Effect of the oral iron chelator deferiprone in diabetic nephropathy rats

BACKGROUND

The aim of the present study was to investigate the effects of the iron chelator deferiprone in diabetic nephropathy (DN) rats and the mechanisms involved.

METHODS

Thirty-two male Wistar rats (180-220 g, 6 weeks old) were randomly divided into a control group, a DN group and two DN groups treated with either 50 or 100 mg/kg per day deferiprone. The DN group was established by feeding of a high-carbohydrate-fat diet and injection of 35 mg/kg streptozotocin into the vena caudalis. The duration of deferiprone treatment was 20 weeks. Histopathological changes were detected by hematoxylin-eosin and Masson staining, as well as transmission electron microscopy. Levels of nuclear factor (NF)-κB, monocyte chemotactic protein (MCP)-1, matrix metalloproteinase (MMP)-9, tissue-specific inhibitor of metalloproteinase (TIMP)-1, cyclo-oxygenase (COX)-2, and nitrotyrosine were determined in kidney tissues using reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and immunohistochemistry.

RESULTS

Histopathological observations showed that deferiprone treatment alleviated inflammation infiltrates and collagenous fibrosis in DN rats. Results from RT-PCR and western blotting indicated that deferiprone inhibited the expression of NF-κB, MCP-1, COