed that, in cultured cells, curcumin exhibits properties of an iron chelator. To test whether the chelator activity of curcumin is sufficient to induce iron deficiency in vivo, mice were placed on diets containing graded concentrations of both iron and curcumin for 26 weeks. Mice receiving the lowest level of dietary iron exhibited borde...

  11. Red Blood Cell Transfusion Independence Following the Initiation of Iron Chelation Therapy in Myelodysplastic Syndrome

    OpenAIRE

    Leitch, Heather A.; Vickars, Linda M.; Chase, Jocelyn M.; Badawi, Maha A.

    2010-01-01

    Iron chelation therapy is often used to treat iron overload in patients requiring transfusion of red blood cells (RBC). A 76-year-old man with MDS type refractory cytopenia with multilineage dysplasia, intermediate-1 IPSS risk, was referred when he became transfusion dependent. He declined infusional chelation but subsequently accepted oral therapy. Following the initiation of chelation, RBC transfusion requirement ceased and he remained transfusion independent over 40 months later. Over the ...

  12. The iron chelator desferrioxamine attenuates postischemic ventricular dysfunction

    International Nuclear Information System (INIS)

    Recent evidence suggests that postischemic myocardial dysfunction (stunning) may be mediated by oxygen free radicals, but the mechanism by which they produce myocellular damage remains unknown. Since iron catalyzes formation of hydroxyl radicals (HO·) as well as HO·-initiated lipid peroxidation, the authors explored the potential role of this metal in the pathogenesis of myocardial stunning. Open-chest dogs undergoing a 15-min occlusion of the left anterior descending coronary artery (LAD) followed by 4 h of reperfusion (REP) received the iron chelator desferrioxamine intravenously or normal saline. Regional myocardial function was assessed by measuring systolic wall thickening with an epicardial Doppler probe. The two groups exhibited comparable systolic thickening under base-line conditions and similar degrees of dyskinesis during ischemia. After REP, however, recovery of contractile function as considerably greater in desferrioxamine-treated compared with control dogs. These differences could not be ascribed to hemodynamic factors. The results suggest that iron-catalyzed reactions (possibly HO· generation) play a significant role in myocardial stunning after a brief episode of reversible regional ischemia

  13. Characterization of commercial iron chelates and their behavior in an alkaline and calcareous soil.

    Science.gov (United States)

    Cantera, Rodrigo G; Zamarreño, Angel M; García-Mina, José M

    2002-12-18

    Iron deficiency is a common problem for many plants grown in alkaline and calcareous soils. To correct this problem, iron is supplied to plants as chelates. Several iron chelates are sold under diverse trademarks with different characteristics. This work evaluated 18 commercial products containing the most representative chelated iron sources used in agricultural practice in Spain when the study was done, namely the ferric chelates of EDDHA, EDDHMA, EDDCHA, EDDHSA, EDTA, and DTPA. The chelates were comprehensively characterized and quantitated by several techniques, including several chromatographic methods. Iron and chelate dynamics in soil were also studied in a model alkaline and calcareous soil. Results indicate that, in this model soil, among the different iron compounds studied only FeEDDHA and analogues have the capacity to maintain soluble iron in soil solution over time. These results are in agreement with general experience under field conditions. Furthermore, among the different ortho-ortho isomers of FeEDDHA's, FeEDDHSA and FeEDDCHA showed greater capacity than FeEDDHA and FeEDDHMA to maintain the chelated iron in soil solution over time. PMID:12475278

  14. Rapid iron loading in a pregnant woman with transfusion-dependent thalassemia after brief cessation of iron chelation therapy

    OpenAIRE

    Farmaki, Kallistheni; Gotsis, Efstathios; Tzoumari, Ioanna; Berdoukas, Vasilios

    2008-01-01

    In general, in women with transfusion-dependent thalassemia, during pregnancy, iron chelation therapy is ceased. We report a splenectomized patient, who was an excellent complier with chelation therapy, who before embarking on a pregnancy showed no evidence of iron overload, with normal cardiac, thyroid function and glucose metabolism. Laboratory findings showed ferritin 67 μg/L, myocardial T2* of 34 ms and liver magnetic resonance imaging (MRI) liver iron concentration of 1 mg/g dry weight. ...

  15. Red Blood Cell Transfusion Independence Following the Initiation of Iron Chelation Therapy in Myelodysplastic Syndrome

    Directory of Open Access Journals (Sweden)

    Maha A. Badawi

    2010-01-01

    Full Text Available Iron chelation therapy is often used to treat iron overload in patients requiring transfusion of red blood cells (RBC. A 76-year-old man with MDS type refractory cytopenia with multilineage dysplasia, intermediate-1 IPSS risk, was referred when he became transfusion dependent. He declined infusional chelation but subsequently accepted oral therapy. Following the initiation of chelation, RBC transfusion requirement ceased and he remained transfusion independent over 40 months later. Over the same time course, ferritin levels decreased but did not normalize. There have been eighteen other MDS patients reported showing improvement in hemoglobin level with iron chelation; nine became transfusion independent, nine had decreased transfusion requirements, and some showed improved trilineage myelopoiesis. The clinical features of these patients are summarized and possible mechanisms for such an effect of iron chelation on cytopenias are discussed.

  16. Intracellular reduction/activation of a disulfide switch in thiosemicarbazone iron chelators

    OpenAIRE

    Akam, Eman A.; Chang, Tsuhen M.; Astashkin, Andrei V.; Tomat, Elisa

    2014-01-01

    Iron scavengers (chelators) offer therapeutic opportunities in anticancer drug design by targeting the increased demand for iron in cancer cells as compared to normal cells. Prochelation approaches are expected to avoid systemic iron depletion as chelators are liberated under specific intracellular conditions. In the strategy described herein, a disulfide linkage is employed as a redox-directed switch within the binding unit of an antiproliferative thiosemicarbazone prochelator, which is acti...

  17. Iron chelating active packaging: Influence of competing ions and pH value on effectiveness of soluble and immobilized hydroxamate chelators.

    Science.gov (United States)

    Ogiwara, Yoshiko; Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2016-04-01

    Many packaged foods utilize synthetic chelators (e.g. ethylenediaminetetraacetic acid, EDTA) to inhibit iron-promoted oxidation or microbial growth which would result in quality loss. To address consumer demands for all natural products, we have previously developed a non-migratory iron chelating active packaging material by covalent immobilization of polyhydroxamate and demonstrated its efficacy in delaying lipid oxidation. Herein, we demonstrate the ability of this hydroxamate-functionalized iron chelating active packaging to retain iron chelating capacity; even in the presence of competing ions common in food. Both immobilized and soluble hydroxamate chelators retained iron chelating capacity in the presence of calcium, magnesium, and sodium competing ions, although at pH 5.0 the presence of calcium reduced immobilized hydroxamate iron chelation. A strong correlation was found between colorimetric and mass spectral analysis of iron chelation by the chelating packaging material. Such chelating active packaging may support reducing additive use in product formulations, while retaining quality and shelf life. PMID:26593563

  18. Translational downregulation of HSP90 expression by iron chelators in neuroblastoma cells.

    Science.gov (United States)

    Sidarovich, Viktoryia; Adami, Valentina; Gatto, Pamela; Greco, Valentina; Tebaldi, Toma; Tonini, Gian Paolo; Quattrone, Alessandro

    2015-01-01

    Iron is an essential cellular nutrient, being a critical cofactor of several proteins involved in cell growth and replication. Compared with normal cells, neoplastic cells have been shown to require a greater amount of iron, thus laying the basis for the promising anticancer activity of iron chelators. In this work, we evaluated the effects of molecules with iron chelation activity on neuroblastoma (NB) cell lines. Of the 17 iron chelators tested, six reduced cell viability of two NB cell lines with an inhibition of growth of 50% below 10 µM; four of the six molecules-ciclopirox olamine (CPX), piroctone, 8-hydroxyquinoline, and deferasirox-were also shown to efficiently chelate intracellular iron within minutes after addition. Effects on cell viability of one of the compounds, CPX, were indeed dependent on chelation of intracellular iron and mediated by both G0/G1 cell cycle block and induction of apoptosis. By combined transcriptome and translatome profiling we identified early translational downregulation of several members of the heat shock protein group as a specific effect of CPX treatment. We functionally confirmed iron-dependent depletion of HSP90 and its client proteins at pharmacologically achievable concentrations of CPX, and we extended this effect to piroctone, 8-hydroxyquinoline, and deferasirox. Given the documented sensitivity of NB cells to HSP90 inhibition, we propose CPX and other iron chelators as investigational antitumor agents in NB therapy. PMID:25564462

  19. Removal of iron by chelation with molecularly imprinted supermacroporous cryogel.

    Science.gov (United States)

    Çimen, Duygu; Göktürk, Ilgım; Yılmaz, Fatma

    2016-06-01

    Iron chelation therapy can be used for the selective removal of Fe(3+) ions from spiked human plasma by ion imprinting. N-Methacryloyl-(L)-glutamic acid (MAGA) was chosen as the chelating monomer. In the first step, MAGA was complexed with the Fe(3+) ions to prepare the precomplex, and then the ion-imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-glutamic acid) [PHEMAGA-Fe(3+)] cryogel column was prepared by cryo-polymerization under a semi-frozen temperature of - 12°C for 24 h. Subsequently, the template, of Fe(3+) ions was removed from the matrix by using 0.1 M EDTA solution. The values for the specific surface area of the imprinted PHEMAGA-Fe(3+) and non-imprinted PHEMAGA cryogel were 45.74 and 7.52 m(2)/g respectively, with a pore size in the range of 50-200 μm in diameter. The maximum Fe(3+) adsorption capacity was 19.8 μmol Fe(3+)/g cryogel from aqueous solutions and 12.28 μmol Fe(3+)/g cryogel from spiked human plasma. The relative selectivity coefficients of ion-imprinted cryogel for Fe(3+)/Ni(2+) and Fe(3+)/Cd(2+) were 1.6 and 4.2-fold greater than the non-imprinted matrix, respectively. It means that the PHEMAGA-Fe(3+) cryogel possesses high selectivity to Fe(3+) ions, and could be used many times without significantly decreasing the adsorption capacity. PMID:25727711

  20. Generation, Fractionation, and Characterization of Iron-Chelating Protein Hydrolysate from Palm Kernel Cake Proteins.

    Science.gov (United States)

    Zarei, Mohammad; Ghanbari, Rahele; Tajabadi, Naser; Abdul-Hamid, Azizah; Bakar, Fatimah Abu; Saari, Nazamid

    2016-02-01

    Palm kernel cake protein was hydrolyzed with different proteases namely papain, bromelain, subtilisin, flavourzyme, trypsin, chymotrypsin, and pepsin to generate different protein hydrolysates. Peptide content and iron-chelating activity of each hydrolysate were evaluated using O-phthaldialdehyde-based spectrophotometric method and ferrozine-based colorimetric assay, respectively. The results revealed a positive correlation between peptide contents and iron-chelating activities of the protein hydrolysates. Protein hydrolysate generated by papain exhibited the highest peptide content of 10.5 mM and highest iron-chelating activity of 64.8% compared with the other hydrolysates. Profiling of the papain-generated hydrolysate by reverse phase high performance liquid chromatography fractionation indicated a direct association between peptide content and iron-chelating activity in most of the fractions. Further fractionation using isoelectric focusing also revealed that protein hydrolysate with basic and neutral isoelectric point (pI) had the highest iron-chelating activity, although a few fractions in the acidic range also exhibited good metal chelating potential. After identification and synthesis of papain-generated peptides, GGIF and YLLLK showed among the highest iron-chelating activities of 56% and 53%, whereas their IC50 were 1.4 and 0.2 μM, respectively. PMID:26720491

  1. Antioxidant Activity of Caffeic Acid against Iron-Induced Free Radical Generation--A Chemical Approach.

    Directory of Open Access Journals (Sweden)

    Thiago C Genaro-Mattos

    Full Text Available Caffeic acid (CA is a phenolic compound widely found in coffee beans with known beneficial effects in vivo. Many studies showed that CA has anti-inflammatory, anti-mutagenic, antibacterial and anti-carcinogenic properties, which could be linked to its antioxidant activity. Taking in consideration the reported in vitro antioxidant mechanism of other polyphenols, our working hypothesis was that the CA antioxidant activity could be related to its metal-chelating property. With that in mind, we sought to investigate the chemical antioxidant mechanism of CA against in vitro iron-induced oxidative damage under different assay conditions. CA was able to prevent hydroxyl radical formation promoted by the classical Fenton reaction, as determined by 2-deoxyribose (2-DR oxidative degradation and DMPO hydroxylation. In addition to its ability to prevent hydroxyl radical formation, CA had a great inhibition of membrane lipid peroxidation. In the lipid peroxidation assays CA acted as both metal-chelator and as hydrogen donor, preventing the deleterious action promoted by lipid-derived peroxyl and alkoxyl radicals. Our results indicate that the observed antioxidant effects were mostly due to the formation of iron-CA complexes, which are able to prevent 2-DR oxidation and DMPO hydroxylation. Noteworthy, the formation of iron-CA complexes and prevention of oxidative damage was directly related to the pH of the medium, showing better antioxidant activity at higher pH values. Moreover, in the presence of lipid membranes the antioxidant potency of CA was much higher, indicating its enhanced effectiveness in a hydrophobic environment. Overall, our results show that CA acts as an antioxidant through an iron chelating mechanism, preventing the formation of free hydroxyl radicals and, therefore, inhibiting Fenton-induced oxidative damage. The chemical properties of CA described here--in association with its reported signaling effects--could be an explanation to its

  2. Effect of the chelation of metal cation on the antioxidant activity of chondroitin sulfates.

    Science.gov (United States)

    Ajisaka, Katsumi; Oyanagi, Yutaka; Miyazaki, Tatsuo; Suzuki, Yasuhiro

    2016-06-01

    The antioxidant potencies of chondroitin sulfates (CSs) from shark cartilage, salmon cartilage, bovine trachea, and porcine intestinal mucosa were compared by three representative methods for the measurement of the antioxidant activity; DPPH radical scavenging activity, superoxide radical scavenging activity, and hydroxyl radical scavenging activity. CSs from salmon cartilage and bovine trachea showed higher potency in comparison with CSs from shark cartilage and porcine intestinal mucosa. Next, CS from salmon cartilage chelating with Ca(2+), Mg(2+), Mn(2+), or Zn(2+) were prepared, and their antioxidant potencies were compared. CS chelating with Ca(2+) or Mg(2+) ions showed rather decreased DPPH radical scavenging activity in comparison with CS of H(+) form. In contrast, CS chelating with Ca(2+) or Mg(2+) ion showed remarkably enhanced superoxide radical scavenging activity than CS of H(+) or Na(+) form. Moreover, CS chelating with divalent metal ions, Ca(2+), Mg(2+), Mn(2+), or Zn(2+), showed noticeably higher hydroxyl radical scavenging activity than CS of H(+) or Na(+) form. The present results revealed that the scavenging activities of, at least, superoxide radical and hydroxyl radical were enhanced by the chelation with divalent metal ions. PMID:26856546

  3. INFLUENCE OF IRON CHELATION ON R1 AND R2 CALIBRATION CURVES IN GERBIL LIVER AND HEART

    OpenAIRE

    Wood, John C.; AGUILAR, MICHELLE; Otto-Duessel, Maya; Nick, Hanspeter; Nelson, Marvin D.; Moats, Rex

    2008-01-01

    MRI is gaining increasing importance for the noninvasive quantification of organ iron burden. Since transverse relaxation rates depend on iron distribution as well as iron concentration, physiologic and pharmacologic processes that alter iron distribution could change MRI calibration curves. This paper compares the effect of three iron chelators, deferoxamine, deferiprone, and deferasirox on R1 and R2 calibration curves according to two iron loading and chelation strategies. 33 Mongolian gerb...

  4. A study of intracellular iron metabolism using pyridoxal isonicotinoyl hydrazone and other synthetic chelating agents

    International Nuclear Information System (INIS)

    Rabbit reticulocytes with a high level of non-heme radioiron induced by preincubation with isonicotinic acid hydrazide and transferrin-bound 59Fe, were reincubated with various synthetic chelating agents and the amount of radioiron released from the cells was determined. Some substances, especially derivatives of pyridoxal or 2-hydroxybenzaldehyde and isonicotinic acid hydrazide or benzhydrazide, were found to mobilize significantly iron from 59Fe-labelled reticulocytes. Iron mobilizaiton from reticulocytes by pyridoxal isonicotinoyl hydrazone requires ATP to be produced by cells and is completely blocked by low temperatute (40C). Although the effect of desferrioxamine is also prevented by low temperature, modest iron mobilization due to this chelator seems to occur independently of ATP production in reticulocytes. Pyridoxal isonicotinoyl hydrazone mobilized iron mainly from mitochondria and in part also from ferritin. Although 2,2'-bipyridine seems to enter reticulocyte mitochondria and bind iron there, this chelator is not able to relaease iron either from mitochondria or from the cells. Reticulocytes with a high level of non-heme radioiron are envisaged as a useful system for testing biological effectiveness of various iron chelators. Pyridoxal isonicotinoyl hydrazone was shown to be an effective in vivo chelator since its adminstration to mice decreased 59Fe radioactivity in liver, spleen and kidney. (Auth.)

  5. The Management of Iron Chelation Therapy: Preliminary Data from a National Registry of Thalassaemic Patients

    Directory of Open Access Journals (Sweden)

    Adriana Ceci

    2011-01-01

    Full Text Available Thalassaemia and other haemoglobinopathies constitute an important health problem in Mediterranean countries, placing a tremendous emotional, psychological, and economic burden on their National Health systems. The development of new chelators in the most recent years had a major impact on the treatment of thalassaemia and on the quality of life of thalassaemic patients. A new initiative was promoted by the Italian Ministry of Health, establishing a Registry for thalassaemic patients to serve as a tool for the development of cost-effective diagnostic and therapeutic approaches and for the definition of guidelines supporting the most appropriate management of the iron-chelating therapy and a correct use of the available iron-chelating agents. This study represents the analysis of the preliminary data collected for the evaluation of current status of the iron chelation practice in the Italian thalassaemic population and describes how therapeutic interventions can widely differ in the different patients' age groups.

  6. Current and future treatment strategies for iron overload cardiomyopathy.

    Science.gov (United States)

    Wongjaikam, Suwakon; Kumfu, Sirinart; Chattipakorn, Siriporn C; Fucharoen, Suthat; Chattipakorn, Nipon

    2015-10-15

    Iron overload cardiomyopathy is the major cause of death in transfusion-dependent thalassemia (TDT) patients. Growing evidence demonstrates that combined iron chelators, or the combination of an iron chelator with antioxidant(s) are effective in diminishing myocardial iron deposition and attenuating cardiac dysfunction. This review comprehensively summarizes basic and clinical reports on the therapeutic efficacy of combined iron chelators, or the combination of an iron chelator with antioxidant(s) on the heart. Promising benefits of these treatments in preventing cardiac dysfunction due to iron overload could provide extensive insight into future therapeutic strategies for better treatment and prevention of cardiomyopathy in TDT patients. PMID:26291660

  7. Intracellular reduction/activation of a disulfide switch in thiosemicarbazone iron chelators

    Science.gov (United States)

    Akam, Eman A.; Chang, Tsuhen M.; Astashkin, Andrei V.

    2014-01-01

    Iron scavengers (chelators) offer therapeutic opportunities in anticancer drug design by targeting the increased demand for iron in cancer cells as compared to normal cells. Prochelation approaches are expected to avoid systemic iron depletion as chelators are liberated under specific intracellular conditions. In the strategy described herein, a disulfide linkage is employed as a redox-directed switch within the binding unit of an antiproliferative thiosemicarbazone prochelator, which is activated for iron coordination following reduction to the thiolate chelator. In glutathione redox buffer, this reduction event occurs at physiological concentrations and half-cell potentials. Consistent with concurrent reduction and activation, higher intracellular thiol concentrations increase cell susceptibility to prochelator toxicity in cultured cancer cells. The reduction of the disulfide switch and intracellular iron chelation are confirmed in cell-based assays using calcein as a fluorescent probe for paramagnetic ions. The resulting low-spin Fe(III) complex is identified in intact Jurkat cells by EPR spectroscopy measurements, which also document a decreased concentration of active ribonucleotide reductase following exposure to the prochelator. Cell viability and fluorescence-based assays show that the iron complex presents low cytotoxicity and does not participate in intracellular redox chemistry, indicating that this antiproliferative chelation strategy does not rely on the generation of reactive oxygen species. PMID:25100578

  8. Intracellular reduction/activation of a disulfide switch in thiosemicarbazone iron chelators.

    Science.gov (United States)

    Akam, Eman A; Chang, Tsuhen M; Astashkin, Andrei V; Tomat, Elisa

    2014-10-01

    Iron scavengers (chelators) offer therapeutic opportunities in anticancer drug design by targeting the increased demand for iron in cancer cells as compared to normal cells. Prochelation approaches are expected to avoid systemic iron depletion as chelators are liberated under specific intracellular conditions. In the strategy described herein, a disulfide linkage is employed as a redox-directed switch within the binding unit of an antiproliferative thiosemicarbazone prochelator, which is activated for iron coordination following reduction to the thiolate chelator. In glutathione redox buffer, this reduction event occurs at physiological concentrations and half-cell potentials. Consistent with concurrent reduction and activation, higher intracellular thiol concentrations increase cell susceptibility to prochelator toxicity in cultured cancer cells. The reduction of the disulfide switch and intracellular iron chelation are confirmed in cell-based assays using calcein as a fluorescent probe for paramagnetic ions. The resulting low-spin Fe(III) complex is identified in intact Jurkat cells by EPR spectroscopy measurements, which also document a decreased concentration of active ribonucleotide reductase following exposure to the prochelator. Cell viability and fluorescence-based assays show that the iron complex presents low cytotoxicity and does not participate in intracellular redox chemistry, indicating that this antiproliferative chelation strategy does not rely on the generation of reactive oxygen species. PMID:25100578

  9. Function of the iron-binding chelator produced by Coriolus versicolor in lignin biodegradation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An ultrafiltered low-molecular-weight preparation of chelating compounds was isolated from a wood-containing culture of the white-rot basidiomycete Coriolus versicolor. This preparation could chelate Fe3+ and reduce Fe3+ to Fe2+, demonstrating that the substance may serve as a ferric chelator, oxygen-reducing agent, and redox-cycling molecule, which would include functioning as the electron transport carrier in Fenton reaction. Lignin was treated with the iron-binding chelator and the changes in structure were investigated by 1H-NMR, 13C-NMR, difference spectrum caused by ionization under alkaline conditions and nitrobenzene oxidation. The results indicated that the iron-binding chelator could destroy the β-O-4 bonds in etherified lignin units and insert phenolic hydroxyl groups. The low-molecular-weight chelator secreted by C. versicolor resulted in new phenolic substructures in the lignin polymer, making it susceptible to attack by laccase or manganese peroxidase. Thus, the synergic action of the iron-binding chelator and the lignocellulolytic enzymes made the substrate more acces- sible to degradation.

  10. Yerba mate (Ilex paraguariensis St. Hill.)-based beverages: How successive extraction influences the extract composition and its capacity to chelate iron and scavenge free radicals.

    Science.gov (United States)

    Colpo, Ana C; Rosa, Hemerson; Lima, Maria Eduarda; Pazzini, Camila Eliza F; de Camargo, Vanessa B; Bassante, Felipa E M; Puntel, Robson; Ávila, Daiana Silva; Mendez, Andreas; Folmer, Vanderlei

    2016-10-15

    Chimarrão or mate is a popular beverage from South America that is drank with successive infusions. Although yerba mate extracts have been widely studied, few studies have described the extract contents in beverages. Using yerba mate samples from Brazil, Argentina, and Uruguay, we examined the extract chromatographic profiles, total polyphenol content and their capacities to chelate iron. In addition, we analyzed antioxidant activity by examining the ability of the extracts to scavenge DPPH and NO. Our results showed that the amount of extracted compound was highest in yerba mate extract from Uruguay, followed by Argentina, then Brazil. Herbs from all three areas had a significant capacity to inhibit DPPH and NO free radicals. The Brazilian and Uruguayan herbs had an 80% iron chelation capacity (pextractions, while the antioxidant capacity is maintained at significant levels. PMID:27173551

  11. Diethylentriaminepenta acetic acid glucose conjugates as a cell permeable iron chelator

    Directory of Open Access Journals (Sweden)

    Mona Mosayebnia

    2014-01-01

    Full Text Available Objective: To find out whether DTPA-DG complex can enhance clearance of intracellular free iron. Materials and Methods: Diethylenetriaminepentaacetic acid-D-deoxy-glucosamine (DTPA-DG was synthesized and examined for its activity as a cell-permeable iron chelator in human hepatocellular carcinoma (HEPG2 cell line exposed to high concentration of iron sulfate and compared with deferoxamine (DFO, a prototype iron chelator. The effect of DTPA-DG on cell viability was monitored using the 3-(4,5-dimethythiazol-2-yl-2,5-diphenyl tetrazolium bromide MTT assay as well. Results: There was a significant increase of iron level after iron overload induction in HEPG2 cell culture. DTPA-DG presented a remarkable capacity to iron burden reducing with estimated 50% inhibitory concentration value of 65.77 nM. In fact, glycosyl moiety was gained access of DTPA to intracellular iron deposits through glucose transporter systems. Conclusion: DTPA-DG, more potent than DFO to sequester deposits of free iron with no profound toxic effect. The results suggest the potential of DTPA-DG in chelating iron and permitting its excretion from primary organ storage.

  12. Action of chelators on solid iron in phosphate-containing aqueous solutions

    International Nuclear Information System (INIS)

    To study the effect of strong iron-ligands on steel corrosion, mild steel electrodes were immersed in solutions containing 20 mM phosphate buffer (pH=7.2) and between 0.01 mM and 1 M of either the iron(II)-chelators 2,2'-bipyridine or FerroZine, or the iron(III)-chelators citrate or acetylacetonate. Resulting surface reactions were investigated by quantifying the electrochemical potential (E), the electrochemical polarization resistance (Rp), the corrosion current (Icorr) and the release of iron into solution. The surface was further analyzed by scanning electron microscopy (SEM/SEM-EDAX) and atomic force microscopy. Concentrations of 0.1 mM of any of the chelators led to slight, temporary changes in E, Icorr and Rp. Concentrations of 10 mM resulted in characteristic changes of E, which were the same for all chelators and in the precipitation of FePO4 in the case of citrate and acetylacetonate, or vivianite [Fe3(PO4)2 · 8H2O] in the case of bipyridine and FerroZine. Concentrations of 1 mM of both iron(III)-chelators led to a temporary drop of E similar to that found with 0.1 mM chelator. With iron(II)-chelators, E dropped to about -500 mV before oscillating for several days. The amplitudes of the oscillations were up to 200 mV with periods of 30 and 20-25 min for bipyridine and FerroZine, respectively

  13. Iron chelation therapy in transfusion-dependent thalassemia patients: current strategies and future directions

    OpenAIRE

    Saliba AN; Harb AR; Taher AT

    2015-01-01

    Antoine N Saliba, Afif R Harb, Ali T Taher Department of Internal Medicine, Division of Hematology/Oncology, American University of Beirut, Beirut, Lebanon Abstract: Transfusional iron overload is a major target in the care of patients with transfusion-dependent thalassemia (TDT) and other refractory anemias. Iron accumulates in the liver, heart, and endocrine organs leading to a wide array of complications. In this review, we summarize the characteristics of the approved iron chelators, def...

  14. DCCP and DICP: Construction and Analyses of Databases for Copper- and Iron-Chelating Proteins

    Institute of Scientific and Technical Information of China (English)

    Hao Wu; Yan Yang; Sheng-Juan Jiang; Ling-Ling Chen; Hai-Xia Gao; Qing-Shan Fu; Feng Li; Bin-Guang Ma; Hong-Yu Zhang

    2005-01-01

    Copper and iron play important roles in a variety of biological processes, especially when being chelated with proteins. The proteins involved in the metal binding,transporting and metabolism have aroused much interest. To facilitate the study on this topic, we constructed two databases (DCCP and DICP) containing the known copper- and iron-chelating proteins, which are freely available from the website http:∥sdbi.sdut.edu.cn/en. Users can conveniently search and browse all of the entries in the databases. Based on the two databases, bioinformatic analyses were performed, which provided some novel insights into metalloproteins.

  15. Synergistic Activities of an Efflux Pump Inhibitor and Iron Chelators against Pseudomonas aeruginosa Growth and Biofilm Formation

    DEFF Research Database (Denmark)

    Liu, Yang; Yang, Liang; Molin, Søren

    2010-01-01

    The efflux pump inhibitor phenyl-arginine-beta-naphthylamide (PA beta N) was paired with iron chelators 2,2'-dipyridyl, acetohydroxamic acid, and EDTA to assess synergistic activities against Pseudomonas aeruginosa growth and biofilm formation. All of the tested iron chelators synergistically...

  16. Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

    Directory of Open Access Journals (Sweden)

    Kell Douglas B

    2009-01-01

    Full Text Available Abstract Background The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. Review We review the considerable and wide-ranging evidence for the involvement of this combination of (superoxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation. The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron molecules that are nominally antioxidants can actually act as pro

  17. A Powerful Mitochondria-Targeted Iron Chelator Affords High Photoprotection against Solar Ultraviolet A Radiation.

    Science.gov (United States)

    Reelfs, Olivier; Abbate, Vincenzo; Hider, Robert C; Pourzand, Charareh

    2016-08-01

    Mitochondria are the principal destination for labile iron, making these organelles particularly susceptible to oxidative damage on exposure to ultraviolet A (UVA, 320-400 nm), the oxidizing component of sunlight. The labile iron-mediated oxidative damage caused by UVA to mitochondria leads to necrotic cell death via adenosine triphosphate depletion. Therefore, targeted removal of mitochondrial labile iron via highly specific tools from these organelles may be an effective approach to protect the skin cells against the harmful effects of UVA. In this work, we designed a mitochondria-targeted hexadentate (tricatechol-based) iron chelator linked to mitochondria-homing SS-like peptides. The photoprotective potential of this compound against UVA-induced oxidative damage and cell death was evaluated in cultured primary skin fibroblasts. Our results show that this compound provides unprecedented protection against UVA-induced mitochondrial damage, adenosine triphosphate depletion, and the ensuing necrotic cell death in skin fibroblasts, and this effect is fully related to its potent iron-chelating property in the organelle. This mitochondria-targeted iron chelator has therefore promising potential for skin photoprotection against the deleterious effects of the UVA component of sunlight. PMID:27109868

  18. Effect of Iron Chelators on Methemoglobin and Thrombin Preconditioning

    OpenAIRE

    Chen-Roetling, Jing; Sinanan, Jesse; Regan, Raymond F.

    2012-01-01

    Cell loss immediately adjacent to an intracerebral hemorrhage may be mediated in part by the toxicities of extracellular hemoglobin (Hb) and thrombin. However, at low concentrations, these proteins induce tolerance to hemin and iron that may limit further peri-hematomal injury as erythrocyte lysis progresses. The mechanisms mediating these preconditioning effects have not been completely defined, but increased expression of both heme oxygenase (HO)-1 and iron binding proteins likely contribut...

  19. When is iron overload deleterious, and when and how should iron chelation therapy be administered in myelodysplastic syndromes?

    Science.gov (United States)

    Steensma, David P; Gattermann, Norbert

    2013-12-01

    Iron overload in MDS starts even before patients become red-blood cell transfusion dependent, because disease-associated ineffective erythropoiesis suppresses hepcidin production in the liver and thus causes unrestrained iron absorption in the duodenum. However, the main cause of iron overload is regular transfusion therapy, which in MDS is associated with a risk of unclear magnitude for iron-related complications. Iron deposition in tissues can now be detected with non-invasive techniques such as T2* MRI. Iron toxicity in MDS may not only depend on the degree of tissue iron accumulation but also on the extent of chronic exposure to non-transferrin-bound iron (NTBI), including labile plasma iron (LPI) and intracellular labile iron pools, which increase the level of oxidative stress. Iron chelation therapy (ICT) can rapidly lower NTBI and LPI and more slowly mobilizes tissue iron stores. Further studies, including the ongoing TELESTO controlled trial, will more clearly define the role of ICT in MDS, including any effect on specific morbidities or mortality in the MDS setting. PMID:24507819

  20. FORMULATION OF ORAL IRON CHELATOR DEFERASIROX IN A NEW STABLE AND SUITABLE DOSAGE FORM WITH OPTIMUM RELEASE PARAMETERS

    OpenAIRE

    Yugandhar KM, Vasanth PM, Suresh K, Ramesh T, Ramesh Malothu*

    2013-01-01

    Regular blood transfusions for patients with chronic anemia inevitably lead to iron overload in the blood. The cumulative effect of iron overload may cause morbidity and mortality if not treated with chelator. Oral iron chelator, Deferasirox used in the treatment of β-thalessemia is designed and developed into a stable solid oral dispersion dosage form to deliver with optimum concentration of the drug at desired site at specific time comparable to the innovator product. The excipients were fo...

  1. Biological activity of ellagitannins: Effects as anti-oxidants, pro-oxidants and metal chelators.

    Science.gov (United States)

    Moilanen, Johanna; Karonen, Maarit; Tähtinen, Petri; Jacquet, Rémi; Quideau, Stéphane; Salminen, Juha-Pekka

    2016-05-01

    Ellagitannins are a subclass of hydrolysable tannins that have been suggested to function as defensive compounds of plants against herbivores. However, it is known that the conditions in the digestive tracts of different herbivores are variable, so it seems reasonable to anticipate that the reactivities and modes of actions of these ingested defensive compounds would also be different. A previous study on a few ellagitannins has shown that these polyphenolic compounds are highly oxidizable at high pH and that their bioactivity can be attributed to certain structural features. Herein, the activities of 13 ellagitannins using the deoxyribose assay were measured. The results provided information about the anti-oxidant, pro-oxidant and metal chelating properties of ellagitannins. Surprisingly, many of the tested ellagitannins exhibited pro-oxidant activities even at neutral pH and only moderate to low radical scavenging activities, although the metal chelating capacities of all tested ellagitannins were relatively high. PMID:26899362

  2. Antioxidant and Chelating Activity of Nontoxic Jatropha curcas L. Protein Hydrolysates Produced by In Vitro Digestion Using Pepsin and Pancreatin

    Directory of Open Access Journals (Sweden)

    Santiago Gallegos Tintoré

    2015-01-01

    Full Text Available The antioxidant and metal chelating activities in J. curcas protein hydrolysates have been determined. The hydrolysates were produced by treatment of a nontoxic genotype with the digestive enzymes pepsin and pancreatin and then were characterized by fast protein liquid chromatography and reverse phase chromatography. Peptidic fractions with higher radical scavenging activity were analysed by matrix-assisted laser desorption/ionization mass spectrometry. The antioxidant activity was determined by measuring inhibition of the oxidative degradation of β-carotene and by measuring the reactive oxygen species (ROS in Caco-2 cell cultures. Cu2+ and Fe2+ chelating activities were also determined. The hydrolysates inhibited the degradation of β-carotene and the formation of ROS in Caco-2 cells. The lower molecular weight peptidic fractions from FPLC had stronger antioxidant activity in cell cultures compared with the hydrolysates, which correlated with a higher content in antioxidant and chelating amino acids. These fractions were characterized by a large presence of peptides with different molecular masses. The hydrolysates exhibited both Cu2+ and Fe2+ chelating activity. It was concluded that J. curcas is a good source of antioxidant and metal chelating peptides, which may have a positive impact on the economic value of this crop, as a potential source of food functional components.

  3. Competition of dipositive metal ions for Fe (III) binding sites in chelation therapy of Iron Load

    International Nuclear Information System (INIS)

    Iron overload is a condition in which excessive iron deposited in the liver, kidney and spleen of human beings in the patients of beta thalassemia and sickle cell anemia. Instead of its importance iron could be toxic when in excess, it damages the tissues. For the treatment of iron overload, a drug desferrioxamine mesylate has been used. It is linear trihydroxamic acid, a natural siderophore produced by streptomyces which removes the extra iron from body. Salicylhydroxamate type siderphore. In present research salicylhydroxamate was used for the complexation with dipositive metal ions which are available in biological environments such as Mn (II), Co (II), Ni (II) and Cu (II). The aim of our work was to study the competition reactions between Fe (III) and other dipositive ions; to calculate the thermodynamic data of chelation of these metal ions complexes with hydroxamate by computer program and comparison with hydroxamate complexes. (author)

  4. IRON CHELATION THERAPY WITH DEFERASIROX IN THE MANAGEMENT OF IRON OVERLOAD IN PRIMARY MYELOFIBROSIS

    Directory of Open Access Journals (Sweden)

    Elena Maria Elli

    2014-05-01

    Full Text Available Deferasirox (DSX is the principal option currently available for iron-chelation-therapy (ICT, principally in the management of myelodysplastic syndromes (MDS, while in primary myelofibrosis (PMF the expertise is limited. We analyzed our experience in 10 PMF with transfusion-dependent anemia, treated with DSX from September 2010 to December 2013. The median dose tolerated of DSX was 750 mg/day (10 mg/kg/day, with 3 transient interruption of treatment for drug-related adverse events (AEs and 3 definitive discontinuation for grade 3/4 AEs. According to IWG 2006 criteria, erythroid responses with DSX were observed in 4/10 patients (40%, 2 of them (20% obtaining transfusion independence. Absolute changes in median serum ferritin levels (Delta ferritin were greater in hematologic responder (HR compared with non-responder (NR  patients, already at 6 months of ICT respect to baseline. Our preliminary data open new insights regarding the benefit of ICT not only in MDS, but also in PMF with the possibility to obtain an erythroid response, overall in 40 % of patients. HR patients receiving DSX seem to have a better survival and a lower incidence of leukemic transformation (PMF-BP. Delta ferritin evaluation at 6 months could represent a significant predictor for a different survival and PMF-BP.  However, the tolerability of the drug seems to be lower compared to MDS, both in terms of lower median tolerated dose and for higher frequency of discontinuation for AEs. The biological mechanism of action of DSX in chronic myeloproliferative setting through an independent NF-κB inhibition could be involved, but further investigations are required.

  5. Comparative study of antioxidant, metal chelating and antiglycation activities of Momordica charantia flesh and pulp fractions.

    Science.gov (United States)

    Ghous, Tahseen; Aziz, Nouman; Mehmood, Zahid; Andleeb, Saiqa

    2015-07-01

    Momordica charantia is commonly used as a vegetable and folk medicine in most parts of South Asia. This study aims to determine and compare the antioxidant, metal chelating and antiglycation activities of aqueous extracts of M. charantia fruit flesh (MCF) and fruit pulp (MCP) fractions. Our results show that MCP has pronounced DPPH and ABTS radical scavenging potential compared to MCF. In the antiglycation assay both fractions illustrated considerable inhibitory activities against the formation of AGEs induced by glucose with an efficacy of 75 and 67% with 150 μl of MCP and MCF extracts respectively, almost equal to 0.3mM amino guanidine. Results for metal catalysed protein fragmentation and autoxidative and glycoxidation assays demonstrate that MCF and MCP inhibited metal catalysed protein fragmentation. The percentage of relative standard deviation for three replicate measurements of 150 μl of MCF and MCP was < 3.0% for antiglycation. The antioxidant assays with regression values of MCP (0.981 and 0.991) and MCF (0.967 and 0.999) were also recorded. We conclude that both extracts possess high antioxidant and antiglycation activities and are equally good sources of antioxidant and antiglycating agents. PMID:26142512

  6. Heart cells in culture: a model of myocardial iron overload and chelation

    International Nuclear Information System (INIS)

    The effect of iron loading and chelation was studied in heart cell cultures obtained from newborn rats. Radioactive iron uptake per 2 X 10(6) cells/24 hr was 3.8% for 59Fe-transferrin, 15.8% for 59Fe-ferric ammonium citrate (FeAC) at 20 micrograms Fe/ml in 20% serum, and 37.1% for 59FeAC at 20 micrograms Fe/ml in serum-free medium. About one third of the cellular radioactive iron was in ferritin and the rest in an insoluble lysosomal fraction. Iron uptake was almost completely inhibited by reducing the incubation temperature from 37 degrees C to 10 degrees C. Intracellular concentrations of malonyldialdehyde (MDA) were doubled after 15 minutes of iron loading and reached maximal concentrations at 3 hours. Conversely, iron mobilization by deferoxamine at concentrations ranging from 0.025 mmol/L to 0.3 mmol/L resulted in normalization of cellular MDA concentrations, in direct proportion to the amounts of iron removed. These findings indicate that cultured myocardial cells are able to assimilate large amounts of nontransferrin iron and that iron uptake and mobilization are associated with striking changes in lipid peroxidation as manifested by the respective increase and decrease in cellular MDA concentrations

  7. CIPK23 is involved in iron acquisition of Arabidopsis by affecting ferric chelate reductase activity.

    Science.gov (United States)

    Tian, Qiuying; Zhang, Xinxin; Yang, An; Wang, Tianzuo; Zhang, Wen-Hao

    2016-05-01

    Iron deficiency is one of the major limiting factors affecting quality and production of crops in calcareous soils. Numerous signaling molecules and transcription factors have been demonstrated to play a regulatory role in adaptation of plants to iron deficiency. However, the mechanisms underlying the iron deficiency-induced physiological processes remain to be fully dissected. Here, we demonstrated that the protein kinase CIPK23 was involved in iron acquisition. Lesion of CIPK23 rendered Arabidopsis mutants hypersensitive to iron deficiency, as evidenced by stronger chlorosis in young leaves and lower iron concentration than wild-type plants under iron-deficient conditions by down-regulating ferric chelate reductase activity. We found that iron deficiency evoked an increase in cytosolic Ca(2+) concentration and the elevated Ca(2+) would bind to CBL1/CBL9, leading to activation of CIPK23. These novel findings highlight the involvement of calcium-dependent CBL-CIPK23 complexes in the regulation of iron acquisition. Moreover, mutation of CIPK23 led to changes in contents of mineral elements, suggesting that CBL-CIPK23 complexes could be as "nutritional sensors" to sense and regulate the mineral homeostasis in Arabisopsis. PMID:26993237

  8. Highly nucleophilic dipropanolamine chelated boron reagents for aryl-transmetallation to iron complexes.

    Science.gov (United States)

    Dunsford, Jay J; Clark, Ewan R; Ingleson, Michael J

    2015-12-21

    New aryl- and heteroarylboronate esters chelated by dipropanolamine are synthesised directly from boronic acids. The corresponding anionic borates are readily accessible by deprotonation and demonstrate an increase in hydrocarbyl nucleophilicity in comparison to other common borates. The new borates proved competent for magnesium or zinc additive-free, direct boron-to-iron hydrocarbyl transmetallations with well-defined iron(II) (pre)catalysts. The application of the new borate reagents in representative Csp(2)-Csp(3) cross-coupling led to almost exclusive homocoupling unless coupling is performed in the presence of a zinc additive. PMID:26554484

  9. Novel "hybrid" iron chelators derived from aroylhydrazones and thiosemicarbazones demonstrate selective antiproliferative activity against tumor cells.

    Science.gov (United States)

    Lovejoy, David B; Richardson, Des R

    2002-07-15

    We previously demonstrated that 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311) and other aroylhydrazone chelators possess potent antineoplastic activity because of their ability to bind iron (Fe). From these studies, we identified structural components of the hydrazones that provide antineoplastic activity, namely the salicylaldehyde and 2-hydroxy-1-naphthylaldehyde moieties. A related group of chelators known as the thiosemicarbazones also show pronounced antitumor activity because of their ability to inhibit ribonucleotide reductase. Considering this, we designed a new series of "hybrid ligands" by condensation of the aldehydes described above with a range of thiosemicarbazides. The parent compound of these ligands is 2-hydroxy-1-naphthylaldehyde thiosemicarbazone (NT). Of 8 NT analogues, 3 chelators, namely NT, N4mT (2-hydroxy-1-naphthylaldehyde-4-methyl-3-thiosemicarbazone), and N44mT (2-hydroxy-1-naphthylaldehyde-4,4-dimethyl-3-thiosemicarbazone), showed high antiproliferative activity against SK-N-MC neuroepithelioma cells (50% inhibitory concentration [IC(50)] = 0.5-1.5 microM). Indeed, their activity was significantly (P <.0001) greater than that of desferrioxamine (DFO) (IC(50) = 22 microM). We demonstrate that 311, a 311 analogue (311m), and several NT-series chelators have significantly (P <.001) greater antiproliferative activity against tumor cells than against a range of normal cell types. For example, the IC(50) values of NT and N4mT in SK-N-MC neuroepithelioma cells were 0.5 microM, whereas for fibroblasts the IC(50) values were greater than 25 microM. Further, the effect of one of the most potent chelators (311m) on preventing the growth of bone marrow stem cell cultures was far less than that of doxorubicin and similar to that of cisplatin. These studies support the further development of these chelators as antiproliferative agents. PMID:12091363

  10. New developments and controversies in iron metabolism and iron chelation therapy

    OpenAIRE

    Christina N. Kontoghiorghe; Kontoghiorghes, George J.

    2016-01-01

    Iron is essential for all organisms including microbial, cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using ...

  11. Degradation of toluene, ethylbenzene, and xylene using heat and chelated-ferrous iron activated persulfate oxidation

    Science.gov (United States)

    Mondal, P.; Sleep, B.

    2014-12-01

    Toluene, ethylbenze, and xylene (TEX) are common contaminants in the subsurface. Activated persulfate has shown promise for degrading a wide variety of organic compounds. However, studies of persulfate application for in situ degradation of TEX and effects on the subsequent bioremediation are limited. In this work, degradation studies of TEX in aqueous media and soil are being conducted using heat activated and chelated-ferrous iron activated persulfate oxidation in batch and flow-through column experiments. In the batch experiments, sodium persulfate is being used at different concentrations to provide an initial persulfate to TEX molar ratios between 10:1 and 100:1. Sodium persulfate solutions are being activated at 20, 37, 60, and 80 oC temperatures for the heat activated oxidation. For the chelated-ferrous iron activated oxidation, ferrous iron and citric acid, both are being used at concentration of 5 mM. In the experiments with soil slurry, a soil to water ratio of 1 to 5 is being used. Flow through water saturated column experiments are being conducted with glass columns (45 cm in length and 4 cm in diameter) uniformly packed with soils, and equilibrated with water containing TEX at the target concentrations. Both the heat activation and chelated-ferrous iron activation of persulfate are being employed in the column experiments. Future experiments are planned to determine the suitability of persulfate oxidation of TEX on the subsequent biodegradation using batch microcosms containing TEX degrading microbial cultures. In these experiments, the microbial biomass will be monitored using total phospholipids, and the microbial community will be determined using quantitative real-time polymerase chain reaction (qPCR) on the extracted DNA. This study is expected to provide suitable operating conditions for in situ chemical oxidation of TEX with activated persulfate followed by bioremediation.

  12. Reduction in labile plasma iron during treatment with deferasirox, a once-daily oral iron chelator, in heavily iron-overloaded patients with β-thalassaemia

    OpenAIRE

    Daar, Shahina; Pathare, Anil; Nick, Hanspeter; Kriemler-Krahn, Ulrike; Hmissi, Abdel; Habr, Dany; Taher, Ali

    2009-01-01

    This subgroup analysis evaluated the effect of once-daily oral deferasirox on labile plasma iron (LPI) levels in patients from the prospective, 1-yr, multicentre ESCALATOR study. Mean baseline liver iron concentration and median serum ferritin levels were 28.6 ± 10.3 mg Fe/g dry weight and 6334 ng/mL respectively, indicating high iron burden despite prior chelation therapy. Baseline LPI levels (0.98 ± 0.82 μmol/L) decreased significantly to 0.12 ± 0.16 μmol/L, 2 h after first deferasirox dose...

  13. CARDIAC FUNCTION AND IRON CHELATION IN THALASSEMIA MAJOR AND INTERMEDIA: A REVIEW OF THE UNDERLYING PATHOPHYSIOLOGY AND APPROACH TO CHELATION MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Athanasios Aessopos

    2009-07-01

    Full Text Available Heart disease is the leading cause of mortality and one of the main causes of morbidity in beta-thalassemia. Patients with homozygous thalassemia may have either a severe phenotype which is usually transfusion dependent or a milder form that is thalassemia intermedia.  The two main factors that determine cardiac disease in homozygous β thalassemia are the high output state that results from chronic tissue hypoxia, hypoxia-induced compensatory reactions and iron overload.  The high output state playing a major role in thalassaemia intermedia and the iron load being more significant in the major form. Arrhythmias, vascular involvement that leads to an increased pulmonary vascular resistance and an increased systemic vascular stiffness and valvular abnormalities also contribute to the cardiac dysfunction in varying degrees according to the severity of the phenotype.  Endocrine abnormalities, infections, renal function and medications can also play a role in the overall cardiac function.  For thalassaemia major, regular and adequate blood transfusions and iron chelation therapy are the mainstays of management. The approach to thalassaemia intermedia, today, is aimed at monitoring for complications and initiating, timely, regular transfusions and/or iron chelation therapy.  Once the patients are on transfusions, then they should be managed in the same way as the thalassaemia major patients.  If cardiac manifestations of dysfunction are present in either form of thalassaemia, high pre transfusion Hb levels need to be maintained in order to reduce cardiac output and appropriate intensive chelation therapy needs to be instituted.  In general recommendations on chelation, today, are usually made according to the Cardiac Magnetic Resonance findings, if available.  With the advances in the latter technology and the ability to tailor chelation therapy according to the MRI findings as well as the availability of three iron chelators, together with

  14. Tailoring iron chelation by iron intake and serum ferritin : the prospective EPIC study of deferasirox in 1744 patients with transfusion-dependent anemias

    OpenAIRE

    Cappellini, M. D.; Porter, J.; A. El-Beshlawy; Li, C. K.; Seymour, J.F.; Elalfy, M.; Gattermann, N; Giraudier, S.; Lee, J. W.; Chan, L L; Lin, K H; Rose, C.; Taher, A; Thein, S L; Viprakasit, V

    2010-01-01

    BackgroundFollowing a clinical evaluation of deferasirox (Exjade (R)) it was concluded that, in addition to baseline body iron burden, ongoing transfusional iron intake should be considered when selecting doses. The 1-year EPIC study, the largest ever investigation conducted for an iron chelator, is the first to evaluate whether fixed starting doses of deferasirox, based on transfusional iron intake, with dose titration guided by serum ferritin trends and safety markers, provides clinically a...

  15. Effects of Iron Chelators on the Formation and Development of Aspergillus fumigatus Biofilm.

    Science.gov (United States)

    Nazik, Hasan; Penner, John C; Ferreira, Jose A; Haagensen, Janus A J; Cohen, Kevin; Spormann, Alfred M; Martinez, Marife; Chen, Vicky; Hsu, Joe L; Clemons, Karl V; Stevens, David A

    2015-10-01

    Iron acquisition is crucial for the growth of Aspergillus fumigatus. A. fumigatus biofilm formation occurs in vitro and in vivo and is associated with physiological changes. In this study, we assessed the effects of Fe chelators on biofilm formation and development. Deferiprone (DFP), deferasirox (DFS), and deferoxamine (DFM) were tested for MIC against a reference isolate via a broth macrodilution method. The metabolic effects (assessed by XTT [2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide inner salt]) on biofilm formation by conidia were studied upon exposure to DFP, DFM, DFP plus FeCl3, or FeCl3 alone. A preformed biofilm was exposed to DFP with or without FeCl3. The DFP and DFS MIC50 against planktonic A. fumigatus was 1,250 μM, and XTT gave the same result. DFM showed no planktonic inhibition at concentrations of ≤2,500 μM. By XTT testing, DFM concentrations of biofilms forming in A. fumigatus or preformed biofilms (P biofilm formation (P Biofilm formation with 625 μM DFP plus any concentration of FeCl3 was lower than that in the controls (P biofilms, DFP in the range of ≥625 to 1,250 μM was inhibitory compared to the controls (P biofilm formation (P biofilm increased with 2,500 μM FeCl3 only (P biofilms of A. fumigatus clinical isolates to DFP were noted. In conclusion, iron stimulates biofilm formation and preformed biofilms. Chelators can inhibit or enhance biofilms. Chelation may be a potential therapy for A. fumigatus, but we show here that chelators must be chosen carefully. Individual isolate susceptibility assessments may be needed. PMID:26239975

  16. Iron (II)-chelating activity of buffalo αS-casein hydrolysed by corolase PP, alcalase and flavourzyme

    OpenAIRE

    Jaiswal, Arvind; Bajaj, Rajesh; Mann, Bimlesh; Lata, Kiran

    2014-01-01

    Iron is a vital substance for human health which participates in many biochemical reactions. It also act as initiator for many harmful oxidative process. Buffalo αS-casein enriched fraction (80 %) was hydrolysed independently by corolase PP (H1), alcalase (H2), flavourzyme (H3) and sequentially by alcalase-flavourzyme (H4). After ultrafiltration (10 and 3 kDa) hydrolysates were analysed for their iron chelation activity using ferrozine. For H1 group of hydrolysates highest iron (II)-chelation...

  17. [Iron chelation therapy and its influence on the alleviation of EPO resistance in MDS patients].

    Science.gov (United States)

    Zhang, Yao; Xiao, Chao; Gu, Shu-Cheng; Chang, Chun-Kang

    2014-08-01

    This study was aimed to investigate the changes of erythropoietin (EPO), hemoglobin(Hb) and recombinant EPO (rEPO) levels in MDS patients receiving iron chelation therapy, and to explore the relationship between EPO and serum ferritin(SF). A total of 172 MDS patients and 30 healthy controls were studied. The levels of SF, EPO, serum iron (SI), total iron binding capacity (TIBC), C-reaction protein (CRP) and Hb were measured respectively, the level of SF was adjusted according to the changes of CRP. Among them, there were 34 cases of low-risk (SF>1 000 mg/L) receiving deferoxamine therapy, whose changes of SF, EPO, SI, TIBC, Hb levels were detected and compared before and after treatment. Besides, the difference in the incidence of EPO resistance in iron overload group and non-iron overload group was assessed before and after therapy, and 58 cases of low-risk and EPO<1 000 U/L MDS patients were given rEPO therapy. The results showed that the level of EPO in non-iron overload group was higher than that in the normal control group (997.44 ± 473.48 vs 467.27 ± 238.49, P < 0.05). Obviously, the level of EPO in iron overload group was higher than that in non-iron overload group and control group (3257.59 ± 697.19 vs 997.44 ± 473.48, P = 0.012, 3257.59 ± 697.19 vs 467.27 ± 238.49, P = 0.002). Otherwise, the incidence of EPO resistance in iron overload group was higher than that in non-iron overload group (18/35 vs 2/23, P = 0.001), and the level of EPO and SF was positively related to each other in iron overload group (r = 0.310,P = 0.036). After receiving iron chelation therapy, the levels of SF, SI, TIBC and EPO in iron overload group were significantly lower than that before therapy (3942.38 ± 641.82 vs 2266.35 ± 367.31, P = 0.028;48.61 ± 10.65 vs 28.52 ± 12.61, P = 0.034;59.84 ± 12.62 vs 33.76 ± 15.43, P = 0.045;3808.01 ± 750.22 vs 1954.78 ± 473.18, P = 0.042). Moreover, the level of Hb increased (35 ± 18 vs 57 ± 21, P = 0.046) and the EPO resistance

  18. The iron chelator deferasirox affects redox signalling in haematopoietic stem/progenitor cells.

    Science.gov (United States)

    Tataranni, Tiziana; Agriesti, Francesca; Mazzoccoli, Carmela; Ruggieri, Vitalba; Scrima, Rosella; Laurenzana, Ilaria; D'Auria, Fiorella; Falzetti, Franca; Di Ianni, Mauro; Musto, Pellegrino; Capitanio, Nazzareno; Piccoli, Claudia

    2015-07-01

    The iron chelator deferasirox (DFX) prevents complications related to transfusional iron overload in several haematological disorders characterized by marrow failure. It is also able to induce haematological responses in a percentage of treated patients, particularly in those affected by myelodysplastic syndromes. The underlying mechanisms responsible for this feature, however, are still poorly understood. In this study, we investigated the effect of DFX-treatment in human haematopoietic/progenitor stem cells, focussing on its impact on the redox balance, which proved to control the interplay between stemness maintenance, self-renewal and differentiation priming. Here we show, for the first time, that DFX treatment induces a significant diphenyleneiodonium-sensitive reactive oxygen species (ROS) production that leads to the activation of POU5F1 (OCT4), SOX2 and SOX17 gene expression, relevant in reprogramming processes, and the reduction of the haematopoietic regulatory proteins CTNNB1 (β-Catenin) and BMI1. These DFX-mediated events were accompanied by decreased CD34 expression, increased mitochondrial mass and up-regulation of the erythropoietic marker CD71 (TFRC) and were compound-specific, dissimilar to deferoxamine. Our findings would suggest a novel mechanism by which DFX, probably independently on its iron-chelating property but through ROS signalling activation, may influence key factors involved in self-renewal/differentiation of haematopoietic stem cells. PMID:25825160

  19. Chemical, physical, and sensory characteristics of mozzarella cheese fortified using protein-chelated iron or ferric chloride.

    Science.gov (United States)

    Rice, W H; McMahon, D J

    1998-02-01

    Mozzarella cheese containing 25 and 50 mg of iron/kg of cheese was manufactured from milk that had been fortified with casein-chelated iron, whey protein-chelated iron, or FeCl3. Chemical, physical, and sensory characteristics were compared with those of a control cheese. Physical properties were assessed by testing melting, apparent viscosity, and browning of heated cheese. Cheeses were evaluated by trained panelists for the presence of metallic flavors, oxidized flavors, and other undesirable flavors. Addition of 25 mg iron/kg of cheese had no effects on the physical properties of Mozzarella cheese. Apparent viscosity of cheese fortified with 50 mg of iron/kg of cheese tended to be slightly higher than the control cheese, although this difference was not statistically significant at all storage times. Cook color was not affected by iron fortification. No increase in chemical oxidation (measured using thiobarbituric acid assay) was observed between the control and iron-fortified cheeses. Slight but statistically significant increases in metallic flavors, oxidized flavors, and off-flavors in the iron-fortified cheese were observed by the trained sensory panel, but the flavor defects were of very low intensity. For metallic flavors, oxidized flavors, and off-flavors, the control cheese scored 1.5, 1.5, and 1.3, respectively; the iron-fortified cheese scored 2.1, 2.0, and 1.6 based on a nine-point scale (where 1 = not perceptible to 3 = slightly perceptible). Sensory scores for iron-fortified cheese made using casein-chelated iron or whey protein-chelated iron was not significantly different from those of cheese made using ferric chloride. When used on pizza, consumer panels rated the iron-fortified cheeses as comparable with the control cheese. PMID:9532487

  20. Mutational reconstructed ferric chelate reductase confers enhanced tolerance in rice to iron deficiency in calcareous soil

    OpenAIRE

    Ishimaru, Yasuhiro; Kim, Suyeon; Tsukamoto, Takashi; Oki, Hiroyuki; Kobayashi, Takanori; Watanabe, Satoshi; Matsuhashi, Shinpei; Takahashi, Michiko; Nakanishi, Hiromi; Mori, Satoshi; Naoko K. Nishizawa

    2007-01-01

    Iron (Fe) deficiency is a worldwide agricultural problem on calcareous soils with low-Fe availability due to high soil pH. Rice plants use a well documented phytosiderophore-based system (Strategy II) to take up Fe from the soil and also possess a direct Fe2+ transport system. Rice plants are extremely susceptible to low-Fe supply, however, because of low phytosiderophore secretion and low Fe3+ reduction activity. A yeast Fe3+ chelate-reductase gene refre1/372, selected for better performance...

  1. Rapid Regeneration of Chelated Iron Desulfurization Solution Using Electrochemical Reactor with Rotating Cylindrical Electrodes

    Institute of Scientific and Technical Information of China (English)

    于永; 刘有智; 祁贵生

    2014-01-01

    A new electrochemical reactor with rotating cylindrical electrodes was designed and used to increase the regeneration efficiency of chelated iron desulfurization solution. The influence of operating parameters, such as the rotation speed of electrode, voltage, and inlet air and liquid flow rates, on the regeneration rate was investigated. Compared with the traditional tank-type reactor, the regeneration rate with the new electrochemical reactor was in-creased significantly. Under the optimum conditions, the regeneration rate was increased from 45.3% to 84.8%. Experimental results of continuous operation indicated that the new electrochemical regeneration method had some merits including higher regeneration efficiency, smaller equipment size and good stability in operation.

  2. Iron Chelation

    Science.gov (United States)

    ... information, it does not guarantee the accuracy or currency of this information. ... makes it possible to meet patients' needs, hold impactful conferences, develop fresh education programs and fund research for the cures, along ...

  3. Chelating, antioxidant and hypoglycaemic potential of Muscari comosum (L.) Mill. bulb extracts.

    Science.gov (United States)

    Loizzo, Monica R; Tundis, Rosa; Menichini, Federica; Pugliese, Alessandro; Bonesi, Marco; Solimene, Umberto; Menichini, Francesco

    2010-12-01

    The metal chelating activity, antioxidant properties and the effect on carbohydrate-hydrolysing enzyme inhibition of Muscari comosum extracts have been investigated. M. comosum bulbs contain a total amount of the phenols with a value of 56.6 mg chlorogenic acid equivalent per gram of extract and a flavonoid content of 23.4 mg quercetin equivalent per gram of extract. In order to evaluate the non-polar constituents, n-hexane extract was obtained. Gas chromatography-mass spectrometry analysis revealed the presence of fatty acids and ethyl esters as major constituents, with different aldehydes and alkanes as minor components. Ethanolic extract had the highest ferric-reducing ability power (66.7 μM Fe(II)/g) and DPPH scavenging activity with a concentration giving 50% inhibition (IC₅₀) value of 40.9 μg/ml. Moreover, this extract exhibited a good hypoglycaemic activity with IC₅₀ values of 81.3 and 112.8 μg/ml for α-amylase and α-glucosidase, respectively. In conclusion, M. comosum bulbs show promising antioxidant and hypoglycaemic activity via the inhibition of carbohydrate digestive enzymes. These activities may be of interest from a functional point of view and for the revalorization of this ancient non-cultivated vegetable of Mediterranean traditional gastronomy. PMID:20465433

  4. Novel orally active iron chelators (3-hydroxypyridin-4-ones) enhance the biliary excretion of plasma non-transferrin-bound iron in rats

    Energy Technology Data Exchange (ETDEWEB)

    Zanninelli, G.; Loreal, O. [Pontchaillou Univ. Hospital, INSERM U-49, Liver Research Unit, Rennes (France); Choudury, R. [King`s College, Dept. of Pharmacey, London (United Kingdom)] [and others

    1997-10-01

    Background/Aims: It is well documented that levels of plasma non-transferrin-bound iron (NTBI), a particularly toxic form of iron, are increased in iron overload disorders. In light of the pathogenetic importance of NTBI in chronic iron overload, we have studied the ability of new orally active iron chelators to promote the biliary excretion of iron originating as plasma {sup 55}Fe-NTBI. Methods: Biliary iron kinetics of plasma {sup 55}Fe-labeled NTBI and cumulative recoveries of {sup 55}Fe in bile were determined in normal and carbonyl iron-loaded rats receiving a single intragastric dose of iron chelator. These chelators were the novel hydroxypyridin-4-one compounds CP102, CP41, and their respective prodrugs CP117 and CP165. Results: The cumulative recovery of {sup 5} {sup 5}Fe in bile of normal rats was increased by 5.2-, 7.9-, 11.5-, and 9.2-fold with CP102, CP117, CP41 and CP165, respectively. In iron overloaded rats, these compounds increased the cumulative recovery by 28.6-, 48.6-, 72.6-, and 32-fold, respectively. All the chelators had a choleretic effect, were metabolized by the liver as demonstrated by HPLC study of bile, and were not cytotoxic since normal plasma transaminase levels were maintained at the end of the experiments. Conclusions: These chelators have potential interest for the treatment of iron overload conditions and may offer advantages over simple N-alkyl-hydroxypyridinones such as deferiprone (CP20, L1). (au) 29 refs.

  5. Novel orally active iron chelators (3-hydroxypyridin-4-ones) enhance the biliary excretion of plasma non-transferrin-bound iron in rats

    International Nuclear Information System (INIS)

    Background/Aims: It is well documented that levels of plasma non-transferrin-bound iron (NTBI), a particularly toxic form of iron, are increased in iron overload disorders. In light of the pathogenetic importance of NTBI in chronic iron overload, we have studied the ability of new orally active iron chelators to promote the biliary excretion of iron originating as plasma 55Fe-NTBI. Methods: Biliary iron kinetics of plasma 55Fe-labeled NTBI and cumulative recoveries of 55Fe in bile were determined in normal and carbonyl iron-loaded rats receiving a single intragastric dose of iron chelator. These chelators were the novel hydroxypyridin-4-one compounds CP102, CP41, and their respective prodrugs CP117 and CP165. Results: The cumulative recovery of 55Fe in bile of normal rats was increased by 5.2-, 7.9-, 11.5-, and 9.2-fold with CP102, CP117, CP41 and CP165, respectively. In iron overloaded rats, these compounds increased the cumulative recovery by 28.6-, 48.6-, 72.6-, and 32-fold, respectively. All the chelators had a choleretic effect, were metabolized by the liver as demonstrated by HPLC study of bile, and were not cytotoxic since normal plasma transaminase levels were maintained at the end of the experiments. Conclusions: These chelators have potential interest for the treatment of iron overload conditions and may offer advantages over simple N-alkyl-hydroxypyridinones such as deferiprone (CP20, L1). (au) 29 refs

  6. The Pseudomonas aeruginosa extracellular secondary metabolite, Paerucumarin, chelates iron and is not localized to extracellular membrane vesicles.

    Science.gov (United States)

    Qaisar, Uzma; Kruczek, Cassandra J; Azeem, Muhammed; Javaid, Nasir; Colmer-Hamood, Jane A; Hamood, Abdul N

    2016-08-01

    Proteins encoded by the Pseudomonas aeruginosa pvcA-D operon synthesize a novel isonitrile functionalized cumarin termed paerucumarin. The pvcA-D operon enhances the expression of the P. aeruginosa fimbrial chaperone/usher pathway (cup) genes and this effect is mediated through paerucumarin. Whether pvcA-D and/or paerucumarin affect the expression of other P. aeruginosa genes is not known. In this study, we examined the effect of a mutation in pvcA-D operon the global transcriptome of the P. aeruginosa strain PAO1-UW. The mutation reduced the expression of several ironcontrolled genes including pvdS, which is essential for the expression of the pyoverdine genes. Additional transcriptional studies showed that the pvcA-D operon is not regulated by iron. Exogenously added paerucumarin enhanced pyoverdine production and pvdS expression in PAO1-UW. Iron-chelation experiments revealed that purified paerucumarin chelates iron. However, exogenously added paerucumarin significantly reduced the growth of a P. aeruginosa mutant defective in pyoverdine and pyochelin production. In contrast to other secondary metabolite, Pseudomonas quinolone signal (PQS), paerucumarin is not localized to the P. aeruginosa membrane vesicles. These results suggest that paerucumarin enhances the expression of iron-controlled genes by chelating iron within the P. aeruginosa extracellular environment. Although paerucumarin chelates iron, it does not function as a siderophore. Unlike PQS, paerucumarin is not associated with the P. aeruginosa cell envelope. PMID:27480638

  7. High-performance liquid chromatography method for ferric iron chelators using a post-column reaction with Calcein Blue.

    Science.gov (United States)

    Ariga, Tomoko; Ito, Kyoko; Imura, Yuki; Yoshimura, Etsuro

    2015-03-15

    Iron (Fe) is an essential element for higher plants, which take it up from the soil at the root surface and transport it to shoots through the xylem. Fe(III) chelators, such as organic acids and phytosiderophores, play important roles in the acquisition and transportation of Fe(III). Therefore, a selective and sensitive method for analyzing Fe(III) chelators is required to study the many Fe-related physiological mechanisms in plants. A novel analytical approach employing a high-performance liquid chromatography post-column method with fluorescence detection was developed to separate and detect Fe(III) chelators. This method takes advantage of the quenching of the fluorescence of Calcein Blue (CB) that occurs with the formation of an Fe(III)-CB complex and the dequenching that occurs with the release of CB as a result of competition for Fe(III) between CB and an Fe(III) chelator. This simple experimental method does not require complicated pretreatments and can selectively detect Fe(III) chelators according to their Fe(III)-chelating ability. The detection limit for citric acid using this method was 72pmol. Furthermore, this method can also detect unknown Fe(III) chelators that exhibit a high affinity for Fe(III). The method was evaluated with xylem sap of barley, which was shown to contain several Fe(III) chelators. PMID:25658515

  8. Expanding horizons in iron chelation and the treatment of cancer: role of iron in the regulation of ER stress and the epithelial-mesenchymal transition.

    Science.gov (United States)

    Lane, Darius J R; Mills, Thomas M; Shafie, Nurul H; Merlot, Angelica M; Saleh Moussa, Rayan; Kalinowski, Danuta S; Kovacevic, Zaklina; Richardson, Des R

    2014-04-01

    Cancer is a major public health issue and, despite recent advances, effective clinical management remains elusive due to intra-tumoural heterogeneity and therapeutic resistance. Iron is a trace element integral to a multitude of metabolic processes, including DNA synthesis and energy transduction. Due to their generally heightened proliferative potential, cancer cells have a greater metabolic demand for iron than normal cells. As such, iron metabolism represents an important "Achilles' heel" for cancer that can be targeted by ligands that bind and sequester intracellular iron. Indeed, novel thiosemicarbazone chelators that act by a "double punch" mechanism to both bind intracellular iron and promote redox cycling reactions demonstrate marked potency and selectivity in vitro and in vivo against a range of tumours. The general mechanisms by which iron chelators selectively target tumour cells through the sequestration of intracellular iron fall into the following categories: (1) inhibition of cellular iron uptake/promotion of iron mobilisation; (2) inhibition of ribonucleotide reductase, the rate-limiting, iron-containing enzyme for DNA synthesis; (3) induction of cell cycle arrest; (4) promotion of localised and cytotoxic reactive oxygen species production by copper and iron complexes of thiosemicarbazones (e.g., Triapine(®) and Dp44mT); and (5) induction of metastasis and tumour suppressors (e.g., NDRG1 and p53, respectively). Emerging evidence indicates that chelators can further undermine the cancer phenotype via inhibiting the epithelial-mesenchymal transition that is critical for metastasis and by modulating ER stress. This review explores the "expanding horizons" for iron chelators in selectively targeting cancer cells. PMID:24472573

  9. Anti-Plasmodial Activity of Aroylhydrazone and Thiosemicarbazone Iron Chelators: Effect on Erythrocyte Membrane Integrity, Parasite Development and the Intracellular Labile Iron Pool

    OpenAIRE

    Walcourt, Asikiya; Kurantsin-Mills, Joseph; Kwagyan, John; Adenuga, Babafemi B.; Kalinowski, Danuta S.; Lovejoy, David B.; Lane, Darius J.R.; Richardson, Des R.

    2013-01-01

    Iron chelators inhibit the growth of the malaria parasite, Plasmodium falciparum, in culture and in animal and human studies. We previously reported the anti-plasmodial activity of the chelators, 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311), 2-hydroxy-1-naphthylaldehyde 4-methyl-3-thiosemicarbazone (N4mT), and 2-hydroxy-1-naphthylaldehyde 4-phenyl-3-thiosemicarbazone (N4pT). In fact, these ligands showed greater growth inhibition of chloroquine-sensitive (3D7) and chloroquine-re...

  10. An Antioxidant Extract of the Insectivorous Plant Drosera burmannii Vahl. Alleviates Iron-Induced Oxidative Stress and Hepatic Injury in Mice.

    Science.gov (United States)

    Ghate, Nikhil Baban; Chaudhuri, Dipankar; Das, Abhishek; Panja, Sourav; Mandal, Nripendranath

    2015-01-01

    Free iron typically leads to the formation of excess free radicals, and additional iron deposition in the liver contributes to the oxidative pathologic processes of liver disease. Many pharmacological properties of the insectivorous plant Drosera burmannii Vahl. have been reported in previous studies; however, there is no evidence of its antioxidant or hepatoprotective potential against iron overload. The antioxidant activity of 70% methanolic extract of D. burmannii (DBME) was evaluated. DBME showed excellent DPPH, hydroxyl, hypochlorous, superoxide, singlet oxygen, nitric oxide, peroxynitrite radical and hydrogen peroxide scavenging activity. A substantial iron chelation (IC50 = 40.90 ± 0.31 μg/ml) and supercoiled DNA protection ([P]50 = 50.41 ± 0.55 μg) were observed. DBME also displayed excellent in vivo hepatoprotective activity in iron-overloaded Swiss albino mice compared to the standard desirox treatment. Administration of DBME significantly normalized serum enzyme levels and restored liver antioxidant enzymes levels. DBME lowered the raised levels of liver damage parameters, also reflected from the morphological analysis of the liver sections. DBME also reduced liver iron content by 115.90% which is also seen by Perls' staining. A phytochemical analysis of DBME confirms the presence of various phytoconstituents, including phenols, flavonoids, carbohydrates, tannins, alkaloids and ascorbic acid. Alkaloids, phenols and flavonoids were abundantly found in DBME. An HPLC analysis of DBME revealed the presence of purpurin, catechin, tannic acid, reserpine, methyl gallate and rutin. Purpurin, tannic acid, methyl gallate and rutin displayed excellent iron chelation but exhibited cytotoxicity toward normal (WI-38) cells; while DBME found to be non-toxic to the normal cells. These findings suggest that the constituents present in DBME contributed to its iron chelation activity. Additional studies are needed to determine if DBME can be used as a treatment for

  11. An Antioxidant Extract of the Insectivorous Plant Drosera burmannii Vahl. Alleviates Iron-Induced Oxidative Stress and Hepatic Injury in Mice.

    Directory of Open Access Journals (Sweden)

    Nikhil Baban Ghate

    Full Text Available Free iron typically leads to the formation of excess free radicals, and additional iron deposition in the liver contributes to the oxidative pathologic processes of liver disease. Many pharmacological properties of the insectivorous plant Drosera burmannii Vahl. have been reported in previous studies; however, there is no evidence of its antioxidant or hepatoprotective potential against iron overload. The antioxidant activity of 70% methanolic extract of D. burmannii (DBME was evaluated. DBME showed excellent DPPH, hydroxyl, hypochlorous, superoxide, singlet oxygen, nitric oxide, peroxynitrite radical and hydrogen peroxide scavenging activity. A substantial iron chelation (IC50 = 40.90 ± 0.31 μg/ml and supercoiled DNA protection ([P]50 = 50.41 ± 0.55 μg were observed. DBME also displayed excellent in vivo hepatoprotective activity in iron-overloaded Swiss albino mice compared to the standard desirox treatment. Administration of DBME significantly normalized serum enzyme levels and restored liver antioxidant enzymes levels. DBME lowered the raised levels of liver damage parameters, also reflected from the morphological analysis of the liver sections. DBME also reduced liver iron content by 115.90% which is also seen by Perls' staining. A phytochemical analysis of DBME confirms the presence of various phytoconstituents, including phenols, flavonoids, carbohydrates, tannins, alkaloids and ascorbic acid. Alkaloids, phenols and flavonoids were abundantly found in DBME. An HPLC analysis of DBME revealed the presence of purpurin, catechin, tannic acid, reserpine, methyl gallate and rutin. Purpurin, tannic acid, methyl gallate and rutin displayed excellent iron chelation but exhibited cytotoxicity toward normal (WI-38 cells; while DBME found to be non-toxic to the normal cells. These findings suggest that the constituents present in DBME contributed to its iron chelation activity. Additional studies are needed to determine if DBME can be used as a

  12. Effect of Systemic Iron Overload and a Chelation Therapy in a Mouse Model of the Neurodegenerative Disease Hereditary Ferritinopathy.

    Science.gov (United States)

    Garringer, Holly J; Irimia, Jose M; Li, Wei; Goodwin, Charles B; Richine, Briana; Acton, Anthony; Chan, Rebecca J; Peacock, Munro; Muhoberac, Barry B; Ghetti, Bernardino; Vidal, Ruben

    2016-01-01

    Mutations in the ferritin light chain (FTL) gene cause the neurodegenerative disease neuroferritinopathy or hereditary ferritinopathy (HF). HF is characterized by a severe movement disorder and by the presence of nuclear and cytoplasmic iron-containing ferritin inclusion bodies (IBs) in glia and neurons throughout the central nervous system (CNS) and in tissues of multiple organ systems. Herein, using primary mouse embryonic fibroblasts from a mouse model of HF, we show significant intracellular accumulation of ferritin and an increase in susceptibility to oxidative damage when cells are exposed to iron. Treatment of the cells with the iron chelator deferiprone (DFP) led to a significant improvement in cell viability and a decrease in iron content. In vivo, iron overload and DFP treatment of the mouse model had remarkable effects on systemic iron homeostasis and ferritin deposition, without significantly affecting CNS pathology. Our study highlights the role of iron in modulating ferritin aggregation in vivo in the disease HF. It also puts emphasis on the potential usefulness of a therapy based on chelators that can target the CNS to remove and redistribute iron and to resolubilize or prevent ferritin aggregation while maintaining normal systemic iron stores. PMID:27574973

  13. Effects of intracellular chelatable iron and oxidative stress on transcription of classical cellular glutathione peroxidase gene in murine erythroleukemia cells

    International Nuclear Information System (INIS)

    The effect of intracellular chelatable iron levels and of oxidative stress on nuclear classical cellular glutathione peroxidase (GSHPx-1) RNA nascent chain elongation (run-on transcription) and on the stability of cytoplasmic GSHPx-1 mRNA was investigated in murine erythroleukemia (MEL) cells. The amount in the intracellular low molecular mass iron pool was changed by incubation of MEL cells transformed by Friend virus with iron donors or iron chelators. Transcription in vitro in isolated nuclei from treated cells showed that the treatment with chelators (desferrioxamine (DFO), pyridoxal isonicotinoyl hydrazone) decrease the rate of nuclear GSHPx-1 RNA nascent chain elongation in both un-induced and with 5 mmol hexamethylenebisacetamide to erythroid differentiation induced MEL cells. Iron donors (diferric transferrin,, Fe-PIH or their combination) and t-butyl hydroperoxide (t-BuOOH) had the opposite effect on GSHPx-1 gene transcription in run-on experiments. On the other hand, 50 μmol DFO or 2.5 μmol t-BuOOH did not change the stability of cytoplasmic GSHPx-1 mRNA in both un-induced and induced MEL cells treated with 5 μmol actinomycin D and with or without these agents for 9 h. These findings indicate that iron and oxidative stress play their role at the transcriptional level of GSHPx-1 gene expression. (author)

  14. Bp44mT: an orally active iron chelator of the thiosemicarbazone class with potent anti-tumour efficacy

    Science.gov (United States)

    Yu, Y; Rahmanto, Y Suryo; Richardson, DR

    2012-01-01

    BACKGROUND AND PURPOSE Our previous studies demonstrated that a thiosemicarbazone iron chelator (di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone; Dp44mT) possesses potent and selective anti-cancer activity but led to cardiotoxicity at non-optimal doses. In this study, we examined the in vivo anti-tumour efficacy and tolerability of a new-generation 2-benzoylpyridine thiosemicarbazone iron chelator (2-benzoylpyridine-4,4-dimethyl-3-thiosemicarbazone; Bp44mT) administered via the oral or i.v. routes. EXPERIMENTAL APPROACH BpT chelators were tested in vitro against human lung cancer cells (DMS-53) and in vivo in DMS-53 tumour xenografts in mice. The toxicity of Bp44mT in vivo and its effects on the expression of iron-regulated molecules involved in growth and cell cycle control were investigated. KEY RESULTS Administration of Bp44mT by either route resulted in marked dose-dependent inhibition of tumour growth. When administered at 50 mg·kg−1 via oral gavage three times per week for 23 days, the net xenograft growth was inhibited by 75%, compared with vehicle-treated mice. Toxicological examination showed reversible alterations including slight reduction of RBC count, with a decrease of liver and splenic iron levels, which confirmed iron chelation in vivo. Importantly, in contrast to Dp44mT, the chelator-treated mice did not show cardiac histological abnormalities. There was also no significant weight loss in mice, suggesting oral administration of Bp44mT was well tolerated. CONCLUSIONS AND IMPLICATIONS This is the first study to show that Bp44mT can be given orally with potent anti-tumour efficacy. Oral administration of a novel and effective chemotherapeutic agent provides the benefits of convenience for chronic dosing regimens. PMID:21658021

  15. Phenyl-1-Pyridin-2yl-Ethanone-Based Iron Chelators Increase IκB-α Expression, Modulate CDK2 and CDK9 Activities, and Inhibit HIV-1 Transcription

    Science.gov (United States)

    Kumari, Namita; Iordanskiy, Sergey; Kovalskyy, Dmytro; Breuer, Denitra; Niu, Xiaomei; Lin, Xionghao; Xu, Min; Gavrilenko, Konstantin; Kashanchi, Fatah; Dhawan, Subhash

    2014-01-01

    HIV-1 transcription is activated by the Tat protein, which recruits CDK9/cyclin T1 to the HIV-1 promoter. CDK9 is phosphorylated by CDK2, which facilitates formation of the high-molecular-weight positive transcription elongation factor b (P-TEFb) complex. We previously showed that chelation of intracellular iron inhibits CDK2 and CDK9 activities and suppresses HIV-1 transcription, but the mechanism of the inhibition was not understood. In the present study, we tested a set of novel iron chelators for the ability to inhibit HIV-1 transcription and elucidated their mechanism of action. Novel phenyl-1-pyridin-2yl-ethanone (PPY)-based iron chelators were synthesized and examined for their effects on cellular iron, HIV-1 inhibition, and cytotoxicity. Activities of CDK2 and CDK9, expression of CDK9-dependent and CDK2-inhibitory mRNAs, NF-κB expression, and HIV-1- and NF-κB-dependent transcription were determined. PPY-based iron chelators significantly inhibited HIV-1, with minimal cytotoxicity, in cultured and primary cells chronically or acutely infected with HIV-1 subtype B, but they had less of an effect on HIV-1 subtype C. Iron chelators upregulated the expression of IκB-α, with increased accumulation of cytoplasmic NF-κB. The iron chelators inhibited CDK2 activity and reduced the amount of CDK9/cyclin T1 in the large P-TEFb complex. Iron chelators reduced HIV-1 Gag and Env mRNA synthesis but had no effect on HIV-1 reverse transcription. In addition, iron chelators moderately inhibited basal HIV-1 transcription, equally affecting HIV-1 and Sp1- or NF-κB-driven transcription. By virtue of their involvement in targeting several key steps in HIV-1 transcription, these novel iron chelators have the potential for the development of new therapeutics for the treatment of HIV-1 infection. PMID:25155598

  16. Kinetic studies on the oxidation of oxyhemoglobin by biologically active iron thiosemicarbazone complexes: relevance to iron-chelator-induced methemoglobinemia.

    Science.gov (United States)

    Basha, Maram T; Rodríguez, Carlos; Richardson, Des R; Martínez, Manuel; Bernhardt, Paul V

    2014-03-01

    The oxidation of oxyhemoglobin to methemoglobin has been found to be facilitated by low molecular weight iron(III) thiosemicarbazone complexes. This deleterious reaction, which produces hemoglobin protein units unable to bind dioxygen and occurs during the administration of iron chelators such as the well-known 3-aminopyridine-2-pyridinecarbaldehyde thiosemicarbazone (3-AP; Triapine), has been observed in the reaction with Fe(III) complexes of some members of the 3-AP structurally-related thiosemicarbazone ligands derived from di-2-pyridyl ketone (HDpxxT series). We have studied the kinetics of this oxidation reaction in vitro using human hemoglobin and found that the reaction proceeds with two distinct time-resolved steps. These have been associated with sequential oxidation of the two different oxyheme cofactors in the α and β protein chains. Unexpected steric and hydrogen-bonding effects on the Fe(III) complexes appear to be the responsible for the observed differences in the reaction rate across the series of HDpxxT ligand complexes used in this study. PMID:24317633

  17. FORMULATION OF ORAL IRON CHELATOR DEFERASIROX IN A NEW STABLE AND SUITABLE DOSAGE FORM WITH OPTIMUM RELEASE PARAMETERS

    Directory of Open Access Journals (Sweden)

    Yugandhar KM, Vasanth PM, Suresh K, Ramesh T, Ramesh Malothu*

    2013-02-01

    Full Text Available Regular blood transfusions for patients with chronic anemia inevitably lead to iron overload in the blood. The cumulative effect of iron overload may cause morbidity and mortality if not treated with chelator. Oral iron chelator, Deferasirox used in the treatment of β-thalessemia is designed and developed into a stable solid oral dispersion dosage form to deliver with optimum concentration of the drug at desired site at specific time comparable to the innovator product. The excipients were formulated by direct compression method (F-1 and wet granulation method (F-2 to F-9. The disintegration time (33 seconds, dispersion time (62 seconds and the percentage of drug release (98.3% (F-8 were found to be satisfactory and it matches with the innovator product.

  18. Side effects of Deferasirox Iron Chelation in Patients with Beta Thalassemia Major or Intermedia

    Directory of Open Access Journals (Sweden)

    Murtadha Al-Khabori

    2013-03-01

    Full Text Available Objectives: Chelating agents remain the mainstay in reducing the iron burden and extending patient survival in homozygous beta-thalassemia but adverse and toxic effects may increase with the institution and long term use of this essential therapy. This study aimed to estimate the incidence of deferasirox (DFX side effects in patients with thalassemia major or intermedia.Methods: A retrospective study of 72 patients (mean age: 20.3±0.9 yrs; 36 male, 36 female with thalassemia major or intermedia treated at Sultan Qaboos University Hospital, Oman, was performed to assess the incidence of side effects related to deferasirox over a mean of 16.7 month follow-up period.Results: Six patients experienced rashes and 6 had gastro-intestinal upset. DFX was discontinued in 18 patients for the following reasons: persistent progressive rise(s in serum creatinine (7 patients; 40% mean serum creatinine rise from baseline, feeling unwell (2, severe diarrhea (1, pregnancy (1, death unrelated to chelator (2 and rise in serum transaminases (2. Three patients were reverted to desferoxamine and deferiprone combination therapy as DFX was no longer biochemically effective after 18 months of therapy. There was no correlation between baseline serum ferritin and serum creatinine or a rise in serum creatinine. Cardiac MRI T2* did not change with DFX therapy. However, there was an improvement in liver MRI T2* (p=0.013.Conclusion: Renal side effects related to deferasirox appear to be higher than those reported in published clinical trials. Further larger studies are required to confirm these findings.

  19. On improvement in ejection fraction with iron chelation in thalassemia major and the risk of future heart failure

    Directory of Open Access Journals (Sweden)

    Carpenter JP

    2011-09-01

    Full Text Available Abstract Background Trials of iron chelator regimens have increased the treatment options for cardiac siderosis in beta-thalassemia major (TM patients. Treatment effects with improved left ventricular (LV ejection fraction (EF have been observed in patients without overt heart failure, but it is unclear whether these changes are clinically meaningful. Methods This retrospective study of a UK database of TM patients modelled the change in EF between serial scans measured by cardiovascular magnetic resonance (CMR to the relative risk (RR of future development of heart failure over 1 year. Patients were divided into 2 strata by baseline LVEF of 56-62% (below normal for TM and 63-70% (lower half of the normal range for TM. Results A total of 315 patients with 754 CMR scans were analyzed. A 1% absolute increase in EF from baseline was associated with a statistically significant reduction in the risk of future development of heart failure for both the lower EF stratum (EF 56-62%, RR 0.818, p Conclusion These data show that during treatment with iron chelators for cardiac siderosis, small increases in LVEF in TM patients are associated with a significantly reduced risk of the development of heart failure. Thus the iron chelator induced improvements in LVEF of 2.6% to 3.1% that have been observed in randomized controlled trials, are associated with risk reductions of 25.5% to 46.4% for the development of heart failure over 12 months, which is clinically meaningful. In cardiac iron overload, heart mitochondrial dysfunction and its relief by iron chelation may underlie the changes in LV function.

  20. Wild Edible Fruit of Prunus nepalensis Ser. (Steud, a Potential Source of Antioxidants, Ameliorates Iron Overload-Induced Hepatotoxicity and Liver Fibrosis in Mice.

    Directory of Open Access Journals (Sweden)

    Dipankar Chaudhuri

    Full Text Available The antioxidant and restoration potentials of hepatic injury by Prunus nepalensis Ser. (Steud, a wild fruit plant from the Northeastern region of India, were investigated. The fruit extract (PNME exhibited excellent antioxidant and reducing properties and also scavenged the 2,2-diphenyl-1-picrylhydrazyl (DPPH radical (IC50 = 30.92 ± 0.40 μg/ml. PNME demonstrated promising scavenging potency, as assessed by the scavenging of different reactive oxygen and nitrogen species. Moreover, the extract revealed an exceptional iron chelation capacity with an IC50 of 25.64 ± 0.60 μg/ml. The extract induced significant improvement of hepatic injury and liver fibrosis against iron overload induced hepatotoxicity in mice in a dose-dependent manner, and this effect was supported by different histopathological studies. The phytochemical constitutions and their identification by HPLC confirmed the presence of purpurin, tannic acid, methyl gallate, reserpine, gallic acid, ascorbic acid, catechin and rutin. The identified compounds were investigated for their individual radical scavenging and iron chelation activity; some compounds exhibited excellent radical scavenging and iron chelation properties, but most were toxic towards normal cells (WI-38. On the other hand, crude PNME was found to be completely nontoxic to normal cells, suggesting its feasibility as a safe oral drug. The above study suggests that different phytochemicals in PNME contributed to its free radical scavenging and iron chelation activity; however, further studies are required to determine the pathway in which PNME acts to treat iron-overload diseases.

  1. Effects of acute creatine supplementation on iron homeostasis and uric acid-based antioxidant capacity of plasma after wingate test

    Directory of Open Access Journals (Sweden)

    Barros Marcelo P

    2012-06-01

    Full Text Available Abstract Background Dietary creatine has been largely used as an ergogenic aid to improve strength and athletic performance, especially in short-term and high energy-demanding anaerobic exercise. Recent findings have also suggested a possible antioxidant role for creatine in muscle tissues during exercise. Here we evaluate the effects of a 1-week regimen of 20 g/day creatine supplementation on the plasma antioxidant capacity, free and heme iron content, and uric acid and lipid peroxidation levels of young subjects (23.1 ± 5.8 years old immediately before and 5 and 60 min after the exhaustive Wingate test. Results Maximum anaerobic power was improved by acute creatine supplementation (10.5 %, but it was accompanied by a 2.4-fold increase in pro-oxidant free iron ions in the plasma. However, potential iron-driven oxidative insult was adequately counterbalanced by proportional increases in antioxidant ferric-reducing activity in plasma (FRAP, leading to unaltered lipid peroxidation levels. Interestingly, the FRAP index, found to be highly dependent on uric acid levels in the placebo group, also had an additional contribution from other circulating metabolites in creatine-fed subjects. Conclusions Our data suggest that acute creatine supplementation improved the anaerobic performance of athletes and limited short-term oxidative insults, since creatine-induced iron overload was efficiently circumvented by acquired FRAP capacity attributed to: overproduction of uric acid in energy-depleted muscles (as an end-product of purine metabolism and a powerful iron chelating agent and inherent antioxidant activity of creatine.

  2. Terapia quelante oral com deferiprona em pacientes com sobrecarga de ferro Oral iron chelator therapy with deferiprone in patients with overloaded iron

    Directory of Open Access Journals (Sweden)

    Antonio Fabron Jr

    2003-01-01

    Full Text Available Apesar da introdução da quelação parenteral de ferro com desferoxamina há mais de trinta anos, 50% dos pacientes com talassemia major morrem antes dos 35 anos de idade, predominantemente por insuficiência cardíaca secundária a sobrecarga de ferro. Embora a desferrioxamina, possa reduzir ou estabilizar o acúmulo de ferro no corpo, um grande número de pacientes não recebe terapia adequada com este quelante devido principalmente à intolerância a um regime que requer administração parenteral prolongada, cinco a sete dias por semana. Para esses pacientes, a deferiprona, um quelante oralmente ativo, surge com uma alternativa de tratamento para o controle da sobrecarga de ferro. Um grande número de estudos clínicos demonstraram a segurança e eficácia da deferiprona. Estima-se que mais de 6 mil pacientes com sobrecarga de ferro já tenham sido tratados com este quelante, com alguns pacientes tomando a droga por mais de dez anos. A quantidade de ferro excretada induzida pela deferiprona é diretamente influenciada pela dose da droga e pelo grau de sobrecarga de ferro do paciente. Recentemente, demonstrou-se que desferrioxamina e deferiprona exibem capacidades quelantes diversas e que, usados simultaneamente ou numa terapia sequencial, promovem uma excreção de ferro adicional ou sinérgica com rápida redução na carga de ferro do corpo. Pela primeira vez é possível considerar esquemas de quelação individualizados baseados nas necessidades individuais de cada paciente.Despite the introduction of the parenteral iron chelator desferrioxamine more than 30 years ago, 50% of patients with thalassemia major die before the age of 35 years, predominantly due to iron-induced heart failure. Although desferrioxamine can reduce or stabilize the iron load, many patients still do not receive adequate chelation mainly due to its cumbersome mode of administration which impairs the compliance with the regime of repeatedly subcutaneous infusions

  3. Improved survival in MDS patients receiving iron chelation therapy - a matched pair analysis of 188 patients from the Düsseldorf MDS registry.

    Science.gov (United States)

    Neukirchen, Judith; Fox, Frank; Kündgen, Andrea; Nachtkamp, Kathrin; Strupp, Corinna; Haas, Rainer; Germing, Ulrich; Gattermann, Norbert

    2012-08-01

    MDS patients are prone to develop transfusional iron overload. Iron overload may partly explain why transfusion dependency is associated with a decreased likelihood of survival. Our matched-pair analysis included 94 patients on long-term chelation therapy and 94 matched patients without it. All patients had iron overload, defined as serum ferritin (SF) above 1000 ng/ml or a history of multiple transfusions and SF ≥ 500 ng/ml. Median SF was 1954 ng/ml in chelated and 875 ng/ml in non-chelated patients. The difference in median survival (74 vs. 49 months, respectively; p=0.002) supports the idea that iron chelation therapy is beneficial for MDS patients. PMID:22564985

  4. Durable Red Blood Cell Transfusion Independence in a Patient with an MDS/MPN Overlap Syndrome Following Discontinuation of Iron Chelation Therapy

    OpenAIRE

    Harpreet Kochhar; Chantal S. Leger; Leitch, Heather A.

    2015-01-01

    Background. Hematologic improvement (HI) occurs in some patients with acquired anemias and transfusional iron overload receiving iron chelation therapy (ICT) but there is little information on transfusion status after stopping chelation. Case Report. A patient with low IPSS risk RARS-T evolved to myelofibrosis developed a regular red blood cell (RBC) transfusion requirement. There was no response to a six-month course of study medication or to erythropoietin for three months. At 27 months of ...

  5. Iron-chelating and anti-lipid peroxidation properties of 1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methylpyridin-4-one (CM1) in long-term iron loadingβ-thalassemic mice

    Institute of Scientific and Technical Information of China (English)

    Kanokwan Kulprachakarn; Nittaya Chansiw; Kanjana Pangjit; Chada Phisalaphong; Suthat Fucharoen; Robert C Hider; Sineenart Santitherakul; Somdet Srichairatanakool

    2014-01-01

    Objective:To evaluate the iron-chelating properties and free-radical scavenging activities of 1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methylpyridin-4-one (CM1) treatment in chronic iron-loadedβ-thalassemic (BKO) mice. Methods:The BKO mice were fed with a ferrocene-rich diet and were orally administered with CM1 [50 mg/(kg.day)] for 6 months. Blood levels of non-transferrin bound iron, labile plasma iron, ferritin (Ft) and malondialdehyde were determined. Results:The BKO mice were fed with an iron diet for 8 months which resulted in iron overload. Interestingly, the mice showed a decrease in the non-transferrin bound iron, labile plasma iron and malondialdehyde levels, but not the Ft levels after continuous CM1 treatment. Conclusions:CM1 could be an effective oral iron chelator that can reduce iron overload and lipid peroxidation in chronic iron overloadβ-thalassemic mice.

  6. Design, synthesis and characterization of new iron and aluminium chelating agents

    OpenAIRE

    Toso, Leonardo

    2014-01-01

    Chelation therapy is widely used for metal-unbalance related diseases, namely those due to disorders on metal metabolism, such as beta-thalassemia, hemochromatosis (Fe), and neurodegenerative diseases (Cu, Fe, Zn and Al). The study of metal chelators for clinical applications, either as chelating therapeutics able to target specific metal ions in the body, or as metal-carriers for therapeutic or imaging purposes, is a topical research area which faces up to urgent medical problems. Meta...

  7. Benzyl and Methyl Fatty Hydroxamic Acids Based on Palm Kernel Oil as Chelating Agent for Liquid-Liquid Iron(III) Extraction

    OpenAIRE

    Jamileh Amin; Roshanak Rafiee-Moghaddam; Behnam Mahdavi; Mazyar Peyda; Anuar Kassim; Nor Azah Yusof; Md Jelas Haron; Hossein Jahangirian; Yadollah Abdollahi; Sidik Silong

    2012-01-01

    Liquid-liquid iron(III) extraction was investigated using benzyl fatty hydroxamic acids (BFHAs) and methyl fatty hydroxamic acids (MFHAs) as chelating agents through the formation of iron(III) methyl fatty hydroxamate (Fe-MFHs) or iron(III) benzyl fatty hydroxamate (Fe-BFHs) in the organic phase. The results obtained under optimized conditions, showed that the chelating agents in hexane extract iron(III) at pH 1.9 were realized effectively with a high percentage of extraction (97.2% and 98.1%...

  8. Brain catalase in the streptozotocin-rat model of sporadic Alzheimer's disease treated with the iron chelator-monoamine oxidase inhibitor, M30.

    Science.gov (United States)

    Sofic, E; Salkovic-Petrisic, M; Tahirovic, I; Sapcanin, A; Mandel, S; Youdim, M; Riederer, P

    2015-04-01

    Low intracerebroventricular (icv) doses of streptozotocin (STZ) produce regionally specific brain neurochemical changes in rats that are similar to those found in the brain of patients with sporadic Alzheimer's disease (sAD). Since oxidative stress is thought to be one of the major pathologic processes in sAD, catalase (CAT) activity was estimated in the regional brain tissue of animals treated intracerebroventricularly with STZ and the multitarget iron chelator, antioxidant and MAO-inhibitor M30 [5-(N-methyl-N-propargylaminomethyl)-8-hydroxyquinoline]. Five-day oral pre-treatment of adult male Wistar rats with 10 mg/kg/day M30 dose was followed by a single injection of STZ (1 mg/kg, icv). CAT activity was measured colorimetrically in the hippocampus (HPC), brain stem (BS) and cerebellum (CB) of the control, STZ-, M30- and STZ + M30-treated rats, respectively, 4 weeks after the STZ treatment. STZ-treated rats demonstrated significantly lower CAT activity in all three brain regions in comparison to the controls (p < 0.05 for BS and CB, p < 0.01 for HPC). M30 pre-treatment of the control rats did not influence the CAT activity in HPC and CB, but significantly increased it in BS (p < 0.05). M30 pre-treatment of STZ-treated rats significantly increased CAT activity in the HPC in comparison to the STZ treatment alone (p < 0.05) and normalized to the control values. These findings are in line with the assumption that reactive oxygen species contribute to the pathogenesis of STZ in a rat model of sAD and indicate that multifunctional iron chelators such as M30 might also have beneficial effects in this non-transgenic sAD model. PMID:25252744

  9. Immunological Evaluation of -Thalassemia Major Patients Receiving Oral Iron Chelator Deferasirox

    International Nuclear Information System (INIS)

    Objective: To determine the immune abnormalities and occurrence of infections in transfusion-dependent -thalassemia major patients receiving oral iron chelator deferasirox (DFX). Study Design: An observational study. Place and Duration of Study: Hematology Clinics, King Khalid University Hospital, Riyadh, Saudi Arabia, from July to December 2010. Methodology: Seventeen patients with -thalassemia major (12 females, median age 26 years) receiving deferasirox (DFX) for a median duration of 27 months were observed for any infections and had their immune status determined. Immune parameters studied included serum immunoglobulins and IgG subclasses, serum complement (C3 and C4) and anti-nuclear antibody (ANA) level, total B and T-lymphocytes, CD4+ and CD8+ counts, CD4+/CD8+ ratio, and natural killer (NK) cells. Immunological parameters of the patients were compared with age, gender, serum ferritin level and splenectomy status. Lymphocyte subsets were also compared with age and gender matched normal controls. Results: A considerable reduction in serum ferritin was achieved by DFX from a median level of 2528 to 1875 mol/l. Serum IgG levels were increased in 7 patients. Low C4 levels were found in 9 patients. Total B and T-lymphocytes were increased in 14 patients each, while CD4+, CD8+ and NK cells were increased in 13, 12 and 11 patients respectively. Absolute counts for all lymphocyte subsets were significantly higher compared to the normal controls (p=0.05 for all parameters). Raised levels of IgG were associated with older age, female gender, splenectomized status and higher serum ferritin levels but this did not reach statistical significance except for the higher ferritin levels (p=0.044). Increased tendency to infections was not observed. Conclusion: Patients with -thalassemia major receiving DFX exhibited significant immune abnormalities. Changes observed have been described previously, but could be related to DFX. The immune abnormalities were not associated with

  10. Anti-plasmodial activity of aroylhydrazone and thiosemicarbazone iron chelators: effect on erythrocyte membrane integrity, parasite development and the intracellular labile iron pool.

    Science.gov (United States)

    Walcourt, Asikiya; Kurantsin-Mills, Joseph; Kwagyan, John; Adenuga, Babafemi B; Kalinowski, Danuta S; Lovejoy, David B; Lane, Darius J R; Richardson, Des R

    2013-12-01

    Iron chelators inhibit the growth of the malaria parasite, Plasmodium falciparum, in culture and in animal and human studies. We previously reported the anti-plasmodial activity of the chelators, 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311), 2-hydroxy-1-naphthylaldehyde 4-methyl-3-thiosemicarbazone (N4mT), and 2-hydroxy-1-naphthylaldehyde 4-phenyl-3-thiosemicarbazone (N4pT). In fact, these ligands showed greater growth inhibition of chloroquine-sensitive (3D7) and chloroquine-resistant (7G8) strains of P. falciparum in culture compared to desferrioxamine (DFO). The present study examined the effects of 311, N4mT and N4pT on erythrocyte membrane integrity and asexual parasite development. While the characteristic biconcave disk shape of the erythrocytes was unaffected, the chelators caused very slight hemolysis at IC50 values that inhibited parasite growth. The chelators 311, N4mT and N4pT affected all stages of the intra-erythrocytic development cycle (IDC) of P. falciparum in culture. However, while these ligands primarily affected the ring-stage, DFO inhibited primarily trophozoite and schizont-stages. Ring, trophozoite and schizont-stages of the IDC were inhibited by significantly lower concentrations of 311, N4mT, and N4pT (IC50=4.45±1.70, 10.30±4.40, and 3.64±2.00μM, respectively) than DFO (IC50=23.43±3.40μM). Complexation of 311, N4mT and N4pT with iron reduced their anti-plasmodial activity. Estimation of the intracellular labile iron pool (LIP) in erythrocytes showed that the chelation efficacy of 311, N4mT and N4pT corresponded to their anti-plasmodial activities, suggesting that the LIP may be a potential source of non-heme iron for parasite metabolism within the erythrocyte. This study has implications for malaria chemotherapy that specifically disrupts parasite iron utilization. PMID:24028863

  11. Iron Chelators of the Di-2-pyridylketone Thiosemicarbazone and 2-Benzoylpyridine Thiosemicarbazone Series Inhibit HIV-1 Transcription: Identification of Novel Cellular Targets—Iron, Cyclin-Dependent Kinase (CDK) 2, and CDK9S⃞

    OpenAIRE

    Debebe, Zufan; Ammosova, Tatyana; Breuer, Denitra; Lovejoy, David B.; Kalinowski, Danuta S.; Karla, Pradeep K.; Kumar, Krishna; Jerebtsova, Marina; Ray, Patricio; KASHANCHI, FATAH; Gordeuk, Victor R; Richardson, Des R.; Nekhai, Sergei

    2011-01-01

    HIV-1 transcription is activated by HIV-1 Tat protein, which recruits cyclin-dependent kinase 9 (CDK9)/cyclin T1 and other host transcriptional coactivators to the HIV-1 promoter. Tat itself is phosphorylated by CDK2, and inhibition of CDK2 by small interfering RNA, the iron chelator 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311), and the iron chelator deferasirox (ICL670) inhibits HIV-1 tran...

  12. Iron chelation therapy with deferasirox in patients with aplastic anemia: a subgroup analysis of 116 patients from the EPIC trial

    DEFF Research Database (Denmark)

    Lee, Jong Wook; Yoon, Sung-Soo; Shen, Zhi Xiang;

    2010-01-01

    The prospective 1-year Evaluation of Patients' Iron Chelation with Exjade (EPIC) study enrolled a large cohort of 116 patients with aplastic anemia; the present analyses evaluated the efficacy and safety of deferasirox in this patient population. After 1 year, median serum ferritin decreased...... neutrophil and platelet counts remained stable during treatment, and there were no drug-related cytopenias. This prospective dataset confirms the efficacy and well characterizes the tolerability profile of deferasirox in a large population of patients with aplastic anemia. This study was registered at www...

  13. Iron chelation therapy with deferasirox in patients with aplastic anemia: a subgroup analysis of 116 patients from the EPIC trial

    DEFF Research Database (Denmark)

    Lee, Jong Wook; Yoon, Sung-Soo; Shen, Zhi Xiang;

    2010-01-01

    The prospective 1-year Evaluation of Patients' Iron Chelation with Exjade (EPIC) study enrolled a large cohort of 116 patients with aplastic anemia; the present analyses evaluated the efficacy and safety of deferasirox in this patient population. After 1 year, median serum ferritin decreased...... absolute neutrophil and platelet counts remained stable during treatment, and there were no drug-related cytopenias. This prospective dataset confirms the efficacy and well characterizes the tolerability profile of deferasirox in a large population of patients with aplastic anemia. This study was...

  14. Safety of deferasirox as an oral iron chelator in thalassemic children

    OpenAIRE

    Shikha Jaiswal; Rajesh Hishikar; Basant Maheshwari; Onkar Khandwal; Raka Sheohare

    2016-01-01

    Background: Thalassemia major patients require frequent blood transfusion leading to iron overload. Iron overload is characterized by excessive iron deposition and consequent injury and dysfunction of the heart, liver, anterior pituitary, pancreas, and joints. Because physiologic mechanisms to excrete iron are very limited, patients with iron overload and its complications need safe, effective therapy that is compatible with their coexisting medical conditions. Current prospective, observatio...

  15. Quantitative Analysis of the Anti-Proliferative Activity of Combinations of Selected Iron-Chelating Agents and Clinically Used Anti-Neoplastic Drugs

    OpenAIRE

    Eliska Potuckova; Hana Jansova; Miloslav Machacek; Anna Vavrova; Pavlina Haskova; Lucie Tichotova; Vera Richardson; Kalinowski, Danuta S.; Richardson, Des R.; Tomas Simunek

    2014-01-01

    Recent studies have demonstrated that several chelators possess marked potential as potent anti-neoplastic drugs and as agents that can ameliorate some of the adverse effects associated with standard chemotherapy. Anti-cancer treatment employs combinations of several drugs that have different mechanisms of action. However, data regarding the potential interactions between iron chelators and established chemotherapeutics are lacking. Using estrogen receptor-positive MCF-7 breast cancer cells, ...

  16. Curcumin protects nigral dopaminergic neurons by iron-chelation in the 6-hydroxydopamine rat model of Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    Xi-Xun Du; Hua-Min Xu; Hong Jiang; Ning Song; Jun Wang; Jun-Xia Xie

    2012-01-01

    [Objective] Curcumin is a plant polyphenolic compound and a major component of spice turmeric (Curcuma longa).It has been reported to possess free radical-scavenging,iron-chelating,and anti-inflammatory properties in different tissues.Our previous study showed that curcumin protects MES23.5 dopaminergic cells from 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in vitro.The present study aimed to explore this neuroprotective effect in the 6-OHDAlesioned rat model of Parkinson's disease in vivo.[Methods] Rats were given intragastric curcumin for 24 days.6-OHDA lesioning was conducted on day 4 of curcumin treatment.Dopamine content was assessed by high-performance liquid chromatography with electrochemical detection,tyrosine hydroxylase (TH)-containing neurons by immunohistochemistry,and iron-containing cells by Perls' iron staining.[Results] The dopamine content in the striatum and the number of THimmunoreactive neurons decreased after 6-OHDA treatment.Curcumin pretreatment reversed these changes.Further studies demonstrated that 6-OHDA treatment increased the number of iron-staining cells,which was dramatically decreased by curcumin pretreatment.[Conclusion]The protective effects of curcumin against 6-OHDA may be attributable to the ironchelating activity of curcumin to suppress the iron-induced degeneration of nigral dopaminergic neurons.

  17. Scientific opinion on the safety and efficacy of iron compounds (E1 as feed additives for all species: iron chelate of amino acids, hydrate, based on a dossier submitted by Zinpro Animal Nutrition Inc.

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP

    2013-07-01

    Full Text Available The use of iron chelate of amino acids, hydrate, as source of iron is considered safe for all animal species/categories when used up to the currently authorised maximum content of total iron in complete feed, with the exception of bovines and poultry for which the maximum tolerated level is 450 mg/kg complete feed, and pets, for which the maximum tolerated level is 600 mg/kg complete feed. The FEEDAP Panel is not in the position to derive a maximum safe iron concentration in feed for horses or fish. Consumption surveys include iron-containing foodstuffs of animal origin. Since the supplementation of animal feed with iron-containing compounds has not essentially changed during the last decades, it is reasonable to assume that the iron levels in food of animal origin used in exposure scenarios originated from animals fed iron-supplemented diets. Since iron chelate of amino acids, hydrate, will be used as a substitute for other iron compounds, its use in animal nutrition would not modify consumer exposure to iron. The additive should be considered as a skin, eye and respiratory irritant and, owing to its residual peptide component, as a skin/respiratory sensitiser. Considering the high background concentration of iron in soil and water, the supplementation of feed with iron chelate of amino acids, hydrate, is not expected to pose an environmental risk. Iron chelate of amino acids, hydrate, is an effective source of iron for all animal species and categories. The FEEDAP Panel recommends that the maximum iron contents in complete feed be reduced as follows: bovines and poultry, 450 mg Fe/kg; and pets, 600 mg Fe/kg.

  18. Effects of metal ion chelators on DNA strand breaks and inactivation produced by hydrogen peroxide in Escherichia coli: detection of iron-independent lesions.

    OpenAIRE

    Asad, N R; A.C. Leitão

    1991-01-01

    In order to study the role of metallic ions in the H2O2 inactivation of Escherichia coli cells, H2O2-sensitive mutants were treated with metal ion chelators and then submitted to H2O2 treatment. o-Phenanthroline, dipyridyl, desferrioxamine, and neocuproine were used as metal chelators. Cell sensitivity to H2O2 treatment was not modified by neocuproine, suggesting that copper has a minor role in OH production in E. coli. On the other hand, prior treatment with iron chelators protected the cell...

  19. Translation of ferritin light and heavy subunit mRNAs is regulated by intracellular chelatable iron levels in rat hepatoma cells

    International Nuclear Information System (INIS)

    Acute administration of iron to rats has been previously shown to induce liver ferritin synthesis by increasing the translation of inactive cytoplasmic ferritin mRNAs for both heavy (H) and light (L) subunits by mobilizing them onto polyribosomes. In this report rat hepatoma cells in culture are used to explore the relationship of this response to intracellular iron levels. After adding iron as ferric ammonium citrate to the medium, latent ferritin H- and L-mRNAs were extensively transferred to polyribosomes, accompanied by increased uptake of [35S]methionine into ferritin protein. Because total cellular levels of L- and H-mRNA were not significantly changed by exposure to iron, the increased ferritin mRNAs on polyribosomes most probably come from an inactive cytoplasmic pool, consistent with the inability of actinomycin-D and of cordycepin to inhibit iron-induced ferritin synthesis. When deferoxamine mesylate, an intracellular iron chelator, was added after the addition of iron to the medium, ferritin mRNA on the polyribosomes was reduced, while the free messenger pool increased, and ferritin synthesis diminished. In contrast, the extracellular iron chelator diethylenetriaminepentaacetic acid failed to inhibit the induction of ferritin protein synthesis. Addition of iron in the form of hemin also caused translocation of mRNA to polyribosomes, a response that could be similarly quenched by deferoxamine. Because hemin does not release chelatable iron extracellularly, they conclude that the level of chelatable iron within the cell has a regulatory role in ferritin synthesis through redistribution of the messenger RNAs between the free mRNA pool and the polyribosomes

  20. Neuroprotective effect of the natural iron chelator, phytic acid in a cell culture model of Parkinson's disease

    International Nuclear Information System (INIS)

    Disrupted iron metabolism and excess iron accumulation has been reported in the brains of Parkinson's disease (PD) patients. Because excessive iron can induce oxidative stress subsequently causing degradation of nigral dopaminergic neurons in PD, we determined the protective effect of a naturally occurring iron chelator, phytic acid (IP6), on 1-methyl-4-phenylpyridinium (MPP+)-induced cell death in immortalized rat mesencephalic/dopaminergic cells. Cell death was induced with MPP+ in normal and iron-excess conditions and cytotoxicity was measured by thiazolyl blue tetrazolium bromide (MTT assay) and trypan blue staining. Apoptotic cell death was also measured with caspase-3 activity, DNA fragmentation, and Hoechst nuclear staining. Compared to MPP+ treatment, IP6 (30 μmol/L) increased cell viability by 19% (P + treatment was decreased by 55% (P < 0.01) and 52% (P < 0.05), respectively with IP6. Cell survival was increased by 18% (P < 0.05) and 42% (P < 0.001) with 30 and 100 μmol/L of IP6, respectively in iron-excess conditions. A 40% and 52% (P < 0.001) protection was observed in caspase-3 activity with 30 and 100 μmol/L IP6, respectively in iron-excess condition. Similarly, a 45% reduction (P < 0.001) in DNA fragmentation was found with 100 μmol/L IP6. In addition, Hoechst nuclear staining results confirmed the protective effect of IP6 against apoptosis. Similar protection was also observed with the differentiated cells. Collectively, our results demonstrate a significant neuroprotective effect of phytate in a cell culture model of PD

  1. Curcumin Inhibits Growth of Saccharomyces cerevisiae through Iron Chelation ▿ ††

    OpenAIRE

    Minear, Steven; O'Donnell, Allyson F.; Ballew, Anna; Giaever, Guri; Nislow, Corey; Stearns, Tim; Martha S Cyert

    2011-01-01

    Curcumin, a polyphenol derived from turmeric, is an ancient therapeutic used in India for centuries to treat a wide array of ailments. Interest in curcumin has increased recently, with ongoing clinical trials exploring curcumin as an anticancer therapy and as a protectant against neurodegenerative diseases. In vitro, curcumin chelates metal ions. However, although diverse physiological effects have been documented for this compound, curcumin's mechanism of action on mammalian cells remains un...

  2. The Management of Iron Chelation Therapy: Preliminary Data from a National Registry of Thalassaemic Patients

    OpenAIRE

    Adriana Ceci; Laura Mangiarini; Mariagrazia Felisi; Franco Bartoloni; Angela Ciancio; Marcello Capra; Domenico D'Ascola; Paolo Cianciulli; Aldo Filosa

    2011-01-01

    Thalassaemia and other haemoglobinopathies constitute an important health problem in Mediterranean countries, placing a tremendous emotional, psychological, and economic burden on their National Health systems. The development of new chelators in the most recent years had a major impact on the treatment of thalassaemia and on the quality of life of thalassaemic patients. A new initiative was promoted by the Italian Ministry of Health, establishing a Registry for thalassaemic patients to serve...

  3. "Evaluation Of compliance To Iron Chelation Therapy With Defe-Roxamine In Patients With Major Thalassemia In Iran In 2004 "

    Directory of Open Access Journals (Sweden)

    M. Izadyar

    2006-06-01

    Full Text Available Background and Aim: With the introduction of long term subcutaneous administration of Deferoxamine there has been a decline in the morbidity and mortality of transfusion-dependent beta thalassemia patients. But parenteral iron chelation therapy is still a burden and a major reason for unsatisfactory compliance and places an additional psychological burden on the patients. There are some factors contributing to low compliance in these patients. To evaluate compliance to Deferoxamine and barriers of non adherence and assessment the prevalence of depression and it’s association with compliance. Materials and Methods: 205 patients with major thalassemia in children medical center older than 6 years old were included. They were classified in 3 groups by compliance index (CI: No. of days of treatment per one month/No. of treatment days prescribed by physician. CI>75 % was considered good ,CI< 50-75%: moderate,CI<50%:weak and 3d group the patients without compliance. For assessment of depression: Beck Depression questionnaires were given to the patients older than 18 years old and Children Depression Inventories (CDI“kovacs” were given to the rest Results: Of 205 patients (110 females (54% and 95 males (46%, 13.3% were non compliant, 14% had poor compliance, 62.7% had good compliance. Females were more compliant than males (P=0.034. Compliance improved in older age groups meaningfully (P=0.037. There was negative association between compliance and serum ferritin level (P=0.02. 22% of children and 12% of Adults had severe depression according to the questionnaires. There was no association between compliance and depression. The most prevalent problem rgarding Desferal injection was local reactions in injection site (83%. Conclusion: As oral chelation therapies are not used routinely, more investigations regarding the noncompliance must be considered; and this method of chelation therapy must be encouraged. Compliance is a multifactorial problem

  4. Ulcerated hemosiderinic dyschromia and iron deposits within lower limbs treated with a topical application of biological chelator

    Directory of Open Access Journals (Sweden)

    Eugenio Brizzio

    2012-12-01

    Full Text Available The ulcerative haemosiderinic dyschromia of chronic venous insufficiency is difficult to heal and presents a high accumulation of iron. Lactoferrin, a potent natural iron chelator, could help to scar this ulcerative haemosi - derinic dyschromia. The objective of this study was to determine whether the topical application of a liposomal gel with Lactoferrin favors scarring/degradation of the brown colored spot typical of ulcerative haemosiderinic dyschromia. Nine patients with severe chronic venous insufficiency and ulcerative haemosiderinic dyschromia (CEAP-C6, with a natural evolution of over 12 months, were included in the study. Hemo chromatosis gene mutations were investigated. The levels of serum ferritin, transferrin saturation and blood cell counts were analyzed. The presence of hemosiderin was investigated through periulcerous and ulcer fundus biopsies carried out at baseline and 30 days after treatment with Lactoferrin. The severity of the injuries (CEAP classification was evaluated at the beginning of and throughout the whole 3-month treatment period. No patient had received compression treatment during the three months previous to this therapy. Significant improvement in these injuries, with a reduction in the dimensions of the brown spot (9 of 9 at Day 90, and complete scarring with a closure time ranging from 15 to 180 days (7 of 9 were observed. The use of topical lactoferrin is a non-invasive therapeutic tool that favors clearance of hemosiderinic dyschromia and scarring of the ulcer. The success of this study was not influenced either by the hemochromatosis genetics or the iron metabolism profile observed.

  5. Orally Bioavailable Metal Chelators and Radical Scavengers: Multifunctional Antioxidants for the Coadjutant Treatment of Neurodegenerative Diseases.

    Science.gov (United States)

    Kawada, Hiroyoshi; Kador, Peter F

    2015-11-25

    Neurodegenerative diseases are associated with oxidative stress that is induced by the presence of reactive oxygen species and the abnormal cellular accumulation of transition metals. Here, a new series of orally bioavailable multifunctional antioxidants (MFAO-2s) possessing a 2-diacetylamino-5-hydroxypyrimidine moiety is described. These MFAO-2s demonstrate both free radical and metal attenuating properties that are similar to the original published MFAO-1s that are based on 1-N,N'-dimethylsulfamoyl-1-4-(2-pyrimidyl)piperazine. Oral bioavailability studies in C57BL/6 mice demonstrate that the MFAO-2s accumulate in the brain at significantly higher levels than the MFAO-1s while achieving similar neural retina levels. The MFAO-2s protect human neuroblastoma and retinal pigmented epithelial cells against hydroxyl radicals in a dose-dependent manner by maintaining cell viability and intracellular glutathione levels. The MFAO-2s outperform clioquinol, a metal attenuator that has been investigated for the treatment of Alzheimer's disease. PMID:26068053

  6. EFFICACY AND SAFETY OF DEFERASIROX WHEN COMPARED TO D EFERIPRONE AS ORAL IRON CHELATING AGENT : A RANDOMIZED CONTROL TRIAL

    Directory of Open Access Journals (Sweden)

    Sanjeeva

    2015-03-01

    Full Text Available BACKGROUND : Thalassemia is one of the most common inherited hemoglobinopathy seen in southern India. With regular blood transfusion, these children live longer but associated morbidity due to iron overload impairs the quality of life. We studied the efficacy and safety of new oral iron chelator, deferasirox, compared with deferiprone which was used for long time. MATERIAL AND METHODS : We cond ucted a prospective randomised control study, between January 2011 to June 2012 at thalassemia day care centre of Indira Gandhi I nstitute of C hild H ealth, Bengaluru. The children who were diagnosed as Thalassemia and receiving regular blood transfusion wit h serum ferritin levels more than 1000ng/ml and not receiving any chelation therapy were included in the study. These children were randomly divided into two groups as group 1 and group 2 by computer generated randomization. The children included in g roup 1 received Deferasirox and group 2 received Deferiprone as chelation therapy. The dosage of deferasirox was 20mg/kg/day once daily and that of deferiprone 75 mg/kg/day in three divided daily doses. The primary study outcome was to measure and compare the d ecrease in serum ferritin levels between the two study groups. The secondary outcome measures were to compare the side effect profiles among the two groups. RESULTS : We included 41 thalessemic children and 19 of them were included in group 1 (Deferasirox and 22 children in Group 2 (Deferiprone. At the end of study period of 18 months three children in group II discontinued therapy due to side effects, hence the remaining 19 were available for final analysis in group 2 whereas no drop outs in the group 1. During the study period, the serum ferritin decreased from 3261±2613ng/dl to 1586±766 ng/dl in group 1 as compared in group 2 from 4109±3153 ng/dl to 1743±1138 ng/dl (fig 2. This was also not statistically significant. In group 2, 68% of the children expe rienced adverse effect as compared

  7. Electrochemical study of the increased antioxidant capacity of flavonoids through complexation with iron(II) ions

    International Nuclear Information System (INIS)

    Highlights: • Metal-Flavonoid complexes exhibit greater antioxidant capacity than the free flavonoid;. • Voltammetric profile is an additional information for determining antioxidant capacity;. • Pyrogallol group is a stronger complex-forming group than the catechol;. • Morin, quercetin and fisetin increased their antioxidant capacity in 15%, 32% and 28%, respectively. - Abstract: Flavonoids are polyphenolic compounds that act as natural antioxidants in the human body through various mechanisms, with an emphasis on suppressing reactive oxygen species (ROS) formation by inhibiting enzymes, the direct capture of ROS, and the regulation/protection of antioxidant defenses. Additionally, flavonoids can coordinate with transition metals to catalyze electron transport and promote free radical capture. Recently, metal ion chelation mechanisms have generated considerable interest, as experimental data show that flavonoids in metal complexes exhibit greater antioxidant activity than free flavonoids. However, few studies have correlated the complexing properties of flavonoids with their antioxidant capacity. Thus, the aim of this study was to use the CRAC (Ceric Reducing Antioxidant Capacity) electrochemical assay to measure the antioxidant capacity of five free flavonoids and Fe2+-flavonoid complexes. In addition, the interactions between the flavonoids and Fe2+ were analyzed based on the oxidation peaks formed in their cyclic voltammograms

  8. Benzyl and Methyl Fatty Hydroxamic Acids Based on Palm Kernel Oil as Chelating Agent for Liquid-Liquid Iron(III Extraction

    Directory of Open Access Journals (Sweden)

    Jamileh Amin

    2012-02-01

    Full Text Available Liquid-liquid iron(III extraction was investigated using benzyl fatty hydroxamic acids (BFHAs and methyl fatty hydroxamic acids (MFHAs as chelating agents through the formation of iron(III methyl fatty hydroxamate (Fe-MFHs or iron(III benzyl fatty hydroxamate (Fe-BFHs in the organic phase. The results obtained under optimized conditions, showed that the chelating agents in hexane extract iron(III at pH 1.9 were realized effectively with a high percentage of extraction (97.2% and 98.1% for MFHAs and BFHAs, respectively. The presence of a large amount of Mg(II, Ni(II, Al(III, Mn(II and Co(II ions did affect the iron(III extraction. Finally stripping studies for recovering iron(III from organic phase (Fe-MFHs or Fe-BFHs dissolved in hexane were carried out at various concentrations of HCl, HNO3 and H2SO4. The results showed that the desired acid for recovery of iron(III was 5 M HCl and quantitative recovery of iron(III was achieved from Fe(III-MFHs and Fe(III-BFHs solutions in hexane containing 5 mg/L of Fe(III.

  9. Iron and exercise induced alterations in antioxidant status. Protection by dietary milk proteins.

    Science.gov (United States)

    Zunquin, Gautier; Rouleau, Vincent; Bouhallab, Said; Bureau, Francois; Theunynck, Denis; Rousselot, Pierre; Arhan, Pierre; Bougle, Dominique

    2006-05-01

    Lipid peroxidation stress induced by iron supplementation can contribute to the induction of gut lesions. Intensive sports lead to ischemia reperfusion, which increases free radical production. Athletes frequently use heavy iron supplementation, whose effects are unknown. On the other hand, milk proteins have in vitro antioxidant properties, which could counteract these potential side effects. The main aims of the study were: (1) to demonstrate the effects of combined exercise training (ET) and iron overload on antioxidant status; (2) to assess the protective properties of casein in vivo; (3) to study the mechanisms involved in an in vitro model. Antioxidant status was assessed by measuring the activity of antioxidant enzymes (superoxide dismutase (SOD); glutathione peroxidase (GSH-Px)), and on the onset of aberrant crypts (AC) in colon, which can be induced by lipid peroxidation. At day 30, all ET animals showed an increase in the activity of antioxidant enzymes, in iron concentration in colon mucosa and liver and in the number of AC compared to untrained rats. It was found that Casein's milk protein supplementation significantly reduced these parameters. Additional information on protective effect of casein was provided by measuring the extent of TBARS formation during iron/ascorbate-induced oxidation of liposomes. Free casein and casein bound to iron were found to significantly reduce iron-induced lipid peroxidation. The results of the overall study suggest that Iron supplementation during intensive sport training would decrease anti-oxidant status. Dietary milk protein supplementation could at least partly prevent occurrence of deleterious effects to tissue induced by iron overload. PMID:17390518

  10. Role of iron metabolism genetic determinants in response to chelation therapy in a cohort of β-thalassemia and sickle cell syndromes Italian patients

    Directory of Open Access Journals (Sweden)

    Maria Concetta Renda

    2014-09-01

    Full Text Available In patients with β-thalassemia and sickle cell syndromes there is an important secondary iron overload due to regular blood transfusions and increased duodenal iron absorption. As in genetic hemochromatosis, also the secondary iron storage leads to tissue injury that involves all the major organs: liver, heart, kidney, endocrine glands. At present, in patients with β-thalassemia and sickle cell syndrome, iron chelation therapy is widely used for the treatment of secondary hemochromatosis, to limit the toxic effects of iron overload. In order to maintain the correct homeostasis, several genes are involved in the metabolic pathways of iron, including HFE, FPN (ferroportin and TF (transferrin. In this study we analyzed the genes HFE, FPN and TF, to assess their possible effects on response to therapy with deferasirox and deferiprone, either as monotherapy or in combination therapy in a cohort of patients with β-thalassemia and sickle cell syndromes.

  11. Iron homeostasis and nutritional iron deficiency.

    Science.gov (United States)

    Theil, Elizabeth C

    2011-04-01

    Nonheme food ferritin (FTN) iron minerals, nonheme iron complexes, and heme iron contribute to the balance between food iron absorption and body iron homeostasis. Iron absorption depends on membrane transporter proteins DMT1, PCP/HCP1, ferroportin (FPN), TRF2, and matriptase 2. Mutations in DMT1 and matriptase-2 cause iron deficiency; mutations in FPN, HFE, and TRF2 cause iron excess. Intracellular iron homeostasis depends on coordinated regulation of iron trafficking and storage proteins encoded in iron responsive element (IRE)-mRNA. The noncoding IRE-mRNA structures bind protein repressors, IRP1 or 2, during iron deficiency. Integration of the IRE-RNA in translation regulators (near the cap) or turnover elements (after the coding region) increases iron uptake (DMT1/TRF1) or decreases iron storage/efflux (FTN/FPN) when IRP binds. An antioxidant response element in FTN DNA binds Bach1, a heme-sensitive transcription factor that coordinates expression among antioxidant response proteins like FTN, thioredoxin reductase, and quinone reductase. FTN, an antioxidant because Fe(2+) and O(2) (reactive oxygen species generators) are consumed to make iron mineral, is also a nutritional iron concentrate that is an efficiently absorbed, nonheme source of iron from whole legumes. FTN protein cages contain thousands of mineralized iron atoms and enter cells by receptor-mediated endocytosis, an absorption mechanism distinct from transport of nonheme iron salts (ferrous sulfate), iron chelators (ferric-EDTA), or heme. Recognition of 2 nutritional nonheme iron sources, small and large (FTN), will aid the solution of iron deficiency, a major public health problem, and the development of new policies on iron nutrition. PMID:21346101

  12. Preservation of glutamic acid-iron chelate into montmorillonite to efficiently degrade Reactive Blue 19 in a Fenton system under sunlight irradiation at neutral pH

    Science.gov (United States)

    Huang, Zhujian; Wu, Pingxiao; Gong, Beini; Yang, Shanshan; Li, Hailing; Zhu, Ziao; Cui, Lihua

    2016-05-01

    To further enhance the visible light responsive property and the chemical stability of Fe/clay mineral catalysts, glutamic acid-iron chelate intercalated montmorillonite (G-Fe-Mt) was developed. The physiochemical properties of G-Fe-Mt were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), etc. The results showed that glutamic acid-iron chelates were successfully intercalated into the gallery of montmorillonite and the intercalated glutamic acid-iron chelate molecules were well preserved. The product G-Fe-Mt displayed excellent catalytic performance in heterogeneous photo-Fenton reaction under sunlight irradiation at acidic and neutral pH values. The chelation and the visible light responsiveness of glutamic acid produce a synergistic effect leading to greatly enhanced sunlight-Fenton reaction catalyzed by the heterogeneous G-Fe-Mt under neutral pH. G-Fe-Mt is a promising catalyst for advanced oxidation processes.

  13. Spectrophotometric determination of trace iron(III in natural water after its preconcentration with a chelating resin

    Directory of Open Access Journals (Sweden)

    ELEONORA-ANA NEAGU

    2002-10-01

    Full Text Available A method for the determination of Fe(III at trace levels is described. Thus, prior to the spectrophotometric determination, a preconcentration of the trace amounts of iron(III using a chelate forming resin is proposed. A strong base anion-exchange resin (Dowex 2X4 loaded with Ferron (7-iodo-8-hydroxyquinoline-5-sulphonic acid was used for Fe(III preconcentration, at pH 2.2. After desorption with 5 % ascorbic acid in 0.5 M HCl, the analyte (converted from Fe(III to Fe(II was determined spectrophotometrically at 510 nm as Fe(II-o-phenanthroline complex. The accuracy of the proposed method was verified by comparing the obtained results with those obtained using AAS with the standard addition method. The sensitivity of the spectrophotometric method (after preconcentration was 0.01 mg Fe(III/ml. The recovery for iron(III at the 7 mg/l level was 97 %.

  14. Investigation of antioxidant property of iron oxide particles by 1'-1'diphenylpicryl-hydrazyle (DPPH) method

    Energy Technology Data Exchange (ETDEWEB)

    Paul, S. [Department of Energy, Tezpur University, Tezpur 784028 (India)], E-mail: paul.tezu@gmail.com; Saikia, J.P. [Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784028 (India); Samdarshi, S.K. [Department of Energy, Tezpur University, Tezpur 784028 (India)], E-mail: drsksamdarshi@rediffmail.com; Konwar, B.K. [Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur 784028 (India)

    2009-11-15

    We investigated the antioxidant properties of iron oxide particles. Particles of different sizes were synthesized and their antioxidant potency was investigated by using an in vitro system. The antioxidant capacity assay was done via a modified DPPH method for insoluble solid materials. The percentages of DPPH scavenging were calculated for iron oxide particles. The particles were found to show antioxidant potency. The DPPH scavenging increases with decrease in particle size.

  15. Investigation of antioxidant property of iron oxide particlesby 1‧-1‧diphenylpicryl-hydrazyle (DPPH) method

    Science.gov (United States)

    Paul, S.; Saikia, J. P.; Samdarshi, S. K.; Konwar, B. K.

    2009-11-01

    We investigated the antioxidant properties of iron oxide particles. Particles of different sizes were synthesized and their antioxidant potency was investigated by using an in vitro system. The antioxidant capacity assay was done via a modified DPPH method for insoluble solid materials. The percentages of DPPH scavenging were calculated for iron oxide particles. The particles were found to show antioxidant potency. The DPPH scavenging increases with decrease in particle size.

  16. Investigation of antioxidant property of iron oxide particles by 1'-1'diphenylpicryl-hydrazyle (DPPH) method

    International Nuclear Information System (INIS)

    We investigated the antioxidant properties of iron oxide particles. Particles of different sizes were synthesized and their antioxidant potency was investigated by using an in vitro system. The antioxidant capacity assay was done via a modified DPPH method for insoluble solid materials. The percentages of DPPH scavenging were calculated for iron oxide particles. The particles were found to show antioxidant potency. The DPPH scavenging increases with decrease in particle size.

  17. Characterisation of powerful antioxidants and synthetic iron ligands, as protective agents against oxidative damages, using new high throughput screening assays

    International Nuclear Information System (INIS)

    This work was devoted to the development of pertinent high throughput screening assays in the aim of studying oxidative stress. Three screening assays have been developed for the evaluation of protective agents toward ROS generated by gamma irradiation, UV or by a Fenton-like system. 24 natural extracts and a library of 120 pure compounds, containing among the most powerful antioxidants known to date, have been readily studied using, these new techniques. We found that two pulvinic acid derivatives possess excellent protective properties, and especially a pigment of fungus named norbadione A. Beyond its in vitro activity, this molecule displays remarkable biological properties. In the aim of studying an alternative pathway of protection against oxidation induced by iron, ligands able to modify the redox properties of this metal, have been synthesised. We have developed a parallel synthesis allowing the variation of the architecture, denticity, chelating moieties and hydrophobicity of iron chelates. Using this strategy, 47 potential Fe(III) ligands were obtained. Their protective capacities have been studied using a fourth screening assay, demonstrating the effectiveness of some ligands. Finally, the immunoassay technique called SPI-RAD has been used in order to study a particular consequence of drastic oxidative stress, namely covalent crosslinks between proteins. Our results demonstrate that these linkages occur in the presence of metals (FeII or CuII) and hydrogen peroxide, as well as in the presence of NO. radical. Moreover, it has been demonstrated that tyrosines residues and disulfide bridges play an important role in these phenomena. (author)

  18. Green tea or rosemary extract added to foods reduces nonheme- iron absorption

    DEFF Research Database (Denmark)

    Samman, S.; Sandstrøm, B.; Toft, M.B.; Bukhave, Klaus; Jensen, M.; Sørensen, S.S.; Hansen, M.

    2001-01-01

    Background: Phenolic compounds act as food antioxidants. One of the postulated mechanisms of action is chelation of prooxidant metals, such as iron. Although the antioxidative effect is desirable, this mechanism may impair the utilization of dietary iron. Objective: We sought to determine the.......5 +/- 4.0% to 6.4 +/- 4.7% (P < 0.05) in the presence of rosemary extract. Conclusion: Phenolic-rich extracts used as antioxidants in foods reduce the utilization of dietary iron....

  19. Iron Chelators of the Di-2-pyridylketone Thiosemicarbazone and 2-Benzoylpyridine Thiosemicarbazone Series Inhibit HIV-1 Transcription: Identification of Novel Cellular Targets—Iron, Cyclin-Dependent Kinase (CDK) 2, and CDK9S⃞

    Science.gov (United States)

    Debebe, Zufan; Ammosova, Tatyana; Breuer, Denitra; Lovejoy, David B.; Kalinowski, Danuta S.; Karla, Pradeep K.; Kumar, Krishna; Jerebtsova, Marina; Ray, Patricio; Kashanchi, Fatah; Gordeuk, Victor R.; Richardson, Des R.

    2011-01-01

    HIV-1 transcription is activated by HIV-1 Tat protein, which recruits cyclin-dependent kinase 9 (CDK9)/cyclin T1 and other host transcriptional coactivators to the HIV-1 promoter. Tat itself is phosphorylated by CDK2, and inhibition of CDK2 by small interfering RNA, the iron chelator 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311), and the iron chelator deferasirox (ICL670) inhibits HIV-1 transcription. Here we have analyzed a group of novel di-2-pyridylketone thiosemicarbazone- and 2-benzoylpyridine thiosemicarbazone-based iron chelators that exhibit marked anticancer activity in vitro and in vivo (Proc Natl Acad Sci USA 103:7670–7675, 2006; J Med Chem 50:3716–3729, 2007). Several of these iron chelators, in particular 2-benzoylpyridine 4-allyl-3-thiosemicarbazone (Bp4aT) and 2-benzoylpyridine 4-ethyl-3-thiosemicarbazone (Bp4eT), inhibited HIV-1 transcription and replication at much lower concentrations than did 311 and ICL670. Neither Bp4aT nor Bp4eT were toxic after a 24-h incubation. However, longer incubations for 48 h or 72 h resulted in cytotoxicity. Analysis of the molecular mechanism of HIV-1 inhibition showed that the novel iron chelators inhibited basal HIV-1 transcription, but not the nuclear factor-κB-dependent transcription or transcription from an HIV-1 promoter with inactivated SP1 sites. The chelators inhibited the activities of CDK2 and CDK9/cyclin T1, suggesting that inhibition of CDK9 may contribute to the inhibition of HIV-1 transcription. Our study suggests the potential usefulness of Bp4aT or Bp4eT in antiretroviral regimens, particularly where resistance to standard treatment occurs. PMID:20956357

  20. Scientific opinion on the safety and efficacy of iron compounds (E1) as feed additives for all species: iron chelate of amino acids, hydrate, based on a dossier submitted by Zinpro Animal Nutrition Inc.

    OpenAIRE

    EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)

    2013-01-01

    The use of iron chelate of amino acids, hydrate, as source of iron is considered safe for all animal species/categories when used up to the currently authorised maximum content of total iron in complete feed, with the exception of bovines and poultry for which the maximum tolerated level is 450 mg/kg complete feed, and pets, for which the maximum tolerated level is 600 mg/kg complete feed. The FEEDAP Panel is not in the position to derive a maximum safe iron concentration in feed for horses o...

  1. Iron overload and chelation therapy in patients with low-risk myelodysplastic syndromes with transfusion requirements

    OpenAIRE

    Remacha, Angel F.; Arrizabalaga, Beatriz; Cañizo, Consuelo; Sanz, Guillermo; Villegas, Ana

    2009-01-01

    Abstract The main objective of the study was to analyze the incidence of iron overload (IO) and its management in transfusion-dependent patients with low-risk myelodysplastic syndrome (MDS) before the license of deferasirox. This observational, cross-sectional, and multicenter study was conducted from January to May 2007 in 81 Spanish hospitals. Eligible patients had a low or intermediate-1 risk score and had to have received at least ten units of packed red blood cell (PRBC). Of t...

  2. The novel mitochondrial iron chelator 5-((methylamino)methyl)-8-hydroxyquinoline protects against mitochondrial-induced oxidative damage and neuronal death.

    Science.gov (United States)

    Mena, Natalia P; García-Beltrán, Olimpo; Lourido, Fernanda; Urrutia, Pamela J; Mena, Raúl; Castro-Castillo, Vicente; Cassels, Bruce K; Núñez, Marco T

    2015-08-01

    Abundant evidence indicates that iron accumulation, oxidative damage and mitochondrial dysfunction are common features of Huntington's disease, Parkinson's disease, Friedreich's ataxia and a group of disorders known as Neurodegeneration with Brain Iron Accumulation. In this study, we evaluated the effectiveness of two novel 8-OH-quinoline-based iron chelators, Q1 and Q4, to decrease mitochondrial iron accumulation and oxidative damage in cellular and animal models of PD. We found that at sub-micromolar concentrations, Q1 selectively decreased the mitochondrial iron pool and was extremely effective in protecting against rotenone-induced oxidative damage and death. Q4, in turn, preferentially chelated the cytoplasmic iron pool and presented a decreased capacity to protect against rotenone-induced oxidative damage and death. Oral administration of Q1 to mice protected substantia nigra pars compacta neurons against oxidative damage and MPTP-induced death. Taken together, our results support the concept that oral administration of Q1 is a promising therapeutic strategy for the treatment of NBIA. PMID:26051278

  3. Deferasirox treatment of iron-overloaded chelation-naïve and prechelated patients with myelodysplastic syndromes in medical practice: results from the observational studies eXtend and eXjange

    OpenAIRE

    Gattermann, Norbert; Jarisch, Andrea; Schlag, Rudolf; Blumenstengel, Klaus; Goebeler, Mariele; Groschek, Matthias; Losem, Christoph; Procaccianti, Maria; Junkes, Alexia; Leismann, Oliver; Germing, Ulrich

    2012-01-01

    EXtend and eXjange were prospective, 1-yr, non-interventional, observational, multicentre studies that investigated deferasirox, a once-daily oral iron chelator, in iron-overloaded chelation-naïve and prechelated patients with myelodysplastic syndromes (MDS), respectively, treated in the daily-routine setting of office-based physicians. No inclusion or exclusion criteria or additional monitoring procedures were applied. Deferasirox was administered as recommended in the European Summary of Pr...

  4. A unique antioxidant activity of phosphatidylserine on iron-induced lipid peroxidation of phospholipid bilayers.

    Science.gov (United States)

    Dacaranhe, C D; Terao, J

    2001-10-01

    The relationship between the antioxidant effect of acidic phospholipids, phosphatidic acid (PA), phosphatidylglycerol (PG) and phosphatidylserine (PS), on iron-induced lipid peroxidation of phospholipid bilayers and their abilities to bind iron ion was examined in egg yolk phosphatidylcholine large unilamellar vesicles (EYPC LUV). The effect of each acidic phospholipid added to the vesicles at 10 mol% was assessed by measuring phosphatidylcholine hydroperoxides (PC-OOH) and thiobarbituric acid-reactive substances. The addition of dipalmitoyl PS (DPPS) showed a significant inhibitory effect, although the other two acidic phospholipids, dipalmitoyl PA (DPPA) and dipalmitoyl PG (DPPG), did not exert the inhibition. Neither dipalmitoyl PC (DPPC) nor dipalmitoyl phophatidylethanolamine (DPPE) showed any remarkable inhibition on this system. None of the tested phospholipids affected the lipid peroxidation rate remarkably when the vesicles were exposed to a water-soluble radical generator. The iron-binding ability of each phospholipid was estimated on the basis of the amounts of iron recovered in the chloroform/methanol phase after separation of the vesicle solution to water/methanol and chloroform/methanol phases. EYPC LUV containing DPPS, DPPA, and DPPG had higher amounts of bound iron than those containing DPPC and DPPE, indicating that these three acidic phospholipids possess an iron-binding ability at a similar level. Nevertheless, only DPPS suppressed iron-dependent decomposition of PC-OOH significantly. Therefore, it is likely that these three acidic phospholipids possess a significant iron-binding ability, although this ability per se does not warrant them antioxidative activities. The ability to suppress the iron-dependent decomposition of PC-OOH may explain the unique antioxidant activity of PS. PMID:11768154

  5. Quantitative analysis of the anti-proliferative activity of combinations of selected iron-chelating agents and clinically used anti-neoplastic drugs.

    Directory of Open Access Journals (Sweden)

    Eliska Potuckova

    Full Text Available Recent studies have demonstrated that several chelators possess marked potential as potent anti-neoplastic drugs and as agents that can ameliorate some of the adverse effects associated with standard chemotherapy. Anti-cancer treatment employs combinations of several drugs that have different mechanisms of action. However, data regarding the potential interactions between iron chelators and established chemotherapeutics are lacking. Using estrogen receptor-positive MCF-7 breast cancer cells, we explored the combined anti-proliferative potential of four iron chelators, namely: desferrioxamine (DFO, salicylaldehyde isonicotinoyl hydrazone (SIH, (E-N'-[1-(2-hydroxy-5-nitrophenylethyliden] isonicotinoyl hydrazone (NHAPI, and di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT, plus six selected anti-neoplastic drugs. These six agents are used for breast cancer treatment and include: paclitaxel, 5-fluorouracil, doxorubicin, methotrexate, tamoxifen and 4-hydroperoxycyclophosphamide (an active metabolite of cyclophosphamide. Our quantitative chelator-drug analyses were designed according to the Chou-Talalay method for drug combination assessment. All combinations of these agents yielded concentration-dependent, anti-proliferative effects. The hydrophilic siderophore, DFO, imposed antagonism when used in combination with all six anti-tumor agents and this antagonistic effect increased with increasing dose. Conversely, synergistic interactions were observed with combinations of the lipophilic chelators, NHAPI or Dp44mT, with doxorubicin and also the combinations of SIH, NHAPI or Dp44mT with tamoxifen. The combination of Dp44mT with anti-neoplastic agents was further enhanced following formation of its redox-active iron and especially copper complexes. The most potent combinations of Dp44mT and NHAPI with tamoxifen were confirmed as synergistic using another estrogen receptor-expressing breast cancer cell line, T47D, but not estrogen receptor

  6. Quantitative analysis of the anti-proliferative activity of combinations of selected iron-chelating agents and clinically used anti-neoplastic drugs.

    Science.gov (United States)

    Potuckova, Eliska; Jansova, Hana; Machacek, Miloslav; Vavrova, Anna; Haskova, Pavlina; Tichotova, Lucie; Richardson, Vera; Kalinowski, Danuta S; Richardson, Des R; Simunek, Tomas

    2014-01-01

    Recent studies have demonstrated that several chelators possess marked potential as potent anti-neoplastic drugs and as agents that can ameliorate some of the adverse effects associated with standard chemotherapy. Anti-cancer treatment employs combinations of several drugs that have different mechanisms of action. However, data regarding the potential interactions between iron chelators and established chemotherapeutics are lacking. Using estrogen receptor-positive MCF-7 breast cancer cells, we explored the combined anti-proliferative potential of four iron chelators, namely: desferrioxamine (DFO), salicylaldehyde isonicotinoyl hydrazone (SIH), (E)-N'-[1-(2-hydroxy-5-nitrophenyl)ethyliden] isonicotinoyl hydrazone (NHAPI), and di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT), plus six selected anti-neoplastic drugs. These six agents are used for breast cancer treatment and include: paclitaxel, 5-fluorouracil, doxorubicin, methotrexate, tamoxifen and 4-hydroperoxycyclophosphamide (an active metabolite of cyclophosphamide). Our quantitative chelator-drug analyses were designed according to the Chou-Talalay method for drug combination assessment. All combinations of these agents yielded concentration-dependent, anti-proliferative effects. The hydrophilic siderophore, DFO, imposed antagonism when used in combination with all six anti-tumor agents and this antagonistic effect increased with increasing dose. Conversely, synergistic interactions were observed with combinations of the lipophilic chelators, NHAPI or Dp44mT, with doxorubicin and also the combinations of SIH, NHAPI or Dp44mT with tamoxifen. The combination of Dp44mT with anti-neoplastic agents was further enhanced following formation of its redox-active iron and especially copper complexes. The most potent combinations of Dp44mT and NHAPI with tamoxifen were confirmed as synergistic using another estrogen receptor-expressing breast cancer cell line, T47D, but not estrogen receptor-negative MDA

  7. Effectiveness of antioxidants in preventing oxidation of palm oil enriched with heme iron: A model for iron fortification in baked products

    OpenAIRE

    Alemán Ezcaray, Mercedes; Nuchi, C. D.; Bou Novensà, Ricard; Tres Oliver, Alba; Polo Pozo, Francisco Javier; Guardiola Ibarz, Francesc; Codony Salcedo, Rafael

    2010-01-01

    Bakery products such as biscuits, cookies, and pastries represent a good medium for iron fortification in food products, since they are consumed by a large proportion of the population at risk of developing iron deficiency anemia, mainly children. The drawback, however, is that iron fortification can promote oxidation. To assess the extent of this, palm oil added with heme iron and different antioxidants was used as a model for evaluating the oxidative stability of some bakery products, such ...

  8. Chelation in metal intoxication

    DEFF Research Database (Denmark)

    Aaseth, Jan; Skaug, Marit Aralt; Cao, yang;

    2015-01-01

    The present review provides an update of the general principles for the investigation and use of chelating agents in the treatment of intoxications by metals. The clinical use of the old chelators EDTA (ethylenediamine tetraacetate) and BAL (2,3-dimercaptopropanol) is now limited due to the...... inconvenience of parenteral administration, their own toxicity and tendency to increase the neurotoxicity of several metals. The hydrophilic dithiol chelators DMSA (meso-2,3-dimercaptosuccinic acid) and DMPS (2,3-dimercapto-propanesulphonate) are less toxic and more efficient than BAL in the clinical treatment...... of heavy metal poisoning, and available as capsules for oral use. In copper overload, DMSA appears to be a potent antidote, although d-penicillamine is still widely used. In the chelation of iron, the thiols are inefficient, since iron has higher affinity for ligands with nitrogen and oxygen, but the...

  9. Evaluation of In Vitro Antioxidant Potential of Cordia retusa

    OpenAIRE

    Amudha, Murugesan; Rani, Shanmugam

    2016-01-01

    The present study was carried out to investigate the antioxidant potential, total flavonoid and phenolic content in extracts of aerial parts of Cordia retua (Vahl.) Masam. The samples such as ethyl acetate and ethanol extracts were tested using six in vitro models such as 2,2-diphenyl-1-picrylhydrazyl, nitric oxide radical, iron chelating, hydroxyl radical, superoxide radical scavenging activity and total antioxidant activity to evaluate the in vitro antioxidant potential of C. retusa by spec...

  10. Evaluation of In Vitro Antioxidant Potential of Cordia retusa

    OpenAIRE

    Murugesan Amudha; Shanmugam Rani

    2016-01-01

    The present study was carried out to investigate the antioxidant potential, total flavonoid and phenolic content in extracts of aerial parts of Cordia retua(Vahl.) Masam. The samples such as ethyl acetate and ethanol extracts were tested using six in vitromodels such as 2,2-diphenyl-1-picrylhydrazyl, nitric oxide radical, iron chelating, hydroxyl radical, superoxide radical scavenging activity and total antioxidant activity to evaluate the in vitro antioxidant potential of C. retusa by spectr...

  11. Effect of antioxidants on lipid peroxidation in iron-loaded rats.

    Science.gov (United States)

    Dillard, C J; Downey, J E; Tappel, A L

    1984-02-01

    Indirect evidence has suggested that lipid peroxidation is associated with iron overload in vivo. As a measure of lipid peroxidation, pentane expired in the breath of rats loaded with an accumulated dose of either 100 mg or 186-200 mg of iron injected intraperitoneally as iron dextran was measured over a 7 to 8 week period, and the effect on pentane production of feeding antioxidant-supplemented diets was determined. By the seventh week of feeding the diets, rats fed 0.3% L-ascorbic acid produced 17% less (P = 0.03) pentane than did rats fed the basal antioxidant-deficient diet, whereas rats fed 0.004% dl-alpha-tocopherol acetate produced 92% less (P less than 0.001). After being fed the basal diet for 7 weeks, iron-loaded rats produced 76 +/- 9 pmol pentane/100 g body wt/min. When synthetic antioxidants were added to the diet at a concentration of 0.25%, the order of effectiveness in decreasing pentane production after 1 week was: N,N'-diphenyl-p-phenylenediamine greater than ethoxyquin greater than butylated hydroxyanisole greater than butylated hydroxytoluene greater than propyl gallate approximately equal to no antioxidant. After removal of either ethoxyquin or N,N'-diphenyl-p-phenylenediamine from the diets for 1 week, pentane production increased to a high level. The total amount of lipid soluble fluorophores in individual spleens of rats fed N,N'-diphenyl-p-phenylenediamine, ethoxyquin, dl-alpha- tocopherol acetate, ascorbic acid and no antioxidant were correlated significantly with the corresponding total integrated amount of pentane produced by the individual rats over the 7 to 8 week period. This study has provided some of the most direct evidence to date that lipid peroxidation is associated with iron overload in vivo. PMID:6708751

  12. Cardiac Function and Iron Chelation in Thalassemia Major and Intermedia: a Review of the Underlying Pathophysiology and Approach to Chelation Management

    OpenAIRE

    Aessopos, Athanasios; Berdoukas, Vasilios

    2009-01-01

    Heart disease is the leading cause of mortality and one of the main causes of morbidity in beta-thalassemia. Patients with homozygous thalassemia may have either a severe phenotype which is usually transfusion dependent or a milder form that is thalassemia intermedia. The two main factors that determine cardiac disease in homozygous β thalassemia are the high output state that results from chronic tissue hypoxia, hypoxia-induced compensatory reactions and iron overload. The high output state ...

  13. Novel 1,3-thiazolidin-4-one derivatives as promising anti-Candida agents endowed with anti-oxidant and chelating properties.

    Science.gov (United States)

    Secci, Daniela; Carradori, Simone; Bizzarri, Bruna; Chimenti, Paola; De Monte, Celeste; Mollica, Adriano; Rivanera, Daniela; Zicari, Alessandra; Mari, Emanuela; Zengin, Gokhan; Aktumsek, Abdurrahman

    2016-07-19

    Pursuing our recent outcomes regarding the antifungal activity of N-substituted 1,3-thiazolidin-4-ones, we synthesized thirty-six new derivatives introducing aliphatic, cycloaliphatic and heteroaromatic moieties at N1-hydrazine connected with C2 position of the thiazolidinone nucleus and functionalizing the lactam nitrogen with differently substituted (NO2, NH2, Cl and F) benzyl groups. These compounds were tested to evaluate their minimum inhibitory concentration (MIC) against several clinical Candida spp. with respect to topical and systemic reference drugs (clotrimazole, fluconazole, ketoconazole, miconazole, tioconazole, amphotericin B). Moreover, anti-oxidant properties were also evaluated by using different protocols including free radical scavenging (DPPH and ABTS), reducing power (CUPRAC and FRAP), metal chelating and phosphomolybdenum assays. Moreover, for the most active derivatives we assessed the toxicity (CC50) against Hep2 human cells in order to characterize them as multi-target agents for fungal infections. PMID:27100030

  14. The protective role of iron chelation and zinc supplements in atherosclerosis induced in New Zealand white rabbits: A nuclear microscopy study

    International Nuclear Information System (INIS)

    The protective properties of iron chelator desferal and zinc supplements on atherosclerosis induced in New Zealand white rabbits were investigated using nuclear microscopy, incorporating particle induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and scanning transmission ion microscopy (STIM). Firstly, we examined the effects of the desferal (desferrioxamine - a chelator which forms a stable complex with ferric iron) on atherosclerosis progression and lesion iron content in cholesterol-fed New Zealand white rabbits. Rabbits were fed with a 1% w/w cholesterol diet (HFD - high fat diet) for either 8 weeks (with the last 5 weeks injected daily with desferal), or for 12 weeks (with the last 9 weeks injected with desferal). Controls were injected with saline. A significant reduction in average lesion area (p = 0.038) was observed in the 12-week treated animals as compared with the 12-week controls. The average lesion iron level of the 12 week treated animals (58 ppm dry weight) was significantly lower (p = 0.03) than for the 12-week control animals (95 ppm dry weight). No reduction in lesion area or iron content was observed in the 8 week treated animals compared with controls, and no change in lesion zinc concentration was observed for either group. This data is consistent with the concept that iron contributes to the early stages in the development of atherosclerosis and that removal of iron from the lesion retards the progression of the disease. Secondly, the effect of zinc supplements on atherosclerotic lesion growth was examined. The rabbits in the test group received a 1% w/w cholesterol diet with Zn supplements for 8 weeks and the rabbits in the control group were fed only with a 1% w/w cholesterol diet for the same period of time. Lesion area analyses using light microscopy showed that the average lesion area was 1.0 mm2 for the test models compared with 3.0 mm2 for the control group models (p = 0.0045). Elemental analysis of the lesion

  15. Treatment of mild non-chemotherapy-induced iron deficiency anemia in cancer patients: comparison between oral ferrous bisglycinate chelate and ferrous sulfate.

    Science.gov (United States)

    Ferrari, Paola; Nicolini, Andrea; Manca, Maria Laura; Rossi, Giuseppe; Anselmi, Loretta; Conte, Massimo; Carpi, Angelo; Bonino, Ferruccio

    2012-09-01

    In cancer patients mild-moderate non-chemotherapy-induced iron deficiency anemia (IDA) is usually treated with oral iron salts, mostly ferrous sulfate. In this study, we compare efficacy and toxicity of oral ferrous bisglycinate chelate and ferrous sulfate in cancer patients with mild IDA. Twenty-four patients operated on for solid tumors (10 breast, 12 colorectal, 2 gastric), aged 61±10 years (range 45-75), with non-chemotherapy-induced hemoglobin (Hb) values between 10 and 12 g/dL and ferritin lower than 30 ng/mL were randomized to receive oral ferrous bisglycinate chelate, 28 mg per day for 20 days, and then 14 mg per day for 40 days (12 patients) (A group) or oral ferrous sulphate, 105 mg per day for 60 days (12 patients) (B group). Values of hemoglobin and ferritin obtained at diagnosis, 1 and 2 months from the beginning of treatment were compared. Adverse events (AEs) related to the two treatments were recorded. In the 12 patients treated with ferrous bisglycinate chelate, basal hemoglobin and ferritin values (mean±SD) were 11.6±0.8 g/dL and 16.1±8.0 ng/mL. After 2 months of treatment, they were 13.0±1.4 g/dL and 33.8±22.0 ng/mL, respectively (P=0.0003 and P=0.020). In the group treated with ferrous sulphate, hemoglobin and ferritin mean values were 11.3±0.6 g/dL and 19.0±6.4 ng/mL basally, and 12.7±0.70 g/dL and 40.8±28.1 ng/mL (Pferrous bisglycinate chelate and four (33%) with ferrous sulphate, toxicity was grade 1. In conclusion, these data suggest that ferrous bisglycinate chelate has similar efficacy and likely lower GI toxicity than ferrous sulphate given at the conventional dose of 105 mg per day for the same time. PMID:22795809

  16. Antioxidant Enzyme Activity, Iron Content and Lipid Oxidation of Raw and Cooked Meat of Korean Native Chickens and Other Poultry

    OpenAIRE

    Muhlisin,; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-01-01

    This study was conducted to observe antioxidant enzyme activity, iron content and lipid oxidation of Korean native chickens and other poultry. The breast and thigh meat of three Korean native chicken breeds including Woorimatdak, Hyunin black and Yeonsan ogye, and three commercial poultry breeds including the broiler, White Leghorn and Pekin duck (Anasplatyrhyncos domesticus) were studied. The analyses of the antioxidant enzymes activity, iron content and lipid oxidation were performed in raw...

  17. Overview of current chelation practices

    OpenAIRE

    Aydinok, Y.

    2011-01-01

    Deferoxamine (DFO) is reference standard therapy for transfusional iron overload since the 1980s. Although it is a highly effective iron chelator, the compliance problem to subcutaneous administration of DFO remains as the major problem. The oral chelator Deferiprone (DFP) has no marketing licence in North America, however, it has been licensed in India since 1994 and the European Union (EU) granted marketing approval for DFP in 1999, specifically for patients with thalassemia major when DFO ...

  18. cis-Dioxomolybdenum(VI) complexes of a new ONN chelating thiosemicarbazidato ligand; Synthesis, characterization, crystal, molecular structures and antioxidant activities

    Science.gov (United States)

    İlhan Ceylan, Berat; Deniz, Nahide Gulsah; Kahraman, Sibel; Ulkuseven, Bahri

    2015-04-01

    5-Chloro-4-methyl-2-hydroxybenzophenone S-propyl-4-phenyl-thiosemicarbazone (H2L) and its cis-dioxomolybdenum(VI) complexes, in the general formula [MoO2(L)R-OH)] (R: methyl, 1; ethyl, 2; n-propyl, 3; n-butyl, 4; n-pentyl, 5), were synthesized and characterized by micro analysis, electronic, infrared and 1H and 13C NMR spectra. The crystal structures of complexes, 1 and 3, have been solved by direct methods (SIR92) and refined to the residual indexes R1 = 0.098 and R1 = 0.052 respectively. Complexes 1 and 3 are crystallized in the triclinic space group P-1 with Z = 2. The crystal study of complex 1 showed the first example of intermolecular hydrogen bond for this type of molybdenum-thiosemicarbazone complexes. The hydrogen bond is between the hydroxyl proton of attached alcohol and an oxo oxygen (in MoO22+ unit) of another complex molecule, and its bond distance (1.767(1) Å) is shorter than from the σ-coordination bonds in complex 1. Antioxidant activities of the compounds were determined by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. Ligand showed 23.61% DPPH radical scavenging activity at 250 mg/L concentration. Cupric Reducing Antioxidant Capacity (CUPRAC) was also evaluated and trolox-equivalent antioxidant capacity (TEAC) values were found for ligand, 1 and 3 as 0.51, 0.33 and 0.30 respectively.

  19. Hepatic but not brain iron is rapidly chelated by deferasirox in aceruloplasminemia due to a novel gene mutation

    OpenAIRE

    Finkenstedt, Armin; Wolf, Elisabeth; Höfner, Elmar; Gasser, Bethina Isasi; Bösch, Sylvia; Bakry, Rania; Creus, Marc; Kremser, Christian; Schocke, Michael; Theurl, Milan; Moser, Patrizia; Schranz, Melanie; Bonn, Guenther; Poewe, Werner; Vogel, Wolfgang

    2010-01-01

    Background & Aims Aceruloplasminemia is a rare autosomal recessive neurodegenerative disease associated with brain and liver iron accumulation which typically presents with movement disorders, retinal degeneration, and diabetes mellitus. Ceruloplasmin is a multi-copper ferroxidase that is secreted into plasma and facilitates cellular iron export and iron binding to transferrin. Results A novel homozygous ceruloplasmin gene mutation, c.2554+1G>T, was identified as the cause of aceruloplasminem...

  20. cis-Dioxomolybdenum(VI) complexes of a new ONN chelating thiosemicarbazidato ligand; synthesis, characterization, crystal, molecular structures and antioxidant activities.

    Science.gov (United States)

    İlhan Ceylan, Berat; Deniz, Nahide Gulsah; Kahraman, Sibel; Ulkuseven, Bahri

    2015-04-15

    5-Chloro-4-methyl-2-hydroxybenzophenone S-propyl-4-phenyl-thiosemicarbazone (H2L) and its cis-dioxomolybdenum(VI) complexes, in the general formula [MoO2(L)R-OH)] (R: methyl, 1; ethyl, 2; n-propyl, 3; n-butyl, 4; n-pentyl, 5), were synthesized and characterized by micro analysis, electronic, infrared and (1)H and (13)C NMR spectra. The crystal structures of complexes, 1 and 3, have been solved by direct methods (SIR92) and refined to the residual indexes R1=0.098 and R1=0.052 respectively. Complexes 1 and 3 are crystallized in the triclinic space group P-1 with Z=2. The crystal study of complex 1 showed the first example of intermolecular hydrogen bond for this type of molybdenum-thiosemicarbazone complexes. The hydrogen bond is between the hydroxyl proton of attached alcohol and an oxo oxygen (in MoO2(2+) unit) of another complex molecule, and its bond distance (1.767(1)Å) is shorter than from the σ-coordination bonds in complex 1. Antioxidant activities of the compounds were determined by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. Ligand showed 23.61% DPPH radical scavenging activity at 250 mg/L concentration. Cupric Reducing Antioxidant Capacity (CUPRAC) was also evaluated and trolox-equivalent antioxidant capacity (TEAC) values were found for ligand, 1 and 3 as 0.51, 0.33 and 0.30 respectively. PMID:25681810

  1. Alkylation of Sulfur Ligand in Cysteinate-Iron Chelates by a 1,2,4,5-Tetraoxane

    Institute of Scientific and Technical Information of China (English)

    刘鹤华; 伍贻康; 沈鑫

    2003-01-01

    Reaction of a 1,2, 4, 5-tetraoxane with cysteinate-iron in the presence of excess methyl cysteinate led to formation of sulfuralkylated methyl cysteinate in 33 % yield, illustrating a possible mechanism for tetraoxanes' antimalarial action.

  2. Updated recommendations on the management of gastrointestinal disturbances during iron chelation therapy with Deferasirox in transfusion dependent patients with myelodysplastic syndrome - Emphasis on optimized dosing schedules and new formulations.

    Science.gov (United States)

    Nolte, Florian; Angelucci, Emanuele; Breccia, Massimo; Gattermann, Norbert; Santini, Valeria; Vey, Norbert; Hofmann, Wolf-Karsten

    2015-10-01

    Myelodysplastic syndromes (MDS) are oligoclonal hematopoietic disorders characterized by peripheral cytopenias with anemias being the most prevalent feature. The majority of patients will depend on regular transfusions of packed red blood cells (PRBC) during the course of the disease. Particularly patients with MDS and low risk for transformation into acute myeloid leukemia and low risk of early death will receive PRBC transfusions on a regular basis, which puts them at high risk for transfusional iron overload. Transfusion dependence has been associated with negative impact on organ function and reduced life expectancy. Recently, several retrospective but also some prospective studies have indicated, that transfusion dependent patients with MDS might benefit from consequent iron chelation with regard to morbidity and mortality. However, low treatment adherence due to adverse events mainly gastrointestinal in nature is an important obstacle in achieving sufficient iron chelation in MDS patients. Here, we will summarize and discuss the existing data on Deferasirox in low risk MDS published so far and provide recommendations for optimal management of gastrointestinal adverse events during iron chelation aiming at improving treatment compliance and, hence, sufficiently removing excess iron from the patients. PMID:26293555

  3. Antioxidant and anti-inflammatory activities of selected medicinal plants and fungi containing phenolic and flavonoid compounds

    OpenAIRE

    Diaz Patricia; Jeong Sang Chul; Lee Samiuela; Khoo Cheang; Koyyalamudi Sundar Rao

    2012-01-01

    Abstract Background This study aims to determine the relationship between the antioxidant and anti-inflammatory activities of the thirteen herbs and two fungi extracts, and their total phenolic and flavonoid contents. Methods Antioxidant activities were evaluated by four assays: an antioxidant activity assay using Saccharomyces cerevisiae, a DPPH ((2, 2-diphenyl-1-picrylhydrazyl) assay to assess free radical scavenging, an assay assessing ferrous ions or iron (II) chelating ability, and a fer...

  4. Clinical monitoring and management of complications related to chelation therapy in patients with β-thalassemia.

    Science.gov (United States)

    Saliba, Antoine N; El Rassi, Fuad; Taher, Ali T

    2016-01-01

    Iron chelating agents - deferoxamine (DFO), deferiprone (DFP), and deferasirox (DFX) - are used to treat chronic iron overload in patients with β-thalassemia in an attempt to reduce morbidity and mortality related to siderosis. Each of the approved iron chelating agents has its own advantages over the others and also has its own risks, whether related to over-chelation or not. In this review, we briefly discuss the methods to monitor the efficacy of iron chelation therapy (ICT) and the evidence behind the use of each iron chelating agent. We also portray the risks and complications associated with each iron chelating agent and recommend strategies to manage adverse events. PMID:26613264

  5. An Antioxidant Extract of the Insectivorous Plant Drosera burmannii Vahl. Alleviates Iron-Induced Oxidative Stress and Hepatic Injury in Mice

    OpenAIRE

    Nikhil Baban Ghate; Dipankar Chaudhuri; Abhishek Das; Sourav Panja; Nripendranath Mandal

    2015-01-01

    Free iron typically leads to the formation of excess free radicals, and additional iron deposition in the liver contributes to the oxidative pathologic processes of liver disease. Many pharmacological properties of the insectivorous plant Drosera burmannii Vahl. have been reported in previous studies; however, there is no evidence of its antioxidant or hepatoprotective potential against iron overload. The antioxidant activity of 70% methanolic extract of D. burmannii (DBME) was evaluated. DBM...

  6. In vitro Studies of Iron Chelation Activity of Purified Active Ingredients Extracted from Triticum aestivum Linn. (Wheat Grass)

    OpenAIRE

    Das Priyabrata; Mukhopadhyay Ashis; Mandal Suvra; Pal Bikas Chandra; Mishra Raghwendra; Mukherjee Debarati; Mukhopadhyay Soma; Basak Jayasri; Kar Manoj

    2012-01-01

    Objective: Seven to eight days germinated plants of Triticum aestivum (wheat grass) are a rich source of vitamin A, C, calcium, magnesium, phosphorus, potassium, sodium, sulphur, cobalt, zinc and protein. Traditionally the aqueous extract of T. aestivum was reported to be used as a health tonic in folk and ayurvedic medicine. We previously reported that aqueous extract of T. aestivum was found to reduce the blood transfusion requirement in iron overloaded Thalassemia and Myelod...

  7. Iron Overload

    Science.gov (United States)

    ... drug called an iron chelator to remove excess iron from your body because of transfusion-dependent anemias. Be sure to talk with your doctor about the potential benefits and risks of using these drugs. Previous Article ...

  8. Overview of chelation recommendations for thalassaemia and sickle cell disease

    OpenAIRE

    Banu Kaya

    2014-01-01

    The long term consequences of iron toxicity are mostly reversible with effective iron chelation therapy. Recommendations for use of chelation therapy in transfusion dependent thalassaemia (TDT), sickle cell disease (SCD) and non transfusion dependent thalassaemia (NTDT) continue to evolve as our knowledge and clinical experience increases. Improved chelation options including drug combinations and a better understanding of condition specific factors may help to improve efficiency of chelation...

  9. Overview of chelation recommendations for thalassaemia and sickle cell disease

    Directory of Open Access Journals (Sweden)

    Banu Kaya

    2014-12-01

    Full Text Available The long term consequences of iron toxicity are mostly reversible with effective iron chelation therapy. Recommendations for use of chelation therapy in transfusion dependent thalassaemia (TDT, sickle cell disease (SCD and non transfusion dependent thalassaemia (NTDT continue to evolve as our knowledge and clinical experience increases. Improved chelation options including drug combinations and a better understanding of condition specific factors may help to improve efficiency of chelation regimens and meet the needs of patients more effectively.

  10. Antioxidants

    Science.gov (United States)

    ... prevent or delay some types of cell damage. Antioxidants are found in many foods, including fruits and vegetables. They are also available ... t clear whether this is because of the antioxidants, something else in the foods, or other factors. High-dose supplements of antioxidants ...

  11. Preparation and antioxidant activity evaluation of cod skin peptides chelated calcium%鳕鱼皮复合肽螯合钙的制备及抗氧化活性研究

    Institute of Scientific and Technical Information of China (English)

    黄薇; 邓尚贵; 唐艳; 李淑芳; 孔巧香

    2012-01-01

    This paper focused on the preparation of cod skin protein chelating Ca^2+ by compound enzymolysis method, and studied the antioxidation function of the chelate. The results showed that the optimal chelation reaction between hydrolysates and CaCl2 conducted for 20 min at 25 ℃ and pH 7.0 with a calcium/peptide mass ratio of 0.3/3, yielded 58.85% of Ca^2+ chelating rate. The chelated products exhibited inhibitory effects on hydroxyl radical and super oxide anion radical.%利用木瓜蛋白酶与风味酶组合成的复合酶对鳕鱼皮蛋白进行酶解,制得酶解液,以氯化钙为钙源,与多肽酶解液反应制备多肽螯合钙,并对其抗氧化性进行了研究。结果表明,制备多肽螯合钙的最佳条件是:氯化钙与多肽的质量比为0.3:3,pH值为7.0,反应温度为25℃,反应时间为20min,在此条件下钙离子的螯合率为58.85%,产物对羟自由基(·OH)和超氧阴离子自由基(O2^-·)均有较强的清除作用。

  12. [Anomalies of the masticatory apparatus in beta-thalassemia. The present status after transfusion and iron-chelating therapy].

    Science.gov (United States)

    Scutellari, P N; Orzincolo, C; Andraghetti, D; Gamberini, M R

    1994-04-01

    Fifty-four homozygous beta-thalassemic patients (26 men and 28 women) aged 7 to 24 years, who had been treated with high transfusion regimen (Hb levels = 9-10 g/dl) and chelation therapy (desferrioxamine, 35-50 mg/kg), underwent clinical and radiographic investigations. This study was aimed at assessing the clinical and radiographic changes in the stomatognathic system (teeth, mandible and maxilla, occlusion relationship and dental bases). All patients underwent orthopantomography and teleradiography of the skull, in the lateral view. Twenty thalassemic patients (13 men and 7 women) of the same age but treated with low transfusion regimes (Hb levels = 5-6 g/dl) were examined as a control group. Our results indicate that: 1) in the control group, osteopenia is the specific lesion of anemia, in both the alveolar process and the mandible, following marrow expansion. Consequently, diastema of incisors and several types of malocclusion follow--i.e., overjet, anterior open-bite and crossbite, nearly all of them associated with II dental and skeletal patterns of Angle's classification. 2) In adequately transfused patients, no lesions are observed in 55% of cases, in both the teeth and the facial skeleton. This means that current treatment methods can prevent bone abnormalities, especially if transfusions begin at birth. Nevertheless, osteopenia of the mandible (31.4%) and dental and/or skeletal malocclusions (40.7%) remain in many cases, because of persistent marrow expansion, which usually follows incorrect treatment. 3) General dental diseases--e.g., caries, paradentosis, gingivitis, etc.--affect both populations with the same incidence. PMID:8190919

  13. Antioxidant Enzyme Activity, Iron Content and Lipid Oxidation of Raw and Cooked Meat of Korean Native Chickens and Other Poultry.

    Science.gov (United States)

    Muhlisin; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-05-01

    This study was conducted to observe antioxidant enzyme activity, iron content and lipid oxidation of Korean native chickens and other poultry. The breast and thigh meat of three Korean native chicken breeds including Woorimatdak, Hyunin black and Yeonsan ogye, and three commercial poultry breeds including the broiler, White Leghorn and Pekin duck (Anasplatyrhyncos domesticus) were studied. The analyses of the antioxidant enzymes activity, iron content and lipid oxidation were performed in raw and cooked samples. The activity of catalase (CAT) in the thigh meat was higher than that of the breast meat of three Korean native chickens and the broiler, respectively. The activity of glutathione peroxidase (GPx) in the uncooked thigh meat of three Korean native chickens was higher than that of the breasts. The breast meat of Woorimatdak and Pekin duck had higher superoxide dismutase (SOD) activity than the others, while only the thigh meat of Pekin duck had the highest activity. Cooking inactivated CAT and decreased the activity of GPx and SOD. The thigh meat of Woorimatdak, White Leghorn, Yeonsan ogye and Hyunin black contained more total iron than the breast meat of those breeds. The heme-iron lost during cooking ranged from 3.2% to 14.8%. It is noted that the thigh meat had higher thiobarbituric acid reactive substances values than the breast in all chicken breeds. Though Woorimatdak showed higher antioxidant enzyme activity and lower released-iron percentage among Korean native chickens, no differences were found on lipid oxidation. We confirm that the dark meat of poultry exhibited higher antioxidant enzyme activity and contained more iron than the white meat. PMID:26954148

  14. Antioxidant Enzyme Activity, Iron Content and Lipid Oxidation of Raw and Cooked Meat of Korean Native Chickens and Other Poultry

    Science.gov (United States)

    Muhlisin; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-01-01

    This study was conducted to observe antioxidant enzyme activity, iron content and lipid oxidation of Korean native chickens and other poultry. The breast and thigh meat of three Korean native chicken breeds including Woorimatdak, Hyunin black and Yeonsan ogye, and three commercial poultry breeds including the broiler, White Leghorn and Pekin duck (Anasplatyrhyncos domesticus) were studied. The analyses of the antioxidant enzymes activity, iron content and lipid oxidation were performed in raw and cooked samples. The activity of catalase (CAT) in the thigh meat was higher than that of the breast meat of three Korean native chickens and the broiler, respectively. The activity of glutathione peroxidase (GPx) in the uncooked thigh meat of three Korean native chickens was higher than that of the breasts. The breast meat of Woorimatdak and Pekin duck had higher superoxide dismutase (SOD) activity than the others, while only the thigh meat of Pekin duck had the highest activity. Cooking inactivated CAT and decreased the activity of GPx and SOD. The thigh meat of Woorimatdak, White Leghorn, Yeonsan ogye and Hyunin black contained more total iron than the breast meat of those breeds. The heme-iron lost during cooking ranged from 3.2% to 14.8%. It is noted that the thigh meat had higher thiobarbituric acid reactive substances values than the breast in all chicken breeds. Though Woorimatdak showed higher antioxidant enzyme activity and lower released-iron percentage among Korean native chickens, no differences were found on lipid oxidation. We confirm that the dark meat of poultry exhibited higher antioxidant enzyme activity and contained more iron than the white meat. PMID:26954148

  15. Tratamento da anemia ferropriva com ferro quelato glicinato e crescimento de crianças na primeira infância Treatment of iron deficiency anemia with iron bis-glycinate chelate and growth of young children

    Directory of Open Access Journals (Sweden)

    Luciana Cisoto Ribeiro

    2008-10-01

    Full Text Available OBJETIVO: Avaliar a resposta à suplementação diária com ferro quelato glicinato e seu impacto sobre o crescimento linear. MÉTODOS: Realizou-se um estudo prospectivo com 790 crianças, de 6 a 36 meses, que freqüentavam creches municipais de São Paulo no período de 1999 a 2003. Ao início e ao final do estudo a hemoglobina, o peso corporal e a estatura/comprimento foram coletados. Utilizou-se suplemento contendo ferro quelato glicinato em gotas na dose de 5mg Fe elementar/kg peso/dia, administrado na própria instituição pelo profissional de saúde da creche, por um período de 12 semanas. RESULTADOS: A suplementação resultou em um significante e positivo efeito sobre os níveis de hemoglobina. A resposta ao tratamento foi positiva em 85,3% das crianças, com um aumento médio de 1,6g/dL nos valores de hemoglobina (pOBJECTIVE: The objective of this study was to evaluate response to daily supplementation with iron bis-glycinate chelate and its impact on linear growth. METHODS: A prospective study was done with 790 children aging from 6 to 36 months who attended daycare in São Paulo from 1999 to 2003. Hemoglobin levels, body weight and height/length were determined at the beginning and end of the study. Liquid iron bis-glycinate chelate was administered in a dosage of 5mg of elemental iron/kg of body weight/day given by the health provider of the daycare facility for a period of 12 weeks. RESULTS: Supplementation resulted in a significant, positive effect on the hemoglobin levels of 85.3% of the children with a mean increase of 1.6g/dL (p<0.001. In children aging from 25 to 36 months and in those with lower hemoglobin levels at the beginning of supplementation, there was a significantly higher increase. No gastrointestinal problem or intolerance to the supplement was observed during the intervention period. Supplementation also had an impact on growth and on the height-for-age indicator (z-score in children older than 12 months but

  16. Beliefs about chelation among thalassemia patients

    OpenAIRE

    Trachtenberg Felicia L; Mednick Lauren; Kwiatkowski Janet L; Neufeld Ellis J; Haines Dru; Pakbaz Zahra; Thompson Alexis A; Quinn Charles T; Grady Robert; Sobota Amy; Olivieri Nancy; Horne Robert; Yamashita Robert

    2012-01-01

    Abstract Background Understanding patients’ views about medication is crucial to maximize adherence. Thalassemia is a congenital blood disorder requiring chronic blood transfusions and daily iron chelation therapy. Methods The Beliefs in Medicine Questionnaire (BMQ) was used to assess beliefs in chelation in thalassemia patients from North America and London in the Thalassemia Longitudinal Cohort (TLC) of the Thalassemia Clinical Research Network (TCRN). Chelation adherence was based on patie...

  17. Role of chelates in treatment of cancer

    Directory of Open Access Journals (Sweden)

    Tripathi Laxmi

    2007-01-01

    Full Text Available Chelates are used in cancer as cytotoxic agent, as radioactive agent in imaging studies and in radioimmunotherapy. Various chelates based on ruthenium, copper, zinc, organocobalt, gold, platinum, palladium, cobalt, nickel and iron are reported as cytotoxic agent. Monoclonal antibodies labeled with radioactive metals such as yttrium-90, indium-111 and iodine-131 are used in radioimmunotherapy. This review is an attempt to compile the use of chelates as cytotoxic drugs and in radioimmunotherapy.

  18. Antioxidant potential of water hyacinth (Eichornia crassipes): In vitro antioxidant activity and phenolic composition

    DEFF Research Database (Denmark)

    Surendraraj, A.; Farvin, Sabeena; Anandan, R.

    2013-01-01

    scavenging ability, iron chelating activity, reducing power, and prevention of oxidation in a liposome model system); and (c) its effectiveness in retarding lipid peroxidation in fish oil by accelerated stability test. Significant differences were observed in total and individual phenolic contents and in the...... oil. Our results demonstrate that E. crassipes, an underutilized aquatic weed, could be a potential natural antioxidant source for food, feed, and pharmaceutical applications. © 2013 Copyright Taylor & Francis Group, LLC....

  19. Enhanced antioxidation and electromagnetic properties of Co-coated flaky carbonyl iron particles prepared by electroless plating

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yingying, E-mail: zyzlchappy1989@163.com [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an, Shaanxi 710072 (China); Zhou, Wancheng [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an, Shaanxi 710072 (China); Li, Rong [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an, Shaanxi 710072 (China); No. 603 Faculty, Xi’an Institute of High Technology, Xi’an 710025 (China); Mu, Yang; Qing, Yuchang [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an, Shaanxi 710072 (China)

    2015-07-15

    Highlights: • Co-coated carbonyl iron particles were prepared by electroless plating method. • The obvious weight gain of carbonyl iron was deferred to 400 °C after Co-coated. • The permeability of the Co-coated particle composite kept almost invariable. • Co-coated carbonyl iron composite reserves a better absorption after heat treatment. - Abstract: Co was successfully coated on the surface of flaky carbonyl iron particles using an electroless plating method. The morphologies, composition, as well as magnetic, antioxidation and electromagnetic properties of the samples were characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), vibrating sample magnetometer (VSM), thermogravimetric (TG) and microwave network analyzer. TG curve shows that the obvious weight gain of carbonyl iron was deferred from 300 to 400 °C after Co-coated. In contrast to raw carbonyl iron, the Co-coated carbonyl iron shows better stability on electromagnetic properties after 300 °C heat treatment for 10 h, demonstrating that the Co coating can act as the protection of carbonyl iron.

  20. Purification and antioxidant activities of baicalin isolated from the root of huangqin (Scutellaria baicalensis gcorsi)

    OpenAIRE

    Peng-fei, Liu; Fu-gen, Han; Bin-bin, Duan; Tian-sheng, Deng; Xiang-lin, Hou; Ming-qin, Zhao

    2012-01-01

    Baicalin is a flavonoid from the root of huangqin (Scutellaria baicalensis gcorsi, a kind of Traditional Chinese Medicine and food condiment) with two pro phenolic hydroxyls. In this manuscript, high purity of baicalin (95.5 %) was isolated from the root of huangqin and its antioxidant activities were investigated. The antioxidant properties of baicalin were evaluated by scavenging of the diphenylpicrylhydrazyl radical (DPPH), reducing power, and iron-chelating assays, compared to ascorbic ac...

  1. Deferasirox treatment of iron-overloaded chelation-naïve and prechelated patients with myelodysplastic syndromes in medical practice: results from the observational studies eXtend and eXjange.

    Science.gov (United States)

    Gattermann, Norbert; Jarisch, Andrea; Schlag, Rudolf; Blumenstengel, Klaus; Goebeler, Mariele; Groschek, Matthias; Losem, Christoph; Procaccianti, Maria; Junkes, Alexia; Leismann, Oliver; Germing, Ulrich

    2012-03-01

    EXtend and eXjange were prospective, 1-yr, non-interventional, observational, multicentre studies that investigated deferasirox, a once-daily oral iron chelator, in iron-overloaded chelation-naïve and prechelated patients with myelodysplastic syndromes (MDS), respectively, treated in the daily-routine setting of office-based physicians. No inclusion or exclusion criteria or additional monitoring procedures were applied. Deferasirox was administered as recommended in the European Summary of Product Characteristics. Haematological parameters and adverse events (AEs) were collected at two-monthly intervals. Data from 123 chelation-naïve patients with MDS (mean age 70.4 yrs) with median baseline serum ferritin level of 2679 (range 184-16,500) ng/mL, and 44 prechelated patients with MDS (mean age 69.6 yrs) with median baseline serum ferritin level of 2442 (range 521-8565) ng/mL, were assessed. The mean prescribed daily dose of deferasirox at the first visit was 15.7 and 18.7 mg/kg/d, respectively. Treatment with deferasirox produced a significant reduction in median serum ferritin levels in chelation-naïve patients with MDS from 2679 to 2000 ng/mL (P = 0.0002) and a pronounced decrease in prechelated patients with MDS from 2442 to 2077 ng/mL (P = 0.06). The most common drug-related AEs were gastrointestinal, increased serum creatinine levels and rash. These studies demonstrate that deferasirox used in physicians' medical practices is effective in managing iron burden in transfusion-dependent patients with MDS. PMID:22023452

  2. The efficacy of compounds with different polarities as antioxidant in emulsions with omega-3 lipids

    DEFF Research Database (Denmark)

    Sørensen, Ann-Dorit Moltke; Nielsen, Nina Skall; Decker, Eric A.;

    2011-01-01

    evaluate the efficacy of antioxidants [ascorbic acid, ascorbyl palmitate, ascorbyl CLA and CLA (conjugated linoleic acid)] with different polarities in two different emulsion systems: o/w emulsion (5% oil) and w/o emulsion (98% oil) stabilized with citrem and PGPR, respectively. The efficacy of the...... antioxidants was compared to their partitioning in an o/w emulsion system and to results obtained from different antioxidant assays: iron reducing power, chelating activity and radical scavenging activity. For the w/o emulsions the efficacy of the antioxidants followed the polar paradox hypothesis: ascorbyl...

  3. Overview of current chelation practices

    Directory of Open Access Journals (Sweden)

    Y. Aydinok

    2011-12-01

    Full Text Available Deferoxamine (DFO is reference standard therapy for transfusional iron overload since the 1980s. Although it is a highly effective iron chelator, the compliance problem to subcutaneous administration of DFO remains as the major problem. The oral chelator Deferiprone (DFP has no marketing licence in North America, however, it has been licensed in India since 1994 and the European Union (EU granted marketing approval for DFP in 1999, specifically for patients with thalassemia major when DFO is inadequate, intolerable or unacceptable. There are still limited data available on the use of DFP in children between 6 and 10 years of age, and no data on DFP use in children under 6 years of age. Subsequently the oral chelator Deferasirox (DFX was approved by FDA and EMA for the treatment of patients with transfusional iron overload -older than 2 years of age- as first line therapy, in 2005 and 2006 respectively. The primary objective of iron chelation is to maintain body iron at safe levels at all times but once iron is accumulated, the objective of iron chelation is to reduce tissue iron to safe levels which is a slow process. The chelation regimen, dose and frequency of administration, of the chelator(s are mainly determined based on body iron burden, presence of myocardial iron and the transfusional iron loading rate. A proper monitoring of chelation is of importance for measuring the response rate to a particular regimen and providing dose adjustments to enhance chelation efficacy and to avoid toxicity. Efficacy of a chelation regimen may exhibit individual variability resulting from factors such as absorbtion and metabolism of the chelator. Tolerability and compliance are also individual variables effecting the response to chelation. Understanding of advantages and limitations of chelators, accurately determining chelation needs of patients with iron overload and designing individualized chelation regimens with less toxicity but optimum efficacy

  4. Novel double prodrugs of the iron chelator N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED): Synthesis, characterization, and investigation of activation by chemical hydrolysis and oxidation.

    Science.gov (United States)

    Thiele, Nikki A; Abboud, Khalil A; Sloan, Kenneth B

    2016-08-01

    The development of iron chelators suitable for the chronic treatment of diseases where iron accumulation and subsequent oxidative stress are implicated in disease pathogenesis is an active area of research. The clinical use of the strong chelator N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED) and its alkyl ester prodrugs has been hindered by poor oral bioavailability and lack of conversion to the parent chelator, respectively. Here, we present novel double prodrugs of HBED that have the carboxylate and phenolate donors of HBED masked with carboxylate esters and boronic acids/esters, respectively. These double prodrugs were successfully synthesized as free bases (7a-f) or as dimesylate salts (8a-c,e), and were characterized by (1)H, (13)C, and (11)B NMR; MP; MS; and elemental analysis. The crystal structure of 8a was solved. Three of the double prodrugs (8a-c) were selected for further investigation into their abilities to convert to HBED by stepwise hydrolysis and H2O2 oxidation. The serial hydrolysis of the pinacol and methyl esters of N,N'-bis(2-boronic acid pinacol ester benzyl)ethylenediamine-N,N'-diacetic acid methyl ester dimesylate (8a) was verified by LC-MS. The macro half-lives for the hydrolyses of 8a-c, measured by UV, ranged from 3.8 to 26.3 h at 37 °C in pH 7.5 phosphate buffer containing 50% MeOH. 9, the product of hydrolysis of 8a-c and the intermediate in the conversion pathway, showed little-to-no affinity for iron or copper in UV competition experiments. 9 underwent a serial oxidative deboronation by H2O2 in N-methylmorpholine buffer to generate HBED (k = 10.3 M(-1) min(-1)). The requirement of this second step, oxidation, before conversion to the active chelator is complete may confer site specificity when only localized iron chelation is needed. Overall, these results provide proof of principle for the activation of the double prodrugs by chemical hydrolysis and H2O2 oxidation, and merit further investigation into the

  5. Unsymmetrical Chelation of N-Thioether-Functionalized Bis(diphenylphosphino)amine-Type Ligands and Substituent Effects on the Nuclearity of Iron(II) Complexes: Structures, Magnetism, and Bonding.

    Science.gov (United States)

    Fliedel, Christophe; Rosa, Vitor; Falceto, Andrés; Rosa, Patrick; Alvarez, Santiago; Braunstein, Pierre

    2015-07-01

    Starting from the short-bite ligands N-thioether-functionalized bis(diphenylphosphino)amine-type (Ph2P)2N(CH2)3SMe (1) and (Ph2P)2N(p-C6H4)SMe (2), the Fe(II) complexes [FeCl2(1)]n (3), [FeCl2(2)]2 (4), [Fe(OAc)(1)2]PF6 (5), and [Fe(OAc)(2)2]PF6 (6) were synthesized and characterized by Fourier transform IR, mass spectrometry, elemental analysis, and also by X-ray diffraction for 3, 4, and 6. Complex 3 is a coordination polymer in which 1 acts as a P,P-pseudochelate and a (P,P),S-bridge, whereas 4 has a chlorido-bridged dinuclear structure in which 2 acts only as a P,P-pseudochelate. Since these complexes were obtained under strictly similar synthetic and crystallization conditions, these unexpected differences were ascribed to the different spacer between the nitrogen atom and the −SMe group. In both compounds, one Fe–P bond was found to be unusually long, and a theoretical analysis was performed to unravel the electronic or steric reasons for this difference. Density functional theory calculations were performed for a set of complexes of general formula [FeCl2(SR2){R21PN(R2)P′R23}] (R = H, Me; R1, R2, and R3 = H, Me, Ph), to understand the reasons for the significant deviation of the iron coordination sphere away from tetrahedral as well as from trigonal bipyramidal and the varying degree of unsymmetry of the two Fe–P bonds involving pseudochelating PN(R)P ligands. Electronic factors nicely explain the observed structures, and steric reasons were further ruled out by the structural analysis in the solid-state of the bis-chelated complex 6, which displays usual and equivalent Fe–P bond lengths. Magnetic susceptibility studies were performed to examine how the structural differences between 3 and 4 would affect the interactions between the iron centers, and it was concluded that 3 behaves as an isolated high-spin Fe(II) mononuclear complex, while significant intra- and intermolecular ferromagnetic interactions were evidenced for 4 at low temperatures

  6. Synthesis and characterization of manganese (III), iron (III), zirconium (IV), thorium (IV), oxovanadium (IV) and dioxouranium (VI) chelates of a polymeric Schiff base (PSB)

    International Nuclear Information System (INIS)

    A few symmetrical tetradentate polymeric Schiff base (PSB) chelates of the type [M(PSB)n where M=Mn (III), Fe (III), Zr (IV), oxovanadium (IV), Th (IV), dioxouranium (VI) and PSB is derived from 4, 4'-dihydroxy-3, 3'-dipropylbiphenyl and 1,3- diaminopropane, have been synthesised and characterized by elemental analysis, magnetic moment, IR, electronic spectra and TGA studies. The D.C. electrical conductivity and antimicrobial activities of ligand and the chelates have also been studied. The thermal decomposition of the chelates occurs mainly in two steps. Thermal activation energy has been determined by Broido method. (author)

  7. Phenolipids as antioxidants in emulsified systems

    DEFF Research Database (Denmark)

    Sørensen, Ann-Dorit Moltke; Bayrasy, Christelle; Laguerre, Mickäel;

    Lipid oxidation is a major issue in foods containing LC PUFA and substantial efforts have been made to protect lipids against oxidation. Recent studies carried out with phenolipids (lipophilized phenolics) in emulsified systems have shown that increased lipophilicity did not necessarily lead to an...... antioxidant effect has been shown to be influenced by the specific phenolic compound and the type of emulsion. The overall aim for our work was to evaluate phenolipids with different lipophilicity as antioxidants in emulsified food. In the study presented here caffeic, ferulic and coumaric acid were selected...... along with their corresponding alkyl esters (C4-C20). The methods used to evaluate the antioxidative effect of the different phenolipids were the CAT assay (o/w emulsion), antioxidant assays (DPPH, Iron chelating and reducing power) and partitioning studies. Moreover, the results from the CAT assay on...

  8. Lipid peroxidation, antioxidant enzymes and glutathione levels in human erythrocytes exposed to colloidal iron hydroxide in vitro

    Directory of Open Access Journals (Sweden)

    Ferreira A.L.A.

    1999-01-01

    Full Text Available The free form of the iron ion is one of the strongest oxidizing agents in the cellular environment. The effect of iron at different concentrations (0, 1, 5, 10, 50, and 100 µM Fe3+ on the normal human red blood cell (RBC antioxidant system was evaluated in vitro by measuring total (GSH and oxidized (GSSG glutathione levels, and superoxide dismutase (SOD, catalase, glutathione peroxidase (GSH-Px and reductase (GSH-Rd activities. Membrane lipid peroxidation was assessed by measuring thiobarbituric acid reactive substance (TBARS. The RBC were incubated with colloidal iron hydroxide and phosphate-buffered saline, pH 7.45, at 37oC, for 60 min. For each assay, the results for the control group were: a GSH = 3.52 ± 0.27 µM/g Hb; b GSSG = 0.17 ± 0.03 µM/g Hb; c GSH-Px = 19.60 ± 1.96 IU/g Hb; d GSH-Rd = 3.13 ± 0.17 IU/g Hb; e catalase = 394.9 ± 22.8 IU/g Hb; f SOD = 5981 ± 375 IU/g Hb. The addition of 1 to 100 µM Fe3+ had no effect on the parameters analyzed. No change in TBARS levels was detected at any of the iron concentrations studied. Oxidative stress, measured by GSH kinetics over time, occurs when the RBC are incubated with colloidal iron hydroxide at concentrations higher than 10 µM of Fe3+. Overall, these results show that the intact human RBC is prone to oxidative stress when exposed to Fe3+ and that the RBC has a potent antioxidant system that can minimize the potential damage caused by acute exposure to a colloidal iron hydroxide in vitro.

  9. Relation between iron metabolism and antioxidants enzymes and δ-ALA-D activity in rats experimentally infected by Fasciola hepatica.

    Science.gov (United States)

    Bottari, Nathieli B; Mendes, Ricardo E; Baldissera, Matheus D; Bochi, Guilherme V; Moresco, Rafael N; Leal, Marta L R; Morsch, Vera M; Schetinger, Maria R C; Christ, Ricardo; Gheller, Larissa; Marques, Éder J; Da Silva, Aleksandro S

    2016-06-01

    The aim of this study was to evaluate the iron metabolism in serum, as well as antioxidant enzymes, in addition to the Delta-Aminolevulinic Acid Dehydratase (δ-ALA-D) activity in the liver of rats experimentally infected by Fasciola hepatica. Thirty male adult rats (Wistar) specific pathogen free were divided into four groups: two uninfected group (CTRL 1 and CTRL 2) with five animals each and two infected groups (INF 1 and INF 2) with 10 animals each. Infection was performed orally with 20 metacercariae at day 1. On day 15 (CTRL 1 and INF 1 groups) and 87 PI (CTRL 2 and INF 2 groups) blood and bone marrow were collected and the animals were subsequently euthanized for liver sampling. Blood was allocated in tubes without anticoagulant for serum acquisition to measure iron, transferrin and unsaturated iron binding capacity (UIBC). δ-ALA-D, superoxide dismutase (SOD), and catalase (CAT) activities were measured in the liver. A decrease in iron, transferrin and UIBC levels was observed in all infected animals compared to control groups (P < 0.05). Furthermore, iron accumulation was observed in bone marrow of infected mice. Infected animals showed an increase in δ-ALA-D activity at 87 post-infection (PI) (INF 2) as well as in SOD activity at days 15 (INF 1) and 87 PI (INF 2). On the other hand, CAT activity was reduced in rats infected by F. hepatica during acute and chronic phase of fasciolosis (INF 1 and INF 2 groups), when moderate (acute) and severe necrosis in the liver histopathology were observed. These results may suggest that oxidative damage to tissues along with antioxidant mechanisms might have taken part in fasciolosis pathogenesis and are also involved in iron deficiency associated to changes in δ-ALA-D activity during chronic phase of disease. PMID:26995536

  10. Iron chelation therapy of transfusion-dependent β-thalassemia during pregnancy in the era of novel drugs: is deferasirox toxic?

    Science.gov (United States)

    Diamantidis, Michael D; Neokleous, Nikolaos; Agapidou, Aleka; Vetsiou, Evaggelia; Manafas, Achilles; Fotiou, Paraskevi; Vlachaki, Efthymia

    2016-05-01

    The life expectancy of thalassemic patients has increased, and now approaches that of healthy individuals, thanks to improved treatment regimens. However, pregnancy in women with β-Thalassemia Μajor remains a challenging condition. Recent advances in managing this haemoglobinopathy offer the potential for safe pregnancies with favorable outcome. However, clinical data regarding the use of chelation therapy during pregnancy are limited, and it is unclear whether these agents impose any risk to the developing fetus. Successful pregnancies following unintentional treatment with deferoxamine or deferasirox have rarely been reported. Generally, chelators are not recommended during pregnancy. Regarding the new oral chelators, data on fetotoxicity are lacking. In the present study, we describe the evolution and successful outcome of nine pregnancies in six Greek thalassemic women who received deferasirox inadvertently during early pregnancy, and review the literature regarding fetal anomalies due to chelators. Use of chelation before embarking upon a non-programmed pregnancy remains a difficult and unresolved question. In our study, chelation treatment during pregnancy did not prevent the delivery of healthy children. Nonetheless, the use of deferasirox is contraindicated in pregnant women, based on the product label. Deferasirox should only be used during pregnancy if the potential benefit outweighs the potential fetal risk. PMID:26861970

  11. Mechanisms of the antioxidant activity of a high molecular weight fraction of whey.

    Science.gov (United States)

    Tong, L M; Sasaki, S; McClements, D J; Decker, E A

    2000-05-01

    The antioxidant mechanisms of whey proteins in a Tween 20-stabilized salmon oil-in-water emulsion were investigated. The antioxidant activity of the high molecular weight (HMW) fraction of whey from pasteurized milk was found to increase with concentration, as determined by its ability to inhibit TBARS and lipid peroxide formation. The ability of sulfhydryl-blocked whey to inhibit TBARS formation was reduced 60% compared to the HMW fraction alone at 7 days of storage. HMW fraction was able to scavenge peroxyl radicals, with scavenging decreasing approximately 20% when sulfhydryls were blocked. HMW fraction was able to chelate iron away from the surface of negatively charged BSA-stabilized emulsion droplets, indicating that the whey proteins were able to chelate iron. A better understanding of the mechanisms by which whey proteins inhibit lipid oxidation could increase the use of whey proteins as food antioxidants. PMID:10820045

  12. Effect of supplementation with ferrous sulfate or iron bis-glycinate chelate on ferritin concentration in Mexican schoolchildren: a randomized controlled trial

    OpenAIRE

    Duque, Ximena; Martinez, Homero; Vilchis-Gil, Jenny; Mendoza, Eugenia; Flores-Hernández, Sergio; Morán, Segundo; Navarro, Fabiola; Roque-Evangelista, Victoria; Serrano, Anayeli; Mera, Robertino M.

    2014-01-01

    Background Iron deficiency is one of the most common nutritional deficiencies worldwide. It is more prevalent when iron requirements are increased during pregnancy and during growth spurts of infancy and adolescence. The last stage in the process of iron depletion is characterized by a decrease in hemoglobin concentration, resulting in iron deficiency anemia. Iron deficiency, even before it is clinically identified as anemia, compromises the immune response, physical capacity for work, and in...

  13. Coenzyme Q10 Supplementation Prevents Iron Overload While Improving Glycaemic Control and Antioxidant Protection in Insulin-Resistant Psammomys obesus.

    Science.gov (United States)

    Lazourgui, Mohamed Amine; El-Aoufi, Salima; Labsi, Moussa; Maouche, Boubekeur

    2016-09-01

    This study investigated the anti-diabetic preventive activity of coenzyme Q10 (CoQ10) in a murine model of diet-induced insulin resistance (IR), Psammomys obesus (Po). IR was induced by feeding a standard laboratory diet (SD). CoQ10 oil suspension was orally administered at 10 mg/kg body weight (BW)/day along with SD for 9 months. Anthropometric parameters, namely, total body weight gain (BWG) and the relative weight of white adipose tissue (WAT) were determined. Blood glucose, insulin, quantitative insulin sensitivity check index (QUICKI), total antioxidant status (TAS), iron, malondialdehyde (MDA) and nitrite (NO2 (-)) were evaluated. NO2 (-) level was also assessed in peripheral blood mononuclear cells (PBMCs) culture supernatants. Our results show that CoQ10 supplementation significantly improved blood glucose, insulin, QUICKI, TAS, iron and MDA, but influenced neither NO2 (-) levels nor the anthropometric parameters. These findings support the hypothesis that CoQ10 would exert an anti-diabetic activity by improving both glycaemic control and antioxidant protection. The most marked effect of CoQ10 observed in this study concerns the regulation of iron levels, which may carry significant preventive importance. PMID:26779622

  14. Antioxidant potential of water hyacinth (Eichornia crassipes): In vitro antioxidant activity and phenolic composition

    DEFF Research Database (Denmark)

    Surendraraj, Alagarsamy; Farvin, Sabeena; Anandan, R.

    2011-01-01

    activity, reducing power and prevention of oxidation in a liposome model system) and its effectiveness in retarding lipid peroxidation in fish oil by accelerated stability test. Significant differences were observed in total and individual phenolic content and antioxidant activities of extracts from the......The aims of the present study were (a) to extract and quantify the main phenolic acids and tocopherols from the petiole, leaf and flowers of Eichornia crassipes, (b) to evaluate the antioxidant capacity of the extracts in four in vitro systems (DPPH radical scavenging ability, iron chelating...... highest total phenolic content, were found to have high DPPH radical scavenging activity and reducing power. Ethanolic extracts of leaf were found to have high Fe2+ chelating activity and inhibited lipid peroxidation in liposomes and fish oil. Our results demonstrate that E. crassipes, an underutilized...

  15. LABILE IRON IN CELLS AND BODY FLUIDS . Physiology, Pathology and Pharmacology

    Directory of Open Access Journals (Sweden)

    Zvi Ioav Cabantchik

    2014-03-01

    Full Text Available In living systems iron appears predominantly associated with proteins, but can also be detected in forms referred as labile iron, which denotes the combined redox properties of iron and its amenability to exchange between ligands, including chelators. The labile cell iron (LCI composition varies with metal concentration and substances with chelating groups but also with pH and the redox potential. Although physiologically in the lower µM range, LCI plays a key role in cell iron economy as cross-roads of metabolic pathways. LCI levels are continually regulated by an iron-responsive machinery that balances iron uptake versus deposition into ferritin. However, LCI rises aberrantly in some cell types due to faulty cell utilization pathways or infiltration by pathological iron forms that are found in hemosiderotic plasma. As LCI attains pathological levels, it can catalyze reactive O species (ROS formation that, at particular threshold, can surpass cellular anti-oxidant capacities and seriously damage its constituents. While in normal plasma and interstitial fluids, virtually all iron is securely carried by circulating transferrin (that renders iron essentially non-labile, in systemic iron overload (IO, the total plasma iron binding capacity is often surpassed by a massive iron influx from hyperabsorptive gut or from erythrocyte overburdened spleen and/or liver. As plasma transferrin approaches iron saturation, labile plasma iron (LPI emerges in forms that can infiltrate cells by unregulated routes and raise LCI to toxic levels. Despite the limited knowledge available on LPI speciation in different types and degrees of iron overload, LPI measurements can be and are in fact used for identifying systemic IO and for initiating/adjusting chelation regimens to attain full-day LPI protection. A recent application of labile iron assay is the detection of labile components in iv iron formulations per se as well as in plasma (LPI following parenteral iron

  16. Iron-ascorbate-mediated lipid peroxidation causes epigenetic changes in the antioxidant defense in intestinal epithelial cells: impact on inflammation.

    Directory of Open Access Journals (Sweden)

    Sabrina Yara

    Full Text Available INTRODUCTION: The gastrointestinal tract is frequently exposed to noxious stimuli that may cause oxidative stress, inflammation and injury. Intraluminal pro-oxidants from ingested nutrients especially iron salts and ascorbic acid frequently consumed together, can lead to catalytic formation of oxygen-derived free radicals that ultimately overwhelm the cellular antioxidant defense and lead to cell damage. HYPOTHESIS: Since the mechanisms remain sketchy, efforts have been exerted to evaluate the role of epigenetics in modulating components of endogenous enzymatic antioxidants in the intestine. To this end, Caco-2/15 cells were exposed to the iron-ascorbate oxygen radical-generating system. RESULTS: Fe/Asc induced a significant increase in lipid peroxidation as reflected by the elevated formation of malondialdehyde along with the alteration of antioxidant defense as evidenced by raised superoxide dismutase 2 (SOD2 and diminished glutathione peroxidase (GPx activities and genes. Consequently, there was an up-regulation of inflammatory processes illustrated by the activation of NF-κB transcription factor, the higher production of interleukin-6 and cycloxygenase-2 as well as the decrease of IκB. Assessment of promoter's methylation revealed decreased levels for SOD2 and increased degree for GPx2. On the other hand, pre-incubation of Caco-2/15 cells with 5-Aza-2'-deoxycytidine, a demethylating agent, or Trolox antioxidant normalized the activities of SOD2 and GPx, reduced lipid peroxidation and prevented inflammation. CONCLUSION: Redox and inflammatory modifications in response to Fe/Asc -mediated lipid peroxidation may implicate epigenetic methylation.

  17. Trivalent Iron Chelator with Flavone Moiety: Synthesis and Pharmacological Properties%含黄酮的三价铁配合物合成及其药理性质

    Institute of Scientific and Technical Information of China (English)

    Emel Yildiz; Sadet Karabulut; Neslihan S.Pinar; Yusuf Karatas; Figen Doran

    2010-01-01

    3,3,4,7-四羟基黄酮与1,3-二环己基碳二亚胺在4-二甲胺吡啶存在下反应,得到2,2-双(3,3,4,7-四羟基黄酮)1,3-二环已基碳二亚胺.三价金属离子与上述合成得到的配体螯合.对此四面体结构的双核Fe(Ⅲ)配合物的血液学及病理学数据进行了讨论,同时研究了合成的配体作为螯合剂清除鼠肝胰组织中超载的铁的能力.结果表明作为口服药其作为双齿配体的螫合能力与市售用于治疗地中海贫血的药物"去铁敏"相近.%2,2-bis(3,3,4,7-tetra hydroxyflavone) 1,3-dicyclohexyl carbamine, 3,3,4,7-tetra hydroxyflavone was obtained by the reaction of 3,3,4,7-tetra hydroxyflavone with 1,3-dicyclohexyl carbodiimid in presence of 4-dimethyl amino pyridine. The above obtained ligand can chelate with trivalent metal ion. Hematologic and pathologic data of the dinuclear iron complex with tetrahedral geometry were discussed. The ability of the synthesized ligand as a chelator to remove overloaded iron from rat liver and spleen tissues was studied. The results show that the chelate effect of the ligand as the bidentate is near that of desferrioxamine available in market in oral applications for the treatment of ?thalassemia.

  18. Comparative evaluation of Metal Chelating, Antioxidant and Free Radical Scavenging activity of TROIS and six products commonly used to control pain and inflammation associated with Arthritis

    Directory of Open Access Journals (Sweden)

    NAITHANI V

    2011-12-01

    Full Text Available Arthritis is an inflammation of joints due to infectious, metabolic or constitutional cause usually accompanied with pain, swelling, and stiffness resulting from infection, trauma, degenerative changes, metabolic disturbances, or other causes. Free radicals damage biomolecules, including lipids, proteins and nucleic acids leading to various diseases including but not limited to arthritis. The objective of the study was to investigate and compare the free radical scavenging, metal chelating, DNA repair potential and nitric oxide inhibitory property of Trois (a nano-technology based research product indicated for the treatment of pain and inflammation associated with arthritis and with six commercial brands.

  19. Antioxidant activity of wild plants collected in Beni-Sueif governorate, Upper Egypt.

    Science.gov (United States)

    Abouzid, S; Elshahaat, A; Ali, S; Choudhary, M I

    2008-10-01

    Antioxidant activity of a selection of commonly occurring wild plants growing in Beni-Sueif governorate, Upper Egypt, has been tested. The plants selected are Tamarix nilotica, Ambrosia maritima, Zygophyllum coccenium, Conyza dioscoridis, Chenopodium ambrosioides, and Calotropis procera. The in vitro antioxidant assays used in this study were 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, superoxide anion scavenging activity and iron chelating activity. Extracts prepared from the leaves and flowers of Tamarix nilotica have shown the highest antioxidant activity in the three kinds of assay. PMID:22504722

  20. Exogenous Nitric Oxide Alleviated the Inhibition of Photosynthesis and Antioxidant Enzyme Activities in Iron-Deficient Chinese Cabbage(Brassica chinensis L.)

    Institute of Scientific and Technical Information of China (English)

    DING Fei; WANG Xiu-feng; SHI Qing-hua; WANG Mei-ling; YANG Feng-juan; GAO Qing-hai

    2008-01-01

    The effects of exogenous nitric oxide(NO)on plant growth,chlorophyll contents,photosynthetic and chlorophyll fluorescence parameters as well as lipid peroxidation and activities of antioxidant enzymes were investigated in Chinese cabbage plants exposed to iron(Fe)deficiency.Iron deficiency led to serious chlorosis in Chinese cabbage leaves,and resulted in significant decrease in plant growth,photosynthetic pigments,net photosynthetic rate,Fv/Fm,ΦPsⅡand activities of antioxidant enzymes,and increase in lipid peroxidation.While treatment with SNP,a NO donor,it could revert the iron deficiency symptoms,increased photosynthetic rate as well as activities of antioxidant enzymes,and protected membrane from lipid peroxidation,as a result,the growth inhibition of Chinese cabbage by Fe deficiency was alleviated.

  1. Helicobacter pylori seropositivity's association with markers of iron, 1-carbon metabolism, and antioxidant status among US adults: a structural equations modeling approach.

    Directory of Open Access Journals (Sweden)

    May A Beydoun

    Full Text Available We tested a model in which Helicobacter pylori seropositivity (Hps predicted iron status, which in turn acted as a predictor for markers of 1-C metabolism that were then allowed to predict antioxidant status.National Health and Nutrition Examination Surveys (NHANES 1999-2000 cross-sectional data among adults aged 20-85 y were analyzed (n = 3,055. Markers of Hps, iron status (serum ferritin and transferrin saturation (TS; 1-C metabolism (serum folate (FOLserum, B-12, total homocysteine (tHcy, methylmalonic acid (MMA and antioxidant status (vitamins A and E were entered into a structural equations model (SEM.Predictors of Hps included older age, lower education and income, racial/ethnic groups (lowest among Non-Hispanic Whites, and lifetime cigarette smoking. SEM modeling indicated that Hps had a direct inverse relationship with iron status (combining serum ferritin and TS which in turn was positively related to 1-C metabolites (higher serum folate, B-12 or lower tHcy/MMA that were positively associated with antioxidant status (combining serum vitamins A and E. Another pathway that was found bypassed 1-C metabolites (Hps → Iron_st → Antiox. The sum of all indirect effects from Hps combining both pathways and the other indirect pathways in the model (Hps → Iron_st → OneCarbon; Hps →OneCarbon →Antiox was estimated at β = -0.006±0.003, p<0.05.In sum, of the total effect of H. pylori seropositivity on antioxidant status, two significant indirect pathways through Iron status and 1-Carbon metabolites were found. Randomized controlled trials should be conducted to uncover the concomitant causal effect of H. pylori eradication on improving iron status, folate, B-12 and antioxidant status among H. pylori seropositive individuals.

  2. Iron

    Science.gov (United States)

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  3. Antioxidant Properties of the Extracts of Talinum Triangulare and its Effect on Antioxidant enzymes in Tissue Homogenate of Swiss Albino Rat

    OpenAIRE

    Afolabi, Olakunle Bamikole; Oloyede, Omotade Ibidun

    2014-01-01

    Objectives: This study was designed to put into consideration both the in vitro and in vivo investigations on Talinum triangulare (Tt), an herbaceous perennial plant that is a native of tropical America and one of the most important vegetables in Nigeria. Methods: Total phenolic contents in (mg GAE/100 g), flavonoid contents, the ferric reducing antioxidant properties (FRAP), 2, 2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl free radical scavenging ability (OH-) and iron chelating ability were ...

  4. Malondialdehyde, antioxidant enzymes, and renal tubular functions in children with iron deficiency or iron-deficiency anemia.

    Science.gov (United States)

    Altun, Demet; Kurekci, Ahmet Emin; Gursel, Orhan; Hacıhamdioglu, Duygu Ovunc; Kurt, Ismail; Aydın, Ahmet; Ozcan, Okan

    2014-10-01

    We aimed to investigate the effects of iron deficiency (ID) or iron-deficiency anemia (IDA) on oxidative stress and renal tubular functions before and after treatment of children. A total of 30 children with a diagnosis of IDA constituted the IDA group and 32 children with a diagnosis of ID constituted the ID group. Control group consisted 38 age-matched children. Serum ferritin, soluble transferrin receptor (sTfR), serum, and urinary sodium (Na), potassium (K), calcium (Ca), phosphorus (P), creatinine (Cr), uric acid (UA), urinary N-acetyl-β-D-glucosaminidase (NAG) levels, and intra-erythrocyte malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) levels were measured before and after iron therapy in the IDA and ID groups, whereas it was studied once in the control group. We have divided the study group in groups according to age (infants children 3-9 years, and adolescents 10-15 years). Patients with IDA (infant, adolescent) and ID (infant, children, and adolescent) had a significantly high level of MDA in post-treatment period in comparison to those of healthy control. Patients with IDA (children, adolescent) and ID (infant, children) had a significantly high level of pre-treatment GSH-Px than controls. Post-treatment SOD was lower in IDA (children and adolescent) groups than control and post-treatment CAT was lower in IDA and ID (adolescent) groups than control. These findings show that ferrous sulfate used in the treatment of ID or IDA could lead to oxidative stress; however, a marked deterioration of in proximal renal tubular functions was not seen. PMID:25099508

  5. Antioxidative low molecular weight compounds in marinated herring (Clupea harengus) salt brine

    DEFF Research Database (Denmark)

    Gringer, Nina; Safafar, Hamed; du Mesnildot, Axelle;

    2016-01-01

    This study aimed at unravelling the antioxidative capacity of low molecular weight compounds (LMWC) (peptides, amino acids and phenolic acids) present in salt brines from the marinated herring production. Brines were fractionated into <10 kDa fractions using dialysis and further into 94 fractions...... salt brines contain LMWC holding ABTS-radical scavenging activity, reducing power and iron chelating activity. Generally, a strong correlation between TPC and ABTSradical scavenging was found. In contrast, reducing power and iron chelating activity seemed to be caused by peptides. Protein....../peptide sequencing revealed 1 kDa peptides with the presence of HDFmotif which could be responsible for some of the antioxidant capacity observed in marinated herring salt brine....

  6. Flame atomic absorption spectrometric determination of zinc, nickel, iron and lead in different matrixes after solid phase extraction on sodium dodecyl sulfate (SDS)-coated alumina as their bis (2-hydroxyacetophenone)-1, 3-propanediimine chelates

    International Nuclear Information System (INIS)

    A sensitive and simple solid phase extraction method for the simultaneous determination of trace and toxic metals in food samples has been reported. The method is based on the adsorption of zinc, nickel, iron and lead on sodium dodecyl sulfate (SDS)-coated alumina, which is also chelated with bis (2-hydroxyacetophenone)-1, 3-propanediimine (BHAPN). The retained analyte ions on modified solid phase were eluted using 8 mL of 4 mol L-1 HNO3. The analyte determinations were carried out by flame atomic absorption spectrometry. The influences of some metal ions and anions on the recoveries of understudy analyte ions were investigated. The proposed method has been successfully applied for the evaluation of these trace and toxic metals in some traditional food samples from Iran.

  7. Novel Lipid-Soluble Thiol-Redox Antioxidant and Heavy Metal Chelator, N,N′-bis(2-Mercaptoethyl)Isophthalamide (NBMI) and Phospholipase D-Specific Inhibitor, 5-Fluoro-2-Indolyl Des-Chlorohalopemide (FIPI) Attenuate Mercury-Induced Lipid Signaling Leading to Protection Against Cytotoxicity in Aortic Endothelial Cells

    OpenAIRE

    Secor, Jordan D.; Kotha, Sainath R.; Gurney, Travis O.; Patel, Rishi B.; Kefauver, Nicholas R.; Gupta, Niladri; Morris, Andrew J.; Haley, Boyd E.; Parinandi, Narasimham L.

    2011-01-01

    Here, we investigated thiol-redox-mediated phospholipase D (PLD) signaling as a mechanism of mercury cytotoxicity in mouse aortic endothelial cell (MAEC) in vitro model utilizing the novel lipid-soluble thiol-redox antioxidant and heavy metal chelator, N,N′-bis(2-mercaptoethyl)isophthalamide (NBMI) and the novel PLD-specific inhibitor, 5-fluoro-2-indolyl des-chlorohalopemide (FIPI). Our results demonstrated (i) mercury in the form of mercury(II) chloride, methylmercury, and thimerosal induced...

  8. Dysregulation of Iron Metabolism in Alzheimer's Disease, Parkinson's Disease, and Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Satoru Oshiro

    2011-01-01

    Full Text Available Dysregulation of iron metabolism has been observed in patients with neurodegenerative diseases (NDs. Utilization of several importers and exporters for iron transport in brain cells helps maintain iron homeostasis. Dysregulation of iron homeostasis leads to the production of neurotoxic substances and reactive oxygen species, resulting in iron-induced oxidative stress. In Alzheimer's disease (AD and Parkinson's disease (PD, circumstantial evidence has shown that dysregulation of brain iron homeostasis leads to abnormal iron accumulation. Several genetic studies have revealed mutations in genes associated with increased iron uptake, increased oxidative stress, and an altered inflammatory response in amyotrophic lateral sclerosis (ALS. Here, we review the recent findings on brain iron metabolism in common NDs, such as AD, PD, and ALS. We also summarize the conventional and novel types of iron chelators, which can successfully decrease excess iron accumulation in brain lesions. For example, iron-chelating drugs have neuroprotective effects, preventing neural apoptosis, and activate cellular protective pathways against oxidative stress. Glial cells also protect neurons by secreting antioxidants and antiapoptotic substances. These new findings of experimental and clinical studies may provide a scientific foundation for advances in drug development for NDs.

  9. Chelation in Metal Intoxication

    OpenAIRE

    Flora, Swaran J.S.; Vidhu Pachauri

    2010-01-01

    Chelation therapy is the preferred medical treatment for reducing the toxic effects of metals. Chelating agents are capable of binding to toxic metal ions to form complex structures which are easily excreted from the body removing them from intracellular or extracellular spaces. 2,3-Dimercaprol has long been the mainstay of chelation therapy for lead or arsenic poisoning, however its serious side effects have led researchers to develop less toxic analogues. Hydrophilic chelators like meso-2,3...

  10. Hematological and Immunological Studies on the Effect of Hepatitis B Virus Vaccination in Hepatitis and Non-Hepatitis, Iron Chelating Dependent or Independent Egyptian Thalassemia Patients

    OpenAIRE

    Eman G. Helal*, Ali F.M. El-Sayed**, Noran Abu- Ouf* , Nahla G. Mohamed** and Mona A.M. Ahmed

    2013-01-01

    Background: Regular transfusion in thalassemia major patients increases life expectancy and improves quality of life. Blood transfusion is the main sources for viral transmission to Thalassemia patients. So, detection of viral antigens using more than one technique must be adopted. Iron and its binding proteins have immune regulatory properties and shifting of immune regulatory balance by iron excess or deficiency may produce severe deleterious physiological effects. Thus, the aim of this stu...

  11. Antioxidant Enzymes and Physiological Responses of Safflower (Carthamus tinctorius L. to Iron Application, under Water Deficit Condition

    Directory of Open Access Journals (Sweden)

    Kayvan Fathi AMIRKHIZ

    2015-06-01

    Full Text Available The effect of soil and foliar iron (Fe application on the activity of some antioxidant enzymes and plant metabolites of Carthamus tinctorius L. (IL111, under water stress conditions was tested. The results showed that under drought stress conditions, the activity of ascorbate peroxidase, superoxide dismutase, polyphenol oxidase and catalase enzymes increased with soil application of Fe. In contrast, the activity of peroxidase enzyme under drought conditions increased with foliar application of Fe treatments. In general, leaf total soluble proteins, proline and malondialdehyde amounts were affected by interaction effects of drought stress and Fe. The results showed that leaf total soluble proteins had a positive reaction to soil and foliar applications of Fe. The result of this interaction effects showed that soil application of Fe is able to decrease malondialdehyde amount under water stress conditions. In addition, it was indicated that soil application of Fe in drought stress conditions lead to increasing proline. In conclusion, soil and foliar application of Fe during drought stress may counteract negative effects of such stress and enhance safflower tolerance to drought by increasing some antioxidant enzymes and plant metabolites (organic compounds such as proline and soluble proteins.

  12. Iron

    Science.gov (United States)

    ... seafood, and foods that contain vitamin C , like citrus fruits, strawberries, sweet peppers, tomatoes, and broccoli. What ... diets. What are some effects of iron on health? Scientists are studying iron to understand how it ...

  13. Iron

    DEFF Research Database (Denmark)

    Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T

    2014-01-01

    The interest in the role of ferrous iron in diabetes pathophysiology has been revived by recent evidence of iron as an important determinant of pancreatic islet inflammation and as a biomarker of diabetes risk and mortality. The iron metabolism in the β-cell is complex. Excess free iron is toxic......, but at the same time, iron is required for normal β-cell function and thereby glucose homeostasis. In the pathogenesis of diabetes, iron generates reactive oxygen species (ROS) by participating in the Fenton chemistry, which can induce oxidative damage and apoptosis. The aim of this review is to...... present and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation...

  14. Radiolabeled iron in soybeans: intrinsic labeling and bioavailability of iron to rats from defatted flour

    International Nuclear Information System (INIS)

    Soybeans can be efficiently labeled with radiolabeled iron by supplying the iron via a nutrient culture medium as an iron salt or as a chelate. By using dual labeled iron and EDTA, it was determined that none of the chelator was transported to the shoots with the iron. Therefore, the use of chelated iron as the iron source in the nutrient medium should not affect assessments of bioavailability of iron from plants. Bioavailability (determined from whole-body retention curves of 59Fe in rats) of iron from defatted soy flour was relatively high and addition of vitamin C did not significantly enhance absorption of iron from defatted soy flour

  15. The preparation and antioxidant activity of glucosamine sulfate

    Science.gov (United States)

    Xing, Ronge; Liu, Song; Wang, Lin; Cai, Shengbao; Yu, Huahua; Feng, Jinhua; Li, Pengcheng

    2009-05-01

    Glucosamine sulfate was prepared from glucosamine hydrochloride that was produced by acidic hydrolysis of chitin by ion-exchange method. Optical rotation and elemental analysis characterized the degree of its purity. In addition, the antioxidant potency of chitosan derivative-glucosamine sulfate was investigated in various established in vitro systems, such as superoxide (O{2/-})/hydroxyl (·OH) radicals scavenging, reducing power, iron ion chelating. The following results are obtained: first, glucosamine sulfate had pronounced scavenging effect on superoxide radical. For example the O{2/-} scavenging activity of glucosamine sulfate was 92.11% at 0.8 mg/mL. Second, the ·OH scavenging activity of glucosamine sulfate was also strong, and was about 50% at 3.2 mg/mL. Third, the reducing power of glucosamine sulfate was more pronounced. The reducing power of glucosamine sulfate was 0.643 at 0.75 mg/mL. However, its potency for ferrous ion chelating was weak. Furthermore, except for ferrous ion chelating potency, the scavenging rate of radical and reducing power of glucosamine sulfate were concentration-dependent and increased with their increasing concentrations, but its ferrous ion chelating potency decreased with the increasing concentration. The multiple antioxidant activities of glucosamine sulfate were evidents of reducing power and superoxide/hydroxyl radicals scavenging ability. These in vitro results suggest the possibility that glucosamine sulfate could be used effectively as an ingredient in health or functional food, to alleviate oxidative stress.

  16. Fortification with iron chelate and substitution of sucrose by sucralose in light uvaia sherbet (Eugenia pyriformis Cambess): physical, chemical and sensory characteristics.

    Science.gov (United States)

    Giarola, Tales Márcio de Oliveira; Pereira, Cristina Guimarães; de Resende, Jaime Vilela

    2015-09-01

    In this work, iron fortified light uvaia sherbet, with low sucrose content, was developed and its physical, chemical and sensory characteristics were evaluated. The central composite rotational design (CCRD), applicable to the response surface methodology, was used to analyze the formulations. In the formulations, in addition of iron fortification (9 to 15 mg/100 g), the sucrose was substituted by micronized sucralose in a proportion of 66-94 %. The responses were analyzed with respect to changes in pH, total solids, ash, carbohydrates, proteins, calories, overrun, nucleation and thawing temperatures, rheological parameters and sensory attributes. Protein contents and acidity were similar in all formulations. There was a reduction of over 25 % in the caloric value. The rheological results showed pseudoplastic behavior and significant viscosity differences among the tested sherbets. In the overrun and thawing behavior results the sucrose concentration had a significant influence as the formulations with substitution by 28 g of sucralose/kg of sucrose showed greater air incorporation. In the flavor attribute there was not significance in relation to the iron fortification. Sherbets prepared with substitution of sucrose by sucralose and fortified with iron showed good acceptability, more stability and more resistant to thawing. PMID:26344966

  17. Investigation of the chelation effect on the voltammetric behaviour of selected metals

    International Nuclear Information System (INIS)

    Iron, cadmium, aluminum and chromium could be easily determined by voltammetric methods. The chelation behaviour of chelating agents like hydroxyquinoline, NaDEDC, cupferron etc. have been investigated on the voltammetric behavior of these metals. The results were compared with the spectro fluorimetric investigation of these metal chelates and a relation between voltammetric and fluorimetric behaviour have been established. (author)

  18. Possible different behaviour of 4,4'-(4,4'-biphenylylenebisazo)--di(2-hydroxyacetophenone) in its copper(II), zinc(II), iron(II), iron(III) and dioxouranium(VI) chelates

    International Nuclear Information System (INIS)

    Properties of polychelates are derived by polymerising monomeric symmetric tetra-functioning ligands through metal ion. In an attempt to prepare such polychelates of 4,4'-(4,4'-biphenylylenebisazo)-di(2-hydroxyacetophenone) (L), polychelates for Fe(II) are obtained and Fe(III), Cu(II) give dinuclear chelate of the formula CU2L(NO3)2.(H2O)6, while mononuclear chelates for UO2sup(II) and Znsup(II). In the first case the polychelates have been obtained by polymerisation of L through metal ion in which L is tetra-functioning. In the second case L is tetra-functioning without any further polymerisation while in the last case it is bifunctioning. (author). 12 refs

  19. Pharmacology of Iron Transport

    OpenAIRE

    Byrne, Shaina L.; Krishnamurthy, Divya; Wessling-Resnick, Marianne

    2012-01-01

    Elucidating the molecular basis for the regulation of iron uptake, storage, and distribution is necessary to understand iron homeostasis. Pharmacological tools are emerging to identify and distinguish among different iron transport pathways. Stimulatory or inhibitory small molecules with effects on iron uptake can help characterize the mechanistic elements of iron transport and the roles of the transporters involved in these processes. In particular, iron chelators can serve as potential phar...

  20. The root ferric-chelate reductase of Ceratonia siliqua (L.) and Poncirus trifoliata (L.) Raf. responds differently to a low level of iron

    OpenAIRE

    Pestana, M; Gama, Florinda; Saavedra, Teresa; de Varennes, Amarilis; P.J. Correia

    2012-01-01

    Iron (Fe) deficiency is a common nutritional disorder in several crops grown in calcareous soils, but some species are well adapted to these conditions. A hydroponic experiment was conducted to compare the response of a calcicole species Ceratonia siliqua L. (carob) and of Poncirus trifoliata (L.) Raf., a citrus rootstock very sensitive to Fe deficiency. Rootstocks from both species were grown in nutrient solutions without Fe (0 M Fe), with 1 M Fe, and with 10 M Fe (carob) or 4...

  1. Applied research on domestic MCS chelated iron desulfurization process in Western Sichuan marine sour gas reservoir%国产MCS络合铁脱硫工艺在川西海相含硫气田的应用研究

    Institute of Scientific and Technical Information of China (English)

    姚广聚; 陈海龙; 赵凯; 彭红利

    2015-01-01

    川西海相气藏目前处于勘探开发评价阶段,所开采的天然气中 H2 S摩尔分数为0.7%~5%,需进行单井脱硫试采并开展气藏评价。针对该气藏第一口试采井CK1井MCS国产络合铁脱硫工艺进行了跟踪分析,对现场的环保及硫堵问题进行了脱硫工艺的调整和优化,提出工艺推广建议,计算了装置的运行能耗及运行成本。目前,该井M C S络合铁脱硫装置年操作时间超过8000 h ,日生产硫膏4 t ,累计生产天然气8500×104 m3,与工艺优化前相比,天然气年产量提高约625×104 m3,保证了该井的顺利试采和川西海相气藏的有效评价,可为同类含硫气井试采提供参考。%Western Sichuan marine gas reservoir is in the exploration and development evaluation stage at present .The natural gas contains 0 .7% -5% hydrogen sulfide ,which needs the single well desulfurization test mining and gas reservoir evaluation .The tracking analysis of the first oral produc‐tion well (Chuanke 1) using MCS domestic chelated iron desulfurization process was carried out .Ai‐ming at the environmental protection and sulfur plugging problems ,the desulfurization process was adjusted and optimized ,the suggestions for process popularizing were put forward ,and the operating energy consumption and costs were calculated .Currently the operating time of MCS chelated iron des‐ulfurization unit is over 8 000 h per year ,sulfur ointment production is 4 t/d ,and the cumulative pro‐duction of natural gas is 85 × 106 m3 ,which increase about 6 .25 × 106 m3 per year compared with the annual output of natural gas before optimization .It ensures the successfully test mining of the well and the effective evaluation of Western Sichuan marine gas reservoir ,w hich can provide references for the production test of similar sour gas well .

  2. Macrocyclic bifunctional chelating agents

    Science.gov (United States)

    Meares, Claude F.; DeNardo, Sally J.; Cole, William C.; Mol, Min K.

    1987-01-01

    A copper chelate conjugate which is stable in human serum. The conjugate includes the copper chelate of a cyclic tetraaza di-, tri-, or tetra-acetic acid, a linker attached at one linker end to a ring carbon of the chelate, and a biomolecule joined at the other end of the linker. The conjugate, or the linker-copper chelate compound used in forming the conjugate, are designed for use in diagnostic and therapeutic applications which involve Cu(II) localization via the systemic route.

  3. ANTIOXIDANT MUSHROOMS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Aggarwal Preeti

    2012-06-01

    Full Text Available The antioxidant properties of wild mushrooms have been extensively studied and many antioxidant compounds such as phenolic compounds, tocopherols, ascorbic acid, and carotenoids identified. The various antioxidant mechanisms of the mushroom species extracts may be attributed to strong hydrogen-donating ability, metal-chelating ability, and their effectiveness as good scavengers of superoxide and free radicals. This indicates the potential of mushrooms as panacea for many diseases and also reveals a novel potential to fight against tumors in man.

  4. Antioxidant Enzymes and Physiological Responses of Safflower (Carthamus tinctorius L.) to Iron Application, under Water Deficit Condition

    OpenAIRE

    Kayvan Fathi AMIRKHIZ; Majid Amini DEHAGHI; Siavash HESHMATI

    2015-01-01

    The effect of soil and foliar iron (Fe) application on the activity of some antioxidant enzymes and plant metabolites of Carthamus tinctorius L. (IL111), under water stress conditions was tested. The results showed that under drought stress conditions, the activity of ascorbate peroxidase, superoxide dismutase, polyphenol oxidase and catalase enzymes increased with soil application of Fe. In contrast, the activity of peroxidase enzyme under drought conditions increased with foliar application...

  5. Antioxidant activities and functional properties of protein and peptide fractions isolated from salted herring brine

    DEFF Research Database (Denmark)

    Taheri, Ali; Farvin, Sabeena; Jacobsen, Charlotte;

    2014-01-01

    delay iron catalyzed lipid oxidation in 5% fish oil in water emulsions and the 10–50kDa fraction was the best. These results show the potential of proteins and peptide fractions recovered from waste water from the herring industry as source of natural antioxidants for use in food products....... fractions showed good radical scavenging activity and reducing power at a concentration of 0.5mg protein/ml. All the fractions demonstrated low iron chelating activity and did not inhibit oxidation in a soybean phosphatidylcholine liposome model system. However all the fractions were to some extent able to...

  6. Combination of Antioxidants from Different Sources Could Offer Synergistic Benefits: A Case Study of Tea and Ginger Blend.

    Science.gov (United States)

    Makanjuola, Solomon A; Enujiugha, Victor N; Omoba, Olufunmilayo S; Sanni, David M

    2015-11-01

    Tea and ginger are plants with high antioxidant potential. Combinations of antioxidants from different sources could also produce synergistic antioxidant effects. This study investigated the influence of solvent on antioxidant content of tea, ginger, and tea + ginger blends. Under the investigated extraction conditions, water was the most effective extraction solvent to maximise peroxide scavenging and iron chelating activity of tea, ginger, and their blends. Aqueous ethanol was the most effective solvent to maximise ABTS radical scavenging activity and ethanol was the best solvent to maximise DPPH radical scavenging activity. A good multivariate regression model that explains the relationship between the total flavonoid content of the extracts and their antioxidant activities was obtained (R2 and Q2 of 0.93 and 0.83, respectively). Extracts of tea-ginger blends exhibited synergistic effects in their ABTS and DPPH radical scavenging activity. PMID:26749808

  7. 51例重型β珠蛋白生成障碍性贫血患儿长期输血去铁治疗与铁过载的关系研究%Relationship of long-term blood transfusion, iron chelation therapy with iron overload in 51 children with beta-thalassaemia major

    Institute of Scientific and Technical Information of China (English)

    陈光福; 陈娟娟; 高红英; 龙琦; 富国华

    2012-01-01

    Objective To explore the relationship of long-term blood transfusion, iron chelation therapy with iron overload in the patients with beta-thalassaemia major. Methods The serum ferritin (SF) , liver function, renal function, myocardial enzyme, ultrasonograph of liver and spleen, blood glucose and urine glucose were detected in the patients with beta-thalassaemia major in "Friends of thalassemia" and "Service team for thalassemia in Shenzhen" with regular long-term blood transfusion and iron chelation therapy in three months. Left ventricular ejection fraction (LVEF) , myocardial, liver, pancreas and pituitary MR imaging T2* were performed on 51 patients of them. The51 patients were divided into 3 groups. 10 cases with sufficient dose DFO and sufficient dose DFP iron chelation treatment group (sufficient dose joint group) ; 31 cases with insufficient DFO and DFP iron chelation treatment group (insufficient joint group) ; 10 cases with sufficient dose DFX iron chelation treatment group (DFX group). Results There was no difference in myocardial T2*, pituitary T2*, LVEF in every group. (P > 0.05). Liver T2* in sufficient dose joint group was higher than that in insufficient joint group (P 0.05), and there was moderate negative correlation with liver T2*(r = 0.558,P < 0.01). Conclusion The sufficient dose DFO with DFP treatment, and the DFX treatment can effectively reduce SF, compared with that of insufficient DFO with DFP treatment. All iron chelation therapy can alleviate myocardial iron overload.%目的 探讨重型β珠蛋白生成障碍性贫血(beta-thalassaemia,简称β -TM)患儿长期输血、去铁治疗与铁过载的关系.方法 深圳市第二人民医院2001年成立“地贫之友”与“地贫服务队”,对β-TM患儿进行规范性的长期输血和去铁治疗.每3个月监测血清铁蛋白浓度(SF)、肝肾功能、心肌酶谱、心功能、心脏和肝脾B超、血糖和尿糖.2001年2月至2010年6月对其中51例患儿进

  8. Dysregulation of iron of amyotrophic lateral sclerosis mice and neuroprotective effects of iron chelator%肌萎缩侧索硬化小鼠脊髓铁离子浓度及铁离子螯合剂的神经保护作用

    Institute of Scientific and Technical Information of China (English)

    王倩; 张晓洁; 乐卫东

    2009-01-01

    AIM To observe the change of iron accumulation in spinal cords of amyotrophic lateral sclerosis(ALS)mice and the neuroprotective effects,and mechanism of iron chelators in the mice model. METHODS After iron chelators VK-28 or M3O administration,the onset of morbidity and life span of the transgenic mice was observed,the levels of iron and MDA and the activity of SOD in spinal cords of SOD1- G93A mice and wide type(WT)mice were assessed by using proper kits,and spinal motor neuron and active glias were counted by spectrophotometry. RESULTS The iron levels in spinal cords of SOD1-G93A transgenic mice were significantly increased compared with WT mice at age of 90 d (42%, P < 0.05) and 120 d (82%, P < 0.01). And it was attenuated by iron chelators VK-28 and M30 at the age of 90 d (μg·g~(-1)protein, 1784 ± s 132, 2 103 ± 983 vs. 2 398 ± 243; both P < 0.05) and 120 d (μg·g~(-1) protein, 2 080 ±118, 2 483 ± 134 vs. 3 180 ± 201; both P < 0.01). Compared with the SOD1-G93A control group, VK-28 and M30 significantly delayed the onset of morbidity ((116.2 ± 4.4) d, (110.5 ± 3.7) d vs. (104.5 ± 1.7); both P < 0.05) and extended the survival ((139.3 ± 3.9) d, (134.6 ±2.1) d vs. (126.5 ± 2.2) d; P < 0.01, P < 0.05) , accompanied by a significant reduction of motor neuron loss (P < 0.01). Moreover, the chelators reversed the increased MDA level and the decreased SOD activity (P < 0.05, P < 0.01), and suppressed the activation of microglia (P < 0.01) and astrocytes (P < 0.01). CONCLUSION There were increased iron accumulation in spinal cord of SOD1-G93A transgenic mice. Iron chelators VK-28 and M30 therapy may have neuroprotective potential for ALS by decreasing the levels of iron and oxygen free radicals in the spinal cords.%目的 探讨肌萎缩侧索硬化(ALS)小鼠脊髓中铁离子的异常变化和铁离子螯合剂的神经保护作用及其可能机制.方法 SOD1-G93A转基因小鼠腹腔注射铁离子螯合剂VK-28(5 mg·kg~(-1))及M3O(5 mg

  9. Metal based pharmacologically active agents: Synthesis, structural characterization, molecular modeling, CT-DNA binding studies and in vitro antimicrobial screening of iron(II) bromosalicylidene amino acid chelates

    Science.gov (United States)

    Abdel-Rahman, Laila H.; El-Khatib, Rafat M.; Nassr, Lobna A. E.; Abu-Dief, Ahmed M.; Ismael, Mohamed; Seleem, Amin Abdou

    2014-01-01

    In recent years, great interest has been focused on Fe(II) Schiff base amino acid complexes as cytotoxic and antitumor drugs. Thus a series of new iron(II) complexes based on Schiff bases amino acids ligands have been designed and synthesized from condensation of 5-bromosalicylaldehyde (bs) and α-amino acids (L-alanine (ala), L-phenylalanine (phala), L-aspartic acid (aspa), L-histidine (his) and L-arginine (arg)). The structure of the investigated iron(II) complexes was elucidated using elemental analyses, infrared, ultraviolet-visible, thermogravimetric analysis, as well as conductivity and magnetic susceptibility measurements. Moreover, the stoichiometry and the stability constants of the prepared complexes have been determined spectrophotometrically. The results suggest that 5-bromosalicylaldehyde amino acid Schiff bases (bs:aa) behave as dibasic tridentate ONO ligands and coordinate to Fe(II) in octahedral geometry according to the general formula [Fe(bs:aa)2]ṡnH2O. The conductivity values between 37 and 64 ohm-1 mol-1 cm2 in ethanol imply the presence of nonelectrolyte species. The structure of the complexes was validated using quantum mechanics calculations based on accurate DFT methods. Geometry optimization of the Fe-Schiff base amino acid complexes showed that all complexes had octahedral coordination. In addition, the interaction of these complexes with (CT-DNA) was investigated at pH = 7.2, by using UV-vis absorption, viscosity and agarose gel electrophoresis measurements. Results indicated that the investigated complexes strongly bind to calf thymus DNA via intercalative mode and showed a different DNA binding according to the sequence: bsari > bshi > bsali > bsasi > bsphali. Moreover, the prepared compounds are screened for their in vitro antibacterial and antifungal activity against three types of bacteria, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus and three types of anti fungal cultures, Penicillium purpurogenium, Aspergillus

  10. Ferrocene base metal chelates

    International Nuclear Information System (INIS)

    Review of the works, devoted to different types of ferrocene metal chelates and to a possibility of ferrocene-containing ligand modification by means of complexing, is presented. Structure, properties and spectral characteristics of transitional metal, rare earth element, Cd2+, UO22+, Th4+ etc. complexes with ferrocene diketones, ferrocene acyl derivatives based on thiosemicarbazones and hydrazones and other heterometal ferrocene-containing metal chelates, are considered. 134 refs., 1 tab

  11. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-01-22

    The present application offers a solution to the current problems associated with recovery and recycling of precious metals from scrap material, discard articles, and other items comprising one or more precious metals. The solution is premised on a microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  12. HERBAL ANTIOXIDANTS- A REVIEW

    OpenAIRE

    Swathi K; Priyenka Devi K S*; Sangeetha A

    2016-01-01

    Reactive oxygen species, circulating in the human body tend to react with the electron of other molecules which may initiate the chain reaction and contribute to adverse health effects in the body. Antioxidants possess anti-inflammatory property, antitumor property, anticarcinogenic property, antimutagenic property and metal chelating potential which inturn terminates the chain reaction by arresting free radical intermediates. Natural antioxidants derived from plant sources are effective and ...

  13. Antioxidant activity of yoghurt peptides: Part 1-in vitro assays and evaluation in omega-3 enriched milk

    DEFF Research Database (Denmark)

    Farvin, Sabeena; Baron, Caroline; Nina Skall, Nielsen;

    2010-01-01

    The aim of the present study was to investigate important factors contributing to the high oxidative stability of fish-oil-enriched yoghurt, with particular emphasis on the possible antioxidative effects of peptides released during yoghurt fermentation. Yoghurt samples were stripped from sugars and......, iron-chelating activity, and reducing power. The lower molecular weight fractions were found to be more effective antioxidants than higher molecular weight fractions. The lower molecular fractions were further tested as antioxidants in fish-oil-enriched milk. On the basis of peroxide value, volatiles...... lactic acid and subsequently fractionated by ultrafiltration using membranes with cut off sizes of 30 kDa, 10 kDa and 3 kDa. The fractions were tested for antioxidant activity by investigating the inhibition of oxidation in liposome model system, 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity...

  14. Fixation kinetics of chelated and non-chelated zinc in semi-arid alkaline soils: application to zinc management

    Science.gov (United States)

    Udeigwe, Theophilus K.; Eichmann, Madeleine; Menkiti, Matthew C.

    2016-07-01

    This study was designed to examine the fixation pattern and kinetics of zinc (Zn) in chelated (ethylenediaminetetraacetic acid, EDTA) and non-chelated mixed micronutrient systems of semi-arid alkaline soils from the Southern High Plains, USA. Soils were characterized for a suite of chemical and physical properties and data obtained from extraction experiments fitted to various kinetic models. About 30 % more plant-available Zn was fixed in the non-chelated system within the first 14 days with only about 18 % difference observed between the two systems by day 90, suggesting that the effectiveness of the chelated compounds tended to decrease over time. The strengths of the relationships of change in available Zn with respect to other micronutrients (copper, iron, and manganese) were higher and more significant in the non-chelated system (average R2 of 0.83), compared to the chelated (average R2 of 0.42). Fixation of plant-available Zn was best described by the power-function model (R2 = 0.94, SE = 0.076) in the non-chelated system, and was poorly described by all the models examined in the chelated system. Reaction rate constants and relationships generated from this study can serve as important tools for micronutrient management and for future micronutrient modeling studies on these soils and other semi-arid regions of the world.

  15. Comments on chelation therapy

    International Nuclear Information System (INIS)

    The primary purpose of actinide chelation is to decrease the risk from radiation-induced cancer. While occupational exposures in the past have mainly involved low specific activity 239Pu, future exposures will increasingly involve high specific activity plutonium, americium, and curium - all of which clear more rapidly from the lung. This will tend to shift the cancer risk from lung to bone and liver. Although therapy with Ca- or Zn-DTPA rapidly removes 241Am from the canine, the sub-human primate, and the human liver, improved methods for removal from bone and lung are needed. DTPA can remove 241Am more easily from the growing skeleton of a child than from the mature skeleton of an adult. Investigators at Karlsruhe are developing chelation agents for oral administration and are investigating the reduction in local dose to bone resulting from chelation therapy

  16. Treatment of β-Thalassemia/Hemoglobin E with Antioxidant Cocktails Results in Decreased Oxidative Stress, Increased Hemoglobin Concentration, and Improvement of the Hypercoagulable State

    Directory of Open Access Journals (Sweden)

    Orn-uma Yanpanitch

    2015-01-01

    Full Text Available Studies on the antioxidant treatment for thalassemia have reported variable outcomes. However, treatment of thalassemia with a combination of hydrophobic and hydrophilic antioxidants and an iron chelator has not been studied. This study investigated the effects of antioxidant cocktails for the treatment of β-thalassemia/hemoglobin E (HbE, which is the most common form of β-thalassemia in Southeast Asia. Sixty patients were divided into two groups receiving N-acetylcysteine, deferiprone, and either curcuminoids (CUR or vitamin E (Vit-E, and their hematological parameters, iron load, oxidative stress, and blood coagulation potential were evaluated. Patients were classified as responders if they showed the improvements of the markers of iron load and oxidative stress, otherwise as nonresponders. During treatment, the responders in both groups had significantly decreased iron load, oxidative stress, and coagulation potential and significantly increased antioxidant capacity and hemoglobin concentration. The significantly maximum increase (P<0.01 in hemoglobin concentration was 11% at month 4 in CUR group responders and 10% at month 10 in Vit-E group responders. In conclusion, the two antioxidant cocktails can improve anemia, iron overload, oxidative stress, and hypercoagulable state in β-thalassemia/HbE.

  17. MRI marrow observations in thalassemia: the effects of the primary disease, transfusional therapy, and chelation

    International Nuclear Information System (INIS)

    The magnetic resonance bone marrow patterns in thalassemia were evaluated to determine changes produced by transfusion and chelation therapy. Thirteen patients had T1- and T2-weighted images of the spine, pelvis and femurs. Three received no therapy (age range 2.5-3 years). Three were ''hypertransfused'' (transfused to maintain a hemoglobin greater than 10 g/dl) and not chelated because of age (age range 6 months-8 years). Seven were ''hypertransfused'' and chelated (age range 12-35 years). Signal characteristics of marrow were compared with those of surrounding muscle and fat. Fatty marrow (isointense with subcutaneous fat) was compared with red marrow (hypointense to fat and slightly hyperintense to muscle). Marrow hypointense to muscle was identified as iron deposition within red marrow. The untreated group demonstrated signal consistent with red marrow throughout the central and peripheral skeleton. Hypertransfused but not chelated patients demonstrated marked iron deposition in the central and peripheral skeleton. Hypertransfused and chelated patients demonstrated iron deposition in the central skeleton and a mixed appearance of marrow in the peripheral skeleton. The MR appearance of marrow in thalassemia is a reflection of the patient's transfusion and chelation therapy. Iron deposition occurs despite chelation therapy in sites of active red marrow. As red marrow retreats centrally with age, so does the pattern of iron deposition. The long-term biological effects of this iron deposition are unknown. (orig.). With 8 figs., 1 tab

  18. Metal chelation, radical scavenging and inhibition of Aβ₄₂ fibrillation by food constituents in relation to Alzheimer's disease.

    Science.gov (United States)

    Chan, Stephen; Kantham, Srinivas; Rao, Venkatesan M; Palanivelu, Manoj Kumar; Pham, Hoang L; Shaw, P Nicholas; McGeary, Ross P; Ross, Benjamin P

    2016-05-15

    Various food constituents have been proposed as disease-modifying agents for Alzheimer's disease (AD), due to epidemiological evidence of their beneficial effects, and for their ability to ameliorate factors linked to AD pathogenesis, namely by: chelating iron, copper and zinc; scavenging reactive oxygen species; and suppressing the fibrillation of amyloid-beta peptide (Aβ). In this study, nine different food constituents (l-ascorbic acid, caffeic acid, caffeine, curcumin, (-)-epigallocatechin gallate (EGCG), gallic acid, propyl gallate, resveratrol, and α-tocopherol) were investigated for their effects on the above factors, using metal chelation assays, antioxidant assays, and assays of Aβ42 fibrillation. An assay method was developed using 5-Br-PAPS to examine the complexation of Zn(II) and Cu(II). EGCG, gallic acid, and curcumin were identified as a multifunctional compounds, however their poor brain uptake might limit their therapeutic effects. The antioxidants l-ascorbic acid and α-tocopherol, with better brain uptake, deserve further investigation for specifically addressing oxidative stress within the AD brain. PMID:26775960

  19. Rapid reductive degradation of aqueous p-nitrophenol using nanoscale zero-valent iron particles immobilized on mesoporous silica with enhanced antioxidation effect

    International Nuclear Information System (INIS)

    Highlights: • Nanoscale zero-valent iron (nZVI) was doped in mesoporous silica (SBA-15). • High capacity and fast rate for the removal of p-nitrophenol. • Better antioxidant ability of nZVI/SBA-15 than nZVI. • p-Nitrophenol removal depended heavily on immobilized nZVI amount. • Mechanism of PNP removal by nZVI/SBA-15 was proposed. - Abstract: In this study, nanoscale zero-valent iron particles immobilized on mesoporous silica (nZVI/SBA-15) were successfully prepared for effective degradation of p-nitrophenol (PNP). The nZVI/SBA-15 composites were characterized by N2 adsorption/desorption, transmission electron microscopy (TEM), UV–vis spectrum and X-ray photoelectron spectroscopy (XPS). Results showed that abundant ultrasmall nanoscale zero-valent iron particles were formed and well dispersed on mesoporous silica (SBA-15). Batch experiments revealed that PNP removal declined from 96.70% to 16.14% as solution pH increased from 3.0 to 9.0. Besides, degradation equilibrium was reached within 5 min, which was independent of initial PNP concentration. Furthermore, only a little PNP elimination on SBA-15 indicated that nZVI immobilized on mesoporous silica was mainly responsible for the target contaminant removal. The UV–vis spectrum and XPS measurement confirmed that the PNP removal was a reductive degradation process, which was further proved by the detected intermediates using gas chromatography–mass spectrometry (GC/MS). The excellent antioxidation ability had been discovered with more than 80% of PNP being removed by nZVI/SBA-15 treated with 30 days’ exposure to air. These results demonstrated the feasible and potential application of nZVI/SBA-15 composites in organic wastewater treatment

  20. Rapid reductive degradation of aqueous p-nitrophenol using nanoscale zero-valent iron particles immobilized on mesoporous silica with enhanced antioxidation effect

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lin, E-mail: tanglin@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Tang, Jing [College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Zeng, Guangming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Yang, Guide; Xie, Xia; Zhou, Yaoyu [College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Pang, Ya [Department of Biological Engineering and Environmental Science, Changsha College, Changsha 410003 (China); Fang, Yan; Wang, Jiajia [College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Xiong, Weiping [College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082 (China)

    2015-04-01

    Highlights: • Nanoscale zero-valent iron (nZVI) was doped in mesoporous silica (SBA-15). • High capacity and fast rate for the removal of p-nitrophenol. • Better antioxidant ability of nZVI/SBA-15 than nZVI. • p-Nitrophenol removal depended heavily on immobilized nZVI amount. • Mechanism of PNP removal by nZVI/SBA-15 was proposed. - Abstract: In this study, nanoscale zero-valent iron particles immobilized on mesoporous silica (nZVI/SBA-15) were successfully prepared for effective degradation of p-nitrophenol (PNP). The nZVI/SBA-15 composites were characterized by N{sub 2} adsorption/desorption, transmission electron microscopy (TEM), UV–vis spectrum and X-ray photoelectron spectroscopy (XPS). Results showed that abundant ultrasmall nanoscale zero-valent iron particles were formed and well dispersed on mesoporous silica (SBA-15). Batch experiments revealed that PNP removal declined from 96.70% to 16.14% as solution pH increased from 3.0 to 9.0. Besides, degradation equilibrium was reached within 5 min, which was independent of initial PNP concentration. Furthermore, only a little PNP elimination on SBA-15 indicated that nZVI immobilized on mesoporous silica was mainly responsible for the target contaminant removal. The UV–vis spectrum and XPS measurement confirmed that the PNP removal was a reductive degradation process, which was further proved by the detected intermediates using gas chromatography–mass spectrometry (GC/MS). The excellent antioxidation ability had been discovered with more than 80% of PNP being removed by nZVI/SBA-15 treated with 30 days’ exposure to air. These results demonstrated the feasible and potential application of nZVI/SBA-15 composites in organic wastewater treatment.

  1. Chelation Therapy for Mercury Poisoning

    OpenAIRE

    Rong Guan; Han Dai

    2009-01-01

    Chelation therapy has been the major treatment for heavy metal poisoning. Various chelating agents have been developed and tested for treatment of heavy metal intoxications, including mercury poisoning. It has been clearly shown that chelating agents could rescue the toxicity caused by heavy metal intoxication, but the potential preventive role of chelating agents against heavy metal poisoning has not been explored much. Recent paper by Siddiqi and colleagues has suggested a protective role o...

  2. Efficient solvent extraction of antioxidant-rich extract from a tropical diatom,Chaetoceros calcitrans (Paulsen) Takano 1968简

    Institute of Scientific and Technical Information of China (English)

    Su; Chern; Foo; Fatimah; Md.Yusoff; Maznah; Ismail; Mahiran; Basri; Nicholas; Mun; Hoe; Khong; Kim; Wei; Chan; Sook; Kun; Yau

    2015-01-01

    Objective: To compare the in vitro antioxidant capacity of a diatom, Chaetoceros calcitrans(C. calcitrans) extracted using six types of solvents.Methods: Each extract was evaluated in terms of extraction yield, total carotenoid,fucoxanthin content, total phenolic and antioxidant capacities(DPPH and ABTS +scavenging activity and iron chelating activity).Results: The methanol extract exhibited the highest yield [(22.71 ± 0.96) g/100 g dry weight(DW)], total carotenoid [(4.46 ± 0.36) mg/g DW], total phenolic [(2.49 ± 0.08) mg gallic acid equivalents/g DW] and second highest fucoxanthin content [(2.08 ± 0.03) mg fucoxanthin/g DW] as compared to other solvent extracts. Methanolic extract also exhibited significantly higher(P < 0.05) scavenging(DPPH, ABTS +) and iron chelating activities.Conclusions: Methanol was the recommended solvent for the production of antioxidant rich extract from C. calcitrans. Both carotenoids and phenolic acids were found to be positively correlated to the antioxidant capacities of C. calcitrans. Lead bioactives confirmed by subsequent high performance liquid chromatography studies were fucoxanthin, gallic acid and protocatechuic acid.

  3. Iron Therapy for Preterm Infants

    OpenAIRE

    Rao, Raghavendra; Georgieff, Michael K.

    2009-01-01

    Preterm infants are at risk for both iron deficiency and iron overload. The role of iron in multiple organ functions suggests that iron supplementation is essential for the preterm infant. Conversely, the potential for iron overload and the poorly developed anti-oxidant measures in the preterm infant argues against indiscriminate iron supplementation in this population. The purpose of this article is to review the predisposing factors and consequences of iron deficiency and iron overload in t...

  4. MULTIDENTATE TEREPHTHALAMIDATE AND HYDROXYPYRIDONATE LIGANDS: TOWARDS NEW ORALLY ACTIVE CHELATORS

    Energy Technology Data Exchange (ETDEWEB)

    Abergel, Rebecca J.; Raymond, Kenneth N.

    2011-07-13

    The limitations of current therapies for the treatment of iron overload or radioisotope contamination have stimulated efforts to develop new orally bioavailable iron and actinide chelators. Siderophore-inspired tetradentate, hexadentate and octadentate terephthalamidate and hydroxypyridonate ligands were evaluated in vivo as selective and efficacious iron or actinide chelating agents, with several metal loading and ligand assessment procedures, using {sup 59}Fe, {sup 238}Pu, and {sup 241}Am as radioactive tracers. The compounds presented in this study were compared to commercially available therapeutic sequestering agents [deferoxamine (DFO) for iron and diethylenetriaminepentaacetic acid (DPTA) for actinides] and are unrivaled in terms of affinity, selectivity and decorporation efficacy, which attests to the fact that high metal affinity may overcome the low bioavailability properties commonly associated to multidenticity.

  5. Multidentate Terephthalamidate And Hydroxypyridonate Ligands: Towards New Orally Active Chelators

    International Nuclear Information System (INIS)

    The limitations of current therapies for the treatment of iron overload or radioisotope contamination have stimulated efforts to develop new orally bioavailable iron and actinide chelators. Siderophore-inspired tetradentate, hexadentate and octadentate terephthalamidate and hydroxypyridonate ligands were evaluated in vivo as selective and efficacious iron or actinide chelating agents, with several metal loading and ligand assessment procedures, using 59Fe, 238Pu, and 241Am as radioactive tracers. The compounds presented in this study were compared to commercially available therapeutic sequestering agents (deferoxamine (DFO) for iron and diethylenetriaminepentaacetic acid (DPTA) for actinides) and are unrivaled in terms of affinity, selectivity and decorporation efficacy, which attests to the fact that high metal affinity may overcome the low bioavailability properties commonly associated to multidenticity.

  6. Phenolic Compounds of Cereals and Their Antioxidant Capacity.

    Science.gov (United States)

    Van Hung, Pham

    2016-01-01

    Phenolic compounds play an important role in health benefits because of their highly antioxidant capacity. In this review, total phenolic contents (TPCs), phenolic acid profile and antioxidant capacity of the extracted from wheat, corn, rice, barley, sorghum, rye, oat, and millet, which have been recently reported, are summarized. The review shows clearly that cereals contain a number of phytochemicals including phenolics, flavonoids, anthocyanins, etc. The phytochemicals of cereals significantly exhibit antioxidant activity as measured by trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging, reducing power, oxygen radical absorbance capacity (ORAC), inhibition of oxidation of human low-density lipoprotein (LDL) cholesterol and DNA, Rancimat, inhibition of photochemilumenescence (PCL), and iron(II) chelation activity. Thus, the consumption of whole grains is considered to have significantly health benefits in prevention from chronic diseases such as cardiovascular disease, diabetes, and cancer because of the contribution of phenolic compounds existed. In addition, the extracts from cereal brans are considered to be used as a source of natural antioxidants. PMID:25075608

  7. Combinational chelation therapy abrogates lead-induced neurodegeneration in rats

    International Nuclear Information System (INIS)

    Lead, a ubiquitous and potent neurotoxicant causes oxidative stress which leads to numerous neurobehavioral and physiological alterations. The ability of lead to bind sulfhydryl groups or compete with calcium could be one of the reasons for its debilitating effects. In the present study, we addressed: i) if chelation therapy could circumvent the altered oxidative stress and prevent neuronal apoptosis in chronic lead-intoxicated rats, ii) whether chelation therapy could reverse biochemical and behavioral changes, and iii) if mono or combinational therapy with captopril (an antioxidant) and thiol chelating agents (DMSA/MiADMSA) is more effective than individual thiol chelator in lead-exposed rats. Results indicated that lead caused a significant increase in reactive oxygen species, nitric oxide, and intracellular free calcium levels along with altered behavioral abnormalities in locomotor activity, exploratory behavior, learning, and memory that were supported by changes in neurotransmitter levels. A fall in membrane potential, release of cytochrome c, and DNA damage indicated mitochondrial-dependent apoptosis. Most of these alterations showed significant recovery following combined therapy with captopril with MiADMSA and to a smaller extend with captopril + DMSA over monotherapy with these chelators. It could be concluded from our present results that co-administration of a potent antioxidant (like captopril) might be a better treatment protocol than monotherapy to counter lead-induced oxidative stress. The major highlight of the work is an interesting experimental evidence of the efficacy of combinational therapy using an antioxidant with a thiol chelator in reversing neurological dystrophy caused due to chronic lead exposure in rats.

  8. Iron load

    Directory of Open Access Journals (Sweden)

    Filippo Cassarà

    2013-03-01

    Full Text Available Recent research addressed the main role of hepcidin in the regulation of iron metabolism. However, while this mechanism could be relevant in causing iron load in Thalassemia Intermedia and Sickle-Cell Anemia, its role in Thalassemia Major (TM is marginal. This is mainly due to the high impact of transfusional requirement into the severe increase of body iron. Moreover, the damage of iron load may be worsened by infections, as HCV hepatitis, or liver and endocrinological damage. One of the most relevant associations was found between splenectomy and increase of risk for mortality due,probably, to more severe iron load. These issues suggest as morbidity and mortality of this group of patients they do not depend only by our ability in controlling heart damage but even in preventing or treating particular infections and complications. This finding is supported by the impairment of survival curves in patients with complications different from heart damage. However, because, during recent years different direct and indirect methods to detect iron overload in patients affected by secondary hemochromatosis have been implemented, our ability to maintain under control iron load is significantly improved. Anyway, the future in iron load management remains to be able to have an iron load map of our body for targeting chelation and other medical treatment according to the single organ damage.

  9. A Copper Chelate of Thiosemicarbazone NSC 689534 induces Oxidative/ER Stress and Inhibits Tumor Growth In Vitro and In Vivo

    Science.gov (United States)

    Hancock, Chad N.; Stockwin, Luke H.; Han, Bingnan; Divelbiss, Raymond D.; Jun, Jung Ho; Malhotra, Sanjay V.; Hollingshead, Melinda G.; Newton, Dianne L.

    2010-01-01

    In this study, a Cu2+ chelate of the novel thiosemicarbazone NSC 689534 was evaluated for in vitro and in vivo anti-cancer activity. Results demonstrated that NSC 689534 activity (low µM range) was enhanced 4–5 fold by copper chelation and completely attenuated by iron. Importantly, once formed, the NSC 689534/Cu2+ complex retained activity in the presence of additional iron or iron-containing biomolecules. NSC 689534/Cu2+ mediated its effects primarily through the induction of ROS, with depletion of cellular glutathione and protein thiols. Pre-treatment of cells with the antioxidant L-NAC impaired activity, whereas NSC 689534/Cu2+ effectively synergized with the glutathione biosynthesis inhibitor, buthionine sulphoximine. Microarray analysis of NSC 689534/Cu2+-treated cells highlighted activation of pathways involved in oxidative and ER-stress/UPR, autophagy and metal metabolism. Further scrutiny of the role of ER-stress and autophagy indicated that NSC 689534/Cu2+ -induced cell death was ER-stress dependent and autophagy-independent. Lastly, NSC 689534/Cu2+ was shown to have activity in an HL60 xenograft model. These data suggest that NSC 689534/Cu2+ is a potent oxidative stress inducer worthy of further preclinical investigation. PMID:20971185

  10. A joint application of spectroscopic, electrochemical and theoretical approaches in evaluation of the radical scavenging activity of 3-OH flavones and their iron complexes towards different radical species.

    Science.gov (United States)

    Dimitrić Marković, Jasmina M; Marković, Zoran S; Pašti, Igor A; Brdarić, Tanja P; Popović-Bijelić, Ana; Mojović, Miloš

    2012-06-28

    Combined spectroscopic (UV/visible, MS and EPR), electrochemical (CV) and theoretical approaches were used to evaluate the relevant interactions of morin and quercetin, as well as their respective iron(III) complexes with DPPH, tempone, hydroxyl and superoxide radicals. The results on iron complexation specify the stoichiometry and the relevant structural forms entering the chelation of the molecules. The spectroscopic DPPH assay shows better antioxidant activity of quercetin and its iron complex both in terms of EC(50) values and stoichiometry. The results of 2-deoxyribose degradation suggest that antioxidant activities of morin and quercetin may originate from their combined effect of iron chelation and radical scavenging. The distinctive difference in the EPR spectra of morin and quercetin radicals suggests different positions of the radical centers which may account for different sequences of their activities towards investigated radicals. Activity ranking of quercetin and morin, established by cyclic voltammetry, confirms their activity sequence obtained by EPR results and is also in agreement with the results of conformational analysis. The equilibrium geometries, optimized with the M052X functionals and 6-311G(d,p) basis set, predict structural modifications between the ligand molecules in the free state and in the complex structures. The arguments gained through experimental results can also be rationalized in terms of overall molecular geometry and structural features governing antioxidant behavior i.e. substitution pattern of the ring B. PMID:22576733

  11. Reactive polymers: part I - Novel polystyrene-anchored copper (II), nickel (II), cobalt (II), iron (III), zinc (II), cadmium (II), molybdenum (VI) and uranium (VI) complexes of the chelating resin containing thiosemicarbazone

    International Nuclear Information System (INIS)

    A new chelating resin containing thiosemicarbazone has been synthesized by the reaction of aldehydopolystyrene and thiosemicarbazide. The polystyrene bound thiosemicarbazone reacts with salicylaldehyde leading to the formation of a new Schiff base chelating resin which reacts with sodium monochloroacetate and gives the polymer bound S-acetatothiosemicarbazone. The new chelating resin forms complexes of the types PS-LCuX·S, PS-LNiX·3S, PS-LHNi(acac)2, PS-LCoX·3S, PS-LFeX2·2S, PS-LZnX·S, PS-LCdX·S, PS-LMoO2(acac) and PS-LUO2X·S (where PS-LH = polymeranchored ligand; S = DMF or CH3OH; X=Cl or CH3COO- and acacH = acetylacetone). The chelating resins and complexes have been characterized by elemental analysis, IR and electronic spectra and magnetic measurements. The Cu(II), Ni(II), Co(II), and Fe(III) complexes are paramagnetic while the Zn(II), Cd(II), Mo(VI) and U(VI) complexes are diamagnetic. The IR data indicate the thioenolization of the ligand in the complexes (except in PS-LHNi(acac)2 where it behaves as a neutral bidentate ligand). (author). 24 refs., 2 tabs

  12. Chelated minerals for poultry

    Directory of Open Access Journals (Sweden)

    SL Vieira

    2008-06-01

    Full Text Available Organic minerals have been subject of an increasing number of investigations recently. These compounds can be considered the most significant event regarding commercial forms of minerals targeting animal supplementation in the last decades. Minerals, especially metals, are usually supplemented in poultry feeds using cheap saline sources and have never required a lot of attention in terms of quality. On the other hand, definitions of organic minerals are very broad and frequently lead to confusion when decision-making becomes necessary. Organic minerals include any mineral bound to organic compounds, regardless of the type of existing bond between mineral and organic molecules. Proteins and carbohydrates are the most frequent candidates in organic mineral combinations. Organic fraction size and bond type are not limitations in organic mineral definition; however, essential metals (Cu, Fe, Zn, and Mn can form coordinated bonds, which are stable in intestinal lumen. Metals bound to organic ligands by coordinated bonds can dissociate within animal metabolism whereas real covalent bonds cannot. Chelated minerals are molecules that have a metal bound to an organic ligand through coordinated bonds; but many organic minerals are not chelates or are not even bound through coordinated bonds. Utilization of organic minerals is largely dependent on the ligand; therefore, amino acids and other small molecules with facilitated access to the enterocyte are supposed to be better utilized by animals. Organic minerals with ligands presenting long chains may require digestion prior to absorption. After absorption, organic minerals may present physiological effects, which improve specific metabolic responses, such as the immune response. Many studies have demonstrated the benefits of metal-amino acid chelates on animal metabolism, but the detection positive effects on live performance is less consistent.

  13. Nucleobase-based barbiturates: their protective effect against DNA damage induced by bleomycin-iron, antioxidant, and lymphocyte transformation assay.

    Science.gov (United States)

    Dhorajiya, Bhaveshkumar D; Dholakiya, Bharatkumar Z; Ibrahim, Ahmed S; Badria, Farid A

    2014-01-01

    A number of nucleobase-based barbiturates have been synthesized by combination of nucleic acid bases and heterocyclic amines and barbituric acid derivatives through green and efficient multicomponent route and one pot reaction. This approach was accomplished efficiently using aqueous medium to give the corresponding products in high yield. The newly synthesized compounds were characterized by spectral analysis (FT-IR, (1)H NMR, (13)C NMR, HMBC, and UV spectroscopy) and elemental analysis. Representative of all synthesized compounds was tested and evaluated for antioxidant, bleomycin-dependent DNA damage, and Lymphocyte Transformation studies. Compounds TBC > TBA > TBG showed highest lymphocyte transformation assay, TBC > TBA > BG showed inhibitory antioxidant activity using ABTS methods, and TBC > BPA > BAMT > TBA > 1, 3 -TBA manifested the best protective effect against DNA damage induced by bleomycin. PMID:24900997

  14. Improvement of Oxidative and Metabolic Parameters by Cellfood Administration in Patients Affected by Neurodegenerative Diseases on Chelation Treatment

    OpenAIRE

    Alessandro Fulgenzi; Rachele De Giuseppe; Fabrizia Bamonti; Maria Elena Ferrero

    2014-01-01

    Objective. This prospective pilot study aimed at evaluating the effects of therapy with antioxidant compounds (Cellfood, and other antioxidants) on patients affected by neurodegenerative diseases (ND), who displayed toxic metal burden and were subjected to chelation treatment with the chelating agent calcium disodium ethylenediaminetetraacetic acid (CaNa2EDTA or EDTA). Methods. Two groups of subjects were studied: (a) 39 patients affected by ND and (b) 11 subjects unaffected by ND (controls)....

  15. Examining the fixation kinetics of chelated and non-chelated copper and the applications to micronutrient management in semiarid alkaline soils

    Science.gov (United States)

    Udeigwe, T. K.; Eichmann, M. B.; Menkiti, M. C.; Kusi, N. Y. O.

    2016-02-01

    This study examined and compared the fixation and fixation kinetics of copper (Cu) in chelated (ethylene diamine tetraacetic acid, EDTA) and non-chelated mixed systems of micronutrients in the semiarid soils of the Southern High Plains, USA, using findings from Cu extraction studies and kinetic models. Approximately, 22 % more Cu was fixed in the non-chelated system compared to the chelated within the first 14 days with only 7 % difference between the two systems by day 90. Findings suggest a decrease in the effectiveness of chelated micronutrients over time, highlighting the significance of timing even when chelated micronutrients are used. The strengths of the relationship of change in available Cu with respect to other micronutrients (iron (Fe), manganese (Mn), and zinc (Zn)) were higher in the non-chelated system (R2: 0.68-0.94), compared to the chelated (R2: 0.42-0.81), with slopes of 0.40 (Cu-Fe), 0.31 (Cu-Mn), and 1.04 (Cu-Zn) in the non-chelated system and 0.26 (Cu-Fe), 0.22 (Cu-Mn), and 0.90 (Cu-Zn) in the chelated system. Reduction in the amount of available Cu was best described by the power function model (R2 = 0.91, SE = 0.081) in the non-chelated system and second-order model (R2 = 0.95, SE = 0.010) in the chelated system. The applications generated from this study could be used as tools for improved micronutrient management and also provide baseline data for future work in other semiarid/arid alkaline soils of the world. Findings are also more applicable to field settings, an improvement over related previous studies.

  16. Antioxidant and anti-inflammatory activities of selected medicinal plants and fungi containing phenolic and flavonoid compounds

    Directory of Open Access Journals (Sweden)

    Diaz Patricia

    2012-11-01

    Full Text Available Abstract Background This study aims to determine the relationship between the antioxidant and anti-inflammatory activities of the thirteen herbs and two fungi extracts, and their total phenolic and flavonoid contents. Methods Antioxidant activities were evaluated by four assays: an antioxidant activity assay using Saccharomyces cerevisiae, a DPPH ((2, 2-diphenyl-1-picrylhydrazyl assay to assess free radical scavenging, an assay assessing ferrous ions or iron (II chelating ability, and a ferric reducing antioxidant power (FRAP assay. Total phenolic and flavonoid contents were determined using the Folin-Ciocalteu and aluminium chloride methods, respectively. Anti-inflammatory activities were determined by measuring the inhibition of nitric oxide and TNF-α production in lipopolysaccharide- and interferon-γ-activated J774A.1 macrophages. Their cytotoxicities against macrophages were determined by MTT assay. Results A positive linear correlation between antioxidant activities and the total phenolic and flavonoid content of the plant extracts was found. The plant extracts with high phenolic and flavonoid content also exhibited significant anti-inflammatory activity with good cell viability. Conclusion The selected herbs could be a rich source of antioxidants and free radical scavenging compounds. The levels of phenolic and flavonoid compounds were correlated with the antioxidant and anti-inflammatory activities of the extracts from the herbs.

  17. Towards further understanding on the antioxidative activities of Prunus persica fruit: A comparative study with four different fractions

    Science.gov (United States)

    Dhingra, Naveen; Sharma, Rajesh; Kar, Anand

    2014-11-01

    In the present study we have evaluated the antioxidant activities of different fractions (hexane, ethyl acetate, n-butanol and aqueous fractions) of Prunus persica fruit. For extraction simple warring blender method was employed and total phenolic and flavonoid contents were correlated with different antioxidant activities (total antioxidant, 2,2-diphenyl-1-picrylhydrazyl (DPPH), H2O2 scavenging, superoxide radical scavenging, iron chelating and their reducing power properties). Different in vitro antioxidant studies showed that ethyl acetate and n-butanol fractions had the maximum activities that were well correlated with total phenolic and flavonoid contents. Maximum yield (25.14 ± 2.2%) was obtained in its aqueous fraction. Both ethyl acetate and n-butanol fractions showed significant inhibitory effects on different antioxidant activities. A significantly high correlation coefficient existed between total antioxidant activities and with total phenolic as well as total flavonoid contents. It appears that ethyl acetate and n-butanol fractions of P. persica may serve as new potential sources of natural antioxidants and could be of therapeutic use in treating several diseases.

  18. Plant mechanisms of siderophore-iron utilization

    International Nuclear Information System (INIS)

    Mechanisms of siderophore iron-utilization by plants were examined to determine whether plants have direct mechanisms for acquiring iron from microbially-produced hydroxamate siderophores or simply take up inorganic iron in equilibrium with the chelate (shuttle mechanism). Experiments were designed to determine whether the monocot plant species, oat (Avena sativa L. cv. Victory) could acquire iron from ferrichrome under hydroponic conditions in which iron uptake was most likely to occur by direct use of the chelating agent. Ten-day-old iron-deficient seedlings, grown in aerated Hoagland's nutrient solution (minus iron) buffered at pH 7.4 with CaCO3, were placed in fresh nutrient solution containing 10/sup -7.4/M radioactive 55FeCl3 (23.7 mCi/mg) with the synthetic chelate, EDDHA (10π5M), ferrichrome (10-5M), or with no chelate. After 6 days, shoot content of 55Fe in shoots of plants provided with ferrichrome was 100-fold greater than that in shoots of plants provided with EDDHA. Therefore iron uptake by oat under these conditions not only indicates direct use of ferrichrome, but also suggest that oat may be better able to acquire iron from siderophores than from synthetic chelates. One possible mechanism for direct use of chelating agents, may involve siderophore binding sites on the plasmalemma of root cortical cells where iron is split from the chelate by enzymatic reduction of ferric to ferrous iron. To demonstrate hypothesized siderophore binding sites on oat roots, experiments examined possible competition for presumed siderophore binding sites by an inert analog of ferrichrome constructed by irreversible chelation with chromium

  19. In vitro evaluation of antioxidant and cytotoxic activities of lignin fractions extracted from Acacia nilotica.

    Science.gov (United States)

    Barapatre, Anand; Meena, Avtar Singh; Mekala, Sowmya; Das, Amitava; Jha, Harit

    2016-05-01

    Lignin is one of the most important phytomacromolecule with diverse therapeutic properties such as anticancer, antimicrobial, anti-inflammatory and immune-stimulatory. The present study was carried out to evaluate the in vitro antioxidant, free radical scavenging and anti-proliferative/cytotoxic activities of eleven different lignin fractions, extracted from the wood of Acacia nilotica by pressurized solvent extraction (PSE) and successive solvent extraction (SSE) methods. Results indicate that the PSE fractions have high polyphenolic content and reducing power. However, the antioxidant efficiency examined by DPPH and ABTS radical scavenging assay was higher in SSE fractions. All lignin fractions revealed a significant ability to scavenge nitric oxide, hydroxyl and superoxide radicals. The extracted lignin fractions display high ferric ion reducing capacity and also possess excellent antioxidant potential in the hydrophobic (linoleic acid) system. Fractions extracted by polar solvent has the highest iron (Fe(2+)) chelating activity as compared to other factions, indicating their effect on the redox cycling of iron. Four lignin fractions depicted higher cytotoxic potential (IC50: 2-15μg/mL) towards breast cancer cell line (MCF-7) but were ineffective (IC50: ≥100μg/mL) against normal primary human hepatic stellate cells (HHSteCs). These findings suggest that the lignin extracts of A. nilotica wood has a remarkable potential to prevent disease caused by the overproduction of radicals and also seem to be a promising candidate as natural antioxidant and anti-cancer agents. PMID:26836619

  20. Antioxidant activity of leaves and inflorescence of Eryngium Caucasicum Trautv at flowering stage

    Directory of Open Access Journals (Sweden)

    Mohamamd Ali Ebrahimzadeh

    2009-01-01

    Full Text Available Methanol extracts of leaves and inflorescence of Eryngium Caucasicum Trautv at flowering stage were investigated for their antioxidant activities employing six in vitro assay systems, i.e. DPPH and nitric oxide radical scavenging, reducing power, linoleic acid and iron ion chelating power. IC50 for DPPH radical-scavenging activity was 0.15 ± 0.01 for leaves and 0.39 ± 0.02 mg ml−1 for inflorescence. Reducing powers of both extracts increased with the increase of their concentrations. Leaves extract showed better activity than Vitamin C (p< 0.05. Extracts showed weak nitric oxide-scavenging activity. Leaves extract exhibited better Fe2+ chelating ability (IC50=0.25 mg ml−1 that was comparable with EDTA. (IC50=18 ìg ml−1. Inflorescence extracts had shown a very weak activity. Extracts showed very good scavenging activity of H2O2. IC50 was 25.5 ± 1.3 for leaves and 177.2 ± 11.6 mg ml−1 for inflorescence, respectively. No antioxidant activity exhibited in linoleic acid test. Extracts exhibited different levels of antioxidant activity in all the models studied.

  1. Potential Anticancer Properties of Grape Antioxidants

    OpenAIRE

    Kequan Zhou; Raffoul, Julian J.

    2012-01-01

    Dietary intake of foods rich in antioxidant properties is suggested to be cancer protective. Foods rich in antioxidant properties include grape (Vitis vinifera), one of the world's largest fruit crops and most commonly consumed fruits in the world. The composition and cancer-protective effects of major phenolic antioxidants in grape skin and seed extracts are discussed in this review. Grape skin and seed extracts exert strong free radical scavenging and chelating activities and inhibit lipid ...

  2. In Vitro Ion Chelating, Antioxidative Mechanism of Extracts from Fruits and Barks of Tetrapleura tetraptera and Their Protective Effects against Fenton Mediated Toxicity of Metal Ions on Liver Homogenates

    Directory of Open Access Journals (Sweden)

    Bruno Moukette Moukette

    2015-01-01

    Full Text Available The aim of the present study was to investigate the antioxidant activity and protective potential of T. tetraptera extracts against ion toxicity. The antioxidant activity of the extracts was investigated spectrophotometrically against several radicals (1,1-diphenyl-2-picrylhydrazyl (DPPH•, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS•, hydroxyl radical (HO•, and nitric oxide (NO•, followed by the ferric reducing power, total phenols, flavonoid, and flavonol contents. The effects of the extracts on catalase (CAT, superoxide dismutase (SOD, and peroxidase activities were also determined using the standard methods as well as the polyphenol profile using HPLC. The results showed that the hydroethanolic extract of T. tetraptera (CFH has the lowest IC50 value with the DPPH, ABTS, OH, and NO radicals. The same extract also exhibited the significantly higher level of total phenols (37.24 ± 2.00 CAE/g dried extract; flavonoids (11.36 ± 1.88 QE/g dried extract; and flavonols contents (3.95 ± 0.39 QE/g dried extract. The HPLC profile of T. tetraptera revealed that eugenol (958.81 ± 00 mg/g DW, quercetin (353.78 ± 00 mg/g DW, and rutin (210.54 ± 00 mg/g DW were higher in the fruit than the bark extracts. In conclusion, extracts from T. tetraptera may act as a protector against oxidative mediated ion toxicity.

  3. Role of antioxidant enzymes in bacterial resistance to organic acids.

    Science.gov (United States)

    Bruno-Bárcena, Jose M; Azcárate-Peril, M Andrea; Hassan, Hosni M

    2010-05-01

    Growth in aerobic environments has been shown to generate reactive oxygen species (ROS) and to cause oxidative stress in most organisms. Antioxidant enzymes (i.e., superoxide dismutases and hydroperoxidases) and DNA repair mechanisms provide protection against ROS. Acid stress has been shown to be associated with the induction of Mn superoxide dismutase (MnSOD) in Lactococcus lactis and Staphylococcus aureus. However, the relationship between acid stress and oxidative stress is not well understood. In the present study, we showed that mutations in the gene coding for MnSOD (sodA) increased the toxicity of lactic acid at pH 3.5 in Streptococcus thermophilus. The inclusion of the iron chelators 2,2'-dipyridyl (DIP), diethienetriamine-pentaacetic acid (DTPA), and O-phenanthroline (O-Phe) provided partial protection against 330 mM lactic acid at pH 3.5. The results suggested that acid stress triggers an iron-mediated oxidative stress that can be ameliorated by MnSOD and iron chelators. These findings were further validated in Escherichia coli strains lacking both MnSOD and iron SOD (FeSOD) but expressing a heterologous MnSOD from S. thermophilus. We also found that, in E. coli, FeSOD did not provide the same protection afforded by MnSOD and that hydroperoxidases are equally important in protecting the cells against acid stress. These findings may explain the ability of some microorganisms to survive better in acidified environments, as in acid foods, during fermentation and accumulation of lactic acid or during passage through the low pH of the stomach. PMID:20305033

  4. Examining the fixation kinetics of chelated and non-chelated copper micronutrient and the applications to micronutrient management in semi-arid alkaline soils

    Science.gov (United States)

    Udeigwe, T. K.; Eichmann, M. B.; Menkiti, M. C.

    2015-10-01

    The relationship between the deficiency of a nutrient in plants and its total concentration in the soil is complex. This study examined and compared the fixation and fixation kinetics of copper (Cu) in chelated (Ethylene diamine tetraacetic acid, EDTA) and non-chelated mixed systems of micronutrients in the semi-arid soils of the Southern High Plains, US using findings from Cu extraction studies and kinetic models. Approximately, 22 % more Cu was fixed in the non-chelated system within the first 14 days with only 7 % difference between the two systems by day 90. Findings suggest a decrease in the effectiveness of chelated micronutrient over time, highlighting the significance of timing even when chelated micronutrients are applied. The strengths of the relationship of change in available Cu with respect to other micronutrients [iron (Fe), manganese (Mn), and zinc (Zn)] were higher in the non-chelated system (R2: 0.68-0.94), compared to the chelated (R2: 0.42-0.81) with slopes of 0.40 (Cu-Fe), 0.31 (Cu-Mn), and 1.04 (Cu-Zn) in the non-chelated system and 0.26 (Cu-Fe), 0.22 (Cu-Mn), and 0.90 (Cu-Zn) in the chelated. Reduction in the amount of available Cu was best described by the power function model (R2 = 0.91, SE = 0.081) in the non-chelated system and second order model (R2 = 0.95, SE = 0.010) in the chelated system. The applications generated from this study could be used as tools for improved micronutrient management and also provide baseline data for future work in other semi-arid/arid alkaline soils of the world. Findings are also more applicable to field settings, an improvement over related previous studies.

  5. Iron is essential for photosynthesis and respiration : iron deficiency

    OpenAIRE

    HEUVELINK, E.; Kierkels, T.

    2016-01-01

    Iron plays a major role in photosynthesis. That’s why a shortage directly affects the production capacity of the plant. The application of chelates has made iron much more easy to absorb. Nevertheless it’s an element that we have to keep an eye on.

  6. Isoflavones Reduce Copper with Minimal Impact on Iron In Vitro

    OpenAIRE

    Jana Karlíčková; Kateřina Macáková; Michal Říha; Liliane Maria Teixeira Pinheiro; Tomáš Filipský; Veronika Horňasová; Radomír Hrdina; Přemysl Mladěnka

    2015-01-01

    Isoflavones are commonly consumed in many Asian countries and have potentially positive effects on human being. Only a few and rather controversial data on their interactions with copper and iron are available to date. 13 structurally related isoflavones were tested in the competitive manner for their Cu/Fe-chelating/reducing properties. Notwithstanding the 5-hydroxy-4-keto chelation site was associated with ferric, ferrous, and cupric chelation, the chelation potential of isoflavones was low...

  7. Some aspects of chelation chemistry

    International Nuclear Information System (INIS)

    The notions used in chelation chemistry are defined and the possibilities of the experimental recognition of complex formation are described. A review of the quantitative aspects of chelation is given, especially under biological conditions. Some rules concerning the general behaviour of the various metal ions and the organic ligands in chelation phenomena are presented and the specificity problem is discussed. The present status of the decontamination of the main fission products, e.g. rare-earth metals and strontium, with the aid of complexing agents is analysed from a chemical point of view. (author)

  8. The Scientific Basis for Chelation: Animal Studies and Lead Chelation

    OpenAIRE

    Smith, Donald; Strupp, Barbara J.

    2013-01-01

    This presentation summarizes several of the rodent and non-human studies that we have conducted to help inform the efficacy and clinical utility of succimer (meso-2,3-dimercaptosuccincinic acid) chelation treatment. We address the following questions: (1) What is the extent of body lead, and in particular brain lead reduction with chelation, and do reductions in blood lead accurately reflect reductions in brain lead? (2) Can succimer treatment alleviate the neurobehavioral impacts of lead poi...

  9. In vitro antioxidant and anti-inflammatory properties of Limonium algarvense flowers' infusions and decoctions: A comparison with green tea (Camellia sinensis).

    Science.gov (United States)

    Rodrigues, Maria João; Neves, Vanessa; Martins, Alice; Rauter, Amélia P; Neng, Nuno R; Nogueira, José M F; Varela, João; Barreira, Luísa; Custódio, Luísa

    2016-06-01

    This work reports the in vitro antioxidant and anti-inflammatory activities and toxicity of infusions and decoctions of Limonium algarvense flowers, and green tea. The total contents in different phenolic groups and the quantification of individual phenolics by HPLC are also reported. L. algarvense and green tea had similar antioxidant properties, except for hydroxyl radical-scavenging activity, higher on green tea, and iron chelating potential, higher on L. algarvense. The later species also had the uppermost anti-inflammatory potential. Green tea decoction had the highest content of phenolic groups, but the infusion of L. algarvense had higher amounts of salicylic, gallic and coumaric acids. L. algarvense was not toxic, whereas green tea was toxic for S17 cells. Under our experimental conditions, infusions and decoctions of L. algarvense flowers had similar or higher antioxidant and anti-inflammatory properties than green tea, and thus, may be useful for alleviating symptoms associated with oxidative and inflammatory-related diseases. PMID:26830595

  10. Green tea or rosemary extract added to foods reduces nonheme- iron absorption

    DEFF Research Database (Denmark)

    Samman, S.; Sandstrøm, B.; Toft, M.B.;

    2001-01-01

    Background: Phenolic compounds act as food antioxidants. One of the postulated mechanisms of action is chelation of prooxidant metals, such as iron. Although the antioxidative effect is desirable, this mechanism may impair the utilization of dietary iron. Objective: We sought to determine the...... effect of phenolic-rich extracts obtained from green tea or rosemary on nonheme-iron absorption. Design: Young women aged 19-39 y consumed test meals on 4 separate occasions. The meals were identical except for the absence (meal A) or presence (meal B) of a phenolic-rich extract from green tea (study 1......-body retention of 59Fe and the ratio of Fe-55 to 59Fe activity in blood samples. Results: The presence of the phenolic-rich extracts resulted in decreased nonheme-iron absorption. Mean (+/-SD) iron absorption decreased from 12.1 +/- 4.5% to 8.9 +/- 5.2% (P < 0.01) in the presence of green tea extract and from 7...

  11. Modulation of chelating factors, trace minerals and their estimated bioavailability in Italian and African sorghum (Sorghum bicolor (L.) Moench) porridges

    OpenAIRE

    Proietti, I.; Mantovani, A.; Mouquet Rivier, Claire; Guyot, Jean-Pierre

    2013-01-01

    Factors able to modulate chelating factors, trace minerals and their bioavailability were investigated in porridges of five sorghum (Sorghum bicolor (L.) Moench) varieties: from Nigeria, Senegal, Burkina Faso and two from Italy. Effects of variety and traditional fermentation and cooking were assessed on iron-binding phenolic groups, phytates and iron and zinc content and bioavailability. Chelating factors, trace elements as well as the effect of processing (mainly fermentation) were modulate...

  12. Bifunctional Chelates for Metal Nuclides

    OpenAIRE

    Brechbiel, Martin W.

    2007-01-01

    The use of “non-standard” metallic radionuclides continues to be an expanding field of investigation. Radiolabeling small molecules, peptides, proteins, and up to nano-particles are all areas of active investigation for both diagnostic and therapeutic applications. All require a common variable – the need for appropriate chelation chemistry for adequate sequestration of the metallic radionuclide that is equal to the intended application. A brief overview of the array of the chelation chemistr...

  13. Alarming use of chelation therapy

    OpenAIRE

    Crisponi, Guido; Nurchi, Valeria Marina; Lachowicz, Joanna I.; Crespo-Alonso, Miriam; Zoroddu, Maria Antonietta; Peana, Massimiliano Francesco

    2014-01-01

    Chelation therapy is a consolidated medical procedure used primarily to hinder the effects of toxic metal ions on human tissues. Its application spans a broad spectrum of disorders, ranging from acute metal intoxication to genetic metal-overload. The use of chelating agents is compromised by a number of serious side effects, mainly attributable to perturbed equilibrium of essential metal ion homeostasis and dislocation of complexed metal ions to dangerous body sites. For this reason, chelatio...

  14. THE INFLUENCE OF TIME AND TYPE OF SOLVENT ON EFFICIENCY OF THE EXTRACTION OF POLYPHENOLS FROM GREEN TEA AND ANTIOXIDANT PROPERTIES OBTAINED EXTRACTS

    Directory of Open Access Journals (Sweden)

    Beata Drużyńska

    2007-03-01

    Full Text Available The aim of the study was to investigate the influence of the type of solvent and time on efficiency of the extraction of polyphenols and antioxidant properties extracts obtained from green tea. Extraction was conducted at room temperature using four solvents: water and 80% ethanol, 80% methanol and 80% acetone (water solutions, v/v at 15, 30 and 60 minutes. Extracts were analysed for contents of polyphenols and catechins. The antioxidant properties have been determined by two methods: scavenging activity against DPPH· and the method with ABTS·+. The abilities of extracts to chelate iron ions (II have been investigated too. On the basis of findings it turned out that both type of solvent and time have a significant influence on extraction of polyphenols from green tea. The best solvent for the extraction of total polyphenols was 80% acetone, whereas for catechins was water. The increase of extraction of polyphenols with prolonged extraction time was observed. All extracts had antioxidant properties against DPPH· and ABTS·+ and abilities to chelate iron ions (II.

  15. Which psychosocial factors are related to chelation adherence in thalassemia? A systematic review

    OpenAIRE

    Evangeli, M.; Mughal, K.; Porter, J. B.

    2010-01-01

    Good adherence to iron chelation therapy in thalassemia is crucial. Although there is evidence that adherence is related to regimen factors, there has been less emphasis on the relationship between psychosocial (psychological, demographic and social) factors and adherence. We present a systematic review of psychosocial correlates of chelation adherence in thalassemia. Nine studies met the inclusion criteria. Information was extracted regarding the study characteristics and the relationship be...

  16. Antioxidant Activity of Crataegus pentaegyna Subsp. elburensis Fruits Extracts Used in Traditional Medicine in Iran

    OpenAIRE

    M.A. Ebrahimzadeh; F. Bahramian

    2009-01-01

    In this study, the antioxidant activity of methanol and aqueous extracts of Crataegus pentaegyna subsp. elburensis (CP) were examined by various in vitro assay systems, i.e., DPPH and nitric oxide radical scavenging, reducing power, linoleic acid and iron ion chelating power. IC50 for DPPH radical-scavenging activity was 341.29±1.29 for methanol and 269.31±2.11 μg mL-1 for aqueous extract. Reducing powers of extracts also increased with the increase of their concentrations. Both extracts exhi...

  17. Mineral Components and Anti-oxidant Activities of Tropical Seaweeds

    Institute of Scientific and Technical Information of China (English)

    Suzuki Takeshi; Yoshie-Stark Yumiko; Santoso Joko

    2005-01-01

    Seaweeds are known to hold substances of high nutritional value; they are the richest resources of minerals important to the biochemical reactions in the human body. Seaweeds also hold non-nutrient compounds like dietary fiber and polyphenols. However, there is not enough information on the mineral compounds of tropical seaweeds. Also we are interested in the antioxidant activities of seaweeds, especially those in the tropical area. In this study, Indonesian green, brown and red algae were used as experimental materials with their mineral components analyzed by using an atomic absorption spectrophotometer. The catechins and flavonoids of these seaweeds were extracted with methanol and analyzed by high performance liquid chromatography (HPLC); the anti-oxidant activities of these seaweeds were evaluated in a fish oil emulsion system. The mineral components of tropical seaweeds are dominated by calcium, potassium and sodium, as well as small amounts of copper, iron and zinc. A green alga usually contains epigallocatechin, gallocatechin, epigallocatechin gallate and catechin. However, catechin and its isomers are not found in some green and red algae. In the presence of a ferrous ion catalyst, all the methanol extracts from the seaweeds show significantly lower peroxide values of the emulsion than the control,and that of a green alga shows the strongest anti-oxidant activity. The highest chelation on ferrous ions is also found in the extract of this alga, which is significantly different from the other methanol extracts in both 3 and 24 h incubations.

  18. Mineral components and anti-oxidant activities of tropical seaweeds

    Science.gov (United States)

    Takeshi, Suzuki; Yumiko, Yoshie-Stark; Joko, Santoso

    2005-07-01

    Seaweeds are known to hold substances of high nutritional value; they are the richest resources of minerals important to the biochemical reactions in the human body. Seaweeds also hold non-nutrient compounds like dietary fiber and polyphenols. However, there is not enough information on the mineral compounds of tropical seaweeds. Also we are interested in the antioxidant activities of seaweeds, especially those in the tropical area. In this study, Indonesian green, brown and red algae were used as experimental materials with their mineral components analyzed by using an atomic absorption spectrophotometer. The catechins and flavonoids of these seaweeds were extracted with methanol and analyzed by high performance liquid chromatography (HPLC); the antioxidant activities of these seaweeds were evaluated in a fish oil emulsion system. The mineral components of tropical seaweeds are dominated by calcium, potassium and sodium, as well as small amounts of copper, iron and zinc. A green alga usually contains epigallocatechin, gallocatechin, epigallocatechin gallate and catechin. However, catechin and its isomers are not found in some green and red algae. In the presence of a ferrous ion catalyst, all the methanol extracts from the seaweeds show significantly lower peroxide values of the emulsion than the control, and that of a green alga shows the strongest antioxidant activity. The highest chelation on ferrous ions is also found in the extract of this alga, which is significantly different from the other methanol extracts in both 3 and 24 h incubations.

  19. Antioxidant Activities of Aqueous Extract from Cultivated Fruit-bodies of Cordyceps militaris (L.) Link In Vitro

    Institute of Scientific and Technical Information of China (English)

    Yu Zhan; Cai-Hong Dong; Yi-Jian Yao

    2006-01-01

    Biological antioxidants extracted from plants and fungi have potential abilities to scavenge free radicals and inhibit lipid peroxidation, playing important roles in preventing diseases, for example, cancer, and aging induced by reactive oxygen species, which may cause oxidative damage to DNA, proteins and other macromolecules. The antioxidant potency of cultivated fruit-bodies of Cordyceps militaris (L.) Link was investigated in this study. Five established in vitro systems were employed, including the 1,1-diphenyl-2-picryldrazyl (DPPH) free radical scavenging, hydroxyl radical eliminating, iron chelating, inhibition of linoleic acid lipid peroxidation and reducing power. The aqueous extract from cultivated fruit-bodies was subjected to the test of amino acid, polysaccharide and mannitol. Ascorbic acid (Vc), butylated hydroxytoluene (BHT)and ethylenediaminetetraacetic acid (EDTA) were used as positive controls for comparisons. Among the assays, the aqueous extract of C. militaris fruit-bodies shows a significant scavenging effect on DPPH,eliminating the capability on hydroxyl radicals and the chelating effect on ferrous iron. The extract also shows positive results of inhibiting linoleic acid lipid peroxidation and reducing power.

  20. Chelate-Assisted Heavy Metal Movement Through the Root Zone

    Science.gov (United States)

    Kirkham, M.; Madrid, F.; Liphadzi, M. S.

    2001-12-01

    Chelating agents are added to soil as a means to mobilize heavy metals for plant uptake during phytoremediation. Yet almost no studies follow the displacement of heavy metals through the vadose zone following solubilization with chelating agents. The objective of this work was to determine the movement of heavy metals through the soil profile and their absorption by barley (Hordeum vulgare L.) in a soil amended with biosolids and in the presence of a chelating agent (EDTA). Twelve columns 75 cm in height and 17 in diameter were packed with a Haynie very fine sandy loam (coarse-silty, mixed, calcareous, mesic Mollic Udifluvents) and watered with liquid biosolids applied at the surface at a rate of 120 kg N/ha. Three weeks after plants germinated, soil was irrigated with a solution of the disodium salt of EDTA added at a rate of 0.5 g/kg soil. Four treatments were imposed: columns with no plants and no EDTA; columns with no plants plus EDTA; columns with plants and no EDTA; and columns with plants and EDTA. Columns were watered intensively for 35 days until two pore volumes of water had been added, and the leachates were collected daily. With or without plants, columns with EDTA had lower total concentrations of Cu, Zn, Cd, Ni, and Pb in the surface 20 cm than columns without EDTA. Concentrations of the heavy metals in this layer were not afffected by the presence of roots. Iron in leachate was followed as an indicator metal for movement to groundwater. No iron appeared in the leachate without EDTA, either in the columns with plants or without plants. The peak concentration of iron in the leachate occurred three days earlier in the columns without plants and EDTA compared to the columns with plants and EDTA. The results indicated the importance of vegetation on retarding heavy metal leaching to groundwater during chelate-facilitated phytoremediation.

  1. Intestinal Iron Homeostasis and Colon Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Yatrik M. Shah

    2013-06-01

    Full Text Available Colorectal cancer (CRC is the third most common cause of cancer-related deaths in industrialized countries. Understanding the mechanisms of growth and progression of CRC is essential to improve treatment. Iron is an essential nutrient for cell growth. Iron overload caused by hereditary mutations or excess dietary iron uptake has been identified as a risk factor for CRC. Intestinal iron is tightly controlled by iron transporters that are responsible for iron uptake, distribution, and export. Dysregulation of intestinal iron transporters are observed in CRC and lead to iron accumulation in tumors. Intratumoral iron results in oxidative stress, lipid peroxidation, protein modification and DNA damage with consequent promotion of oncogene activation. In addition, excess iron in intestinal tumors may lead to increase in tumor-elicited inflammation and tumor growth. Limiting intratumoral iron through specifically chelating excess intestinal iron or modulating activities of iron transporter may be an attractive therapeutic target for CRC.

  2. Acquisition, Transport, and Storage of Iron by Pathogenic Fungi

    OpenAIRE

    Howard, Dexter H.

    1999-01-01

    Iron is required by most living systems. A great variety of means of acquisition, avenues of uptake, and methods of storage are used by pathogenic fungi to ensure a supply of the essential metal. Solubilization of insoluble iron polymers is the first step in iron assimilation. The two methods most commonly used by microorganisms for solubilization of iron are reduction and chelation. Reduction of ferric iron to ferrous iron by enzymatic or nonenzymatic means is a common mechanism among pathog...

  3. Synthesis of polystyrene supported chelating resin containing an oxygen-nitrogen donor bidentate Schiff base and its nickel(II), cobalt(II), copper(II), iron(III), zinc(II), molybdenum(VI) and uranium(VI) complexes

    International Nuclear Information System (INIS)

    A new bidentate oxygen-nitrogen donor Schiff base supported on polystyrene matrix has been synthesized by the reaction of aminomethylated polystyrene and salicylaldehyde. The chelating resin reacts with metal complex/metal salt and forms metal bound polymers of the formulae: PS-LNi(CH3COO).3DMF, PS-LCo(CH3COO).DMF, PS-LCu(CH3COO).DMF, PS-LCu(CH3COO).CH3OH, PS-LFeCL2.2DMF, PS-LZnCl.CH3OH, PS-LCd(CH3COO).DMF, PS-LCdCl.CH3OH, PS-LMoO2(acetylacetonato) and PS-LUO2(CH3COO).DMF (where PS-L=deprotonated anion of polymer-anchored ligand). The metal bound polymers have been characterized by elemental analysis, IR, electronic spectra and magnetic susceptibility measurements. The complexes PS-LNi(CH3COO).3DMF, PS-LCo(CH3COO).DMF, PS-LCu(CH3COO).DMF, PS-LCu(CH3COO).CH3OH and PS-LFeCl2.2DMF are paramagnetic while the Zn(II), Cd(II), Mo(VI) and U(VI) complexes are diamagnetic. The Co(II) and Cu(II) complexes exhibit a square planar structure, whereas Ni(II), Fe(III), Mo(VI) and U(VI) complexes are octahedral and Zn(II) and Cd(II) complexes are tetrahedral. (author). 29 refs., 1 tab

  4. (+/-)-catechin: chemical weapon, antioxidant, or stress regulator?

    Science.gov (United States)

    Chobot, Vladimir; Huber, Christoph; Trettenhahn, Guenter; Hadacek, Franz

    2009-08-01

    (+/-)-Catechin is a flavan-3-ol that occurs in the organs of many plant species, especially fruits. Health-beneficial effects have been studied extensively, and notable toxic effects have not been found. In contrast, (+/-)-catechin has been implicated as a 'chemical weapon' that is exuded by the roots of Centaurea stoebe, an invasive knapweed of northern America. Recently, this hypothesis has been rejected based on (+/-)-catechin's low phytotoxicity, instability at pH levels higher than 5, and poor recovery from soil. In the current study, (+/-)-catechin did not inhibit the development of white and black mustard to an extent that was comparable to the highly phytotoxic juglone, a naphthoquinone that is allegedly responsible for the allelopathy of the walnut tree. At high stress levels, caused by sub-lethal methanol concentrations in the medium, and a 12 h photoperiod, (+/-)-catechin even attenuated growth retardation. A similar effect was observed when (+/-)-catechin was assayed for brine shrimp mortality. Higher concentrations reduced the mortality caused by toxic concentrations of methanol. Further, when (+/-)-catechin was tested in variants of the deoxyribose degradation assay, it was an efficient scavenger of reactive oxygen species (ROS) when they were present in higher concentrations. This antioxidant effect was enhanced when iron was chelated directly by (+/-)-catechin. Conversely, if iron was chelated to EDTA, pro-oxidative effects were demonstrated at higher concentrations; in this case (+/-)-catechin reduced molecular oxygen and iron to reagents required by the Fenton reaction to produce hydroxyl radicals. A comparison of cyclic voltammograms of (+/-)-catechin with the phytotoxic naphthoquinone juglone indicated similar redox-cycling properties for both compounds although juglone required lower electrochemical potentials to enter redox reactions. In buffer solutions, (+/-)-catechin remained stable at pH 3.6 (vacuole) and decomposed at pH 7.4 (cytoplasm

  5. Antioxidant activities of Sarcodon imbricatum wildly grown in the Black Sea Region of Turkey

    OpenAIRE

    Özen, Tevfik; TÜRKEKUL, İbrahim

    2010-01-01

    The antioxidant activities of the methanol extract of Sarcodon imbricatum wildly grown in the Black Sea Region of Turkey were investigated in this study. Antioxidant activities were evaluated in terms of total antioxidant activity, reducing power, metal chelating ability, inhibition of linoleic acid peroxidation, superoxide, peroxide and hydrogen peroxide scavenging effects. Various antioxidant activities were compared to references antioxidants such as α-tocopherol, butylated hydroxyanisole ...

  6. Antioxidant activities of Sarcodon imbricatum wildly grown in the black sea region of Turkey

    OpenAIRE

    Tevfik Ozen; Ibrahim Turkekul

    2010-01-01

    The antioxidant activities of the methanol extract of Sarcodon imbricatum wildly grown in the Black Sea Region of Turkey were investigated in this study. Antioxidant activities were evaluated in terms of total antioxidant activity, reducing power, metal chelating ability, inhibition of linoleic acid peroxidation, superoxide, peroxide and hydrogen peroxide scavenging effects. Various antioxidant activities were compared to references antioxidants such as α-tocopherol, butylated hydroxyanisole ...

  7. Antioxidant activity of hydroalcoholic leaf extracts of Psidium guajava and Persea Americana, an invitro study

    International Nuclear Information System (INIS)

    Ionizing radiation produce deleterious effects in the living organisms. Rapid technological advancement has increased human exposure to ionizing radiations enormously. Several plants have been screened for their radio protective ability and the hunt for identifying many more safe, nontoxic and effective ones is in progress. The aim of the present study was to evaluate the antioxidant activity in hydro alcoholic leaf extract of Psidium guajava (guava) and Persea americana (avocado). The antioxidant assay such as 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) free radical scavenging assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, chelation of iron by plant extract, hydroxyl radical scavenging assay, ferric reducing antioxidant potential (FRAP), and total antioxidant activity of extract was analyzed using spectrophotometer. Phytochemical screening and HPLC analysis of leaf extracts were also performed. The results indicated that the IC50 value of hydro alcoholic leaf extract of P.guajava and P. americana were 14 μg/ml and 15 μg/ml in ABTS free radical scavenging assay, 4 μg/ml and 2.5 μg/ml in DPPH free radical scavenging assay, 7.2 μg/ml and 8.4 μg/ml in chelation of iron by plant extract, 2 μg/ml and, 4.3 μg/ml in hydroxyl radical scavenging assay and effective concentration(EC50) was 57.80 μg/ml and 87.56 μg/ml in FRAP assay respectively. The results for total antioxidant activity indicated that 242.3 μg/ml of P.guajava and 432.7 μg/ml of P.americana extract was equivalent to 100 μg/ml of standard qurecetin respectively. Qualitative analysis of hydroalcoholic leaf extracts revealed the presence of flavonoids, tannins, saponions, terpenoids, and glycosides. HPLC analysis confirmed the presence of flavonoids qurecetin and rutin in leaf extracts on comparison with standard compounds. Our study showed that hydro alcoholic leaf extracts of Psidium guajava and Persea americana act as strong antioxidant and free

  8. Antioxidant ability and mechanism of rhizoma Atractylodes macrocephala.

    Science.gov (United States)

    Li, Xican; Lin, Jian; Han, Weijuan; Mai, Wenqiong; Wang, Li; Li, Qiang; Lin, Miaofang; Bai, Mingsong; Zhang, Lishan; Chen, Dongfeng

    2012-01-01

    Rhizoma Atractylodes macrocephala (AM) has been used in Traditional Chinese Medicine (TCM) for about 2,000 years. In the study, we firstly determined the antioxidant levels of five AM extracts by •OH-scavenging, •O2−-scavenging, Fe2+-chelating, Cu2+-chelating, DPPH·-scavenging, and ABTS+·-scavenging assays. After measurement of the chemical contents in five AM extracts, we quantitatively analyzed the correlations between antioxidant levels and chemical contents. It was observed that total phenolics and total flavonoids had significant positive correlations with antioxidant levels (R = 0.685 and 0.479, respectively). In contrast, total sugars and total saponins presented lower correlations with antioxidant levels (R=−0.272 and 0.244, respectively). It means that antioxidant activity of AM should be attributed to total phenolics (including phenolic acids and flavonoids), and not total sugars and total saponins. Further analysis indicated that phenolic acids exhibited higher R values with radical-scavenging assays (R=0.32–1.00), while flavonoids showed higher R values with metal-chelating assays (R=0.86 and 0.90). In conclusion, AM exerts its antioxidant effect through metal-chelating, and radical-scavenging which is via donating hydrogen atom and donating electron. Its metal-chelating may result from flavonoids, while its radical-scavenging can be attributed to phenolic acids, especially caffeic acid, ferulic acid, and protocatechuic acid. PMID:23149564

  9. Antioxidant properties of some plants growing wild in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Serteser, A.; Kargioglu, M.; Gok, V.; Bagci, Y.; Musa Ozcan, M.; Arslan, D.

    2009-07-01

    In this study, the antioxidant activity of 50% aqueous methanol extracts of 38 plants growing in the Afyonkarahisar province of Turkey were evaluated by various antioxidant assay, including free radical scavenging, hydrogen peroxide (H{sub 2}O{sub 2}) scavenging and metal (Fe{sup 2}+) chelating activities. The methanolic fruit extracts of the Cornus and Morus species (H{sub 2}O{sub 2} and DPPH scavenging activities, Fe{sup 2}+ chelating activity) and the methanolic leaf extracts of the Mentha species (DPPH scavenging activities) examined in the assay showed the strongest activities. These antioxidant properties depended on the concentration of samples. (Author) 30 refs.

  10. Antioxidant properties of various solvent extracts from purple basil

    Science.gov (United States)

    Yeşiloğlu, Yeşim; Şit, Latifşah

    2012-09-01

    Water, ethanol and acetone extracts from leaves and flowers of purple basil, one of the most popular spices consumed in the Thrace region of Turkey, were tested in vitro for their ability to inhibit peroxidation of lipids, to scavenge DPPH, hydrogen peroxide, superoxide anion, to reduce Fe(III) to Fe(II) and to chelate Fe(II) ions. The results showed that purple basil contained naturally occurring antioxidant components and possessed antioxidant activity which may be attributed to its lipid peroxidation inhibitory, radical scavenging and metal chelating activities. It was concluded that purple basil might be a potential source of antioxidants.

  11. Heavy metal induced oxidative stress & its possible reversal by chelation therapy.

    Science.gov (United States)

    Flora, S J S; Mittal, Megha; Mehta, Ashish

    2008-10-01

    Exposure to heavy metals is a common phenomenon due to their environmental pervasiveness. Metal intoxication particularly neurotoxicity, genotoxicity, or carcinogenicity is widely known. This review summarizes our current understanding about the mechanism by which metalloids or heavy metals (particularly arsenic, lead, cadmium and mercury) induce their toxic effects. The unifying factor in determining toxicity and carcinogenicity for all these metals is the generation of reactive oxygen and nitrogen species. The toxic manifestations of these metals are caused primarily due to imbalance between pro-oxidant and antioxidant homeostasis which is termed as oxidative stress. Besides these metals have high affinity for thiol groups containing enzymes and proteins, which are responsible for normal cellular defense mechanism. Long term exposure to these metals could lead to apoptosis. Signaling components affected by metals include growth factor receptors, G-proteins, MAP kinases and transcription factors. Chelation therapy with chelating agents like calcium disodium ethylenediamine tetra acetic acid (CaNa(2)EDTA), British Anti Lewisite (BAL), sodium 2,3-dimercaptopropane 1-sulfonate (DMPS), meso 2,3-dimercaptosuccinic acid (DMSA) etc., is considered to be the best known treatment against metal poisoning. Despite many years of research we are still far away from effective treatment against toxicity caused due to exposure to heavy metals/metalloids. The treatment with these chelating agents is compromised with number of serious side-effects. Studies show that supplementation of antioxidants along-with a chelating agent prove to be a better treatment regimen than monotherapy with chelating agents. This review attempts a comprehensive account of recent developments in the research on heavy metal poisoning particularly the role of oxidative stress/free radicals in the toxic manifestation, an update about the recent strategies for the treatment with chelating agents and a

  12. Luminescent lanthanide chelates and methods of use

    Energy Technology Data Exchange (ETDEWEB)

    Selvin, Paul R. (Berkeley, CA); Hearst, John (Berkeley, CA)

    1997-01-01

    The invention provides lanthanide chelates capable of intense luminescence. The celates comprise a lanthanide chelator covalently joined to a coumarin-like or quinolone-like sensitizer. Exemplary sensitzers include 2- or 4-quinolones, 2- or 4-coumarins, or derivatives thereof e.g. carbostyril 124 (7-amino-4-methyl-2-quinolone), coumarin 120 (7-amino-4-methyl-2-coumarin), coumarin 124 (7-amino-4-(trifluoromethyl)-2-coumarin), aminomethyltrimethylpsoralen, etc. The chelates form high affinity complexes with lanthanides, such as terbium or europium, through chelator groups, such as DTPA. The chelates may be coupled to a wide variety of compounds to create specific labels, probes, diagnostic and/or therapeutic reagents, etc. The chelates find particular use in resonance energy transfer between chelate-lanthanide complexes and another luminescent agent, often a fluorescent non-metal based resonance energy acceptor. The methods provide useful information about the structure, conformation, relative location and/or interactions of macromolecules.

  13. Alginate-Iron Speciation and Its Effect on In Vitro Cellular Iron Metabolism

    Science.gov (United States)

    Horniblow, Richard D.; Dowle, Miriam; Iqbal, Tariq H.; Latunde-Dada, Gladys O.; Palmer, Richard E.

    2015-01-01

    Alginates are a class of biopolymers with known iron binding properties which are routinely used in the fabrication of iron-oxide nanoparticles. In addition, alginates have been implicated in influencing human iron absorption. However, the synthesis of iron oxide nanoparticles employs non-physiological pH conditions and whether nanoparticle formation in vivo is responsible for influencing cellular iron metabolism is unclear. Thus the aims of this study were to determine how alginate and iron interact at gastric-comparable pH conditions and how this influences iron metabolism. Employing a range of spectroscopic techniques under physiological conditions alginate-iron complexation was confirmed and, in conjunction with aberration corrected scanning transmission electron microscopy, nanoparticles were observed. The results infer a nucleation-type model of iron binding whereby alginate is templating the condensation of iron-hydroxide complexes to form iron oxide centred nanoparticles. The interaction of alginate and iron at a cellular level was found to decrease cellular iron acquisition by 37% (p < 0.05) and in combination with confocal microscopy the alginate inhibits cellular iron transport through extracellular iron chelation with the resulting complexes not internalised. These results infer alginate as being useful in the chelation of excess iron, especially in the context of inflammatory bowel disease and colorectal cancer where excess unabsorbed luminal iron is thought to be a driver of disease. PMID:26378798

  14. Phytases for Improved Iron Absorption

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Nyffenegger, Christian; Meyer, Anne S.

    2014-01-01

    Microbial phytases (EC 3.1.3.8) catalyse dephosphorylation of phytic acid, which is the primary storage compound for phosphorous in cereal kernels. The negatively charged phosphates in phytic acid chelate iron (Fe3+) and thus retards iron bioavailability in humans 1. Supplementation of microbial...... phytase can improve iron absorption from cereal-based diets 2. In order for phytase to catalyse iron release in vivo the phytase must be robust to low pH and proteolysis in the gastric ventricle. Our work has compared the robustness of five different microbial phytases, evaluating thermal stability...

  15. Some Linguistic Detail on Chelation

    Science.gov (United States)

    Haworth, Daniel T.

    1998-01-01

    The term chelate was first applied by Morgan and Drew in 1920 to describe the heterocyclic rings formed from bidentate ligands bonding to a central atom. The history of the word ch_l_ is traced from its original Greek meaning through the Latin language to its anglicized form, chela. This word has a very rich history and has been cited by both Greek (Aristotle) and Latin (Cicero, Vergil) philosophers and poets.

  16. Iron and Acinetobacter baumannii Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Valentina Gentile

    2014-08-01

    Full Text Available Acinetobacter baumannii is an emerging nosocomial pathogen, responsible for infection outbreaks worldwide. The pathogenicity of this bacterium is mainly due to its multidrug-resistance and ability to form biofilm on abiotic surfaces, which facilitate long-term persistence in the hospital setting. Given the crucial role of iron in A. baumannii nutrition and pathogenicity, iron metabolism has been considered as a possible target for chelation-based antibacterial chemotherapy. In this study, we investigated the effect of iron restriction on A. baumannii growth and biofilm formation using different iron chelators and culture conditions. We report substantial inter-strain variability and growth medium-dependence for biofilm formation by A. baumannii isolates from veterinary and clinical sources. Neither planktonic nor biofilm growth of A. baumannii was affected by exogenous chelators. Biofilm formation was either stimulated by iron or not responsive to iron in the majority of isolates tested, indicating that iron starvation is not sensed as an overall biofilm-inducing stimulus by A. baumannii. The impressive iron withholding capacity of this bacterium should be taken into account for future development of chelation-based antimicrobial and anti-biofilm therapies.

  17. Antioxidants protect keratinocytes against M. ulcerans mycolactone cytotoxicity.

    Directory of Open Access Journals (Sweden)

    Alvar Grönberg

    Full Text Available BACKGROUND: Mycobacterium ulcerans is the causative agent of necrotizing skin ulcerations in distinctive geographical areas. M. ulcerans produces a macrolide toxin, mycolactone, which has been identified as an important virulence factor in ulcer formation. Mycolactone is cytotoxic to fibroblasts and adipocytes in vitro and has modulating activity on immune cell functions. The effect of mycolactone on keratinocytes has not been reported previously and the mechanism of mycolactone toxicity is presently unknown. Many other macrolide substances have cytotoxic and immunosuppressive activities and mediate some of their effects via production of reactive oxygen species (ROS. We have studied the effect of mycolactone in vitro on human keratinocytes--key cells in wound healing--and tested the hypothesis that the cytotoxic effect of mycolactone is mediated by ROS. METHODOLOGY/PRINCIPAL FINDINGS: The effect of mycolactone on primary skin keratinocyte growth and cell numbers was investigated in serum free growth medium in the presence of different antioxidants. A concentration and time dependent reduction in keratinocyte cell numbers was observed after exposure to mycolactone. Several different antioxidants inhibited this effect partly. The ROS inhibiting substance deferoxamine, which acts via chelation of Fe(2+, completely prevented mycolactone mediated cytotoxicity. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that mycolactone mediated cytotoxicity can be inhibited by deferoxamine, suggesting a role of iron and ROS in mycolactone induced cytotoxicity of keratinocytes. The data provide a basis for the understanding of Buruli ulcer pathology and the development of improved therapies for this disease.

  18. ANTIOXIDANT ACTIVITIES AND PHENOLIC PROFILE OF SIX MOROCCAN SELECTED HERBS

    OpenAIRE

    Madiha Bichra; Cherkaoui El-Modafar; Abdelilah El-Abbassi; Hafida Bouamama; Fatiha Benkhalti

    2013-01-01

    The present work evaluated the antioxidant capacity of six plants commonly used in traditional Moroccan medicine. The antioxidant capacity was estimated by DPPH test, ferrous ion chelating activity and ABTS test. As results, the highest antioxidant activities were found in Mentha suaveolens, Salvia officinalis and Mentha viridis. Different species showed significant differences in their total phenolic content (TPC). The highest level of phenolics was found in Salvia officinalis and the lowest...

  19. Impacto da farinha de mandioca fortificada com ferro aminoácido quelato no nível de hemoglobina de pré-escolares Impact of cassava flour fortified with iron amino acid chelate on the hemoglobin level in pre-schools

    Directory of Open Access Journals (Sweden)

    Rahilda Brito Tuma

    2003-01-01

    Full Text Available OBJETIVO: Avaliou-se o impacto da farinha de mandioca fortificada com ferro aminoácido quelato em 80 pré-escolares de uma Unidade Filantrópica de Manaus, AM, distribuídos aleatoriamente em quatro grupos de 20 crianças cada, por um período de 120 dias. MÉTODOS: Foram utilizadas farinha de mandioca sem fortificação (Grupo zero e fortificada com 1, 2 e 3mg de Fe/dia, correspondendo a quantias diárias de 5, 10 e 15g de farinha, respectivamente, as quais foram distribuídas no horário do almoço, sendo ainda entregue às famílias a quantidade destinada ao consumo do final de semana. O estado nutricional das crianças foi avaliado no início e ao final do experimento, adotando-se como limite discriminatório entre eutrofia/desnutrição o ponto de corte OBJECTIVE: The impact of the cassava flour fortified with iron amino acid chelate was evaluated in 80 pre-scholars of a Philanthropic Unit of Manaus, state of Amazonas, randomly distributed in four groups of 20 children each, for a period of 120 days. METHODS: Cassava flour was used without fortification (group zero or fortified with 1, 2 and 3mg of Fe/day, corresponding respectively to 5, 10 and 15g of flour/day, which were given to the children at lunch time on weekdays. The equivalent amount was previously distributed to their families for flour intake also during the weekends. In the beginning and at the end of the experiment the children's nutritional status was evaluated, being adopted the cutoff point <-2 Z-scores as a discriminating limit between eutrophy/malnutrition, in agreement with the World Health Organization criteria, as well as being established as a cutoff point for the occurrence of iron deficiency anemia a hemoglobin rate of less than 11g/dL. RESULTS: At the end of this study, children recovered from chronic malnutrition, and a significant increase (p <5% of the hemoglobin rates, independently of iron concentration, from 11.4±0.9g/dL to 12.2±0.8g/dL, was observed in

  20. Iron Oxide Nanoparticles as a Potential Iron Fertilizer for Peanut (Arachis hypogaea)

    Science.gov (United States)

    Rui, Mengmeng; Ma, Chuanxin; Hao, Yi; Guo, Jing; Rui, Yukui; Tang, Xinlian; Zhao, Qi; Fan, Xing; Zhang, Zetian; Hou, Tianqi; Zhu, Siyuan

    2016-01-01

    Nanomaterials are used in practically every aspect of modern life, including agriculture. The aim of this study was to evaluate the effectiveness of iron oxide nanoparticles (Fe2O3 NPs) as a fertilizer to replace traditional Fe fertilizers, which have various shortcomings. The effects of the Fe2O3 NPs and a chelated-Fe fertilizer (ethylenediaminetetraacetic acid-Fe; EDTA-Fe) fertilizer on the growth and development of peanut (Arachis hypogaea), a crop that is very sensitive to Fe deficiency, were studied in a pot experiment. The results showed that Fe2O3 NPs increased root length, plant height, biomass, and SPAD values of peanut plants. The Fe2O3 NPs promoted the growth of peanut by regulating phytohormone contents and antioxidant enzyme activity. The Fe contents in peanut plants with Fe2O3 NPs and EDTA-Fe treatments were higher than the control group. We used energy dispersive X-ray spectroscopy (EDS) to quantitatively analyze Fe in the soil. Peanut is usually cultivated in sandy soil, which is readily leached of fertilizers. However, the Fe2O3 NPs adsorbed onto sandy soil and improved the availability of Fe to the plants. Together, these results show that Fe2O3 NPs can replace traditional Fe fertilizers in the cultivation of peanut plants. To the best of our knowledge, this is the first research on the Fe2O3 NPs as the iron fertilizer. PMID:27375665

  1. DESORPTION OF METAL IONS FROM KRAFT PULPS. PART 1. CHELATION OF HARDWOOD AND SOFTWOOD KRAFT PULP WITH EDTA

    OpenAIRE

    Kim Granholm; Leo Harju; Ari Ivaska

    2010-01-01

    Chelation of unbleached and oxygen bleached hardwood and softwood kraft pulps with EDTA was studied. The main focus was on the desorption of magnesium, manganese, and iron due to their impact in TCF-bleaching. Desorption of other metal ions present were also studied in order to get an over-all estimation of the metal ion concentrations and their desorption during chelation. By using the concept of side reaction coefficients, an estimation of the chelating strength of EDTA at different pH can ...

  2. (Dithiocarbamato)iron(II) complexes: Photochemical chelation and ligand exchange, comparison with electron-transfer processes, and X-ray crystal structures of Fe(. eta. sup 5 -C sub 5 Me sub 5 )(. eta. sup 1 -SC(S)NMe sub 2 )(CO) sub 2 and Fe(. eta. sup 5 -C sub 5 Me sub 5 )(. eta. sup 2 -S sub 2 CNMe sub 2 )(PPh sub 3 )

    Energy Technology Data Exchange (ETDEWEB)

    Desbois, M.H.; Astruc, D. (Universite de Bordeaux I, Talence (France)); Nunn, C.M.; Cowley, A.H. (Univ. of Texas, Austin (USA))

    1990-03-01

    The X-ray crystal structure of FeCp{sup *}({eta}{sup 1}-dtc)(CO){sub 2} (1, Cp{sup *} = {eta}{sup 5}-C{sub 5}Me{sub 5}, dtc = S{sub 2}CNMe{sub 2}) confirms that the dithiocarbamate ligand is bound to iron in a monodentate mode. The photochemical chelation of 1 is carried out in dichloromethane using visible light and quantitatively gives the chelate FeCp{sup *}({eta}{sup 2}-dtc)(CO) (2) and CO. This reaction is the best route to 2 and compares with the electron-transfer chain (ETC) processes 1 {yields} 2 catalyzed by either oxidizing or reducing agents. The photolytic reaction, which can be carried out by monochromatic (330 nm) irradiation and monitored by visible spectroscopy, gives to isosbestic points at 394 and 432 nm. Both complexes 1 and 3 crystallize in a triclinic system. 1: a = 8.582 (2) {angstrom}, b = 9.046 (4) {angstrom}, c = 12.377 (7) {angstrom}, {alpha} = 97.05 (4){degree}, {beta} = 96.84 (3){degree}, {gamma} = 111.99 (3){degree}, space group P{bar 1}, Z = 2. 3: a = 11.142 (4) {angstrom}, b = 14.958 (4) {angstrom}, c = 10.382 (4) {angstrom}, {alpha} = 98.22 (2){degree}, {beta} = 115.22 (3){degree}, {gamma} 102.62 (3){degree}, space group P{bar 1}, Z = 2.

  3. Iron and Iron Metabolism

    OpenAIRE

    Melike Sezgin Evim; Birol Baytan; Adalet Meral Güneş

    2012-01-01

    Iron is an essential element for almost all living organisms except some bacteria. A great number of new articles related to the iron metabolism have been published in recent years explaining new findings. Hepsidine, a peptide hormon, that is recently found, regulates iron methabolism by effecting iron absorbsion from gut, secreting iron from hepatic store and flows iron from macrophages. Hepsidin blockes to effluxe iron from cells by bounding to ferroportin and by inducing ferroportin destru...

  4. Evaluation of a new tablet formulation of deferasirox to reduce chronic iron overload after long-term blood transfusions

    Directory of Open Access Journals (Sweden)

    Chalmers AW

    2016-02-01

    Full Text Available Anna W Chalmers, Jamile M Shammo Department of Internal Medicine, Division of Hematology/Oncology, Rush University Medical Center, Chicago, IL, USA Abstract: Transfusion-dependent anemia is a common feature in a wide array of hematological disorders, including thalassemia, sickle cell disease, aplastic anemia, myelofibrosis, and myelodysplastic syndromes. In the absence of a physiological mechanism to excrete excess iron, chronic transfusions ultimately cause iron overload. Without correction, iron overload can lead to end-organ damage, resulting in cardiac, hepatic, and endocrine dysfunction/failure. Iron chelating agents are utilized to reduce iron overload, as they form a complex with iron, leading to its clearance. Iron chelation has been proven to decrease organ dysfunction and improve survival in certain transfusion-dependent anemias, such as β-thalassemia. Several chelating agents have been approved by the United States Food and Drug Administration for the treatment of iron overload, including deferoxamine, deferiprone, and deferasirox. A variety of factors have to be considered when choosing an iron chelator, including dosing schedule, route of administration, tolerability, and side effect profile. Deferasirox is an orally administered iron chelator with proven efficacy and safety in multiple hematological disorders. There are two formulations of deferasirox, a tablet for suspension, and a new tablet form. This paper is intended to provide an overview of iron overload, with a focus on deferasirox, and its recently approved formulation Jadenu® for the reduction of transfusional iron overload in hematological disorders. Keywords: iron chelation therapy, transfusional iron overload, deferasirox

  5. COMPARATIVE EVALUATION OF ANTIOXIDANT AND ANTIHEMOLYTIC CAPACITIES OF PLANTS OF INDIAN ORIGIN USING MULTIPLE ANTIOXIDANT ASSAYS

    OpenAIRE

    Deepinderjeet Singh Joshan; Shruti Rawal

    2012-01-01

    The present study is concerned with both in-vitro assessment of antioxidant activity and anti-hemolytic effects of Ficus bengalensis, Calendula officinalis and Juglans regia. Total flavonoids and phenolics also were determined by using aluminum nitrate and Folin–Ciocalteu colorimetric methods respectively. The antioxidant capacity of sample was assessed through reducing power assay, DPPH-scavenging effect,metal chelation assay and superoxide scavenging assay. The extract of Calendula officina...

  6. Moessbauer Spectroscopy of Iron Containing Vitamins and Dietary Supplements

    International Nuclear Information System (INIS)

    Moessbauer spectroscopy was used to study various industrial samples of vitamins containing ferrous fumarate and ferrous bisglycinate chelate (Ferrochel) and dietary supplements containing ferrous sulfate. The presence of small quantities of various ferric impurities was found. Two vitamins contained major iron compounds that did not correspond to ferrous fumarate and ferrous bisglycinate chelate.

  7. Status of chelation research: a review

    International Nuclear Information System (INIS)

    The current status of research on the removal of actinide elements from the body is reviewed. Items occurring prior to 1980 include evidence for fetal toxicity from Ca-DTPA, the FDA approval of Zn-DTPA for human therapy, the mixed ligand fiasco, and the abrupt wipeout of chelation funding. New concepts that should be explored include improvements in removing radioactivity from lung and bone, the effectiveness of DTPA inside cells, simultaneous therapy with mobilizing agents and chelating agents, prolonging the retention of chelating agents within the body, the oral administration of chelating agents, the effectiveness of LICAM and other new chelating agents, the safety of decorporation procedures, and the effectiveness of chelation therapy on reducing the risk from radionuclide-induced cancer. Some physicians give DTPA by intravenous injection, a safe procedure that should be officially sanctioned

  8. Efficient solvent extraction of antioxidant-rich extract from a tropical diatom,Chaetoceros calcitrans (Paulsen) Takano 1968

    Institute of Scientific and Technical Information of China (English)

    Su Chern Foo; Fatimah Md Yusoff; Maznah Ismail; Mahiran Basri; Nicholas Mun Hoe Khong; Kim Wei Chan; Sook Kun Yau

    2015-01-01

    Objective:To compare thein vitro antioxidant capacity of a diatom,Chaetoceros calcitrans (C. calcitrans) extracted using six types of solvents. Methods:Each extract was evaluated in terms of extraction yield, total carotenoid, fucoxanthin content, total phenolic and antioxidant capacities (DPPH• andABTS•+ scavenging activity and iron chelating activity). Results: The methanol extract exhibited the highest yield [(22.71 ± 0.96) g/100 g dry weight (DW)], total carotenoid [(4.46 ± 0.36) mg/g DW], total phenolic [(2.49 ± 0.08) mg gallic acid equivalents/g DW] and second highest fucoxanthin content [(2.08 ± 0.03) mg fucoxanthin/g DW] as compared to other solvent extracts. Methanolic extract also exhibited significantly higher (P Conclusions: Methanol was the recommended solvent for the production of antioxidant rich extract fromC. calcitrans. Both carotenoids and phenolic acids were found to be positively correlated to the antioxidant capacities ofC. calcitrans. Lead bioactives confirmed by subsequent high performance liquid chromatography studies were fucoxanthin, gallic acid and protocatechuic acid.

  9. Environmental biogeochemistry of chelating agents and recommendations for the disposal of chelated radioactive wastes

    International Nuclear Information System (INIS)

    The environmental chemistry of the three most common aminopolycarboxylic acid chelating agents, NTA (nitrilotriacetic acid), EDTA (ethylenediaminetetraacetic acid), and DTPA (diethylenetriaminepentaacetic acid) is reviewed. This review includes information on their persistence in the environment, as well as their tendency to form complexes with actinides. Data on the sorption of chelated actinides by geologic substrates and on the uptake of chelated actinides by plants are also presented. Three different technical options for disposing chelated low-level radioactive wastes are proposed: bind the solidified chelated waste in some kind of solid matrix that has a slow leach rate and bury the waste in a ''dry'' disposal site; substitute biodegradable chelating agents in the decontamination reagent for the chelating agents that are persistent in the environment; chemically or thermally degrade the chelating agents in the waste prior to disposal. The relative advantages and disadvantages of each of these options are discussed. 81 refs

  10. High-throughput assay comparison and standardization for metal chelating capacity screening: A proposal and application.

    Science.gov (United States)

    Santos, Jânio Sousa; Alvarenga Brizola, Vitor Rafael; Granato, Daniel

    2017-01-01

    Aiming to standardize the experimental protocols to assess the ability to chelate Fe(2+) and Cu(2+) using 96-well microplates, we analyzed Brazilian coffees (n=20) as a study-case in relation to their antioxidant activity using conventional methods (DPPH and FRAP assays) and correlated the results with the total phenolic content (TPC) using bivariate and multivariate statistical approaches. Complementarily, we assessed the repeatability, reproducibility, recovery, and linearity of both methods. Data showed that the proposed assays presented a good repeatability and reproducibility (assays, respectively. Both methods were linear in the range of 0-100mg EDTA equivalents/L. Cu(2+)-chelating ability was significantly correlated to FRAP, DPPH, and TPC, while sparse (passays can be used to assess the ability of plant-based extracts to chelate Fe(2+) and Cu(2+)in vitro. PMID:27507505

  11. Production of chelating agents by Pseudomonas aeruginosa grown in the presence of thorium and uranium

    International Nuclear Information System (INIS)

    Chelating agents produced by microorganisms enhance the dissolution of iron increasing the mobility and bioavailability of the metal. Since some similarities exist in the biological behavior of ferric, thorium and uranyl ions, microorganisms resistant to these metals and which grow in their presence may produce sequestering agents of Th and U, and other metals in a manner similar to the complexation of iron by siderophores. The ability of P. aeruginosa to elaborate sequestering agents in medium containing thorium or uranium salts was tested. Uranium has a stronger inhibitory effect on growth of the organism than thorium at similar concentrations. Analyses of the culture media have shown, that relative to the control, and under the experimental conditions used, the microorganisms have produced several new chelating agents for thorium and uranium. Extracts containing these chelating agents have been tested for their decorporation potential. In vitro mouse liver bioassay and in vivo mouse toxicity tests indicate that their efficiency is comparable to DTPA and DFOA and that they are virtually non-toxic to mice. The bacterially produced compounds resemble, but are not identical to the known iron chelating siderophores isolated from microorganisms. Some of their chemical properties are also discussed. (author)

  12. Direct measurement of metal ion chelation in the active site of human ferrochelatase†

    OpenAIRE

    Hoggins, M.; Dailey, H. A.; Hunter, C.N.; Reid, J. D.

    2007-01-01

    The final step in heme biosynthesis, insertion of ferrous iron into protoporphyrin IX, is catalyzed by protoporphyrin IX ferrochelatase (E.C. 4.99.1.1). It is demonstrated that the pre-steady state human ferrochelatase (R115L) shows a stoichiometric burst of product formation and substrate consumption, consistent with a rate determining step following metal-ion chelation. Detailed analysis shows that chelation requires at least two steps, rapid binding followed by a slower (k ca. 1 s−1) irrev...

  13. Antioxidant status of faeces of captive black rhinoceros (Diceros bicornis) in relation to dietary tannin supplementation.

    Science.gov (United States)

    Clauss, M; Pellegrini, N; Castell, J C; Kienzle, E; Dierenfeld, E S; Hummel, J; Flach, E J; Streich, W J; Hatt, J-M

    2006-08-01

    In context with the frequent observations of excessive iron (Fe) storage in captive black rhinoceroses (Diceros bicornis), it has been suggested that both an excessive dietary Fe content and a lack of dietary Fe-chelating substances, such as tannins, is the underlying cause. Therefore, studies on the effects of tannin supplementation to captive diet are warranted. Six captive rhinoceroses were fed their normal zoo diet (N), and a similar diet supplemented with either tannic acid (T, hydrolysable tannin) or quebracho (Q, condensed tannins), and the total antioxidant capacity (TAC) was measured as mmol Trolox equivalents per kg fresh faeces. The TAC values on diets N (1.24 +/- 0.39 mmol/kg fresh faeces) and T (1.34 +/- 0.33 mmol/kg fresh faeces) were similar, but significantly higher on diet Q (2.32 +/- 0.61 mmol/kg fresh faeces). In contrast to expectations, faecal TAC increased with increasing faecal Fe, possibly as a result of the fact that the faecal Fe content was positively correlated to the proportion of concentrate feeds in the diet, which also contain antioxidants, such as vitamin E, in addition to Fe. Increased antioxidant status caused by the use of tannin substances could have a beneficial effect on animal health, but if tannins should be incorporated in designed diets, other tannin sources, such as grape pomace should be tested. PMID:16901277

  14. Antioxidant activity of methanolic leaf extract of Moringa peregrina (Forssk.) Fiori.

    OpenAIRE

    Dehshahri, S.; Wink, M.; Afsharypuor, S.; Asghari, G.; Mohagheghzadeh, A.

    2012-01-01

    Natural antioxidants have an important role in the prevention of many age-related diseases and promotion of health. Among natural antioxidants from plants, flavonoids and other phenolic compounds are potent antioxidants and chelating agents. Moringa peregrina (Forssk.) Fiori (Moringaceae) is a small desert tree distributed from tropical Africa to east India. Moringa tree is also growing in south-east of Iran. The antioxidant activity of M. peregrina methanolic leaf extract on 2,2-diphenyl-1-p...

  15. Antioxidant activity of ethanolic extract from cultivated strawberries’ leaves (Fragariae folium

    Directory of Open Access Journals (Sweden)

    Stanojević Ljiljana P.

    2015-01-01

    Full Text Available Strawberry is a member of the rose family (Rosaceae, subfamily Rosoideae, tribe Potentilleae in the genus Fragaria. The cultivated varieties of commercial strawberries usually were designated as Fragaria ananassa. Root, leaf, flower and fruit have the healing properties. The strawberry leaves extract is used for blood cleaning, for treatment of oral inflammation, diarrhea, various gastro-intestinal inflammation, and hemorrhoids, as well as a diuretic. So far, many positive biological effects of strawberries (anticancer, antioxidant and anticoagulant effect have been proven. The purpose of this study was to evaluate the antioxidant potential of ethanolic extract from cultivated strawberries (Fragariae folium, varieties Senga Sengana by using different antioxidant assays (DPPH, FRAP, FIC, H2O2 and TBA-MDA. Ethanolic extract from strawberry leaves was obtained by reflux extraction at the boiling temperature. Total phenols and total flavonoids content was determined spectrophotometrically by the method of Folin-Ciocalteu and by method with AlCl3, respectively. In the extract was determined high content of total phenols, while the total flavonoid content is much lower. The concentrations of extract required to neutralize 50% of the initial concentration of DPPH radicals (EC50 after 20 minutes incubation and immediately after adding DPPH radical solution were 7,91 and 19,46 μgcm-3, respectively. Extract was achieved the maximum iron ions chelating ability (67.89% at a concentration of 2 mgcm-3. Inhibition of lipid peroxidation of 70% was achieved by extract concentration of 0.03125 mgcm-3, while the maximum neutralization of H2O2 (30.47% was achieved by extract concentration of 0.5 mgcm-3. FRAP value of the investigated extract is 284.51 mgFe/g of dry extract. Presented results of the antioxidant activity show that the obtained extract from the cultivated strawberry leaves is a potential source of natural antioxidants. [Projekat Ministarstva nauke

  16. Metal ions, Alzheimer's disease and chelation therapy.

    Science.gov (United States)

    Budimir, Ana

    2011-03-01

    In the last few years, various studies have been providing evidence that metal ions are critically involved in the pathogenesis of major neurological diseases (Alzheimer, Parkinson). Metal ion chelators have been suggested as potential therapies for diseases involving metal ion imbalance. Neurodegeneration is an excellent target for exploiting the metal chelator approach to therapeutics. In contrast to the direct chelation approach in metal ion overload disorders, in neurodegeneration the goal seems to be a better and subtle modulation of metal ion homeostasis, aimed at restoring ionic balance. Thus, moderate chelators able to coordinate deleterious metals without disturbing metal homeostasis are needed. To date, several chelating agents have been investigated for their potential to treat neurodegeneration, and a series of 8-hydroxyquinoline analogues showed the greatest potential for the treatment of neurodegenerative diseases. PMID:21406339

  17. Structural, Chemical and Biological Aspects of Antioxidants for Strategies Against Metal and Metalloid Exposure

    Directory of Open Access Journals (Sweden)

    Swaran J. S. Flora

    2009-01-01

    Full Text Available Oxidative stress contributes to the pathophysiology of exposure to heavy metals/metalloid. Beneficial renal effects of some medications, such as chelation therapy depend at least partially on the ability to alleviate oxidative stress. The administration of various natural or synthetic antioxidants has been shown to be of benefit in the prevention and attenuation of metal induced biochemical alterations. These include vitamins, N-acetylcysteine, α-lipoic acid, melatonin, dietary flavonoids and many others. Human studies are limited in this regard. Under certain conditions, surprisingly, the antioxidant supplements may exhibit pro-oxidant properties and even worsen metal induced toxic damage. To date, the evidence is insufficient to recommend antioxidant supplements in subject with exposure to metals. Prospective, controlled clinical trials on safety and effectiveness of different therapeutic antioxidant strategies either individually or in combination with chelating agent are indispensable. The present review focuses on structural, chemical and biological aspects of antioxidants particularly related to their chelating properties.

  18. Baicalin interferes with iron accumulation in C6 glioma cells

    Institute of Scientific and Technical Information of China (English)

    Chunyan Guo; Xin Chen

    2011-01-01

    Baicalin reacts with ferric ammonium citrate and acts as an-iron chelator. The maximal reaction time for baicalin to interact with irons was approximately 3 hours. C6 glioma cell survival decreased following iron-loading, with a large number of cells accumulating iron. In addition, lipid peroxidation increased. Iron accumulation and lipid peroxidation were the major cause of cellular death. Baicalin and ferric ammonium citrate alleviated iron accumulation in C6 cells and lowered the mortality of nerve cells. In addition, malondialdehyde and lactate dehydrogenase levels reduced. These results indicate that baicalin strongly inhibits lipid peroxidation via chelation, reduces the content of iron in C6 cells, lowers lipid peroxidation, and thus plays a protective role against iron-induced nerve cell death.

  19. COMPARATIVE EVALUATION OF ANTIOXIDANT AND ANTIHEMOLYTIC CAPACITIES OF PLANTS OF INDIAN ORIGIN USING MULTIPLE ANTIOXIDANT ASSAYS

    Directory of Open Access Journals (Sweden)

    Deepinderjeet Singh Joshan

    2012-09-01

    Full Text Available The present study is concerned with both in-vitro assessment of antioxidant activity and anti-hemolytic effects of Ficus bengalensis, Calendula officinalis and Juglans regia. Total flavonoids and phenolics also were determined by using aluminum nitrate and Folin–Ciocalteu colorimetric methods respectively. The antioxidant capacity of sample was assessed through reducing power assay, DPPH-scavenging effect,metal chelation assay and superoxide scavenging assay. The extract of Calendula officinalis was found to be more efficient in as antioxidant and anti-hemolytic agents using the in vitro assays as compared to Ficus bengalensis and Juglans regia.

  20. Use of countercurrent chromatography during isolation of 6-hydroxyluteolin-7-O-β-glucoside, a major antioxidant of Athrixia phylicoides.

    Science.gov (United States)

    de Beer, Dalene; Joubert, Elizabeth; Malherbe, Christiaan J; Jacobus Brand, D

    2011-09-01

    Athrixia phylicoides, an indigenous South African herbal tea, has potential as a source of nutraceutical antioxidant extracts. Countercurrent chromatography (CCC) was employed as part of a multi-step process to isolate one of the major antioxidant compounds in A. phylicoides extracts. Antioxidant activity of the extracts was comparable to commercial nutraceutical extracts from Aspalathus linearis and Cyclopia spp. in a range of assays. The extracts were tested for radical scavenging (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) di-ammonium radical cation (ABTS·⁺) scavenging, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging and oxygen radical absorbance capacity (ORAC)), ferric reducing antioxidant potential (FRAP) and iron chelating activity, as well as inhibition of microsomal lipid and linoleic acid emulsion oxidation. After extraction optimisation, the antioxidant activity of the major phenolic compounds in an A. phylicoides extract was determined using the on-line HPLC-diode-array-DPPH and -ABTS·⁺ radical scavenging assays. Major compounds reported for the first time included chlorogenic acid, 1,3-dicaffeoylquinic acid, several hydroxycinnamic acid derivatives, including dicaffeoyl quinic acids, and an unidentified flavone-hexose. Finally, CCC was used in conjunction with liquid-liquid partitioning and semi-preparative reversed-phase HPLC to isolate 6-hydroxyluteolin-7-O-β-glucoside (a major antioxidant) and quercetagetin-7-O-β-glucoside (a minor compound present in CCC fraction containing 6-hydroxyluteolin-7-O-β-glucoside) from an A. phylicoides extract. The chemical structures of the isolated compounds were confirmed by LC high-resolution electrospray ionisation MS, as well as ¹H, ¹³C and 2D NMR spectroscopy. This is the first report of the isolation of these compounds from A. phylicoides. PMID:21236437

  1. Antioxidant activities of Sarcodon imbricatum wildly grown in the black sea region of Turkey

    Directory of Open Access Journals (Sweden)

    Tevfik Ozen

    2010-01-01

    Full Text Available The antioxidant activities of the methanol extract of Sarcodon imbricatum wildly grown in the Black Sea Region of Turkey were investigated in this study. Antioxidant activities were evaluated in terms of total antioxidant activity, reducing power, metal chelating ability, inhibition of linoleic acid peroxidation, superoxide, peroxide and hydrogen peroxide scavenging effects. Various antioxidant activities were compared to references antioxidants such as α-tocopherol, butylated hydroxyanisole (BHA, butylated hydroxytoluene (BHT, and trolox. In total antioxidant (12674.45 ΅mol α-tocopherol/g of extract, superoxide scavenging (53.74% and peroxide scavenging activity (45.73%, the methanol extract of Sarcodon imbricatum showed stronger activity patterns than that of references antioxidants. Reducing power, metal chelating activity and free radical (DPPH· scavenging activity was increased with the increasing concentration. The contents of total phenolic, flavonoid, anthocyanin, ascorbic acid, β-carotene and lycopene of Sarcodon imbricatum were determined and found to be noteworthy.

  2. Bacterial siderophores efficiently provide iron to iron-starved tomato plants in hydroponics culture

    OpenAIRE

    Radzki, W.; Gutierrez Mañero, F. J.; Algar, E.; Lucas García, J. A.; García-Villaraco, A.; Ramos Solano, B.

    2013-01-01

    Iron is one of the essential elements for a proper plant development. Providing plants with an accessible form of iron is crucial when it is scant or unavailable in soils. Chemical chelates are the only current alternative and are highly stable in soils, therefore, posing a threat to drinking water. The aim of this investigation was to quantify siderophores produced by two bacterial strains and to determine if these bacterial siderophores would palliate chlorotic symptoms of iron-starved toma...

  3. Liver iron content determination by magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Konstantinos; Tziomalos; Vassilios; Perifanis

    2010-01-01

    Accurate evaluation of iron overload is necessary to establish the diagnosis of hemochromatosis and guide chelation treatment in transfusion-dependent anemia. The liver is the primary site for iron storage in patients with hemochromatosis or transfusion-dependent anemia, therefore, liver iron concentration (LIC) accurately re? ects total body iron stores. In the past 20 years, magnetic resonance imaging (MRI) has emerged as a promising method for measuring LIC in a variety of diseases. We review the potenti...

  4. Chelating agents in pharmacology, toxicology and therapeutics

    International Nuclear Information System (INIS)

    The proceedings contain 71 abstracts of papers. Fourteen abstracts were inputted in INIS. The topics covered include: the effects of chelating agents on the retention of 63Ni, 109Cd, 203Hg, 144Ce, 95Nb and the excretion of 210Po, 63Ni, 48V, 239Pu, 241Am, 54Mn; the applications of tracer techniques for studies of the efficacy of chelation therapy in patients with heart and brain disorders; and the treatment of metal poisoning with chelating agents. (J.P.)

  5. Degradation of the Ferric Chelate of EDTA by a Pure Culture of an Agrobacterium sp

    OpenAIRE

    Lauff, John J.; Steele, D. Bernie; Coogan, Louise A.; Breitfeller, James M.

    1990-01-01

    A pure culture of an Agrobacterium sp. (deposited as ATCC 55002) that mineralizes the ferric chelate of EDTA (ferric-EDTA) was isolated by selective enrichment from a treatment facility receiving industrial waste containing ferric-EDTA. The isolate grew on ferric-EDTA as the sole carbon source at concentrations exceeding 100 mM. As the degradation proceeded, carbon dioxide, ammonia, and an unidentified metabolite(s) were produced; the pH increased, and iron was precipitated from solution. The...

  6. Responses to Iron-Deficiency in Arabidopsis-Thaliana - The Turbo Iron Reductase does not depend on the Formation of Root Hairs and Transfer Cells.

    NARCIS (Netherlands)

    Moog, P.R.; Van der Kooij, T.A.W.; Bruggemann, W.; Schiefelbein, J.W.; Kuiper, P.J.C.

    1995-01-01

    Arabidopsis thaliana (L.) Heynh. Columbia wild type and a root hair-less mutant RM57 were grown on iron-containing and iron-deficient nutrient solutions. In both genotypes, ferric chelate reductase (FCR) of intact roots was induced upon iron deficiency and followed a Michaelis-Menten kinetic with a

  7. Quality of life, clinical effectiveness, and satisfaction in patients with beta thalassemia major and sickle cell anemia receiving deferasirox chelation therapy

    OpenAIRE

    Senol, Sefika Pinar; Tiftik, Eyup Naci; Unal, Selma; Akdeniz, Aydan; Tasdelen, Bahar; Tunctan, Bahar

    2016-01-01

    Objectives: There is a need to remove excess iron with iron chelation therapy (ICT) to avoid the serious clinical sequelae associated with iron overload in patients with beta thalassemia major (BTM) and sickle cell anemia (SCA). Due to the effects of the diseases and their treatments, ICT is still a major reason for unsatisfactory compliance. The aim of this single-center observational study was to evaluate the quality of life, clinical effectiveness, and satisfaction in pediatric and adult p...

  8. Chelation therapy after the Trial to Assess Chelation Therapy: results of a unique trial

    OpenAIRE

    Maria D. Avila; Escolar, Esteban; Lamas, Gervasio A.

    2014-01-01

    Purpose of review EDTA chelation therapy has been in off-label use for the treatment of atherosclerosis. We review the results of the first large-scale randomized trial of this treatment. Recent findings The trial to assess chelation therapy was a $30 million National Institutes of Health-funded study of the safety and efficacy of EDTA-based chelation infusions in 1708 post-myocardial infarction (MI) patients. The trial to assess chelation therapy demonstrated a significant (P = 0.035) 18% re...

  9. Antioxidant activity of wheat and buckwheat flours

    Directory of Open Access Journals (Sweden)

    Sedej Ivana J.

    2010-01-01

    Full Text Available Antioxidative activities of wheat flours (type 500 and wholegrain and buckwheat flours (light and wholegrain were tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH·-scavenging activity, reducing power and chelating activity on Fe2+. Also, the content of the total phenolics of ethanolic extracts was estimated. Polyphenolics content (expressed as gallic acid equivalent, GAE in wheat flours varied between 37.1 and 137.2 μg GAE/g extract, while its content in buckwheat flour were at least four time higher and ranged between 476.3 and 618.9μg GAE/g extract. Ethanolic extracts of buckwheat flours exhibited higher antioxidant activities in all the assays, except for chelating activity. Regarding all the obtained results, it can be concluded that bakery products produced with buckwheat flour could be regarded as potential functional foods.

  10. Fluid extraction using carbon dioxide and organophosphorus chelating agents

    Science.gov (United States)

    Smart, Neil G.; Wai, Chien M.; Lin, Yuehe; Kwang, Yak Hwa

    1998-01-01

    Methods for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical CO.sub.2, and a chelating agent are described. The chelating agent forms a chelate with the species, the chelate being soluble in the fluid to allow removal of the species from the material. In preferred embodiments the extraction solvent is supercritical CO.sub.2 and the chelating agent comprises an organophosphorous chelating agent, particularly sulfur-containing organophosphorous chelating agents, including mixtures of chelating agents. Examples of chelating agents include monothiophosphinic acid, di-thiophosphinic acid, phosphine sulfite, phosphorothioic acid, and mixtures thereof. The method provides an environmentally benign process for removing metal and metalloids from industrial waste solutions, particularly acidic solutions. Both the chelate and the supercritical fluid can be regenerated and the contaminant species recovered to provide an economic, efficient process.

  11. Chemistry and pharmacological properties of some natural and synthetic antioxidants for heavy metal toxicity.

    Science.gov (United States)

    Flora, S J S; Shrivastava, Rupal; Mittal, Megha

    2013-01-01

    Heavy metals are known to cause oxidative deterioration of bio-molecules by initiating free radical mediated chain reaction resulting in lipid per-oxidation, protein oxidation and oxidation of nucleic acid like DNA and RNA. The development of effective dual functioning antioxidants, possessing both metal-chelating and free radical-scavenging properties should bring into play. Administration of natural and synthetic antioxidants like, quercetin, catechin, taurine, captopril, gallic acid, melatonin, N-acetyl cysteine, α- lipoic acid and others have been recognized in the disease prevention and clinical recovery against heavy metal intoxication. These antioxidants affect biological systems not only through direct quenching of free radicals but also via chelation of toxic metal(s). These antioxidants also, have the capacity to enhance cellular antioxidant defense mechanism by regenerating endogenous antioxidants, such as glutathione and vitamin C and E. They also influence cellular signaling and trigger redox sensitive regulatory pathways. The reactivity of antioxidants in protecting against heavy metal induced oxidative stress depends upon their structural properties, their partitioning abilities between hydrophilic and lipophilic environment and their hydrogen donation antioxidant properties. Herein, we review the structural, biochemical and pharmacological properties of selected antioxidants with particular reference to their ability to (i) chelate heavy metals from its complex (ii) ameliorate free radical (iii) terminate heavy metal induced free radical chain reaction (iv) regenerate endogenous antioxidants and, (v) excretion of metal without its redistribution. PMID:24206124

  12. Current Use of Chelation in American Health Care

    OpenAIRE

    Wax, Paul M.

    2013-01-01

    The National Center for Health Statistics estimates that more than 100,000 Americans receive chelation each year, although far fewer than 1 % of these cases are managed by medical toxicologists. Unfortunately, fatalities have been reported after inappropriate chelation use. There are currently 11 FDA-approved chelators available by prescription although chelation products may also be obtained through compounding pharmacies and directly over the internet. Promotion of chelation training is pro...

  13. Lipophilic aroylhydrazone chelator HNTMB and its multiple effects on ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Singh Rakesh K

    2010-02-01

    Full Text Available Abstract Background Metal chelators have gained much attention as potential anti-cancer agents. However, the effects of chelators are often linked solely to their capacity to bind iron while the potential complexation of other trace metals has not been fully investigated. In present study, we evaluated the effects of various lipophilic aroylhydrazone chelators (AHC, including novel compound HNTMB, on various ovarian cancer cell lines (SKOV-3, OVCAR-3, NUTU-19. Methods Cell viability was analyzed via MTS cytotoxicity assays and NCI60 cancer cell growth screens. Apoptotic events were monitored via Western Blot analysis, fluorescence microscopy and TUNEL assay. FACS analysis was carried out to study Cell Cycle regulation and detection of intracellular Reactive Oxygen Species (ROS Results HNTMB displayed high cytotoxicity (IC50 200-400 nM compared to previously developed AHC (oVtBBH, HNtBBH, StBBH/206, HNTh2H/315, HNI/311; IC50 0.8-6 μM or cancer drug Deferoxamine, a hexadentate iron-chelator (IC50 12-25 μM. In a NCI60 cancer cell line screen HNTMB exhibited growth inhibitory effects with remarkable differences in specificity depending on the cell line studied (GI50 10 nM-2.4 μM. In SKOV-3 ovarian cancer cells HNTMB treatment led to chromatin fragmentation and activation of the extrinsic and intrinsic pathways of apoptosis with specific down-regulation of Bcl-2. HNTMB caused delayed cell cycle progression of SKOV-3 through G2/M phase arrest. HNTMB can chelate iron and copper of different oxidation states. Complexation with copper lead to high cytotoxicity via generation of reactive oxygen species (ROS while treatment with iron complexes of the drug caused neither cytotoxicity nor increased ROS levels. Conclusions The present report suggests that both, non-complexed HNTMB as a chelator of intracellular trace-metals as well as a cytotoxic HNTMB/copper complex may be developed as potential therapeutic drugs in the treatment of ovarian and other

  14. Antioxidant activity of taxifolin: an activity-structure relationship.

    Science.gov (United States)

    Topal, Fevzi; Nar, Meryem; Gocer, Hulya; Kalin, Pınar; Kocyigit, Umit M; Gülçin, İlhami; Alwasel, Saleh H

    2016-08-01

    Taxifolin is a kind of flavanonol, whose biological ability. The objectives of this study were to investigate the antioxidants and antiradical activities of taxifolin by using different in vitro bioanalytical antioxidant methods including DMPD√(+), ABTS√(+), [Formula: see text], and DPPH√-scavenging effects, the total antioxidant influence, reducing capabilities, and Fe(2+)-chelating activities. Taxifolin demonstrated 81.02% inhibition of linoleic acid emulsion peroxidation at 30 µg/mL concentration. At the same concentration, standard antioxidants including trolox, α-tocopherol, BHT, and BHA exhibited inhibitions of linoleic acid emulsion as 88.57, 73.88, 94.29, and 90.12%, respectively. Also, taxifolin exhibited effective DMPD√(+), ABTS√(+), [Formula: see text], and DPPH√-scavenging effects, reducing capabilities, and Fe(2+)-chelating effects. The results obtained from this study clearly showed that taxifolin had marked antioxidant, reducing ability, radical scavenging and metal-chelating activities. Also, this study exhibits a scientific shore for the significant antioxidant activity of taxifolin and its structure-activity insight. PMID:26147349

  15. Antioxidant effect of bisphosphonates and simvastatin on chondrocyte lipid peroxidation

    International Nuclear Information System (INIS)

    The objective of this study was to evaluate the effect of bisphosphonates (BPs) and simvastatin on chondrocyte lipid peroxidation. For this purpose, a flow cytometrical method using C11-BODIPY581/591 was developed to detect hydroperoxide-induced lipid peroxidation in chondrocytes. Tertiary butylhydroperoxide (t-BHP) induced a time and concentration dependent increase in chondrocyte lipid peroxidation. Addition of a Fe2+/EDTA complex to t-BHP or hydrogen peroxide (H2O2) clearly enhanced lipid peroxidation. The lipophilic simvastatin demonstrated a small inhibition in the chondrocyte lipid peroxidation. None of three tested BPs (clodronate, pamidronate, and risedronate) had an effect on chondrocyte lipid peroxidation induced by t-BHP. However, when Fe2+/EDTA complex was added to t-BHP or H2O2, BPs inhibited the lipid peroxidation process varying from 25% to 58%. This study demonstrates that BPs have antioxidant properties as iron chelators, thereby inhibiting the chondrocyte lipid peroxidation. These findings add evidence to the therapeutic potential of bisphosphonates and statins in rheumatoid arthritis

  16. Antioxidant measurements.

    Science.gov (United States)

    Somogyi, Anikó; Rosta, Klára; Pusztai, Péter; Tulassay, Zsolt; Nagy, Géza

    2007-04-01

    Chemical reactions, including oxidation and reduction of molecules, occur in every cell. These reactions can lead to the production of free radicals. Free radicals react with organic substrates such as lipids, proteins, and DNA. Through oxidation free radicals cause damage to these molecules, disturbing their normal function, and may therefore contribute to a variety of diseases. The anti-oxidation system, which consists of enzymatic antioxidants and non-enzymatic antioxidants, defends against oxidative stress. The aim of this review is to summarize general aspects of methods to measure the antioxidant defence system all in one (total antioxidant capacity) and discuss a number of methods which are currently used for detection of antioxidant properties. PMID:17395989

  17. Evaluation of a new tablet formulation of deferasirox to reduce chronic iron overload after long-term blood transfusions

    Science.gov (United States)

    Chalmers, Anna W; Shammo, Jamile M

    2016-01-01

    Transfusion-dependent anemia is a common feature in a wide array of hematological disorders, including thalassemia, sickle cell disease, aplastic anemia, myelofibrosis, and myelo-dysplastic syndromes. In the absence of a physiological mechanism to excrete excess iron, chronic transfusions ultimately cause iron overload. Without correction, iron overload can lead to end-organ damage, resulting in cardiac, hepatic, and endocrine dysfunction/failure. Iron chelating agents are utilized to reduce iron overload, as they form a complex with iron, leading to its clearance. Iron chelation has been proven to decrease organ dysfunction and improve survival in certain transfusion-dependent anemias, such as β-thalassemia. Several chelating agents have been approved by the United States Food and Drug Administration for the treatment of iron overload, including deferoxamine, deferiprone, and deferasirox. A variety of factors have to be considered when choosing an iron chelator, including dosing schedule, route of administration, tolerability, and side effect profile. Deferasirox is an orally administered iron chelator with proven efficacy and safety in multiple hematological disorders. There are two formulations of deferasirox, a tablet for suspension, and a new tablet form. This paper is intended to provide an overview of iron overload, with a focus on deferasirox, and its recently approved formulation Jadenu® for the reduction of transfusional iron overload in hematological disorders. PMID:26929633

  18. Evaluation of a new tablet formulation of deferasirox to reduce chronic iron overload after long-term blood transfusions.

    Science.gov (United States)

    Chalmers, Anna W; Shammo, Jamile M

    2016-01-01

    Transfusion-dependent anemia is a common feature in a wide array of hematological disorders, including thalassemia, sickle cell disease, aplastic anemia, myelofibrosis, and myelo-dysplastic syndromes. In the absence of a physiological mechanism to excrete excess iron, chronic transfusions ultimately cause iron overload. Without correction, iron overload can lead to end-organ damage, resulting in cardiac, hepatic, and endocrine dysfunction/failure. Iron chelating agents are utilized to reduce iron overload, as they form a complex with iron, leading to its clearance. Iron chelation has been proven to decrease organ dysfunction and improve survival in certain transfusion-dependent anemias, such as β-thalassemia. Several chelating agents have been approved by the United States Food and Drug Administration for the treatment of iron overload, including deferoxamine, deferiprone, and deferasirox. A variety of factors have to be considered when choosing an iron chelator, including dosing schedule, route of administration, tolerability, and side effect profile. Deferasirox is an orally administered iron chelator with proven efficacy and safety in multiple hematological disorders. There are two formulations of deferasirox, a tablet for suspension, and a new tablet form. This paper is intended to provide an overview of iron overload, with a focus on deferasirox, and its recently approved formulation Jadenu(®) for the reduction of transfusional iron overload in hematological disorders. PMID:26929633

  19. TLc-A, the leading nanochelating-based nanochelator, reduces iron overload in vitro and in vivo.

    Science.gov (United States)

    Kalanaky, Somayeh; Hafizi, Maryam; Safari, Sepideh; Mousavizadeh, Kazem; Kabiri, Mahboubeh; Farsinejad, Alireza; Fakharzadeh, Saideh; Nazaran, Mohammad Hassan

    2016-03-01

    Iron chelation therapy is an effective approach to the treatment of iron overload conditions, in which iron builds up to toxic levels in the body and may cause organ damage. Treatments using deferoxamine, deferasirox and deferiprone have been introduced and despite their disadvantages, they remain the first-line therapeutics in iron chelation therapy. Our study aimed to compare the effectiveness of the iron chelation agent TLc-A, a nano chelator synthetized based on the novel nanochelating technology, with deferoxamine. We found that TLc-A reduced iron overload in Caco2 cell line more efficiently than deferoxamine. In rats with iron overload, very low concentrations of TLc-A lowered serum iron level after only three injections of the nanochelator, while deferoxamine was unable to reduce iron level after the same number of injections. Compared with deferoxamine, TLc-A significantly increased urinary iron excretion and reduced hepatic iron content. The toxicity study showed that the intraperitoneal median lethal dose for TLc-A was at least two times higher than that for deferoxamine. In conclusion, our in vitro and in vivo studies indicate that the novel nano chelator compound, TLc-A, offers superior performance in iron reduction than the commercially available and widely used deferoxamine. PMID:26830968

  20. Pattern of iron distribution in maternal and filial tissues in wheat grains with contrasting levels of iron

    OpenAIRE

    Singh, S. P.; Vogel-Mikus, K.; Arcon, I.; Vavpetic, P.; Jeromel, L.; Pelicon, P.; Kumar, J.; Tuli, R.

    2013-01-01

    Iron insufficiency is a worldwide problem in human diets. In cereals like wheat, the bran layer of the grains is an important source of iron. However, the dietary availability of iron in wheat flour is limited due to the loss of the iron-rich bran during milling and processing and the presence of anti-nutrients like phytic acid that keep iron strongly chelated in the grain. The present study investigated the localization of iron and phosphorus in grain tissues of wheat genotypes with contrast...

  1. Iron and Acinetobacter baumannii Biofilm Formation

    OpenAIRE

    Valentina Gentile; Emanuela Frangipani; Carlo Bonchi; Fabrizia Minandri; Federica Runci; Paolo Visca

    2014-01-01

    Acinetobacter baumannii is an emerging nosocomial pathogen, responsible for infection outbreaks worldwide. The pathogenicity of this bacterium is mainly due to its multidrug-resistance and ability to form biofilm on abiotic surfaces, which facilitate long-term persistence in the hospital setting. Given the crucial role of iron in A. baumannii nutrition and pathogenicity, iron metabolism has been considered as a possible target for chelation-based antibacterial chemotherapy. In this study, w...

  2. Evaluation of the Antioxidant and Antimicrobial Activities of Clary Sage (Salvia sclarea L.)

    OpenAIRE

    GÜLÇİN, İlhami

    2004-01-01

    The present work evaluates the antioxidant and antimicrobial activity of clary sage (CS) Salvia sclarea L. Antimicrobial, total antioxidant, DPPH radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and metal chelating activities, reducing power, and total contents of phenolic compounds of dried herb samples extracted with chloroform and acetone were studied. The chloroform extract had stronger total antioxidant activity than the acetone extract and exhibited ...

  3. The investigation of some bioactive compounds and antioxidant properties of hawthorn (Crataegus monogyna subsp. monogyna Jacq)

    OpenAIRE

    Serhat KESER; Celik, Sait; Turkoglu, Semra; Yilmaz, Okkes; Turkoglu, Ismail

    2014-01-01

    Aim: The antioxidant and pharmacological effects of hawthorn have mainly been attributed to the polyphenolic contents. The aim of this research is to determine some bioactive compounds and antioxidant properties of hawthorn aqueous and ethanol extracts of leaves, flowers, and ripened fruits. Materials and Methods: For this purpose, antioxidant activities of extracts were assessed on DPPH•, ABTS•+, superoxide scavenging, reducing power and ferrous metal chelating activity assays and phenolic c...

  4. ANTIOXIDANT ACTIVITIES AND PHENOLIC PROFILE OF SIX MOROCCAN SELECTED HERBS

    Directory of Open Access Journals (Sweden)

    Madiha Bichra

    2013-02-01

    Full Text Available The present work evaluated the antioxidant capacity of six plants commonly used in traditional Moroccan medicine. The antioxidant capacity was estimated by DPPH test, ferrous ion chelating activity and ABTS test. As results, the highest antioxidant activities were found in Mentha suaveolens, Salvia officinalis and Mentha viridis. Different species showed significant differences in their total phenolic content (TPC. The highest level of phenolics was found in Salvia officinalis and the lowest in Pelargonium roseum. Linear correlation was found between TPC, especially the non-flavonoid content (NFC and the antioxidant activity. Qualitative and quantitative analyzes of major phenolics by reverse-phase high-performance liquid chromatography (RP-HPLC were also performed. On the basis of the obtained results, these studied medicinal herbs were found to serve as a potential source of natural antioxidants due to their richness in phenolic compounds and marked antioxidant activity.

  5. Plasma thiobarbituric acid reactivity: reaction conditions and the role of iron, antioxidants and lipid peroxy radicals on the quantitation of plasma lipid peroxides

    Energy Technology Data Exchange (ETDEWEB)

    Wade, C.R.; van Rij, A.M.

    1988-01-01

    The effects of Fe/sup 3 +/, lipid peroxy radicals and the antioxidant butylated hydroxytoluene on the 2-thiobarbituric (TBA) acid quantitation of plasma lipid peroxides were investigated. Whole plasma and plasma fractions prepared by trichloroacetic acid (TCA) protein precipitation and lipid extraction, demonstrated markedly differing TBA reactivities in the presence or absence of added Fe/sup 3 +/. Examination of the spectral profiles of the TBA reacted whole plasma and TCA precipitated fractions demonstrated the presence of interfering compounds which gave rise to an artifactual increase in lipid peroxide concentrations. In contrast the TBA reacted lipid extracts had low levels of interfering compounds that could be removed by our previously described high pressure liquid chromatographic method. Further characterization of the TBA reactivity of the lipid extract showed that Fe/sup 3 +/ at an optimal concentration of 0.5 mM was necessary for the quantitative decomposition of the lipid peroxides to the TBA reactive product malondialdehyde (MDA). However the presence of Fe/sup 3 +/ resulted in further peroxidation of any unsaturated lipids present.

  6. Copper Chelation in Alzheimer's Disease Protein

    Science.gov (United States)

    Rose, Frisco; Hodak, Miroslav; Bernholc, Jerry

    2013-03-01

    Alzheimer's disease (AD) is a neurodegenerative disorder affecting millions of people in the U.S. AD is primarily characterized at the cellular level by densely tangled fibrils of amyloid- β protein. These protein clusters have been found in association with elevated levels of multiple transition metals, with copper being the most egregious. Interestingly, metal chelation has shown promise in attenuating the symptoms of AD in recent clinical studies. We investigate this process by constructing an atomistic model of the amyloid- β-copper complex and profile the energetic viability in each of its subsequent disassociation stages. Our results indicate that five energetic barriers must be overcome for full metal chelation. The energy barriers are biologically viable in the presence water mediated bond and proton transfer between the metal and the protein. We model the chelation reaction using a consecutive path nudged elastic band method implemented in our ab initio real-space multi-grid code to obtain a viable sequence. This reaction model details a physically consistent explanation of the chelation process that could lead to the discovery of more effective chelation agents in the treatment of AD.

  7. Zn and Mn o,p-EDDHA chelates for soybean nutrition in hydroponics in high pH conditions

    OpenAIRE

    López-Rayo, Sandra; Lucena, Juan J.

    2009-01-01

    The low solubility of the iron, manganese and zinc oxides in the pH range of calcareous soils contributes, among other factors, to the low availability of these nutrients to plants. The aim of this work was study the efficacy of the application of Fe, Mn, Zn and Cu chelates to correct the deficiencies in soybean in hydroponic solution in the presence of CaCO3. Fe was applied as o,oEDDHA/Fe3+ in all the cases while Mn, Zn and Cu were applied as o,pEDDHA, EDDS, EDTA, HEDTA or DTPA chelates, wit...

  8. Optimisation and status of chelation therapy

    International Nuclear Information System (INIS)

    The calcium trisodium salt of diethylenetriaminepentaacetic acid (Ca-DTPA) remains the chelating agent of choice for treatment of incorporated actinides. The zinc trisodium salt (Zn-DTPA) represents a less toxic alternative, when Ca-DTPA is contra-indicated as well as for prolonged chelation therapy; in acute incorporation cases it would be less effective than Ca-DTPA. Specific ion binding chelators such as desferrioxamine (DFOA) and linear tetracatechoylamides, e.g., LICAM(C) proved more effective in animals injected with Pu, Th and Np (not with Am!) but only concerning the radioactivity in the bone; that in the kidneys was substantially increased. The combinations of DFOA or LICAM(C) with Ca-DTPA exerted the best overall effects. After incorporation of soluble uranium-compounds, an infusion of sodium bicarbonate seems at present the most reasonable for enhancing the uranium-excretion and prevention of kidney damage. (author)

  9. Lanthanon chelates of monoprotic tridentate schiff base

    International Nuclear Information System (INIS)

    3-(N-thiophene-2-aldimino)propanoic acid (HTP), and its lanthanon chelates were synthesised and studied by physico-chemical techniques. Irving-Rossotti method was followed to determine the dissociation constants of the ligand and formation constants of its lanthanon chelates in aqueous medium (ionic strength μ = 0.01, 0.05 and 0.1 M NaClO4) at 25 0C, 35 0C and 45 0C. Solid lanthanon chelates were characterised by molecular mass, elemental analyses, conductance, magnetic, thermal and spectral analyses and were assigned 1 : 3 (metal-ligand) stoichiometry in which the lanthanon shows nine coordination numbers. Covalent nature of metal-ligand bond was found to increase with increase in atomic number of central lanthanide ion. (author)

  10. Antioxidant Activities of 4-Methylumbelliferone Derivatives

    Science.gov (United States)

    Al-Majedy, Yasameen K.; Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2016-01-01

    The synthesis of derivatives of 4-Methylumbelliferone (4-MUs), which are structurally interesting antioxidants, was performed in this study. The modification of 4-Methylumbelliferone (4-MU) by different reaction steps was performed to yield the target compounds, the 4-MUs. The 4-MUs were characterized by different spectroscopic techniques (Fourier transform infrared; FT-IR and Nuclear magnetic resonance; NMR) and micro-elemental analysis (CHNS). The in vitro antioxidant activity of the 4-MUs was evaluated in terms of their free radical scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH), Nitric oxide radical scavenging activity assay, chelating activity and their (FRAP) ferric-reducing antioxidant power, which were compared with a standard antioxidant. Our results reveal that the 4-MUs exhibit excellent radical scavenging activities. The antioxidant mechanisms of the 4-MUs were also studied. Density Function Theory (DFT)-based quantum chemical studies were performed with the basis set at 3-21G. Molecular models of the synthesized compounds were studied to understand the antioxidant activity. The electron levels, namely HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), for these synthesized antioxidants were also studied. PMID:27243231

  11. Antioxidant Activities of 4-Methylumbelliferone Derivatives.

    Directory of Open Access Journals (Sweden)

    Yasameen K Al-Majedy

    Full Text Available The synthesis of derivatives of 4-Methylumbelliferone (4-MUs, which are structurally interesting antioxidants, was performed in this study. The modification of 4-Methylumbelliferone (4-MU by different reaction steps was performed to yield the target compounds, the 4-MUs. The 4-MUs were characterized by different spectroscopic techniques (Fourier transform infrared; FT-IR and Nuclear magnetic resonance; NMR and micro-elemental analysis (CHNS. The in vitro antioxidant activity of the 4-MUs was evaluated in terms of their free radical scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH, Nitric oxide radical scavenging activity assay, chelating activity and their (FRAP ferric-reducing antioxidant power, which were compared with a standard antioxidant. Our results reveal that the 4-MUs exhibit excellent radical scavenging activities. The antioxidant mechanisms of the 4-MUs were also studied. Density Function Theory (DFT-based quantum chemical studies were performed with the basis set at 3-21G. Molecular models of the synthesized compounds were studied to understand the antioxidant activity. The electron levels, namely HOMO (highest occupied molecular orbital and LUMO (lowest unoccupied molecular orbital, for these synthesized antioxidants were also studied.

  12. Minocycline Attenuates Iron Neurotoxicity in Cortical Cell Cultures

    OpenAIRE

    Chen-Roetling, Jing; Chen, Lifen; Regan, Raymond F.

    2009-01-01

    Iron neurotoxicity may contribute to the pathogenesis of intracerebral hemorrhage (ICH). The tetracycline derivative minocycline is protective in ICH models, due putatively to inhibition of microglial activation. Although minocycline also chelates iron, its effect on iron neurotoxicity has not been reported, and was examined in this study. Cortical cultures treated with 10 μM ferrous sulfate for 24h sustained loss of most neurons and an increase in malondialdehyde. Minocycline prevented this ...

  13. Antioxidant activity of Fish Protein Hydrolysates from Sardinella longiceps

    Directory of Open Access Journals (Sweden)

    JEEVITHA K

    2014-12-01

    Full Text Available Sardinella longiceps were hydrolysed with the different concentration of proteolytic enzymes trypsin to obtain peptides with antioxidant activity. The degree of hydrolysis and yield of hydrolysates were found increasing with increasing the concentration of enzyme. The antioxidant activities of hydrolysates were investigated through various assays. The hydrolysate exhibited the higher reducing power capability. The hydrolysates has shown a higher scavenging activity against DPPH, Superoxide, hydroxyl radical and metal chelating activity at the maximum concentration of 5mg/ml. The finding of this study reveals that, protein hydrolysates produced has potent antioxidant properties and it could be used as a food supplement in nutraceutical and pharmaceutical industry.

  14. Cytosolic peroxidases protect the lysosome of bloodstream African trypanosomes from iron-mediated membrane damage.

    Directory of Open Access Journals (Sweden)

    Corinna Hiller

    2014-04-01

    Full Text Available African trypanosomes express three virtually identical non-selenium glutathione peroxidase (Px-type enzymes which preferably detoxify lipid-derived hydroperoxides. As shown previously, bloodstream Trypanosoma brucei lacking the mitochondrial Px III display only a weak and transient proliferation defect whereas parasites that lack the cytosolic Px I and Px II undergo extremely fast lipid peroxidation and cell lysis. The phenotype can completely be rescued by supplementing the medium with the α-tocopherol derivative Trolox. The mechanism underlying the rapid cell death remained however elusive. Here we show that the lysosome is the origin of the cellular injury. Feeding the px I-II knockout parasites with Alexa Fluor-conjugated dextran or LysoTracker in the presence of Trolox yielded a discrete lysosomal staining. Yet upon withdrawal of the antioxidant, the signal became progressively spread over the whole cell body and was completely lost, respectively. T. brucei acquire iron by endocytosis of host transferrin. Supplementing the medium with iron or transferrin induced, whereas the iron chelator deferoxamine and apo-transferrin attenuated lysis of the px I-II knockout cells. Immunofluorescence microscopy with MitoTracker and antibodies against the lysosomal marker protein p67 revealed that disintegration of the lysosome precedes mitochondrial damage. In vivo experiments confirmed the negligible role of the mitochondrial peroxidase: Mice infected with px III knockout cells displayed only a slightly delayed disease development compared to wild-type parasites. Our data demonstrate that in bloodstream African trypanosomes, the lysosome, not the mitochondrion, is the primary site of oxidative damage and cytosolic trypanothione/tryparedoxin-dependent peroxidases protect the lysosome from iron-induced membrane peroxidation. This process appears to be closely linked to the high endocytic rate and distinct iron acquisition mechanisms of the infective

  15. Update on the use of deferasirox in the management of iron overload

    Directory of Open Access Journals (Sweden)

    Ali Taher

    2009-10-01

    Full Text Available Ali Taher,1 Maria Domenica Cappellini21American University of Beirut, Beirut, Lebanon; 2Universitá di Milano, Policlinico Foundation IRCCS, Milan, ItalyAbstract: Regular blood transfusions as supportive care for patients with chronic anemia inevitably lead to iron overload as humans cannot actively remove excess iron. The cumulative effects of iron overload cause significant morbidity and mortality if not effectively treated with chelation therapy. Based on a comprehensive clinical development program, the once-daily, oral iron chelator deferasirox (Exjade® is approved for the treatment of transfusional iron overload in adult and pediatric patients with various transfusion-dependent anemias, including β-thalassemia and the myelodysplastic syndromes. Deferasirox dose should be titrated for each individual patient based on transfusional iron intake, current iron burden and whether the goal is to decrease or maintain body iron levels. Doses of >30 mg/kg/day have been shown to be effective with a safety profile consistent with that observed at doses <30 mg/kg/day. Recent data have highlighted the ability of deferasirox to decrease cardiac iron levels and to prevent the accumulation of iron in the heart. The long-term efficacy and safety of deferasirox for up to 5 years of treatment have now been established. The availability of this effective and generally well tolerated oral therapy represents a significant advance in the management of transfusional iron overload. Keywords: deferasirox, Exjade, oral, iron chelation, iron overload, cardiac iron 

  16. Protective effects of ion-imprinted chitooligosaccharides as uranium-specific chelating agents against the cytotoxicity of depleted uranium in human kidney cells

    International Nuclear Information System (INIS)

    Occupational internal contamination with depleted uranium (DU) compounds can induce radiological and chemical toxicity, and an effective and specific uranium-chelating agent for clinical use is urgently needed. The purpose of this study was to investigate whether a series of synthesized water-soluble metal-ion-imprinted chitooligosaccharides can be used as uranium-specific chelating agents, because the chitooligosaccharides have excellent heavy metal ion chelation property and the ion-imprinting technology can improve the selective recognition of template ions. DU-poisoned human renal proximal tubule epithelium cells (human kidney 2 cells, HK-2) were used to assess the detoxification of these chitooligosaccharides. The DU-chelating capacity and selectivity of the chitooligosaccharides were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Cell viability, cellular accumulation of DU, membrane damage, DNA damage, and morphological changes in the cellular ultrastructure were examined to assess the detoxification of these chitooligosaccharides. The results showed that the Cu2+-imprinted chitooligosaccharides, especially the Cu2+-imprinted glutaraldehyde-crosslinked carboxymethyl chitooligosaccharide (Cu-Glu-CMC), chelated DU effectively and specifically, and significantly reduced the loss of cell viability induced by DU and reduced cellular accumulation of DU in a dose-dependent manner, owing to their chelation of DU outside cells and their prevention of DU internalization. The ultrastructure observation clearly showed that Cu-Glu-CMC-chelated-DU precipitates, mostly outside cells, were grouped in significantly larger clusters, and they barely entered the cells by endocytosis or in any other way. Treatment with Cu-Glu-CMC also increased the activity of antioxidant enzymes, and reduced membrane damage and DNA damage induced by DU oxidant injury. Cu-Glu-CMC was more effective than the positive control drug, diethylenetriaminepentaacetic acid (DTPA), in

  17. Development of an upconverting chelate assay

    Science.gov (United States)

    Xiao, Xudong; Haushalter, Jeanne P.; Kotz, Kenneth T.; Faris, Gregory W.

    2005-04-01

    We report progress on performing a cell-based assay for the detection of EGFR on cell surfaces by using upconverting chelates. An upconversion microscope has been developed for performing assays and testing optical response. A431 cells are labeled with europium DOTA and imaged using this upconverting microscope.

  18. Questions and Answers on Unapproved Chelation Products

    Science.gov (United States)

    ... it Email Print The U.S. Food and Drug Administration (FDA) advises consumers to be wary of so-called “chelation” products that are marketed over-the-counter (OTC) to prevent or treat diseases. Companies are marketing unapproved OTC chelation therapy products to ...

  19. Nature of impurities in fertilizers containing EDDHMA/Fe(3+), EDDHSA/Fe(3+), and EDDCHA/Fe(3+) chelates.

    Science.gov (United States)

    Alvarez-Fernández, Ana; Cremonini, Mauro A; Sierra, Miguel A; Placucci, Giuseppe; Lucena, Juan J

    2002-01-16

    Iron chelates derived from ethylenediaminedi(o-hydroxyphenylacetic) acid (EDDHA), ethylenediaminedi(o-hydroxy-p-methylphenylacetic) acid (EDDHMA), ethylenediaminedi(2-hydroxy-5-sulfophenylacetic) acid (EDDHSA), and ethylenediaminedi(5-carboxy-2-hydroxyphenylacetic) acid (EDDCHA) are remarkably efficient in correcting iron chlorosis in plants growing in alkaline soils. This work reports the determination of impurities in commercial samples of fertilizers containing EDDHMA/Fe(3+), EDDHSA/Fe(3+), and EDDCHA/Fe(3+). The active components (EDDHMA/Fe(3+), EDDHSA/Fe(3+), and EDDCHA/Fe(3+)) were separated easily from other compounds present in the fertilizers by HPLC. Comparison of the retention times and the UV-visible spectra of the peaks obtained from commercial EDDHSA/Fe(3+) and EDDCHA/Fe(3+) samples with those of standard solutions showed that unreacted starting materials (p-hydroxybenzenesulfonic acid and p-hydroxybenzoic acid, respectively) were always present in the commercial products. 1D and 2D NMR experiments showed that commercial fertilizers based on EDDHMA/Fe(3+) contained impurities having structures tentatively assigned to iron chelates of two isomers of EDDHMA. These findings suggest that current production processes of iron chelates used in agriculture need to be improved. PMID:11782196

  20. Influence of chelating ligands on arsenic uptake by hydroponically grown rice seedlings (Oryza sativa L.): a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Mohammad A.; Hasegawa, Hiroshi; Ueda, Kazumasa; Maki, Teruya [Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa (Japan); Rahman, M.M. [Department of Botany, Faculty of Biological Sciences, Jahangirnagar University, Savar, Dhaka (Bangladesh)

    2008-06-15

    Ferric (oxyhydro-)oxides (FeO{sub x}) precipitate in the rhizosphere at neutral or alkaline pH and are adsorbed on the plant root surfaces. Consequently, the higher binding affinity of arsenate to FeO{sub x} and the low iron phytoavailability of the precipitated FeO{sub x} make the phytoremediation of arsenic difficult. In the present study, the influence of chelating ligands on arsenic and iron uptake by hydroponically grown rice seedlings (Oryza sativa L.) was investigated. When chelating ligands were not treated to the growth medium, about 63 and 71% of the total arsenic and iron were distributed in the root extract (outer root surfaces) of rice, respectively. On the other hand, ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid (EDDS) and hydroxyiminodisuccinic acid (HIDS) desorbed a significant amount of arsenic from FeO{sub x} of the outer root surfaces. Therefore, the uptake of arsenic and iron into the roots and their subsequent translocation to the shoots of the rice seedlings increased significantly. The order of increasing arsenic uptake by chelating ligands was HIDS > EDTA > EDDS. Methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS) might not be effective in arsenic solubilization from FeO{sub x}. The results suggest that EDDS and HIDS would be a good and environmentally safe choice to accelerate arsenic phytoavailability in the phytoremediation process because of their biodegradability and would be a competent alternative to the widely used non-biodegradable and environmentally persistent EDTA. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  1. Impaired Iron Status in Aging Research

    Directory of Open Access Journals (Sweden)

    Christiaan Leeuwenburgh

    2012-02-01

    Full Text Available Aging is associated with disturbances in iron metabolism and storage. During the last decade, remarkable progress has been made toward understanding their cellular and molecular mechanisms in aging and age-associated diseases using both cultured cells and animal models. The field has moved beyond descriptive studies to potential intervention studies focusing on iron chelation and removal. However, some findings remain controversial and inconsistent. This review summarizes important features of iron dyshomeostasis in aging research with a particular emphasis on current knowledge of the mechanisms underlying age-associated disorders in rodent models.

  2. COMPARATIVE STUDY OF CHELATION VALUE OF SEVENTEEN PERCENT SELF DEVELOPED AND COMMERCIALLY AVAILABLE ROOT CANAL LUBRICANTS

    OpenAIRE

    Ingale Satish Dinkarrao; Kankariya Rajendra

    2013-01-01

    The main objective of this study is to compare chelation values of 17% self developed & commercially available root canal Lubricants or dental chelating gels as well as to see whether their performance depends on the chelation value or not. The Chelating agent bounds Ca2+ ions of the smear layer & the extent of chelate formation between chelating agent and metal ion is nothing but Chelation Value. Sodium carbonate indicator method is used for determinations of chelation value. Commercially av...

  3. Aceruloplasminaemia: a rare but important cause of iron overload.

    Science.gov (United States)

    Doyle, Adam; Rusli, Ferry; Bhathal, Prithi

    2015-01-01

    We present a case of a 20-year-old man referred to our service with iron overload and mildly deranged liver biochemistry. Although liver histopathology was consistent with haemochromatosis, iron studies were not consistent with this diagnosis. Serum ceruloplasmin levels were undetectable, leading to a diagnosis of aceruloplasminaemia. Unlike other iron overload disorders, neurological complications are a unique feature of this illness, and often irreversible, once established. The patient was treated with iron chelation prior to the onset of neurological injury, and experienced progressive normalisation of his ferritin and liver biochemistry. This is one of the youngest diagnosed cases in the published literature and, crucially, was a rare case of diagnosis and treatment prior to the onset of neurological sequelae. This is presented alongside a review of previously published cases of aceruloplasminaemia, including responses to iron chelation therapy. PMID:25976187

  4. Synthesis of Iminodiacetate Functionalized Polypropylene Films and Their Efficacy as Antioxidant Active-Packaging Materials.

    Science.gov (United States)

    Lin, Zhuangsheng; Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2016-06-01

    The introduction of metal-chelating ligands to the food-contact surface of packaging materials may enable the removal of synthetic chelators (e.g., ethylenediamine tetra-acetic acid (EDTA)) from food products. In this study, the metal-chelating ligand iminodiacetate (IDA) was covalently grafted onto polypropylene surfaces to produce metal-chelating active-packaging films. The resulting films were able to chelate 138.1 ± 26 and 210.0 ± 28 nmol/cm(2) Fe(3+) and Cu(2+) ions, respectively, under acidic conditions (pH 3.0). The films demonstrated potent antioxidant efficacy in two model food systems. In an emulsified-oil system, the chelating materials extended the lag phase of both lipid hydroperoxide and hexanal formation from 5 to 25 days and were as effective as EDTA. The degradation half-life of ascorbic acid in an aqueous solution was extended from 5 to 14 days. This work demonstrates the potential application of surface-grafted chelating IDA ligands as effective antioxidant active food-packaging materials. PMID:27243793

  5. In vivo skin irritation potential of a Castanea sativa (Chestnut) leaf extract, a putative natural antioxidant for topical application.

    Science.gov (United States)

    Almeida, Isabel F; Valentão, Patrícia; Andrade, Paula B; Seabra, Rosa M; Pereira, Teresa M; Amaral, M Helena; Costa, Paulo C; Bahia, M Fernanda

    2008-11-01

    Topical application of natural antioxidants has proven to be effective in protecting the skin against ultraviolet-mediated oxidative damage and provides a straightforward way to strengthen the endogenous protection system. However, natural products can provoke skin adverse effects, such as allergic and irritant contact dermatitis. Skin irritation potential of Castanea sativa leaf ethanol:water (7:3) extract was investigated by performing an in vivo patch test in 20 volunteers. Before performing the irritation test, the selection of the solvent and extraction method was guided by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging test and polyphenols extraction (measured by the Folin Ciocalteu assay). Iron-chelating activity and the phenolic composition (high performance liquid chromatography/diode array detection) were evaluated for the extract obtained under optimized conditions. The extraction method adopted consisted in 5 short extractions (10 min.) with ethanol:water (7:3), performed at 40 degrees. The IC(50) found for the iron chelation and DPPH scavenging assays were 132.94 +/- 9.72 and 12.58 +/- 0.54 microg/ml (mean +/- S.E.M.), respectively. The total phenolic content was found to be 283.8 +/- 8.74 mg GAE/g extract (mean +/- S.E.M.). Five phenolic compounds were identified in the extract, namely, chlorogenic acid, ellagic acid, rutin, isoquercitrin and hyperoside. The patch test carried out showed that, with respect to irritant effects, this extract can be regarded as safe for topical application. PMID:18793273

  6. Fungistatic mechanism of human transferrin for Rhizopus oryzae and Trichophyton mentagrophytes: alternative to simple iron deprivation.

    OpenAIRE

    Artis, W M; Patrusky, E; Rastinejad, F; Duncan, R.L.

    1983-01-01

    Human serum, human transferrin (TF), and the iron chelator 1,10-phenanthroline (OP) produce iron-reversible fungistatic activity which has been attributed to simple iron deprivation. In this study, the influence of the size of the inoculum on the inhibitory activity of serum, TF, and OP prepared with the same iron-binding capacity (2.5 micrograms/ml) for Rhizopus oryzae and Trichophyton mentagrophytes was examined. Inhibition was monitored in liquid microcultures maintained at 37 degrees C an...

  7. Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumannii are bactericidal

    OpenAIRE

    Goel, Vikas Kumar; Kapil, Arti

    2001-01-01

    Background Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10-18M,which is far less than what is needed for the survival of the invading bacterial pathogen.To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores. Results/ Discussion Acinetobacter baumannii ATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, expresses ...

  8. Influence of Chelating Agents on Chromium Fate in Sediment

    Institute of Scientific and Technical Information of China (English)

    WANGXIAOCHANG; SUNJINHE; 等

    1996-01-01

    A laboratory investigation on reaction between chelating agents and chromium was conducted to evaluate the effect of chelating agents on the adsorption and desorption of chromium in sediment.The amount of adsorbed chromium(VI) in sediment decreased slightly by 5%-10% because of addition of chelating agents.Chelating agents inhibited the removal of Cr(Ⅲ)by sediment from solutions and the inhibiting effect was in the order:citric acid>tartaric acid>EDTA,Salicylic acid.No effect of chelating agents on desorption of chromium in sediment was observed.

  9. Iron overdose

    Science.gov (United States)

    Iron is a mineral found in many over-the-counter supplements. Iron overdose occurs when someone takes more than the ... This can be by accident or on purpose. Iron overdose is especially dangerous for children. A severe ...

  10. Oxidants and antioxidants in cardiovascular disease

    OpenAIRE

    Ekblom, Kim

    2010-01-01

    Background Cardiovascular diseases, including myocardial infarction and stroke, are the main reason of death in Sweden and Western Europe. High iron stores are believed to produce oxygen radicals, which is the presumed putative mechanism behind lipid peroxidation, atherosclerosis and subsequent cardiovascular disease. Iron levels are associated with the hemochromatosis associated HFE single nucleotide polymorphisms C282Y and H63D. Bilirubin is an antioxidant present in relatively high levels ...

  11. Minocycline Attenuates Iron-Induced Brain Injury.

    Science.gov (United States)

    Zhao, Fan; Xi, Guohua; Liu, Wenqaun; Keep, Richard F; Hua, Ya

    2016-01-01

    Iron plays an important role in brain injury after intracerebral hemorrhage (ICH). Our previous study found minocycline reduces iron overload after ICH. The present study examined the effects of minocycline on the subacute brain injury induced by iron. Rats had an intracaudate injection of 50 μl of saline, iron, or iron + minocycline. All the animals were euthanized at day 3. Rat brains were used for immunohistochemistry (n = 5-6 per each group) and Western blotting assay (n = 4). Brain swelling, blood-brain barrier (BBB) disruption, and iron-handling proteins were measured. We found that intracerebral injection of iron resulted in brain swelling, BBB disruption, and brain iron-handling protein upregulation (p < 0.05). The co-injection of minocycline with iron significantly reduced iron-induced brain swelling (n = 5, p < 0.01). Albumin, a marker of BBB disruption, was measured by Western blot analysis. Minocycline significantly decreased albumin protein levels in the ipsilateral basal ganglia (p < 0.01). Iron-handling protein levels in the brain, including ceruloplasmin and transferrin, were reduced in the minocycline co-injected animals. In conclusion, the present study suggests that minocycline attenuates brain swelling and BBB disruption via an iron-chelation mechanism. PMID:26463975

  12. Activation of the NLRP3 inflammasome by cellular labile iron.

    Science.gov (United States)

    Nakamura, Kyohei; Kawakami, Toru; Yamamoto, Naoki; Tomizawa, Miyu; Fujiwara, Tohru; Ishii, Tomonori; Harigae, Hideo; Ogasawara, Kouetsu

    2016-02-01

    Cellular labile iron, which contains chelatable redox-active Fe(2+), has been implicated in iron-mediated cellular toxicity leading to multiple organ dysfunction. Iron homeostasis is controlled by monocytes/macrophages through their iron recycling and storage capacities. Furthermore, iron sequestration by monocytes/macrophages is regulated by pro-inflammatory cytokines including interleukin-1, highlighting the importance of these cells in the crosstalk between inflammation and iron homeostasis. However, a role for cellular labile iron in monocyte/macrophage-mediated inflammatory responses has not been defined. Here we describe how cellular labile iron activates the NLRP3 inflammasome in human monocytes. Stimulation of lipopolysaccharide-primed peripheral blood mononuclear cells with ferric ammonium citrate increases the level of cellular Fe(2+) levels in monocytes and induces production of interleukin-1β in a dose-dependent manner. This ferric ammonium citrate-induced interleukin-1β production is dependent on caspase-1 and is significantly inhibited by an Fe(2+)-specific chelator. Ferric ammonium citrate consistently induced interleukin-1β secretion in THP1 cells, but not in NLRP3-deficient THP1 cells, indicating a requirement for the NLRP3 inflammasome. Additionally, activation of the inflammasome is mediated by potassium efflux, reactive oxygen species-mediated mitochondrial dysfunction, and lysosomal membrane permeabilization. Thus, these results suggest that monocytes/macrophages not only sequestrate iron during inflammation, but also mediate inflammation in response to cellular labile iron, which provides novel insights into the role of iron in chronic inflammation. PMID:26577567

  13. Second international round robin for the quantification of serum non-transferrin-bound iron and labile plasma iron in patients with iron-overload disorders.

    Science.gov (United States)

    de Swart, Louise; Hendriks, Jan C M; van der Vorm, Lisa N; Cabantchik, Z Ioav; Evans, Patricia J; Hod, Eldad A; Brittenham, Gary M; Furman, Yael; Wojczyk, Boguslaw; Janssen, Mirian C H; Porter, John B; Mattijssen, Vera E J M; Biemond, Bart J; MacKenzie, Marius A; Origa, Raffaella; Galanello, Renzo; Hider, Robert C; Swinkels, Dorine W

    2016-01-01

    Non-transferrin-bound iron and its labile (redox active) plasma iron component are thought to be potentially toxic forms of iron originally identified in the serum of patients with iron overload. We compared ten worldwide leading assays (6 for non-transferrin-bound iron and 4 for labile plasma iron) as part of an international inter-laboratory study. Serum samples from 60 patients with four different iron-overload disorders in various treatment phases were coded and sent in duplicate for analysis to five different laboratories worldwide. Some laboratories provided multiple assays. Overall, highest assay levels were observed for patients with untreated hereditary hemochromatosis and β-thalassemia intermedia, patients with transfusion-dependent myelodysplastic syndromes and patients with transfusion-dependent and chelated β-thalassemia major. Absolute levels differed considerably between assays and were lower for labile plasma iron than for non-transferrin-bound iron. Four assays also reported negative values. Assays were reproducible with high between-sample and low within-sample variation. Assays correlated and correlations were highest within the group of non-transferrin-bound iron assays and within that of labile plasma iron assays. Increased transferrin saturation, but not ferritin, was a good indicator of the presence of forms of circulating non-transferrin-bound iron. The possibility of using non-transferrin-bound iron and labile plasma iron measures as clinical indicators of overt iron overload and/or of treatment efficacy would largely depend on the rigorous validation and standardization of assays. PMID:26385212

  14. Antioxidant activity of hydrolysates of deer bone gelatin in a liposome

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yuhong; GAO Tian; ZHANG Ligang

    2007-01-01

    Gelatin extracted from deer bone was hydrolyzed for 3.5-120 min. The degree of hydrolysis was higher from Alcalase-hydrolyzed gelatin than that from neutral proteinase-hydrolyzed gelatin. Alcalase-hydrolyzed gelatin exhibited a stronger antioxidant activity than that of neutral proteinase-hydrolyzed gelatin. Hydrolysates showed strong radical-scavenging ability and Fe2+-chelating activity, both of which were influenced by hydrolysis time. Although nonhydrolyzed gelatin displayed a certain antioxidative effect, it was far less than that of hydrolysates. The hydrolysates of deer bone gelatin can work as a radical stabilizer and metal ion chelator to inhibit lipid oxidation.

  15. Pentaarylcyclopentadiene und chirale Ruthenium-Chelat-Komplexe

    OpenAIRE

    Kanthak, Matthias

    2010-01-01

    Die Synthese von mono-ortho-funktionalisierten Pentaphenylcyclopentadienen gelang durch eine Abwandlung der klassischen Tetracyclon-Route. Durch die Umsetzung der funktionalisierten Cyclopentadiene mit Ru3(CO)12 als Metallquelle konnten entsprechende Ruthenium-Komplexe erhalten werden. Die geeignete Wahl der Substituenten an der Phenylgruppe erlaubte die Bildung von Chelat-Komplexen mit chirotopem Metallzentrum. Enantiomerenreine Oxazolin-Seitenarme führten zu diastereomerenreinen...

  16. Federal Regulation of Unapproved Chelation Products

    OpenAIRE

    Lee, Charles E.

    2013-01-01

    Chelation products can be helpful in the treatment of metal poisoning. However, many unapproved products with unproven effectiveness and safety are marketed to consumers, frequently via the internet. This paper describes the primary responsibility of the Health Fraud and Consumer Outreach Branch of the United States Food and Drug Administration to identify and address health fraud products. Efforts to prevent direct and indirect hazards to the population’s health through regulatory actions ar...

  17. EDTA: the chelating agent under environmental scrutiny

    OpenAIRE

    Claudia Oviedo; Jaime Rodríguez

    2003-01-01

    The chelating agent EDTA (ethylenediaminetetraacetic acid) is a compound of massive use world wide with household and industrial applications, being one of the anthropogenic compounds with highest concentrations in inland European waters. In this review, the applications of EDTA and its behavior once it has been released into the environment are described. At a laboratory scale, degradation of EDTA has been achieved; however, in natural environments studies detect poor biodegradability. It is...

  18. Cp/Heph mutant mice have iron-induced neurodegeneration diminished by deferiprone.

    Science.gov (United States)

    Zhao, Liangliang; Hadziahmetovic, Majda; Wang, Chenguang; Xu, Xueying; Song, Ying; Jinnah, H A; Wodzinska, Jolanta; Iacovelli, Jared; Wolkow, Natalie; Krajacic, Predrag; Weissberger, Alyssa Cwanger; Connelly, John; Spino, Michael; Lee, Michael K; Connor, James; Giasson, Benoit; Harris, Z Leah; Dunaief, Joshua L

    2015-12-01

    Brain iron accumulates in several neurodegenerative diseases and can cause oxidative damage, but mechanisms of brain iron homeostasis are incompletely understood. Patients with mutations in the cellular iron-exporting ferroxidase ceruloplasmin (Cp) have brain iron accumulation causing neurodegeneration. Here, we assessed the brains of mice with combined mutation of Cp and its homolog hephaestin. Compared to single mutants, brain iron accumulation was accelerated in double mutants in the cerebellum, substantia nigra, and hippocampus. Iron accumulated within glia, while neurons were iron deficient. There was loss of both neurons and glia. Mice developed ataxia and tremor, and most died by 9 months. Treatment with the oral iron chelator deferiprone diminished brain iron levels, protected against neuron loss, and extended lifespan. Ferroxidases play important, partially overlapping roles in brain iron homeostasis by facilitating iron export from glia, making iron available to neurons. Above: Iron (Fe) normally moves from capillaries to glia to neurons. It is exported from the glia by ferroportin (Fpn) with ferroxidases ceruloplasmin (Cp) and/or Hephaestin (Heph). Below: In mice with mutation of Cp and Heph, iron accumulates in glia, while neurons have low iron levels. Both neurons and glia degenerate and mice become ataxic unless given an iron chelator. PMID:26303407

  19. Conjugates of monoclonal antibodies and chelating polymers

    International Nuclear Information System (INIS)

    The primary purpose of protein modification with chelating polymers is to prepare monoclonal antibodies labeled with heavy metal isotopes (alpha-, beta-, and gamma-emitting metal and paramagnetic ions for NMR tomography). Conventional binding of metals to proteins via chelating agents directly coupled to proteins does not permit binding of a large number of metal atoms per protein molecule without causing alterations in the specific properties of the protein molecules. On the other hand, metal ion binding to proteins via intermediate chelating polymers should permit binding of several dozens of the metal atoms per protein molecule without affect the specific properties adversely. Moreover, the biodistribution and clearance rates can be regulated by varying the polymer properties. Modified antibodies may be used successfully in nuclear and NMR diagnostic applications and in radiotherapy. Possible applications of this approach shall be demonstrated with monoclonal antibody R11D10 for visualization of acute myocardial infarction. Use of this modification with other monoclonal antibodies is also discussed. The chemistry of protein modification with these polymers is presented

  20. Decorporation of metal ions by chelating agents

    International Nuclear Information System (INIS)

    Simple model designs to simulate the effect of therapeutical chelating agents on the behaviour of metals in mammal organisms with and without excretion have been derived and analytical solutions given for the corresponding differential equations. The possibilities of these models in the short-term description of plasma kinetics of various metals, the competition of the therapeutical ligands with proteins for the metal and of the metabolism of chelating agents were tested and the properties applying extreme conceivable parameters were analyzed. The simple models were successsively expanded in logical sequence, so that it was possible to qualitatively well describe over a long period of time, the metallic kinetics in plasma, organs and urine, the retention of the ligands and their effect on the metal excretion. Two suggestions were given to describe the so-called after-effect, an increased excretion of the metal at times when the ligand is almost completely excreted and their different behaviour after injecting the metal chelate is given. Calculations on the therapy with several ligand data as well as on dose fractionation are described resting on the ratios in the plutonium-239 chosen model parameters and the determining mechanisms analyzed. (orig./MG)

  1. Influence of technical processing units on polyphenols and antioxidant capacity of carrot (Daucus carrot L.) juice.

    Science.gov (United States)

    Ma, Tingting; Tian, Chengrui; Luo, Jiyang; Zhou, Rui; Sun, Xiangyu; Ma, Jinjin

    2013-12-01

    The effect of three processing units (blanching, enzyme liquefaction, and pasteurisation) on polyphenols and antioxidant activity of carrot juices was investigated. Polyphenols and antioxidant activity of carrot juices varied with different processes. Five polyphenolic acids were identified in fresh carrot juice, and the predominant compound was chlorogenic acid. Compared with fresh carrot juice, blanching and enzyme liquefaction could result in the increase of the total polyphenol content (TPC) and the antioxidant activity in scavenging DPPH free radicals (DPPH) and Fe(2+)-chelating capacity (FC), whereas pasteurisation could result in the decrease of the TPC and the antioxidant activity in DPPH and FC. Meanwhile blanching, enzyme liquefaction, and pasteurisation showed little influence on the antioxidant activity in lipid peroxidation protection. The antioxidant activities in DPPH and FC increased with increasing concentration while no correlation between lipid peroxidation protection and polyphenols concentration. Polyphenols still retained high antioxidant activity after the processes, which have potential health benefits for consumers. PMID:23870871

  2. Protection against SR 4233 (tirapazamine) aerobic cytotoxicity by the metal chelators desferrioxamine and tiron

    International Nuclear Information System (INIS)

    Metal chelating agents and antioxidants were evaluated as potential protectors against aerobic SR 4233 cytotoxicity in Chinese hamster V79 cells. The differential protection of aerobic and hypoxic cells by two metal chelators, desferrrioxamine and Tiron, is discussed in the context of their potential use in the on-going clinical trials with SR 4233. Cytotoxicity was evaluated using clonogenic assay. SR 4233 exposure was done in glass flasks as a function of time either alone or in the presence of the following agents: superoxide dismutase, catalase, 5,5-dimethyl-1-pyrroline, Trolox, ICRF-187, desferrioxamine, Tiron (1,2-dihydroxybenzene-3,5-disulfonate), and ascorbic acid. Experiments done under hypoxic conditions were carried out in specially designed glass flasks that were gassed with humidified nitrogen/carbon dioxide mixture and with a side-arm reservoir from which SR 4233 was added to cell media after hypoxia was obtained. Electron paramagnetic resonance studies were also performed. Electron paramagnetic resonance and spectrophotometry experiments suggest that under aerobic conditions SR 4233 undergoes futile redox cycling to produce superoxide. Treatment of cells during aerobic exposure to SR 4233 with the enzymes superoxide dismutase and catalase, the spin trapping agent DMPO, the water-soluble vitamin E analog Trolox, and the metal chelator ICRF-187 provided little or no protection against aerobic SR 4233 cytotoxicity. However, two other metal chelators, desferrioxamine and Tiron afforded significant protection against minimal protection to hypoxic cells treated with SR 4233. One potential mechanism of aerobic cytotoxicity is redox cycling of SR 4233 with molecular oxygen resulting in several potentially toxic oxidative species that overburden the intrinsic intracellular detoxification systems such as superoxide dismutase, catalase, and glutathione peroxidase. 23 refs., 4 figs., 1 tab

  3. Deferoxamine inhibition of malaria is independent of host iron status

    Energy Technology Data Exchange (ETDEWEB)

    Hershko, C.; Peto, T.E.

    1988-07-01

    The mechanism whereby deferoxamine (DF) inhibits the growth of malaria parasites was studied in rats infected with Plasmodium berghei. Peak parasitemia was 32.6% (day 14) in untreated controls and 0.15% (day 7) in rats receiving 0.33 mg/g in 8 hourly DF injections, subcutaneously. DF inhibition of parasite growth was achieved without any reduction in transferrin saturation or hemoglobin synthesis and with only a partial (56%) depletion of hepatic iron stores. Dietary iron depletion resulted in anemia (hematocrit 25 vs. 46%), microcytosis (MCV 54 vs. 60 fl), and reduced transferrin saturation (17 vs. 96%) without any effect on infection (peak parasitemia 30 vs. 36%). Similarly, parenteral iron loading with ferric citrate over 10 d (75 mg iron/kg) failed to aggravate infection. In a search for evidence of direct interaction between DF and parasitized erythrocytes, gel filtration and ultrafiltration was performed on hemolysates obtained from in vivo /sup 59/Fe-labeled parasitized erythrocytes. This showed that 1.1-1.9% of the intracellular radioiron was located in a chelatable, labile iron pool. Incubation of intact cells with 0-500 microM DF resulted in a proportional increase in intracellular iron chelation, and the chelation of all available labile intracellular iron was completed within 6 h. These observations indicate that the severity of P. berghei infection in rats and its in vivo suppression by DF are independent of host iron status and suggest that DF inhibition of malaria involves intracellular chelation of a labile iron pool in parasitized erythrocytes.

  4. Deferoxamine inhibition of malaria is independent of host iron status

    International Nuclear Information System (INIS)

    The mechanism whereby deferoxamine (DF) inhibits the growth of malaria parasites was studied in rats infected with Plasmodium berghei. Peak parasitemia was 32.6% (day 14) in untreated controls and 0.15% (day 7) in rats receiving 0.33 mg/g in 8 hourly DF injections, subcutaneously. DF inhibition of parasite growth was achieved without any reduction in transferrin saturation or hemoglobin synthesis and with only a partial (56%) depletion of hepatic iron stores. Dietary iron depletion resulted in anemia (hematocrit 25 vs. 46%), microcytosis (MCV 54 vs. 60 fl), and reduced transferrin saturation (17 vs. 96%) without any effect on infection (peak parasitemia 30 vs. 36%). Similarly, parenteral iron loading with ferric citrate over 10 d (75 mg iron/kg) failed to aggravate infection. In a search for evidence of direct interaction between DF and parasitized erythrocytes, gel filtration and ultrafiltration was performed on hemolysates obtained from in vivo 59Fe-labeled parasitized erythrocytes. This showed that 1.1-1.9% of the intracellular radioiron was located in a chelatable, labile iron pool. Incubation of intact cells with 0-500 microM DF resulted in a proportional increase in intracellular iron chelation, and the chelation of all available labile intracellular iron was completed within 6 h. These observations indicate that the severity of P. berghei infection in rats and its in vivo suppression by DF are independent of host iron status and suggest that DF inhibition of malaria involves intracellular chelation of a labile iron pool in parasitized erythrocytes

  5. Iron, anemia and hepcidin in malaria

    Directory of Open Access Journals (Sweden)

    Natasha eSpottiswoode

    2014-05-01

    Full Text Available Malaria and iron have a complex but important relationship. Plasmodium proliferation requires iron, both during the clinically silent liver stage of growth and in the disease-associated phase of erythrocyte infection. Precisely how the protozoan acquires its iron from its mammalian host remains unclear, but iron chelators can inhibit pathogen growth in vitro and in animal models. In humans, iron deficiency appears to protect against severe malaria, while iron supplementation increases risks of infection and disease. Malaria itself causes profound disturbances in physiological iron distribution and utilization, through mechanisms that include hemolysis, release of heme, dyserythropoiesis, anemia, deposition of iron in macrophages, and inhibition of dietary iron absorption. These effects have significant consequences. Malarial anemia is a major global health problem, especially in children, that remains incompletely understood and is not straightforward to treat. Furthermore, the changes in iron metabolism during a malaria infection may modulate susceptibility to coinfections. The release of heme and accumulation of iron in granulocytes may explain increased vulnerability to non-typhoidal Salmonella during malaria. The redistribution of iron away from hepatocytes and into macrophages may confer host resistance to superinfection, whereby blood-stage parasitemia prevents the development of a second liver-stage Plasmodium infection in the same organism. Key to understanding the pathophysiology of iron metabolism in malaria is the activity of the iron regulatory hormone hepcidin. Hepcidin is upregulated during blood-stage parasitemia and likely mediates much of the iron redistribution that accompanies disease. Understanding the regulation and role of hepcidin may offer new opportunities to combat malaria and formulate better approaches to treat anemia in the developing world.

  6. Separation and recovery of uranium ore by chlorinating, chelate resin and molten salt treatment

    Energy Technology Data Exchange (ETDEWEB)

    Taki, Tomohiro [Japan Nuclear Cycle Development Inst., Kamisaibara, Okayama (Japan). Ningyo Toge Environmental Engineering Center

    2000-12-01

    Three fundamental researches of separation and recovery of uranium from uranium ore are reported in this paper. Three methods used the chloride pyrometallurgy, sodium containing molten salts and chelate resin. When uranium ore is mixed with activated carbon and reacted for one hour under the mixed gas of chlorine and oxygen at 950 C, more than 90% uranium volatilized and vaporization of aluminum, silicone and phosphorus were controlled. The best activated carbon was brown coal because it was able to control the large range of oxygen concentration. By blowing oxygen into the molten sodium hydroxide, the elution rate of uranium attained to about 95% and a few percent of uranium was remained in the residue. On the uranium ore of unconformity-related uranium deposits, a separation method of uranium, molybdenum, nickel and phosphorus from the sulfuric acid elusion solution with U, Ni, As, Mo, Fe and Al was developed. Methylene phosphonic acid type chelate resin (RCSP) adsorbed Mo and U, and then 100 % Mo was eluted by sodium acetate solution and about 100% U by sodium carbonate solution. Ni and As in the passing solution were recovered by imino-diacetic acid type chelate resin and iron hydroxide, respectively. (S.Y.)

  7. Separation and recovery of uranium ore by chlorinating, chelate resin and molten salt treatment

    International Nuclear Information System (INIS)

    Three fundamental researches of separation and recovery of uranium from uranium ore are reported in this paper. Three methods used the chloride pyrometallurgy, sodium containing molten salts and chelate resin. When uranium ore is mixed with activated carbon and reacted for one hour under the mixed gas of chlorine and oxygen at 950 C, more than 90% uranium volatilized and vaporization of aluminum, silicone and phosphorus were controlled. The best activated carbon was brown coal because it was able to control the large range of oxygen concentration. By blowing oxygen into the molten sodium hydroxide, the elution rate of uranium attained to about 95% and a few percent of uranium was remained in the residue. On the uranium ore of unconformity-related uranium deposits, a separation method of uranium, molybdenum, nickel and phosphorus from the sulfuric acid elusion solution with U, Ni, As, Mo, Fe and Al was developed. Methylene phosphonic acid type chelate resin (RCSP) adsorbed Mo and U, and then 100 % Mo was eluted by sodium acetate solution and about 100% U by sodium carbonate solution. Ni and As in the passing solution were recovered by imino-diacetic acid type chelate resin and iron hydroxide, respectively. (S.Y.)

  8. Investigation of metal–flavonoid chelates and the determination of flavonoids via metal–flavonoid complexing reactions

    Directory of Open Access Journals (Sweden)

    DUSAN MALESEV

    2007-10-01

    Full Text Available Flavonoids constitute a large group of polyphenolic phytochemicals with antioxidant properties which are overwhelmingly exerted through direct free radical scavenging. Flavonoids also exhibit antioxidant properties through chelating with transition metals, primarily Fe(II, Fe(III and Cu(II, which participate in reactions generating free radicals. Metal–flavonoid chelates are considerably more potent free radical scavengers than the parent flavonoids and play a prominent role in protecting from oxidative stress. To unravel the origin of their potent biological action extensive physico–chemical studies were undertaken to reveal the chemical structure, chelation sites, assess the impact of the metal/ligand ratio on the structure of the complexes and the capacity of flavonoids to bind metal ions. In spite of such extensive efforts, data on the composition, structure and complex-formation properties are incomplete and sometimes even contradictory. The aim of this paper is to give a personal account on the development of the field through a retrospective evaluation of our own research which covers approximately 40 complexes of flavonoids from different flavonoids subclasses (rutin, quercetin, 3-hydroxyflavone, morin and hesperidin with several metal ions or groups and suggest directions for future research. Special emphasis will be given to the site of the central ion, the composition of the complexes, the role of pH in complex formation, the stability of metal–flavonoid complexes and their potential application for analytical purposes.

  9. Iron-Catalyzed C-H Functionalization Processes.

    Science.gov (United States)

    Cera, Gianpiero; Ackermann, Lutz

    2016-10-01

    Iron-catalyzed C-H activation has recently emerged as an increasingly powerful tool for the step-economical transformation of unreactive C-H bonds. Particularly, the recent development of low-valent iron catalysis has set the stage for novel C-H activation strategies via chelation assistance. The low-cost, natural abundance, and low toxicity of iron prompted its very recent application in organometallic C-H activation catalysis. An overview of the use of iron catalysis in C-H activation processes is summarized herein up to May 2016. PMID:27573499

  10. Sulfated polysaccharide fraction from marine algae Solieria filiformis: Structural characterization, gastroprotective and antioxidant effects.

    Science.gov (United States)

    Sousa, Willer M; Silva, Renan O; Bezerra, Francisco F; Bingana, Rudy D; Barros, Francisco Clark N; Costa, Luís E C; Sombra, Venicios G; Soares, Pedro M G; Feitosa, Judith P A; de Paula, Regina C M; Souza, Marcellus H L P; Barbosa, André Luiz R; Freitas, Ana Lúcia P

    2016-11-01

    A sulfated polysaccharide (SFP) fraction from the marine alga Solieria filiformis was extracted and submitted to microanalysis, molar mass estimation and spectroscopic analysis. We evaluated its gastroprotective potential in vivo in an ethanol-induced gastric damage model and its in vitro antioxidant properties (DPPH, chelating ferrous ability and total antioxidant capacity). Its chemical composition revealed to be essentially an iota-carrageenan with a molar mass of 210.9kDa and high degree of substitution for sulfate groups (1.08). In vivo, SFP significantly (Plevels. SFP presented an IC50 of 1.77mg/mL in scavenging DPPH. The chelating ferrous ability was 38.98%, and the total antioxidant capacity was 2.01mg/mL. Thus, SFP prevents the development of ethanol-induced gastric damage by reducing oxidative stress in vivo and possesses relevant antioxidant activity in vitro. PMID:27516258

  11. Antioxidant activity of ethanolic extract of Penicillium chrysogenum and Penicillium fumiculosum

    Directory of Open Access Journals (Sweden)

    Jakovljević Violeta D.

    2014-01-01

    Full Text Available The aim of this study was to investigate the biological and chemical activity on two species of fungi of the genus Penicillium isolated from wastewater. On the selected species of fungi the different antioxidant activity assays were carried out: DPPH free-radical scavenging activity, total antioxidant activity, Fe2+- chelating ability and Fe3+- reducing power. Total phenol content was also determinate for ethanolic extract of mycelia. Penicillium chrysogenum ethanolic extract contained higher total phenolic content and better total antioxidant capacity as well as ferrous ion chelating ability. Penicillium fumiculosum ethanolic extract showed higher DPPH free-radical scavenging activity, as well as reducing power. Based on the obtained results it can be concluded that two types of fungi are potential new sources of natural antioxidants. [Projekat Ministarstva nauke Republike Srbije, br. III 43004

  12. In vitro antioxidant potential of methanol extract of the medicinal plant, Acacia caesia (L.) Willd

    Institute of Scientific and Technical Information of China (English)

    Thambiraj J; Paulsamy S

    2012-01-01

    Objective: The in vitro antioxidant capability of methanolic leaf extract of the medicinal plant,Acacia caesia (L.) Willd (Mimosaceae) was evaluated by different assaying. Methods: The in vitro antioxidant activity was evaluated for total antioxidant, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, hydroxyl radical scavenging and metal chelating activities. Ascorbic acid and butylated hydroxy toluene (BHT) were kept as standards. Results: IC50 values observed for DPPH, hydroxyl radical scavenging and metal chelating assays were 109, 177 and 295 μg/ml respectively. Conclusions: The results clearly indicate that the methanolic leaf extract of the study species is effective in scavenging free radicals and has the potential to be powerful antioxidant.

  13. Potential Anticancer Properties of Grape Antioxidants

    Directory of Open Access Journals (Sweden)

    Kequan Zhou

    2012-01-01

    Full Text Available Dietary intake of foods rich in antioxidant properties is suggested to be cancer protective. Foods rich in antioxidant properties include grape (Vitis vinifera, one of the world’s largest fruit crops and most commonly consumed fruits in the world. The composition and cancer-protective effects of major phenolic antioxidants in grape skin and seed extracts are discussed in this review. Grape skin and seed extracts exert strong free radical scavenging and chelating activities and inhibit lipid oxidation in various food and cell models in vitro. The use of grape antioxidants are promising against a broad range of cancer cells by targeting epidermal growth factor receptor (EGFR and its downstream pathways, inhibiting over-expression of COX-2 and prostaglandin E2 receptors, or modifying estrogen receptor pathways, resulting in cell cycle arrest and apoptosis. Interestingly, some of these activities were also demonstrated in animal models. However, in vivo studies have demonstrated inconsistent antioxidant efficacy. Nonetheless, a growing body of evidence from human clinical trials has demonstrated that consumption of grape, wine and grape juice exerts many health-promoting and possible anti-cancer effects. Thus, grape skin and seed extracts have great potential in cancer prevention and further investigation into this exciting field is warranted.

  14. Chelating agents related to ethylenediamine bis(2-hydroxyphenyl)acetic acid (EDDHA): synthesis, characterization, and equilibrium studies of the free ligands and their Mg2+, Ca2+, Cu2+, and Fe3+ chelates.

    Science.gov (United States)

    Yunta, Felipe; García-Marco, Sonia; Lucena, Juan J; Gómez-Gallego, Mar; Alcázar, Roberto; Sierra, Miguel A

    2003-08-25

    Iron chelates such as ethylenediamine-N,N'-bis(2-hydroxyphenyl)acetic acid (EDDHA) and their analogues are the most efficient soil fertilizers to treat iron chlorosis in plants growing in calcareous soils. EDDHA, EDDH4MA (ethylenediamine-N,N'-bis(2-hydroxy-4-methylphenyl)acetic acid), and EDDCHA (ethylenediamine-N,N'-bis(2-hydroxy-5-carboxyphenyl)acetic acid) are allowed by the European directive, but also EDDHSA (ethylenediamine-N,N'-bis(2-hydroxy-5-sulfonylphenyl)acetic acid) and EDDH5MA (ethylenediamine-N,N'-bis(2-hydroxy-5-methylphenyl)acetic acid) are present in several commercial iron chelates. In this study, these chelating agents as well as p,p-EDDHA (ethylenediamine-N,N'-bis(4-hydroxyphenyl)acetic acid) and EDDMtxA (ethylenediamine-N,N'-bis(2-metoxyphenyl)acetic acid) have been obtained following a new synthetic pathway. Their chemical behavior has been studied to predict the effect of the substituents in the benzene ring on their efficacy as iron fertilizers for soils above pH 7. The purity of the chelating agents has been determined using a novel methodology through spectrophotometric titration at 480 nm with Fe(3+) as titrant to evaluate the inorganic impurities. The protonation constants were determined by both spectrophotometric and potentiometric methods, and Ca(2+) and Mg(2+) stability constants were determined from potentiometric titrations. To establish the Fe(3+) and Cu(2+) stability constants, a new spectrophotometric method has been developed, and the results were compared with those reported in the literature for EDDHA and EDDHMA and their meso- and rac-isomers. pM values have been also determined to provide a comparable basis to establish the relative chelating ability of these ligands. The purity obtained for the ligands is higher than 87% in all cases and is comparable with that obtained by (1)H NMR. No significant differences have been found among ligands when their protonation and stability constants were compared. As expected, no Fe(3

  15. Effects of different Fe levels from Fe-nano-chelate and Fe-EDDHA sources on growth and some nutrients concentrations in cowpea in a calcareous soil

    Directory of Open Access Journals (Sweden)

    L. Jokar

    2015-08-01

    Full Text Available To evaluate the effects of different levels of iron (Fe (from Fe-nano-chelate and Fe-EDDHA sources on growth parameters, concentration and absorption of Fe and some nutrients in cowpea (Vigna unguiculata in a calcareous soil, a greenhouse experiment was conducted based on completely randomized design with three replications. Treatments consisted of four levels of Fe (0, 0.135, 0.270 and 0.405 mg Fe per kg soil as Fe-nano-chelate or Fe-EDDHA. The studied soil (Fine-loamy, carbonatic, thermic, Typic Calcixerepts had a loam texture with low available Fe content. Results showed that application of both Fe fertilizers increased shoot dry-matter yield, root dry matter yield, number of pods per plant, weight of pods and seeds per plant, grain weight per pot, shoot Fe concentration and Fe uptake by cowpea as compared to control treatment. Some of the evaluated growth parameters at all levels of Fe from Fe-nano-chelate source were higher than the Fe-EDDHA source and some were the same and had no significant difference. Application of both Fe-nano-chelate and Fe-EDDHA decreased phosphorus and manganese concentrations in shoots as compared to control treatment. Concentration of zinc and cooper in shoots was not significantly affected by the Fe level. In conclusion, lower rates of Fe-nano-chelate were required, as compared to Fe-EDDHA, to alleviate iron deficiency in cowpea grown in calcareous soils.

  16. Ferrous Ion Chelating, Superoxide Anion Radical Scavenging and Tyrosinase Inhibitory Properties of Pure and Commercial Essential Oils of Anetrhum Graveolens

    Directory of Open Access Journals (Sweden)

    Sh Darvish Alipour Astaneh

    2013-04-01

    Full Text Available Introduction: Despite slight toxicities of essential oils, they are not under strict control in many countries. Anethum graveolens is widely consumed and its essential oils are at public reach. This study was designed to study essential oils of Anethum graveolens. Methods: The biological properties of pure and commercial essential oils of Anethum graveolens were investigated. In fact, Ferrous ion chelating activity, superoxide anion radical scavenging property, tyrosinase inhibition and total flavonoids of the oils were determined. Results: Chelating activity of 7.8 µg of EDTA was equivalent to 2 µg of the pure oil. The oils had superoxide anion radical scavenging activities which may be related to their total phenol and flavonoid contents. IC50 of ferrous ion chelating, antityrosiase and superoxide anion radical scavenging activities of pure and commercial oils were 1.3, 1.4, 1 and (171.6, 589, 132 µg respectively. Antityrosiase activity of 6.4 µg pure oil was equal to 1000 µg of the commercial oil. Conclusion: Anethum possesses antioxidative and free radical scavenging properties. This oil chelates ferrous ions and superoxide radicals. It is effective in formation of reactive toxic products. Anethum has good potentials regarding its applications in food and drug industries.

  17. Antioxidant Efficacies of Rutin and Rutin Esters in Bulk Oil and Oil-in-Water Emulsion

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Sørensen, Ann-Dorit Moltke; Jacobsen, Charlotte;

    2016-01-01

    concentrations (25 and 200 µM) was assessed in bulk oil and in an o/w emulsion system without and with iron addition. All evaluated compounds revealed antioxidant effects. However, rutin and BHT were the most efficient antioxidants in bulk oil followed by rutin palmitate, whereas rutin laurate acted as either an...... antioxidant or a prooxidant at low and high concentrations (25 and 200 µM), respectively. In emulsions, rutin and BHT in high concentration (200 µM) were more efficient than rutin esters. Thus, alcylation of rutin with medium chain fatty acids did not improve the antioxidant ability, neither in bulk oil nor...... in o/w emulsion. Interestingly, rutin had stronger antioxidative effect than BHT upon iron addition to the emulsion. Practical application: According to the antioxidant hypothesis the polar paradox more amphiphilic antioxidants should perform as better antioxidants in emulsions than more polar...

  18. Simultaneous Determination of Chelating Agents by Ion-Suppression and Ion-Pair Chromatography in Wastewater

    International Nuclear Information System (INIS)

    This article describes two methods for analysing chelating agents found in nuclear waste. First, ion-suppression chromatography using an anion exchange stationary phase and mobile phase consisting of a nitric acid solution and pure water gradient. UV detection was performed at 330 nm after the reaction with a post-column reagent composed of iron nitrate in perchloric acid. Secondly, ion-pair chromatography with a mobile phase consisting of a mixture of nitric acid, tetra-butyl-ammonium hydrogeno-sulphate, tetra-butyl-ammonium hydroxide and iron chloride. A reversed-phase material was used as a stationary phase and detection was performed by direct measurement of the UV absorption at 260 nm. The quantification limits were lower for ion-pair chromatography than for ion-suppression chromatography. Both methods were easy to implement and allow a multi-element separation in less than 30 min with low detection limits. (authors)

  19. Simultaneous Determination of Chelating Agents by Ion-Suppression and Ion-Pair Chromatography in Wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Dodi, Alain; Bouscarel, Maelle [Commissariat a l' energie atomique - C.E.A, Centre d' Etude de Cadarache, Laboratoire d' Analyses Radiochimiques et Chimiques, St Paul lez Durance (France)

    2008-07-01

    This article describes two methods for analysing chelating agents found in nuclear waste. First, ion-suppression chromatography using an anion exchange stationary phase and mobile phase consisting of a nitric acid solution and pure water gradient. UV detection was performed at 330 nm after the reaction with a post-column reagent composed of iron nitrate in perchloric acid. Secondly, ion-pair chromatography with a mobile phase consisting of a mixture of nitric acid, tetra-butyl-ammonium hydrogeno-sulphate, tetra-butyl-ammonium hydroxide and iron chloride. A reversed-phase material was used as a stationary phase and detection was performed by direct measurement of the UV absorption at 260 nm. The quantification limits were lower for ion-pair chromatography than for ion-suppression chromatography. Both methods were easy to implement and allow a multi-element separation in less than 30 min with low detection limits. (authors)

  20. Antioxidant Activities and Tyrosinase Inhibitory Effects of Different Extracts from Pleurotus ostreatus Fruiting Bodies

    OpenAIRE

    Alam, Nuhu; Yoon, Ki Nam; Lee, Kyung Rim; Shin, Pyung Gyun; Cheong, Jong Chun; Yoo, Young Bok; Shim, Ja Mi; Lee, Min Woong; Lee, U Youn; Lee, Tae Soo

    2010-01-01

    We evaluated the antioxidant activity and tyrosinase inhibitory effects of Pleurotus ostreatus fruiting bodies extracted with acetone, methanol, and hot water. The antioxidant activities were tested against β-carotene-linoleic acid, reducing power, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity, and ferrous chelating ability. Furthermore, phenolic acid and flavonoid contents were also analyzed. The methanol extract showed the strongest β-carotene-linoleic acid inhibition as co...

  1. Effect of water cooking on antioxidant capacity of carotenoid-rich vegetables in Taiwan

    OpenAIRE

    Fuh-Juin Kao; Yu-Shan Chiu; Wen-Dee Chiang

    2014-01-01

    Carotenoid-rich green leafy vegetables including cilantro, Thai basil leaves, sweet potato leaves, and choy sum were selected to evaluate the effects of water cooking or boiling on their total carotenoid content (TCC), total phenolic content (TPC), and total antioxidant capacity (TAC). The percentage inhibition of peroxidation (%IP), Trolox equivalent antioxidant capacity (TEAC), and metal-chelating effect were used to evaluate TAC. The results indicated that TCC reached the maximum after boi...

  2. In Vitro Antioxidant and Anticancer Activity Studies on Drosera Indica L. (Droseraceae)

    OpenAIRE

    Raju Asirvatham; Arockiasamy Josphin Maria Christina; Anita Murali

    2013-01-01

    Purpose: The aim of present in vitro studies was performed to examine the antioxidant and anticancer activities of ethanol and aqueous extracts of Drosera indica L. Methods: Different concentrations (5 – 640mcg/ml) of the ethanol (EEDI) and aqueous (AEDI) extracts of D.indica L were used in various antioxidant assay methods such as hydroxyl radicals, DPPH, super oxide radical scavenging activity, chelating ability of ferrous ion, nitric oxide radical inhibition, ABTS and reducing power. Ascor...

  3. Assessment of Antioxidant and Cytotoxicity Activities of Saponin and Crude Extracts of Chlorophytum borivilianum

    OpenAIRE

    Mehdi Farshad Ashraf; Maheran Abd Aziz; Johnson Stanslas; Ismanizan Ismail; Mihdzar Abdul Kadir

    2013-01-01

    The present paper focused on antioxidant and cytotoxicity assessment of crude and total saponin fraction of Chlorophytum borivilianum as an important medicinal plant. In this study, three different antioxidant activities (2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH), ferrous ion chelating (FIC), and β -carotene bleaching (BCB) activity) of crude extract and total saponin fraction of C. borivilianum tubers were performed. Crude extract was found to possess higher free radical scaven...

  4. Modern problems of chelate water conditions for TPPs and NPPs

    International Nuclear Information System (INIS)

    Review of investigations devoted to the application of chelate water conditions for TPPs and NPPs is given. Chelates (mainly EDTA and its salts) are used for increasing corrosion resistance of steels, operation and pre-start-up chemical purifications, correction of water conditions and coolant circuit purification under operation (without shutdown). It is stressed that under certain conditions the optimal continuous chelate water conditions are possible under water conditions are possible under which deposits are not produced

  5. Novel Terbium Chelate Doped Fluorescent Silica Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Ning Qiaoyu; Meng Jianxin; Wang Haiming; Liu Yingliang; Man Shiqing

    2006-01-01

    Novel terbium chelate doped silica fluorescent nanoparticles were prepared and characterized.The preparation was carried out in water-in-oil (W/O) microemulsion containing monomer precursor (pAB-DTPAA-APTEOS), Triton X-100, n-hexanol, and cyclohexane by controlling copolymerization of tetraethyl orthosilicate and 3-aminopropyl-triethyloxysilane.The nanoparticles are spherical and uniform in size, about 30 nm in diameter, strongly fluorescent, and highly stable.The amino groups directly introduced to the surface of the nanoparticles using APTEOS during preparation made the surface modification and bioconjugation of the nanoparticles easier.The nanoparticles are expected as an efficient time-resolved luminescence biological label.

  6. Plutonium-237: comparative uptake in chelated and non-chelated form by channel catfish (Ictalurus punctatus)

    International Nuclear Information System (INIS)

    Chelation can either enhance or reduce the uptake of ingested plutonium relative to PuOH (monomer) in channel catfish. Reduced uptake of 237Pu-fulvate is due either to the molecular weight of the complex or its stability in metabolic systems. Increased uptake of 237Pu-citrate is attributable to instability of the complex in metabolic systems. (author)

  7. Preparation by enzymolysis and bioactivity of iron complex of fish protein hydrolysate (Fe-FPH)from low value fish

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Preparation of Fe2+ chelate of fish protein hydrolysate (Fe-FPH) obtained from low value fish proteins was introduced and its bioactivity was studied by compound enzymolysis. The optimum conditions for hydrolysate chelating Fe2+ are DH (degree of hydrolysis) at 5%, pH 7.0, 20°C and 15 min chelating time for FM (material not being defatted). Four types of Fe-FPH including CA (deposit after chelating), CB (deposit in 50% of absolute ethanol solution), CC (suspended deposit in 80% of absolute ethanol solution), and CD (bottom deposit in 80% of absolute ethanol solution) were fractionated with absolute ethanol from FM. Structural analysis through infra-red spectrum revealed that Fe2+ was combined strongly with amino-group and carboxyl-group in each chelate and each Fe2+ could form two five-member ring structures. All of the four chelates were shown more significant antioxidative activity and can be used as natural hydrophobic and hydrophilic antioxidant. Among all the chelates, the CB possesses the most effective antioxidative activity at 92% as high as that of a-tocopherol. Among all Fe-FPHs, only CD showed the most effective antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Bacillus subtilis and can be used as natural antibacterial. It provides a more effective way for utilization of low value fish proteins and key information of Fe-FPH as additive in food industry.

  8. Antioxidative defense

    Directory of Open Access Journals (Sweden)

    Stevanović Jelka

    2011-01-01

    Full Text Available Free radicals occur constantly during metabolism and take part in numerous physiological processes, such as: intra-cellular and inter-cellular signalization, gene expression, removal of damaged or senescent cells, and control of the tone of blood vessels. However, there is an increased quantity of free radicals in situations of so-called oxidative stress, when they cause serious damage to cellular membranes (peroxidation of their lipids, damage of membrane proteins, and similar, to interior cellular protein molecules, as well as DNA molecules and carbohydrates. This is precisely why the organism has developed numerous mechanisms for removing free radicals and/or preventing their production. Some of these are enzyme-related and include superoxide-dismutase, catalase, glutathione-peroxidase, and others. Other, non-enzyme mechanisms, imply antioxidative activities of vitamins E and C, provitamin A, coenzyme Q, reduced glutation, and others. Since free radicals can leave the cell that has produced them and become dispersed throughout the body, in addition to antioxidative defense that functions within cellular structures, antioxidant extra-cellular defense has also been developed. This is comprised by: transferrin, lactoferrin, haptoglobin, hemopexin, ceruloplasmin, albumins, extra-cellular isoform SOD, extracellular glutathione-peroxidase, glucose, bilirubin, urates, and many other molecules.

  9. COMPARATIVE STUDY OF CHELATION VALUE OF SEVENTEEN PERCENT SELF DEVELOPED AND COMMERCIALLY AVAILABLE ROOT CANAL LUBRICANTS

    Directory of Open Access Journals (Sweden)

    Ingale Satish Dinkarrao

    2013-06-01

    Full Text Available The main objective of this study is to compare chelation values of 17% self developed & commercially available root canal Lubricants or dental chelating gels as well as to see whether their performance depends on the chelation value or not. The Chelating agent bounds Ca2+ ions of the smear layer & the extent of chelate formation between chelating agent and metal ion is nothing but Chelation Value. Sodium carbonate indicator method is used for determinations of chelation value. Commercially available gel incorporated in this study was File Rite which has little bit higher chelation value. Self developed chelating gel or root canal lubricants have comparatively lower chelation value. Root canal lubricants having higher chelation value should perform better in shaping & cleaning of root canal better. However because of slight difference in chelation value of self developed & commercially available gel, no significant difference was found out as root canal lubricants, when applied in root canal for 5 minutes.

  10. The Role of Iron in the Skin & Cutaneous Wound Healing

    Directory of Open Access Journals (Sweden)

    JosephineAnneWright

    2014-07-01

    Full Text Available In this review article we discuss current knowledge about iron in the skin and the cutaneous wound healing process. Iron plays a key role in both oxidative stress and photo-induced skin damage. The main causes of oxidative stress in the skin include reactive oxygen species (ROS generated in the skin by ultraviolet (UVA 320-400 nm portion of the ultraviolet spectrum and biologically available iron. We also discuss the relationships between iron deficiency, anaemia and cutaneous wound healing. Studies looking at this fall into two distinct groups. Early studies investigated the effect of anaemia on wound healing using a variety of experimental methodology to establish anaemia or iron deficiency and focused on wound-strength rather than effect on macroscopic healing or re-epithelialisation. More recent animal studies have investigated novel treatments aimed at correcting the effects of systemic iron deficiency and localised iron overload. Iron overload is associated with local cutaneous iron deposition, which has numerous deleterious effects in chronic venous disease and hereditary haemochromatosis. Iron plays a key role in chronic ulceration and conditions such as Rheumatoid Arthritis (RA and Lupus Erythematosus are associated with both anaemia of chronic disease and dysregulation of local cutaneous iron haemostasis. Iron is a potential therapeutic target in the skin by application of topical iron chelators and novel pharmacological agents, and in delayed cutaneous wound healing by treatment of iron deficiency or underlying systemic inflammation.

  11. Spectroscopic studies on the antioxidant activity of ellagic acid

    Science.gov (United States)

    Kilic, Ismail; Yeşiloğlu, Yeşim; Bayrak, Yüksel

    2014-09-01

    Ellagic acid (EA, C14H6O8) is a natural dietary polyphenol whose benefits in a variety of diseases shown in epidemiological and experimental studies involve anti-inflammation, anti-proliferation, anti-angiogenesis, anticarcinogenesis and anti-oxidation properties. In vitro radical scavenging and antioxidant capacity of EA were clarified using different analytical methodologies such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2‧-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and superoxide anion radical scavenging, ferrous ions (Fe2+) chelating activity and ferric ions (Fe3+) reducing ability. EA inhibited 71.2% lipid peroxidation of a linoleic acid emulsion at 45 μg/mL concentration. On the other hand, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), α-tocopherol and ascorbic acid displayed 69.8%, 66.8%, 64.5% and 59.7% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, EA had an effective DPPH• scavenging, ABTSrad + scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power and ferrous ions (Fe2+) chelating activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and ascorbic acid as references antioxidant compounds. These results suggested that EA can be used in the pharmacological, food industry and medicine because of these properties.

  12. Comparison of Antioxidant Activities of Melanin Fractions from Chestnut Shell

    Directory of Open Access Journals (Sweden)

    Zeng-Yu Yao

    2016-04-01

    Full Text Available Chestnut shell melanin can be used as a colorant and antioxidant, and fractionated into three fractions (Fr. 1, Fr. 2, and Fr. 3 with different physicochemical properties. Antioxidant activities of the fractions were comparatively evaluated for the first time. The fractions exhibited different antioxidative potential in different evaluation systems. Fr. 1, which is only soluble in alkaline water, had the strongest peroxidation inhibition and superoxide anion scavenging activity; Fr. 2, which is soluble in alkaline water and hydrophilic organic solvents but insoluble in neutral and acidic water, had the greatest power to chelate ferrous ions; and Fr. 3, which is soluble both in hydrophilic organic solvents and in water at any pH conditions, had the greatest hydroxyl (·OH and 1,1-diphenyl-2-picryl-hydrazyl (DPPH· radicals scavenging abilities, reducing power, and phenolic content. The pigment fractions were superior to butylated hydroxytolune (BHT in ·OH and DPPH· scavenging and to ethylene diamine tetraacetic acid (EDTA in the Fe2+–chelation. They were inferior to BHT in peroxidation inhibition and O2·− scavenging and reducing power. However, BHT is a synthetic antioxidant and cannot play the colorant role. The melanin fractions might be used as effective biological antioxidant colorants.

  13. Comparison of Antioxidant Activities of Melanin Fractions from Chestnut Shell.

    Science.gov (United States)

    Yao, Zeng-Yu; Qi, Jian-Hua

    2016-01-01

    Chestnut shell melanin can be used as a colorant and antioxidant, and fractionated into three fractions (Fr. 1, Fr. 2, and Fr. 3) with different physicochemical properties. Antioxidant activities of the fractions were comparatively evaluated for the first time. The fractions exhibited different antioxidative potential in different evaluation systems. Fr. 1, which is only soluble in alkaline water, had the strongest peroxidation inhibition and superoxide anion scavenging activity; Fr. 2, which is soluble in alkaline water and hydrophilic organic solvents but insoluble in neutral and acidic water, had the greatest power to chelate ferrous ions; and Fr. 3, which is soluble both in hydrophilic organic solvents and in water at any pH conditions, had the greatest hydroxyl (·OH) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH·) radicals scavenging abilities, reducing power, and phenolic content. The pigment fractions were superior to butylated hydroxytolune (BHT) in ·OH and DPPH· scavenging and to ethylene diamine tetraacetic acid (EDTA) in the Fe(2+)-chelation. They were inferior to BHT in peroxidation inhibition and O₂·(-) scavenging and reducing power. However, BHT is a synthetic antioxidant and cannot play the colorant role. The melanin fractions might be used as effective biological antioxidant colorants. PMID:27110763

  14. Supplementary health benefits of soy aglycons of isoflavone by improvement of serum biochemical attributes, enhancement of liver antioxidative capacities and protection of vaginal epithelium of ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Lo Dan-Yuan

    2009-04-01

    Full Text Available Abstract Background In the literature, supplement of soy aglycons of isoflavone as estrogen agonists in improvement of serum biochemical attributes, liver antioxidative capacities and vaginal epithelium protection has been meagerly investigated. In this study, ovariectomized (OVX rats were used as an animal model to simulate post-menopausal status. Supplementary health benefits of soy aglycons of isoflavone (SAI on improvement of growth and serum biochemical attributes, enhancement of liver antioxidation-related capacities and protection of vaginal epithelium of the OVX rats were assessed. Methods As an in vivo study, 30 OVX Sprague-Dawley rats were distributed into OVX (positive control, OVX/LSAI (low SAI group – supplemented with 0.0135% SAI being equivalent to 80 mg per day for a 60 Kg-human, and OVX/HSAI (high SAI group – supplemented with 0.027% SAI and 10 rats with sham operation as negative control fed with basal diet. Results The average daily gain (ADG, feed intake and feed/gain ratio were higher for the OVX groups than the sham group (P P P P Conclusion Diets supplemented with soy aglycons of isoflavone have conferred health benefits to the OVX rats, in comparison to the sham rats fed with basal diet, by detection of higher serum isoflavone concentrations, significantly lower contents of serum cholesterol and LDL, and higher contents of serum HDL, increased iron chelating ability, lower contents of TBARS (thiobarbituric acid-reactive substance and enhanced catalase and total antioxidative (as trolox equivalency activities of the liver extracts, and protection of the epithelial cellular linings of vagina in the former rather than in the latter. This evidences that estrogen-agonist chemoprevention of menopausal-related cardiovascular diseases, decreased liver antioxidative capacities and epithelial degeneration of vagina could be achieved by dietary supplementation with soy aglycons of isoflavone.

  15. Studies of phenolic chelating agents on free radical scavenging activities and inhibitory action in radiation-induced lipid peroxidation

    International Nuclear Information System (INIS)

    Effects of single molecular and double molecular substituted phenolic chelating agents on scavenging of superoxide anions and hydroxyl radicals and inhibition of rat liver mitochondria lipid peroxidation induced by irradiation were studied. The phenolic chelating agents were shown to different extent to scavenge oxygen free radical and the protect against radiation-induced lipid peroxidation, and their half inhibition concentrations (IC50) on hydroxyl radicals generation and lipid peroxidation were 1 x 10-6 mol/L, which of scavenging of superoxide anions were 1 x 10-3 mol/L. 7601(CBMIDA), 9501 and 9502 were the best among them. The free radical scavenging and antioxidant activities were close related to chemical structure and de-corporate bioactivity

  16. Glucitol-core containing gallotannins inhibit the formation of advanced glycation end-products mediated by their antioxidant potential.

    Science.gov (United States)

    Ma, Hang; Liu, Weixi; Frost, Leslie; Kirschenbaum, Louis J; Dain, Joel A; Seeram, Navindra P

    2016-05-18

    Glucitol-core containing gallotannins (GCGs) are polyphenols containing galloyl groups attached to a 1,5-anhydro-d-glucitol core, which is uncommon among naturally occurring plant gallotannins. GCGs have only been isolated from maple (Acer) species, including the red maple (Acer rubrum), a medicinal plant which along with the sugar maple (Acer saccharum), are the major sources of the natural sweetener, maple syrup. GCGs are reported to show antioxidant, α-glucosidase inhibitory, and antidiabetic effects, but their antiglycating potential is unknown. Herein, the inhibitory effects of five GCGs (containing 1-4 galloyls) on the formation of advanced glycation end-products (AGEs) were evaluated by MALDI-TOF mass spectroscopy, and BSA-fructose, and G.K. peptide-ribose assays. The GCGs showed superior activities compared to the synthetic antiglycating agent, aminoguanidine (IC50 15.8-151.3 vs. >300 μM) at the early, middle, and late stages of glycation. Circular dichroism data revealed that the GCGs were able to protect the secondary structure of BSA protein from glycation. The GCGs did not inhibit AGE formation by the trapping of reactive carbonyl species, namely, methylglyoxal, but showed free radical scavenging activities in the DPPH assay. The free radical quenching properties of the GCGs were further confirmed by electron paramagnetic resonance spectroscopy using ginnalin A (contains 2 galloyls) as a representative GCG. In addition, this GCG chelated ferrous iron, an oxidative catalyst of AGE formation, supported a potential antioxidant mechanism of antiglycating activity for these polyphenols. Therefore, GCGs should be further investigated for their antidiabetic potential given their antioxidant, α-glucosidase inhibitory, and antiglycating properties. PMID:27101975

  17. Decorporation of inhaled actinides by chelation therapy

    International Nuclear Information System (INIS)

    This article describes recent work in NRPB laboratories that has identified some of the factors influencing the behaviour of plutonium, americium and curium compounds in the body after inhalation, together with a number of experimental approaches that are being developed to optimise their treatment with DTPA. It is concluded that the most effective treatment has yet to be developed, but progress must depend on a better understanding of the factors governing the transport of actinides in the body. It cannot be assumed that because the inhaled material is readily translocated to blood, that treatment regimens with Ca-DTPA based solely on previous understanding of the metabolic fate of soluble actinide complexes will be successful. In fact, depending on the nature of the material involved in the accident, inhalation alone or combined with prolonged infusion of DTPA may be more effective than the periodic intravenous injections of the chelating agent alone. For poorly transportable materials such as insoluble plutonium-239 dioxide, chelation treatment remains essentially ineffective. (U.K.)

  18. Chemical treatment of chelated metal finishing wastes.

    Science.gov (United States)

    McFarland, Michael J; Glarborg, Christen; Ross, Mark A

    2012-12-01

    This study evaluated two chemical approaches for treatment of commingled cadmium-cyanide (Cd-CN) and zinc-nickel (Zn-Ni) wastewaters. The first approach, which involved application of sodium hypochlorite (NaOCl), focused on elimination of chelating substances. The second approach evaluated the use of sodium dimethyldithiocarbamate (DMDTC) to specifically target and precipitate regulated heavy metals. Results demonstrated that by maintaining a pH of 10.0 and an oxidation-reduction potential (ORP) value of +600 mV, NaOCl treatment was effective in eliminating all chelating substances. Cadmium, chromium, nickel, and zinc solution concentrations were reduced from 0.27, 4.44, 0.06, and 0.10 ppm to 0.16, 0.17, 0.03, and 0.06 ppm, respectively. Similarly, a 1% DMDTC solution reduced these same metal concentrations in commingled wastewater to 0.009, 1.142, 0.036, and 0.320 ppm. Increasing the DMDTC concentration to 2% improved the removal of all regulated heavy metals except zinc, the removal of which at high pH values is limited by its amphotericity. PMID:23342939

  19. Antioxidant Contents and Antioxidant Activities of White and Colored Potatoes (Solanum tuberosum L.)

    Science.gov (United States)

    Lee, Sang Hoon; Oh, Seung Hee; Hwang, In Guk; Kim, Hyun Young; Woo, Koan Sik; Woo, Shun Hee; Kim, Hong Sig; Lee, Junsoo; Jeong, Heon Sang

    2016-01-01

    This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl- 2-picrylhydrazyl (DPPH)/2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (Panthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities. PMID:27390727

  20. Antioxidant Contents and Antioxidant Activities of White and Colored Potatoes (Solanum tuberosum L.).

    Science.gov (United States)

    Lee, Sang Hoon; Oh, Seung Hee; Hwang, In Guk; Kim, Hyun Young; Woo, Koan Sik; Woo, Shun Hee; Kim, Hong Sig; Lee, Junsoo; Jeong, Heon Sang

    2016-06-01

    This study was performed to evaluate and compare the antioxidant substance content and antioxidant activities of white (Superior) and colored (Hongyoung, Jayoung, Jasim, Seohong, and Jaseo) potatoes. The potatoes were extracted with 80% ethanol and were evaluated for the total polyphenol, flavonoid, and anthocyanin contents and for 1,1-diphenyl- 2-picrylhydrazyl (DPPH)/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferrous metal ion chelating effect. The total polyphenol, flavonoid, and anthocyanin contents of Hongyoung and Jayoung were higher than white and other colored potatoes. All colored potato extracts, except for Jaseo and Seohong, showed higher ABTS radical scavenging activities than the general white potato extract. Hongyoung and Jayoung had the highest ABTS and DPPH radical scavenging activities. Optical density values for the reducing power of Jayoung and Jaseo at concentration of 2 mg/mL were 0.148 and 0.090, respectively. All colored potato extracts had lower ferrous metal ion chelating effect than the white potato. A significant (P<0.05) positive correlation was observed between total polyphenol content and total flavonoid content (r=0.919), anthocyanin content (r=0.992), and ABTS radical scavenging activity (r=0.897). Based on these results, this research may be useful in developing the Hongyoung and Jayoung cultivars with high antioxidant activities. PMID:27390727

  1. The experimental study on protective effects and mechanisms of chelating agents of catechols amino carboxylic acid for radiation injury induced by actimides(Th-234)

    International Nuclear Information System (INIS)

    The decorporative efficacy and antioxidative action of prompt and delayed consecutive administration of catecholicpolyaminopolycarboxylate ligands, 7601 and 9501 for radiothorium in mice were investigated. DTPA and Vitamin E were used as positive controls. The competitive abilities of 7601 and 9501 to mobilize the thorium with BSA were studied. Their inhibition effects on superoxide anionas radicals were measured with electron spin resonance. The results showed that 7601 and 9501 are able to effectively prevent the internal radiation injury induced radiothorium, attributing to their double functions of pronounced removal effectiveness and antioxidative action. Their protective effects were better than DTPA and Vitamin E. The mechanisms of protective effects of 7601 and 9501 for internal radiation injury was close related to competitive ability of chelating agent to chelate the thorium with BSA and oxygen free radical scavenging activities

  2. Cellular Iron Depletion and the Mechanisms Involved in the Iron-dependent Regulation of the Growth Arrest and DNA Damage Family of Genes*

    OpenAIRE

    Saletta, Federica; Rahmanto, Yohan Suryo; Siafakas, Aritee R.; Richardson, Des R.

    2011-01-01

    Iron plays a crucial part in proliferation while iron deficiency results in G1/S arrest, DNA damage, and apoptosis. However, the precise role of iron in cell cycle control remains unclear. We showed that iron depletion using the iron chelators, desferrioxamine (DFO), or 2-hydroxy-1-napthylaldehyde isonicotinoyl hydrazone (311), increased the mRNA levels of the growth arrest and DNA damage 45α gene, GADD45α (Darnell, G. and Richardson, D. R. (1999) Blood 94, 781–792). In this study, we examine...

  3. Methanobactin: a copper binding compound having antibiotic and antioxidant activity isolated from methanotrophic bacteria

    Science.gov (United States)

    DiSpirito, Alan A.; Zahn, James A.; Graham, David W.; Kim, Hyung J.; Alterman, Michail; Larive, Cynthia

    2007-04-03

    A means and method for treating bacterial infection, providing antioxidant activity, and chelating copper using a copper binding compound produced by methanotrophic bacteria is described. The compound, known as methanobactin, is the first of a new class of antibiotics having gram-positive activity. Methanobactin has been sequenced, and its structural formula determined.

  4. Coccoloba uvifera (L. (Polygonaceae Fruit: Phytochemical Screening and Potential Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Maira Rubi Segura Campos

    2015-01-01

    Full Text Available The flora of Latin America attracts gaining interest as it provides a plethora of still unexplored or underutilized fruits that can contribute to human well-being due to their nutritional value and their content of bioactive compounds. Antioxidant compounds are now of considerable interest due to their effect of preventing or delaying aging and their apparent involvement in prevention of numerous human diseases, including cancer, atherosclerosis, Alzheimer’s disease, inflammation, and rheumatoid arthritis. In this work, the fruit of Coccoloba uvifera (L. was investigated for their in vitro antioxidant capacity using two assays based on reactions with a relatively stable single reagent radical (Trolox equivalent antioxidant capacity, TEAC; and DPPH free radical scavenging assay, DPPH, two assays based on chelating of metallic cations, and one based on the reduction of oxidized species. The TEAC value on ABTS radical, DPPH scavenging activity, ion chelation, and reducing power were found to be 897.6 μM of Trolox/100 g of sample, 22.8% of DPPH free radical scavenging, 11.3% of Cu2+-chelating activity, 23.9% of Fe2+-chelating activity, and a Fe2+-reducing power of 0.76 mg/mL, respectively. The free radical scavenging and antioxidant characteristics of C. uvifera may be due to the presence of diverse phytochemicals in the fruit as anthocyanins, ascorbic acid, phenolic compounds, and flavonoids.

  5. Antioxidant activity of wild edible plants in the Black Sea Region of Turkey

    OpenAIRE

    Özen, Tevfik

    2010-01-01

    The antioxidative activity of the 80% ethanol extract obtained from eleven commonly consumed wild edible plants was determined according to the phosphomolybdenum method, reducing power, metal chelating, superoxide anion and free radical scavenging activity and compared to standard compounds such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and trolox. Total phenolic compounds, flavonoids, and anthocyanins in the extracts were also measured. Trachystemon orientalis, Vaccin...

  6. Battles with Iron: Manganese in Oxidative Stress Protection*

    OpenAIRE

    Aguirre, J. Dafhne; Culotta, Valeria C.

    2012-01-01

    The redox-active metal manganese plays a key role in cellular adaptation to oxidative stress. As a cofactor for manganese superoxide dismutase or through formation of non-proteinaceous manganese antioxidants, this metal can combat oxidative damage without deleterious side effects of Fenton chemistry. In either case, the antioxidant properties of manganese are vulnerable to iron. Cellular pools of iron can outcompete manganese for binding to manganese superoxide dismutase, and through Fenton c...

  7. Antioxidant Capacity and the Correlation with Major Phenolic Compounds, Anthocyanin, and Tocopherol Content in Various Extracts from the Wild Edible Boletus edulis Mushroom

    OpenAIRE

    Emanuel Vamanu; Sultana Nita

    2013-01-01

    Boletus edulis is a wild edible mushroom habitually consumed by rural populations. Ethanolic and methanolic extracts was obtained in cold and hot water from dried fruit bodies. The antioxidant activity of freeze-dried extracts from B. edulis were investigated using free radicals scavenging activity, reducing power, metal chelating effect, inhibition of lipid peroxidation, and the identification of antioxidant compounds. The levels of different compounds with antioxidant properties were higher...

  8. The mechanism of patulin's cytotoxicity and the antioxidant activity of indole tetramic acids

    Energy Technology Data Exchange (ETDEWEB)

    Riley, R.T.; Showker, J.L. (Toxicology and Mycotoxins Research Unit, U.S. Department of Agriculture/Agricultural Research Service, Athens, GA (USA))

    1991-06-01

    In LLC-PK1 cells exposed to patulin (50 microM), lipid peroxidation, abrupt calcium influx, extensive blebbing, and total LDH release appeared to be serially connected events with each representing a step in the loss of structural integrity of the plasma membrane. The aforementioned patulin-induced events were prevented by concurrent incubation with butylated hydroxytoluene, deferoxamine, and cyclopiazonic acid, a fungal metabolite. Patulin also caused depletion of nonprotein sulfhydryls, increased 86Rb+ efflux, dome collapse, and eventually the loss of cell viability. These events were not prevented by antioxidants, results consistent with the hypothesis that they were also serially connected but occurring parallel to those previously mentioned. The earliest events observed in patulin-treated cells were the decrease in nonprotein sulfhydryls and increase in 86Rb+ efflux (5 min) which occurred before statistically significant alterations in protein-bound sulfhydryls. The increased potassium efflux (86Rb+ efflux) occurred via a pathway distinct from BaCl2, quinine, or tetraethylammonium sensitive potassium channels. This is the first published report of the antioxidant activity of indole tetramic acids (cyclopiazonic acid and cyclopiazonic acid imine). The protective effect of tetramic acids in LLC-PK1 cells was restricted to indole tetramic acids, and their prevention of lipid peroxidation did not involve iron chelation. The results of this study demonstrate that cyclopiazonic acid is a potent inhibitor of azide-insensitive, ATP-dependent, a23187-sensitive calcium uptake by the lysate of LLC-PK1 cells. This result is consistent with the hypothesis that the endoplasmic reticulum calcium transport ATPase is a sensitive target for cyclopiazonic acid in LLC-PK1 cells.

  9. Polyphenolic content and antioxidant activity of some wild Saudi Arabian asteraceae plants

    Institute of Scientific and Technical Information of China (English)

    Abdelaaty A Shahat; Abeer Y Ibrahim; Mansour S Elsaid

    2014-01-01

    Objective:To study the antioxidant properties of crude extract of differentAsteraceae plants. Methods:The antioxidant properties of six extracts were evaluated using different antioxidant tests, including free radical scavenging, reducing power, metal chelation, superoxide anion radical scavenging, total antioxidant capacity and inhibition of lipid peroxidation activities.Results:Picris cyanocarpa(P. cyanocarpa) andAnthemis deserti(A. deserti) had powerful antioxidant properties as radical scavenger, reducing agent and superoxide anion radical scavenger while Achillia fragrantissima(A. fragrantissima) andArtemissia monosperma(A. monosperma) were the most efficient as ion chelator(100% at100,200 and400 μg/mL)A. fragrantissima and Rhantarium appoposum(R. appoposum) showed100% inhibition on peroxidation of linoleic acid emulsion at200 and400 μg/mL, while butylatedhydroxy toluene and ascorbic acid showed100 and95% inhibition percentage at400 μg/mL, respectively.Those various antioxidant activities were compared to standard antioxidants such as butylated hydroxyl toluene and ascorbic acid. Conclusions:In most testsP. cyanocarpa andA. deserti had powerful antioxidant properties as radical scavenger, reducing agent and superoxide anion radical scavenger.

  10. Genotoxic effect of ethacrynic acid and impact of antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Ward, William M.; Hoffman, Jared D.; Loo, George, E-mail: g_loo@uncg.edu

    2015-07-01

    It is known that ethacrynic acid (EA) decreases the intracellular levels of glutathione. Whether the anticipated oxidative stress affects the structural integrity of DNA is unknown. Therefore, DNA damage was assessed in EA-treated HCT116 cells, and the impact of several antioxidants was also determined. EA caused both concentration-dependent and time-dependent DNA damage that eventually resulted in cell death. Unexpectedly, the DNA damage caused by EA was intensified by either ascorbic acid or trolox. In contrast, EA-induced DNA damage was reduced by N-acetylcysteine and by the iron chelator, deferoxamine. In elucidating the DNA damage, it was determined that EA increased the production of reactive oxygen species, which was inhibited by N-acetylcysteine and deferoxamine but not by ascorbic acid and trolox. Also, EA decreased glutathione levels, which were inhibited by N-acetylcysteine. But, ascorbic acid, trolox, and deferoxamine neither inhibited nor enhanced the capacity of EA to decrease glutathione. Interestingly, the glutathione synthesis inhibitor, buthionine sulfoxime, lowered glutathione to a similar degree as EA, but no noticeable DNA damage was found. Nevertheless, buthionine sulfoxime potentiated the glutathione-lowering effect of EA and intensified the DNA damage caused by EA. Additionally, in examining redox-sensitive stress gene expression, it was found that EA increased HO-1, GADD153, and p21mRNA expression, in association with increased nuclear localization of Nrf-2 and p53 proteins. In contrast to ascorbic acid, trolox, and deferoxamine, N-acetylcysteine suppressed the EA-induced upregulation of GADD153, although not of HO-1. Overall, it is concluded that EA has genotoxic properties that can be amplified by certain antioxidants. - Highlights: • Ethacrynic acid (EA) caused cellular DNA damage. • EA-induced DNA damage was potentiated by ascorbic acid or trolox. • EA increased ROS production, not inhibited by ascorbic acid or trolox. • EA

  11. Chelation Treatment for Autism Spectrum Disorders: A Systematic Review

    Science.gov (United States)

    Davis, Tonya N.; O'Reilly, Mark; Kang, Soyeon; Lang, Russell; Rispoli, Mandy; Sigafoos, Jeff; Lancioni, Giulio; Copeland, Daelynn; Attai, Shanna; Mulloy, Austin

    2013-01-01

    Chelation treatment is used to eliminate specific metals from the body, such as mercury. It has been hypothesized that mercury poisoning may be a factor in autism and data suggest that perhaps 7% of individuals with autism spectrum disorder (ASD) have received chelation treatment. It would therefore seem timely to review studies investigating the…

  12. Macrocyclic Chelator Assembled RGD Multimers for Tumor Targeting

    OpenAIRE

    Zhang, Xiaofen; Liu, Hongguang; Miao, Zheng; Kimura, Richard; Fan, Feiyue; Cheng, Zhen

    2011-01-01

    Macrocyclic chelators have been extensively used for complexation of metal ions. A widely used chelator, DOTA, has been explored as a molecular platform to assemble multiple bioactive peptides in this paper. The multivalent DOTA-peptide bioconjugates demonstrate promising tumor targeting ability.

  13. Inapplicability of high pressure spray injection for chelate administration

    International Nuclear Information System (INIS)

    A high-pressure spray injector was tested for use in injecting chelating agents around radionuclides in wounds. It was difficult to employ because of the force required for proper injection, and it did not improve the effectiveness of the injected chelate in removing intramuscularly injected 238Pu. (U.S.)

  14. Adsorptive separation of rare earths by using chelating chitosan

    International Nuclear Information System (INIS)

    Two kinds of chelating chitosan were prepared by chemically modifying chitosan with functional groups of EDTA or DTPA, abbreviated as EDTA- and DTPA-chitosan hereafter, respectively, to investigate the adsorption behaviour for rare earths the mutual separation of which is the most difficult among metal ions on these chelating chitosan from dilute hydrochloric or sulfuric acid solution. The plots of the distribution ratio of a series of rare earths against equilibrium pH lay on different straight lines with slope of 3 corresponding to each earth for both of two chelating chitosan, suggesting that 3 hydrogen ions are released for the adsorption of unit ion of each rare earth by chelate formation with the functional group of EDTA or DTPA and that mutual adsorptive separation between adjacent rare earth is possible with these chelating chitosan. Apparent equilibrium constants of the adsorption were evaluated from the intercepts of these straight lines with the ordinate for each rare earth and for both chelating chitosan. It was found that the equilibrium constants of adsorption on EDTA- or DTPA-chitosan are quite analogous to those of chelate formation with EDTA or DTPA themselves, suggesting that chelating characteristics of these complexones is still maintained after their immobilization on polymer matrices of chitosan. (author)

  15. Potentials and drawbacks of chelate-enhanced phytoremediation of soils

    NARCIS (Netherlands)

    Römkens, P.F.A.M.; Bouwman, L.A.; Japenga, J.; Draaisma, C.

    2002-01-01

    Chelate-enhanced phytoremediation has been proposed as an effective tool for the extraction of heavy metals from soils by plants. However, side-effects related to the addition of chelates, e.g. metal leaching and effects on soil micro-organisms, were usually neglected. Therefore, greenhouse and lysi

  16. Sugars increase non-heme iron bioavailability in human epithelial intestinal and liver cells.

    Directory of Open Access Journals (Sweden)

    Tatiana Christides

    Full Text Available Previous studies have suggested that sugars enhance iron bioavailability, possibly through either chelation or altering the oxidation state of the metal, however, results have been inconclusive. Sugar intake in the last 20 years has increased dramatically, and iron status disorders are significant public health problems worldwide; therefore understanding the nutritional implications of iron-sugar interactions is particularly relevant. In this study we measured the effects of sugars on non-heme iron bioavailability in human intestinal Caco-2 cells and HepG2 hepatoma cells using ferritin formation as a surrogate marker for iron uptake. The effect of sugars on iron oxidation state was examined by measuring ferrous iron formation in different sugar-iron solutions with a ferrozine-based assay. Fructose significantly increased iron-induced ferritin formation in both Caco-2 and HepG2 cells. In addition, high-fructose corn syrup (HFCS-55 increased Caco-2 cell iron-induced ferritin; these effects were negated by the addition of either tannic acid or phytic acid. Fructose combined with FeCl3 increased ferrozine-chelatable ferrous iron levels by approximately 300%. In conclusion, fructose increases iron bioavailability in human intestinal Caco-2 and HepG2 cells. Given the large amount of simple and rapidly digestible sugars in the modern diet their effects on iron bioavailability may have important patho-physiological consequences. Further studies are warranted to characterize these interactions.

  17. Endothelial Cell Injury Caused by Candida albicans Is Dependent on Iron

    OpenAIRE

    Fratti, Rutilio A.; Belanger, Paul H.; Ghannoum, Mahmoud A.; Edwards, John E.; Filler, Scott G.

    1998-01-01

    Although it is known that Candida albicans causes endothelial cell injury, in vitro and in vivo, the mechanism by which this process occurs remains unknown. Iron is critical for the induction of injury in many types of host cells. Therefore, we investigated the role of iron in Candida-induced endothelial cell injury. We found that pretreatment of endothelial cells with the iron chelators phenanthroline and deferoxamine protected them from candidal injury, even though the organisms germinated ...

  18. The heme–p53 interaction: Linking iron metabolism to p53 signaling and tumorigenesis

    OpenAIRE

    Shen, Jia; Sheng, Xiangpeng; Chang, ZeNan; Wu, Qian; Xie, Dong; Wang, Fudi; HU, Ronggui

    2014-01-01

    Recently, we reported that heme binds to tumor suppressor p53 protein (TP53, best known as p53) and promotes its nuclear export and cytosolic degradation, whereas iron chelation stabilizes p53 protein and suppresses tumors in a p53-dependent manner. This not only provides mechanistic insights into tumorigenesis associated with iron excess, but also helps guide the administration of chemotherapy based on iron deprivation in the clinic.

  19. Iron Prochelator BSIH Protects Retinal Pigment Epithelial Cells against Cell Death Induced by Hydrogen Peroxide

    OpenAIRE

    Charkoudian, Louise K.; Dentchev, Tzvete; Lukinova, Nina; Wolkow, Natalie; Dunaief, Joshua L.; Franz, Katherine J.

    2008-01-01

    Dysregulation of localized iron homeostasis is implicated in several degenerative diseases, including Parkinson’s, Alzheimer’s, and age-related macular degeneration, wherein iron-mediated oxidative stress is hypothesized to contribute to cell death. Inhibiting toxic iron without altering normal metal-dependent processes presents significant challenges for standard small molecule chelating agents. We previously introduced BSIH (isonicotinic acid [2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl...

  20. Urinary iron excretion induced by intravenous infusion of deferoxamine in ß-thalassemia homozygous patients

    OpenAIRE

    Boturão-Neto E.; Marcopito L.F.; Zago M.A.

    2002-01-01

    The purpose of the present study was to identify noninvasive methods to evaluate the severity of iron overload in transfusion-dependent ß-thalassemia and the efficiency of intensive intravenous therapy as an additional tool for the treatment of iron-overloaded patients. Iron overload was evaluated for 26 ß-thalassemia homozygous patients, and 14 of them were submitted to intensive chelation therapy with high doses of intravenous deferoxamine (DF). Patients were classified into six groups of i...

  1. Quantitative measurement of metal chelation by fourier transform infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Monika E. Miller

    2015-12-01

    Full Text Available Nutritionally important minerals are more readily absorbed by living systems when complexed with organic acids, resulting in higher consumer demand and premium prices for these products. These chelated metals are produced by reaction of metal oxides and acids in aqueous solution. However, unreacted dry blends are sometimes misrepresented as metal chelates, when in reality they are only simple mixtures of the reactants typically used to synthesize them. This practice has increased interest in developing analytical methods that are capable of measuring the extent of metal chelation for quality control and regulatory compliance. We describe a novel method to rapidly measure the percent chelation of citric and malic acids with calcium, magnesium, and zinc. Utilization of attenuated total reflectance (FTIR-ATR provides for the direct, rapid measurement of solid samples. The inclusion of an internal standard allows independent determination of either free or chelated acids from integrated areas in a single spectrum.

  2. Copper, dioxouranium(VI) and lanthanide chelates of carboxymethylthiosuccinic acid

    International Nuclear Information System (INIS)

    Carboxymethylthiosuccinic acid (CMTSA) has three dissociable - COOH groups with pK values 2.91, 3.91, 5.03. Assignment of these values to the different carboxylic groups is given. Cu(II) and UO22+ chelates with CMSTA have been studied potentiometrically at 30degC and μ = 0.1M. The effects of dielectric constant of the solvent medium (dioxane-water) and the ionic strength, on these chelates have been examined. The lanthanides form 1:1 and 1:2 chelates with CMTSA. The plots of log K1 and (log K1 + log K2) versus e2/2r show a break at gadolinium. The thermodynamic parameters for these chelates have been determined. Smaller values of DELTAH show the predominance of the entropy effect in the formation of these chelates. (author)

  3. In Vitro Antioxidant Evaluation of Some Mannich Bases which Contain Bis-1,2,4 -Triazole Derivative

    International Nuclear Information System (INIS)

    This study aims to examine the antioxidant effects of some Mannich bases containing bis-1, 2, 4 triazole, which are synthesized afresh. The antioxidant activities of the derivatives were measured using different methods in this study, including reducing power capacity, metal chelating activity, superoxide anion radicals scavenging activity, H/sub 2/ O/sub 2/ scavenging activity and hydroxyl radical scavenging. As a result, derivatives had efficient antioxidant and free radical scavenging activity when compared to ascorbic acid, BHT and alpha-tocopherol as associated antioxidants. (author)

  4. Iron Homeostasis and Nutritional Iron Deficiency123

    OpenAIRE

    Theil, Elizabeth C.

    2011-01-01

    Nonheme food ferritin (FTN) iron minerals, nonheme iron complexes, and heme iron contribute to the balance between food iron absorption and body iron homeostasis. Iron absorption depends on membrane transporter proteins DMT1, PCP/HCP1, ferroportin (FPN), TRF2, and matriptase 2. Mutations in DMT1 and matriptase-2 cause iron deficiency; mutations in FPN, HFE, and TRF2 cause iron excess. Intracellular iron homeostasis depends on coordinated regulation of iron trafficking and storage proteins enc...

  5. New chelation strategies for the uranyl ion

    International Nuclear Information System (INIS)

    Traditional approaches to the design of metal-ion-specific complexing agents have relied to a great extent on the creation of a ligand cavity of the appropriate size and coordination number to accommodate the targeted metal ion. Oxo-metal ions, such as uranyl, cannot be dealt with as spherically symmetric charged atoms and thus present both a special challenge and offer a unique advantage for specific chelation in solution. To maximize recognition of the anisotropic UO22+ ion, new tripodal hexadentate ligands have been prepared providing three carboxyl moieties each to act as a bidentate donor group. The novel ligand design concept, ligand syntheses, and thermodynamic results related to the uranyl complex characterization are presented

  6. Iron in haemoglobinopathies and rare anaemias

    Directory of Open Access Journals (Sweden)

    John Porter

    2014-12-01

    Full Text Available Iron overload in haemoglobinopathies and rare anaemias may develop from increased iron absorption secondary to hepcidin suppression, and/or from repeated blood transfusions. While the accumulation of body iron load from blood transfusion is inevitable and predictable from the variable rates of transfusion in the different conditions, there are some important differences in the distribution of iron overload and its consequences between these. Transfusion-dependent thalassaemia (TDT is the best described condition in which transfusional overload occurs. Initially iron loads into macrophages, subsquently hepatocytes, and then the endocrine system including the anterior pituiatry and finally the myocardium. The propensity to extrahepatic iron spread increases with rapid transfusion and with inadequate chelation therapy but there is considerable interpatient and interpopulation variability in this tendency. The conduits though which iron is delivered to tissues is through non transferrin iron species (NTBI which are taken into liver, endocrine tissues and myocardium through L-type calcium channells and possibly through other channells. Recent work by the MSCIO group1 suggests that levels of NTBI are determined by three mechanisms: i increasing with iron overload; ii increasing with ineffective erythropoieis; iii and decreasing when level of transferrin iron utilisation is high. In TDT all three mechanisms increase NTBI levels because transferrin iron utilisation is suppressed by hypertransfusion. It is hypothesized that the transfusion regimen and target mean Hb may have a key impact on NTBI levels because high transfusion regimes may suppress the ‘sink’ effect of the erythron though decreased clearance of transferrin iron. In sickle cell disease (SCD without blood transfusion the anaemia results mainly from haemolysis rather than from ineffective erythropoiesis.2 Thus there is a tendency to iron depletion because of urinary iron loss from

  7. Antioxidant Properties and Antioxidant Compounds of Various Extracts from the Edible Basidiomycete Grifola Frondosa (Maitake)

    OpenAIRE

    Kaun-Tzer Wu; Cheng-Fang Tsai; Li-Hui Hsieh; Jan-Ying Yeh

    2011-01-01

    Grifola frondosa is an edible mushroom currently available in Taiwan. Ethanolic, cold-water and hot-water extracts were prepared and their antioxidant properties were investigated. At 1 mg/mL, G. frondosa T1 and T2 cold-water extracts showed high reducing powers of 1.02 and 0.50, respectively. Chelating abilities on ferrous ions of G. frondosa T1 and T2 were higher for cold-water extracts than for ethanolic and hot-water extracts. For the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (D...

  8. Chelating impact assessment of biological ad chemical chelates on metal extraction from contaminated soils

    International Nuclear Information System (INIS)

    Soil contamination is the result of uncontrolled waste dumping and poor practices by humans. Of all the pollutants heavy metals are of particular concern due to their atmospheric deposition, leaching capacity and non-biodegradability. Heavy metal containing effluent is discharged into the agricultural fields and water bodies. This results in the accumulation of heavy metals in soil and the crops grown on that soil. Studies have revealed detrimental impacts on soil fertility and the poor health of animals and humans. Phytoextraction is widely researched for remediation of heavy metal contaminated soil. To enhance the effect of phytoextraction heavy metals have to be available to the plants in soluble form. In this study the potential of different chelating agents was assessed in solubilizing the heavy metals making easy for plants to uptake them. For this purpose efficient chemical and biological chelating agent had to be identified. Along with that an optimum dose and application time for chemical chelating agent was determined. Ethylenediamine tetraacetic acid (EDTA), Diethylene triamine pentaacetic acid (DTPA), Nitriloacetic acid (NTA) were applied to the soil, containing Pb, Cr, Cu and Cd, at different concentrations and application time. Aspergillus niger and Aspergillus flavus were incubated in soil for different time periods. In correspondence with findings of the study, Pb and Cr were best solubilized by 5mM EDTA. For Cd and Cu 5mM DTPA carried out efficient chelation. NTA showed relatively inadequate solubilisation, although for Cr it performed equal to EDTA. A. niger and A. flavus instead of solubilizing adsorbed the metals in their biomass. Adsorption was mainly carried out by A. niger. (author)

  9. Estimates of the effect on hepatic iron of oral deferiprone compared with subcutaneous desferrioxamine for treatment of iron overload in thalassemia major: a systematic review

    Directory of Open Access Journals (Sweden)

    Caro J

    2002-11-01

    Full Text Available Abstract Background Beta thalassemia major requires regular blood transfusions and iron chelation to alleviate the harmful accumulation of iron. Evidence on the efficacy and safety of the available agents, desferrioxamine and deferiprone, is derived from small, non-comparative, heterogeneous observational studies. This evidence was reviewed to quantitatively compare the ability of these chelators to reduce hepatic iron. Methods The literature was searched using Medline and all reports addressing the effect of either chelator on hepatic iron were considered. Data were abstracted independently by two investigators. Analyses were performed using reported individual patient data. Hepatic iron concentrations at study end and changes over time were compared using ANCOVA, controlling for initial iron load. Differences in the proportions of patients improving were tested using χ2. Results Eight of 11 reports identified provided patient-level data relating to 30 desferrioxamine- and 68 deferiprone-treated patients. Desferrioxamine was more likely than optimal dose deferiprone to decrease hepatic iron over the average follow-up of 45 months (odds ratio, 19.0, 95% CI, 2.4 to 151.4. The degree of improvement was also larger with desferrioxamine. Conclusions This analysis suggests that desferrioxamine is more effective than deferiprone in lowering hepatic iron. This comparative analysis – despite its limitations – should prove beneficial to physicians faced with the challenge of selecting the optimal treatment for their patients.

  10. Syntheses of polystyrene supported chelating resin containing the Schiff base derived from salicylaldehyde and triethylene tetramine and its copper(II), nickel(II), cobalt(II), iron(III), zinc(II), cadmium(II), molybdenum(VI), zirconium(IV) and uranium(VI) complexes

    International Nuclear Information System (INIS)

    A new polymer-anchored chelating ligand has been synthesized by the reaction of chloromethylated polystyrene (containing 0.94 mmol of Cl per gram of resin and 1% cross-linked with divinylbenzene) and the Schiff base derived from salicylaldehyde and triethylenetetramine. A new series of polystyrene supported, Cu(II), Ni(II), Co(II), Fe(III), Zn(II), Cd(II), Zr(IV), dioxomolybdenum (VI) and dioxouranium (VI) complexes of the formulae PS-LCu, PS-LNi, PS-LCo, PS-LFeCl.DMF, PS-LZn, PS-LCd, PS-LZr(OH)2. DMF, PSLMoO2 and PS-LUO2 (where PS-LH2 = polymer-anchored Schiff base and DMF dimethyl-formamide) have been synthesized and characterised by elemental analysis, infrared, electronic spectra and magnetic susceptibility measurements. The complexes PS-LCu, PS-LNi and PS-LCo have square planar structure, PS-LFeCl.DMF, PS-LMoO2 and PS-LUO2 have octahedral structure, PSLZn and PS-LCd are tetrahedral and PS-LZr(OH)2.DMF is pentagonal bipyramidal. The polymer-anchored Cu(II), Co(II) and Fe(III) complexes are paramagnetic while Ni(II), Zn(II), Cd(II), Zr(IV), dioxomolybdenum(VI) and dioxouranium(VI) complexes are diamagnetic. The negative shift of the v (C=N) (azomethine) and the positive shift of v (C--O)(phenolic) are indicative of ONNO donor behaviour of the polymer-anchored Schiff base. (author)

  11. Preparation and properties of a new chelating resin containing 1-nitroso-2-naphthol as the functional group.

    Science.gov (United States)

    Ghosh, J P; Das, H R

    1981-04-01

    A macroreticular polystyrene-based chelating ion-exchanger containing 1-nitroso-2-naphthol as the functional group has been synthesized. The exchange-capacity of the resin for a number of metal ions such as copper(II), iron(III), cobalt(II), nickel(II), palladium(II) and uranium(VI) as a function of pH has been determined. The sorption and elution characteristics for palladium(II) and uranium(VI) have been thoroughly examined with a view to utilizing the resin for separation and concentration of uranium and palladium. Uranium(VI) has been separated from a mixture of ten other metal ions by sorption on the chelating resin and selective elution with 0.5M sodium carbonate. Palladium(II) has been separated from various metal ions by selective sorption on the resin in 1M hydrochloric acid medium. PMID:18962916

  12. Abiotic reductive extraction of arsenic from contaminated soils enhanced by complexation: Arsenic extraction by reducing agents and combination of reducing and chelating agents

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Jung [Department of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeollabukdo 561-675 (Korea, Republic of); Lee, Jae-Cheol [Department of Environmental Engineering, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeollabukdo 561-675 (Korea, Republic of); Baek, Kitae, E-mail: kbaek@jbnu.ac.kr [Department of Bioactive Material Sciences, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeollabukdo 561-675 (Korea, Republic of); Department of Environmental Engineering, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeollabukdo 561-675 (Korea, Republic of)

    2015-02-11

    Highlights: • Abiotic reductive extraction of As from contaminated soils was studied. • Oxalate/ascorbate were effective in extracting As bound to amorphous iron oxides. • Reducing agents were not effective in extracting As bound to crystalline oxides. • Reductive As extraction was greatly enhanced by complexation. • Combination of dithionite and EDTA could extract about 90% of the total As. - Abstract: Abiotic reductive extraction of arsenic from contaminated soils was studied with various reducing agents and combinations of reducing and chelating agents in order to remediate arsenic-contaminated soils. Oxalate and ascorbic acid were effective to extract arsenic from soil in which arsenic was associated with amorphous iron oxides, but they were not effective to extract arsenic from soils in which arsenic was bound to crystalline oxides or those in which arsenic was mainly present as a scorodite phase. An X-ray photoelectron spectroscopy study showed that iron oxides present in soils were transformed to Fe(II,III) or Fe(II) oxide forms such as magnetite (Fe{sub 3}O{sub 4}, Fe{sup II}Fe{sub 2}{sup III}O{sub 4}) by reduction with dithionite. Thus, arsenic extraction by dithionite was not effective due to the re-adsorption of arsenic to the newly formed iron oxide phase. Combination of chelating agents with reducing agents greatly improved arsenic extraction from soil samples. About 90% of the total arsenic could be extracted from all soil samples by using a combination of dithionite and EDTA. Chelating agents form strong complexation with iron, which can prevent precipitation of a new iron oxide phase and also enhance iron oxide dissolution via a non-reductive dissolution pathway.

  13. MRI Measurements of Iron Load in Transfusion-Dependent Patients: Implementation, Challenges, and Pitfalls.

    Science.gov (United States)

    Quinn, Charles T; St Pierre, Tim G

    2016-05-01

    Magnetic resonance imaging (MRI) has played a key role in studies of iron overload in transfusion-dependent patients, providing insights into the relations among liver and cardiac iron loading, iron chelator dose, and morbidity. Currently, there is rapid uptake of these methods into routine clinical practice as part of the management strategy for iron overload in regularly transfused patients. Given the manifold methods of data acquisition and analysis, there are several potential pitfalls that may result in inappropriate decision making. Herein, we review the challenges of establishing suitable MRI techniques for tissue iron measurement in regularly transfused patients. PMID:26713769

  14. ATOX1 gene silencing increases susceptibility to anticancer therapy based on copper ionophores or chelating drugs.

    Science.gov (United States)

    Barresi, Vincenza; Spampinato, Giorgia; Musso, Nicolò; Trovato Salinaro, Angela; Rizzarelli, Enrico; Condorelli, Daniele Filippo

    2016-03-01

    Copper is a catalytic cofactor required for the normal function of many enzymes involved in fundamental biological processes but highly cytotoxic when in excess. Therefore its homeostasis and distribution is strictly regulated by a network of transporters and intracellular chaperones. ATOX1 (antioxidant protein 1) is a copper chaperone that plays a role in copper homeostasis by binding and transporting cytosolic copper to ATPase proteins in the trans-Golgi network. In the present study the Caco-2 cell line, a colon carcinoma cell line, was used as an in vitro model to evaluate if ATOX1 deficiency could affect sensitivity to experimentally induced copper dyshomeostasis. Silencing of ATOX1 increased toxicity of a short treatment with a high concentration of Cu(2+). Copper ionophores, such as 5-chloro-8-hydroxyquinoline, induced a copper-dependent cell toxicity which was significantly potentiated after ATOX1 silencing. The copper chelator TPEN (N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine) produced a form of cell toxicity that was reversed by the addition of Cu(2+). ATOX1 silencing increased Caco-2 cell sensitivity to TPEN toxicity. Our results suggest the possibility of a therapy with copper-chelating or ionophore drugs in subtypes of tumors showing specific alterations in ATOX1 expression. PMID:26784148

  15. Neuroprotective Role of a Novel Copper Chelator against Aβ42 Induced Neurotoxicity

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar Singh

    2013-01-01

    Full Text Available Alzheimer's disease (AD is a progressive neurodegenerative disease and associated with the extracellular deposits of amyloid-β peptide in hippocampus region. Metal ions like Cu, Fe and Zn are known to associate with the amyloid beta (Aβ at high concentration and interaction of these ions with soluble and aggregated forms of Aβ peptide help in development of AD. Here we showed Cu mediated neurotoxicity in the eye tissues of transgenic Drosophila expressing human amyloid β and its rescue through a novel Cu chelator. In this context, we have synthesised and characterized the compound L 2,6-Pyridinedicarboxylic acid, 2,6-bis[2-[(4-carboxyphenyl methylene] hydrazide] by Mass spectra (MS and Elemental analysis (EA. The Cu chelation potential of the compound L is tested in vivo in Drosophila. Oral administration of Copper to the transgenic larvae resulted in severe degeneration in eye tissues, which was rescued by the supplementation of compound L. The levels of anti-oxidant markers like SOD and MDA were measured in compound L treated flies and found a significant rescue (P<0.001. Further rescue of the eye degeneration phenotypes as revealed by SEM affirm the role of copper in Aβ toxicity. Hence, use of compound L, an amidoamine derivative, could be a possible therapeutic measure for Aβ induced neurotoxicity.

  16. The Investigation of Some Bioactive Compounds and Antioxidant Properties of Hawthorn (Crataegus monogyna subsp. monogyna jacq.

    Directory of Open Access Journals (Sweden)

    Serhat KESER

    2014-04-01

    Full Text Available The antioxidant and pharmacological effects of hawthorn have mainly been attributed to the polyphenolic contents. The aim of this research is to determine some bioactive compounds and antioxidant properties of hawthorn aqueous and ethanol extracts of leaves, flowers and ripened fruits. For this purpose, antioxidant activities of extracts were assessed on DPPH and #8226;, ABTS and #8226;+, superoxide scavenging, reducing power and ferrous metal chelating activity assays and phenolic content of extracts was determined by Folin-Cioacalteu and #8217;s reagent. The flavonoids including rutin, apigenin, myricetin, quercetin, naringenin and kaempferol, were identified by HPLC in the hawthorn extract. It was observed the aqueous and ethanol extracts of Crataegus monogyna subsp. monogyna fruits showed highest activity in reducing power and metal chelating activity assays. Additionally, it was determined that the aqueous flower extract showed higher flavonoid content than aqueous leaves extract. [J Intercult Ethnopharmacol 2014; 3(2.000: 51-55

  17. Chelation therapy for metal intoxication: comments from a thermodynamic viewpoint.

    Science.gov (United States)

    Nurchi, Valeria Marina; Alonso, Miriam Crespo; Toso, Leonardo; Lachowicz, Joanna Izabela; Crisponi, Guido

    2013-10-01

    Chelation therapy plays a prominent role in the clinical treatment of metal intoxication. In this paper the principal causes of metal toxicity are exposed, and the chemical and biomedical requisites of a chelating agent are sketched. The chelating agents currently in use for scavenging toxic metal ions from humans belong to few categories: those characterized by coordinating mercapto groups, by oxygen groups, poliaminocarboxylic acids, and dithiocarbamates. Considering that the complex formation equilibria have been studied for less than 50% of chelators in use, some reflections on the utility of stability constants are presented, together with an evaluation of ligands under the stability profile. The competition between endogenous and toxic target metal ions for the same chelating agent is furthermore examined. A thorough examination of stability constant databases has allowed to select, for each toxic metal, the ligands distinguished by the best pMe values. Even though this selection does not consider the biomedical requisites of a chelating agent, it gives a clear picture both of the pMe values that can be attained, and of the most appropriate chelators for each metal ion. PMID:23895193

  18. Treating thalassemia major-related iron overload: the role of deferiprone

    Directory of Open Access Journals (Sweden)

    Berdoukas V

    2012-10-01

    Full Text Available Vasilios Berdoukas,1 Kallistheni Farmaki,2 Susan Carson,1 John Wood,3 Thomas Coates11Division of Hematology/Oncology, Children's Hospital Los Angeles, Los Angeles, CA, USA; 2Thalassemia Unit, General Hospital of Corinth, Corinth, Greece; 3Division of Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, USAAbstract: Over the last 20 years, management for thalassemia major has improved to the point where we predict that patients' life expectancy will approach that of the normal population. These outcomes result from safer blood transfusions, the availability of three iron chelators, new imaging techniques that allow specific organ assessment of the degree of iron overload, and improvement in the treatment of hepatitis. In October 2011, the Food and Drug Administration licensed deferiprone, further increasing the available choices for iron chelation in the US. The ability to prescribe any of the three chelators as well as their combinations has led to more effective reduction of total body iron. The ability to determine the amount of iron in the liver and heart by magnetic resonance imaging allows the prescription of the most appropriate chelation regime for patients and to reconsider what our aims with respect to total body iron should be. Recent evidence from Europe has shown that by normalizing iron stores not only are new morbidities prevented but also reversal of many complications such as cardiac failure, hypothyroidism, hypogonadism, impaired glucose tolerance, and type 2 diabetes can occur, improving survival and patients' quality of life. The most effective way to achieve normal iron stores seems to be with the combination of deferoxamine and deferiprone. Furthermore, outcomes should continue to improve in the future. Starting relative intensive chelation in younger children may prevent short stature and abnormal pubertal maturation as well as other iron-related morbidities. Also, further information should become available on the

  19. Antioxidant Properties and Antioxidant Compounds of Various Extracts from the Edible Basidiomycete Grifola Frondosa (Maitake

    Directory of Open Access Journals (Sweden)

    Kaun-Tzer Wu

    2011-04-01

    Full Text Available Grifola frondosa is an edible mushroom currently available in Taiwan. Ethanolic, cold-water and hot-water extracts were prepared and their antioxidant properties were investigated. At 1 mg/mL, G. frondosa T1 and T2 cold-water extracts showed high reducing powers of 1.02 and 0.50, respectively. Chelating abilities on ferrous ions of G. frondosa T1 and T2 were higher for cold-water extracts than for ethanolic and hot-water extracts. For the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH radical, G. frondosa T1 and T2 extracts were effective in the following order: ethanolic > hot-water > cold-water. The G. frondosa hot-water extract showed high scavenging ability on superoxide anions. Total phenols, flavonoids, ascorbic acid and α-tocopherol are the major antioxidant components found in the various G. frondosa extracts. Based on EC50 values (

  20. Selectivity in extraction of copper and indium with chelate extractants

    International Nuclear Information System (INIS)

    Simultaneous extraction of copper and indium with chelate extractants (LIX84 and D2E11PA) was described. Stechiometry of metal-organic complexes examined using the method of equimolar ratios resulted in CuR2 and InR3 forms of hydrophobic extracting species. A linear correlation was obtained between logarithm of distribution coefficients and chelate agents and pH, respectively. Selectivity is generally higher with higher concentrations of chelate agents in the organic phase, and is decreased with increase of concentration of hydrogen ions in feeding phase. (Original)

  1. EFFECTS OF ENZYMATIC HYDROLYSIS ON THE ANTIOXIDANT ACTIVITY OF WATER- SOLUBLE ELASTIN EXTRACTED FROM BROILER AND SPENT HEN SKIN

    OpenAIRE

    Mehdi Nadalian; Salma Mohamad Yusop; Abdul Salam Babji; Wan Aida Wan Mustapha; Mohd Azri Azman

    2015-01-01

    Poultry by-products are great economic sources that need to be exploited. Poultry skin could be utilized to extract protein particularly elastin, which is often incorporated in the production of functional food, cosmetic industry or medicine due to its antioxidative properties. In this study, water-soluble elastin was successfully extracted from broiler and spent hen skin and analysed for antioxidant activities including DPPH (1,1-diphenyl-2-picryl hydrazyl), ABTS and metal chelating activity...

  2. Antioxidant Capacity and Phenolic Content of Caesalpinia pyramidalis Tul. and Sapium glandulosum (L.) Morong from Northeastern Brazil

    OpenAIRE

    Carlos Henrique Tabosa Pereira da Silva; Tadeu José da Silva Peixoto Sobrinho; Valérium Thijan Nobre de Almeida e Castro; Danielle da Cunha Amaral Lima; Elba Lúcia Cavalcanti de Amorim

    2011-01-01

    The aims of this study were to quantify the phenolic content and evaluate the antioxidant potential of extracts from the bark and leaves of C. pyramidalis and S. glandulosum. The total phenolic content (TPC) and total tannin content (TTC) were determined using the Folin-Ciocalteu method, and the total flavonoids content (TFC) was measured via complexation with aluminum chloride. The antioxidant activity was evaluated with DPPH (2.2-diphenyl-1-picrylhydrazyl) and FIC (ferrous ion chelating) as...

  3. Prooxidant Mechanisms in Iron Overload Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Ching-Feng Cheng

    2013-01-01

    Full Text Available Iron overload cardiomyopathy (IOC, defined as the presence of systolic or diastolic cardiac dysfunction secondary to increased deposition of iron, is emerging as an important cause of heart failure due to the increased incidence of this disorder seen in thalassemic patients and in patients of primary hemochromatosis. At present, although palliative treatment by regular iron chelation was recommended; whereas IOC is still the major cause for mortality in patient with chronic heart failure induced by iron-overloading. Because iron is a prooxidant and the associated mechanism seen in iron-overload heart is still unclear; therefore, we intend to delineate the multiple signaling pathways involved in IOC. These pathways may include organelles such as calcium channels, mitochondria; paracrine effects from both macrophages and fibroblast, and novel mediators such as thromboxane A2 and adiponectin; with increased oxidative stress and inflammation found commonly in these signaling pathways. With further understanding on these complex and inter-related molecular mechanisms, we can propose potential therapeutic strategies to ameliorate the cardiac toxicity induced by iron-overloading.

  4. Metal distribution and spectroscopic analysis after soil washing with chelating agents and humic substances.

    Science.gov (United States)

    Tsang, Daniel C W; Hartley, Neil R

    2014-03-01

    Biodegradable chelating agents ([S,S]-ethylenediamine-N,N-disuccinic acid (EDDS) and glutamic-N,N-diacetic acid (GLDA)) and natural humic substances (lignite-derived, standard, and commercially available humic acids) are potentially useful for enhancing soil remediation of timber treatment sites. This study integrated macroscopic and spectroscopic analyses to assess their influence on the distribution and chemical speciation of the remaining metals as well as their interaction with the soil surface after 48-h washing of a field-contaminated soil. The results demonstrated that EDDS and GLDA were an appealing alternative to non-biodegradable ethylenediamine-tetraacetic acid, but the three humic substances were less effective. As shown by sequential extractions, Cu was primarily extracted from the carbonate fraction while Cr and As extraction resulted from (co-)dissolution of the oxide fraction. As a result, the relative proportion of strongly bound organic matter and residual fractions increased by 7-16 %. However, it was noteworthy that the exchangeable fraction also increased by 5-11 %, signifying that a portion of the remaining metals was destabilized by chelating agents and transformed to be more labile in the treated soil. The X-ray photoelectron spectroscopy spectra confirmed the substantial removal of readily accessible Cu from the soil surface, but Cr maintained its original chemical forms of trivalent chromium oxides and iron-chromium coprecipitates, whereas As remained as arsenic trioxide/pentoxide and copper arsenate precipitates. On the other hand, the absence of characteristic peaks of adsorbed carboxylate groups in the Fourier-transform infrared (FTIR) spectra inferred that the extent of adsorption of chelating agents and humic substances on the bulk soil was insufficient to be characterized by FTIR analysis. These results suggested that attention should be paid to the exchangeable fraction of Cu and oxides/coprecipitates of As prior to possible on

  5. Scavenging iron: a novel mechanism of plant immunity activation by microbial siderophores.

    Science.gov (United States)

    Aznar, Aude; Chen, Nicolas W G; Rigault, Martine; Riache, Nassima; Joseph, Delphine; Desmaële, Didier; Mouille, Grégory; Boutet, Stéphanie; Soubigou-Taconnat, Ludivine; Renou, Jean-Pierre; Thomine, Sébastien; Expert, Dominique; Dellagi, Alia

    2014-04-01

    Siderophores are specific ferric iron chelators synthesized by virtually all microorganisms in response to iron deficiency. We have previously shown that they promote infection by the phytopathogenic enterobacteria Dickeya dadantii and Erwinia amylovora. Siderophores also have the ability to activate plant immunity. We have used complete Arabidopsis transcriptome microarrays to investigate the global transcriptional modifications in roots and leaves of Arabidopsis (Arabidopsis thaliana) plants after leaf treatment with the siderophore deferrioxamine (DFO). Physiological relevance of these transcriptional modifications was validated experimentally. Immunity and heavy-metal homeostasis were the major processes affected by DFO. These two physiological responses could be activated by a synthetic iron chelator ethylenediamine-di(o-hydroxyphenylacetic) acid, indicating that siderophores eliciting activities rely on their strong iron-chelating capacity. DFO was able to protect Arabidopsis against the pathogenic bacterium Pseudomonas syringae pv tomato DC3000. Siderophore treatment caused local modifications of iron distribution in leaf cells visible by ferrocyanide and diaminobenzidine-H₂O₂ staining. Metal quantifications showed that DFO causes a transient iron and zinc uptake at the root level, which is presumably mediated by the metal transporter iron regulated transporter1 (IRT1). Defense gene expression and callose deposition in response to DFO were compromised in an irt1 mutant. Consistently, plant susceptibility to D. dadantii was increased in the irt1 mutant. Our work shows that iron scavenging is a unique mechanism of immunity activation in plants. It highlights the strong relationship between heavy-metal homeostasis and immunity. PMID:24501001

  6. Siderophore-Mediated Iron Acquisition Influences Motility and Is Required for Full Virulence of the Xylem-Dwelling Bacterial Phytopathogen Pantoea stewartii subsp. stewartii

    OpenAIRE

    Burbank, Lindsey; Mohammadi, Mojtaba; Roper, M Caroline

    2014-01-01

    Iron is a key micronutrient for microbial growth but is often present in low concentrations or in biologically unavailable forms. Many microorganisms overcome this challenge by producing siderophores, which are ferric-iron chelating compounds that enable the solubilization and acquisition of iron in a bioactive form. Pantoea stewartii subsp. stewartii, the causal agent of Stewart's wilt of sweet corn, produces a siderophore under iron-limiting conditions. The proteins involved in the biosy...

  7. Effects of macromolecular chelators on intestinal cadmium absorption in mice

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, O.; Nielsen, J.B.; Bulman, R.A.

    1989-01-01

    Suppression of absorption by macromolecular chelators have been sucessful with several metals. In this paper a series of immobilized chelators ranging from DTPA to S-containing soft bases have been synthetized and investigated for ability to suppress intestinal uptake of /sup 109/Cd/sup 2+/ in mice. Dextran-O-ethyl-mercaptan, xanthates derived from polysaccharides and polyvinyl alcohol, dithiocarbamates of polyethylene imine and aminoethyl cellulose, and DTPA immobilized on aminopropyl silica were all ineffective. DTPA immobilized on aminoethyl cellulose even enhanced the intestinal uptake. The macromolecular chelators were without extensive effect on organ distribution of absorbed cadmium, except for dithiocarbamate immobilized on polyethylene imine, which enhanced the deposition of cadmium in several organs including the brain. Although the results are discouragign, they indicate that desing and synthesis of immobilized vicinal dithio compounds may represent an avenue for development of non-absorbable chelators with high affinity for cadmium.

  8. Mixed-chelate therapy of intratracheally deposited cadmium oxide

    International Nuclear Information System (INIS)

    Mixed-chelate treatment with EDTA and salicylic acid was no more effective in accelerating the removal of intratracheally instilled 109CdO, or in protecting against CdO-induced mortality, than was EDTA given alone

  9. Comparing potential copper chelation mechanisms in Parkinson's disease protein

    Science.gov (United States)

    Rose, Frisco; Hodak, Miroslav; Bernholc, Jerry

    2011-03-01

    We have implemented the nudged elastic band (NEB) as a guided dynamics framework for our real-space multigrid method of DFT-based quantum simulations. This highly parallel approach resolves a minimum energy pathway (MEP) on the energy hypersurface by relaxing intermediates in a chain-of-states. As an initial application we present an investigation of chelating agents acting on copper ion bound to α -synuclein, whose misfolding is implicated in Parkinson's disease (PD). Copper ions are known to act as highly effective misfolding agents in a-synuclein and are thus an important target in understanding PD. Furthermore, chelation therapy has shown promise in the treatment of Alzheimer's and other neuro-degenerative diseases with similar metal-correlated pathologies. At present, our candidate chelating agents include nicotine, curcumin and clioquinol. We examine their MEP activation barriers in the context of a PD onset mechanism to assess the viability of various chelators for PD remediation.

  10. Antioxidant properties and efficacies of synthesized alkyl caffeates, ferulates, and coumarates

    DEFF Research Database (Denmark)

    Sørensen, Ann-Dorit Moltke; Durand, Erwann; Laguerre, Mickaël;

    2014-01-01

    /w microemulsion using the conjugated autoxidizable triene (CAT) assay. All evaluated phenolipids had radical scavenging, reducing power, and metal chelating properties. Only caffeic acid and caffeates were able to form a complex with iron via their catechol group in the phenolic ring. In the o/w emulsion, the...

  11. Analysis of chemical composition and evaluation of antigenotoxic, cytotoxic and antioxidant activities of essential oil of Toddalia asiatica (L.) Lam.

    Institute of Scientific and Technical Information of China (English)

    Ramaraj Thirugnanasampandan; Rajarajeswaran Jayakumar; Murugaiyan Prabhakaran

    2012-01-01

    Objective: To analyse the chemical composition of essential oil isolated from the leaves ofToddalia asiatica (L.) Lam. and to test its bioactive properties. Methods: Gas chromatography-mass spectrometry (GC/MS) analysis and antigenotoxicity, cytotoxicity and antioxidant studies of isolated oil. Results: GC-MS analysis of oil revealed the presence of 42 compounds. The major compound in the oil was β-phellandrene (21.35%). DNA protecting activity of oil was considerably significant against H2O2 induced genotoxicity in human lymphocytes. Concentration of oil needed to protect 50% of DNA was calculated as 100 μg/mL. Cytotoxicity of oil against breast (MCF-7) and colorectal (HT-29) cancer cells were observed with the IC50 value of (7.80±0.03) μg/mL and (100.00±0.16) μg/mL respectively. Considerable DPPH free radical, hydroxyl radical scavenging, iron chelation and inhibition of lipid peroxidation activities of oil were also studied. Conclusions: The results of the present study clearly indicate oil could be a promising candidate for food and drug preparation.

  12. Mapping and characterization of iron compounds in Alzheimer's tissue

    International Nuclear Information System (INIS)

    Understanding the management of iron in the brain is of great importance in the study of neurodegeneration, where regional iron overload is frequently evident. A variety of approaches have been employed, from quantifying iron in various anatomical structures, to identifying genetic risk factors related to iron metabolism, and exploring chelation approaches to tackle iron overload in neurodegenerative disease. However, the ease with which iron can change valence state ensures that it is present in vivo in a wide variety of forms, both soluble and insoluble. Here, we review recent developments in approaches to locate and identify iron compounds in neurodegenerative tissue. In addition to complementary techniques that allow us to quantify and identify iron compounds using magnetometry, extraction, and electron microscopy, we are utilizing a powerful combined mapping/characterization approach with synchrotron X-rays. This has enabled the location and characterization of iron accumulations containing magnetite and ferritin in human Alzheimer's disease (AD) brain tissue sections in situ at micron-resolution. It is hoped that such approaches will contribute to our understanding of the role of unusual iron accumulations in disease pathogenesis, and optimise the potential to use brain iron as a clinical biomarker for early detection and diagnosis.

  13. Chelated Ruthenium Catalysts for Z-Selective Olefin Metathesis

    OpenAIRE

    Endo, Koji; Grubbs, Robert H.

    2011-01-01

    We report the development of ruthenium-based metathesis catalysts with chelating N-heterocyclic carbene (NHC) ligands which catalyze highly Z-selective olefin metathesis. A very simple and convenient synthetic procedure of such a catalyst has been developed. An intramolecular C-H bond activation of the NHC ligand, which is promoted by anion ligand substitution, forms the appropriate chelate for stereo- controlled olefin metathesis.

  14. EDTA chelation therapy for cardiovascular disease: a systematic review

    OpenAIRE

    Wu Ping; Seely Dugald MR; Mills Edward J

    2005-01-01

    Abstract Background Numerous practitioners of both conventional and complementary and alternative medicine throughout North America and Europe claim that chelation therapy with EDTA is an effective means to both control and treat cardiovascular disease. These claims are controversial, and several randomized controlled trials have been completed dealing with this topic. To address this issue we conducted a systematic review to evaluate the best available evidence for the use of EDTA chelation ...

  15. Chelation: Harnessing and Enhancing Heavy Metal Detoxification—A Review

    OpenAIRE

    Sears, Margaret E.

    2013-01-01

    Toxic metals such as arsenic, cadmium, lead, and mercury are ubiquitous, have no beneficial role in human homeostasis, and contribute to noncommunicable chronic diseases. While novel drug targets for chronic disease are eagerly sought, potentially helpful agents that aid in detoxification of toxic elements, chelators, have largely been restricted to overt acute poisoning. Chelation, that is multiple coordination bonds between organic molecules and metals, is very common in the body and at the...

  16. Clawing Back: Broadening the Notion of Metal Chelators in Medicine

    OpenAIRE

    Franz, Katherine J.

    2013-01-01

    The traditional notion of chelation therapy is the administration of a chemical agent to remove metals from the body. But formation of a metal-chelate can have biological ramifications that are much broader than metal elimination. Exploring these other possibilities could lead to pharmacological interventions that alter the concentration, distribution, or reactivity of metals in targeted ways for therapeutic benefit. This review highlights recent examples that showcase four general strategies...

  17. Hydrogen peroxide- metals- chelating agents; interactions and analytical techniques

    OpenAIRE

    Rämö, J.

    2003-01-01

    Abstract Information about interactions among metals, hydrogen peroxide and chelating agents is needed to develop environmental technology and the operating efficiency of modern elemental chlorine free and total chlorine free bleaching processes. The work presented here focused on the properties of metal chelates and corrosion of titanium in an alkaline hydrogen peroxide solution. A comparative study between three rapid analysis methods, ICP-AES, XRF and ISE, was performed in pulp matrix a...

  18. Phenolic compounds and in vitro antioxidant activity of selected species of seaweeds from Danish coast

    DEFF Research Database (Denmark)

    Farvin, Sabeena; Jacobsen, Charlotte

    2013-01-01

    also showed good antioxidative effects indicating that some other co-extracted active compounds such as pigments and tocopherols in ethanolic extracts and sulphated polysaccharides, proteins or peptides in water extracts may also contribute to the overall antioxidant properties and this needs further......Water and ethanolic extracts of 16 species of seaweeds collected along the Danish coasts were screened for antioxidant activities using four in vitro antioxidant assays (2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, reducing power, ferrous ion-chelating and liposome model system...... extraction than water. Polysiphonia fucoides and all the Fucus species tested showed highest radical scavenging activity, reducing power, inhibition of oxidation in liposome model system and in fish oil and were high in phenolic content. These seaweeds could be potential rich sources of natural antioxidants...

  19. Iron deficiency

    DEFF Research Database (Denmark)

    Schou, Morten; Bosselmann, Helle; Gaborit, Freja;

    2015-01-01

    BACKGROUND: Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked. OBJECTIVES...... understand iron metabolism in elderly HF patients....

  20. Combination of deferasirox and deferoxamine in clinical practice: an alternative scheme of chelation in thalassemia major patients.

    Science.gov (United States)

    Cassinerio, E; Orofino, N; Roghi, A; Duca, L; Poggiali, E; Fraquelli, M; Zanaboni, L; Cappellini, M D

    2014-09-01

    The availability of three iron chelators improved the scenario of chelation therapy for transfusion-dependent thalassemia (TDT) patients, allowing tailoring of drugs according to the goals expected for each patient. The use of Deferiprone/Deferoxamine (DFP/DFO) combined in different schemes has been reported since many years. Only recently data from combination of Deferasirox/Deferoxamine (DFX/DFO) have been reported showing that it can be safe and efficacious to remove iron overload, particularly in patients who do not respond adequately to a single chelating agent. We investigated the efficacy, tolerability and safety of combined DFX/DFO in thalassemia major patients. Ten TDT patients have started DFX/DFO for different reasons: 1) lack of efficacy in removing liver/cardiac iron with monotherapy; 2) agranulocytosis on DFP; and 3) adverse events with elevated doses of monotherapies. The study design included: cardiac and hepatic T2* magnetic resonance (CMR), transient elastography evaluation (Fibroscan), biochemical evaluation, and audiometric and ocular examinations. The drugs' starting doses were: DFO 32 ± 4 mg/kg/day for 3-4 days a week and DFX 20 ± 2 mg/kg/day. Seven patients completed the one-year follow-up period. At baseline the mean pre-transfusional Hb level was 9.4 ± 0.4 g/dl, the mean iron intake was 0.40 ± 0.10mg/kg/day, the median ferritin level was 2254 ng/ml (range 644-17,681 ng/ml). Data available at 1 year showed no alteration of renal/hepatic function and no adverse events. A marked reduction in LIC (6.54 vs 11.44 mg/g dw at baseline) and in median ferritin (1346 vs 2254 ng/ml at baseline) was achieved. A concomitant reduction of non-transferrin-bound iron (NTBI) at six months was observed (2.1 ± 1.0 vs 1.7 ± 1.2 μM). An improvement in cardiac T2* values was detected (26.34 ± 15.85 vs 19.85 ± 12.06 at baseline). At 1 year an increased dose of DFX was administered (27 ± 6 mg/kg/day vs 20 ± 2 mg/kg/day at baseline, p=0.01) with a stable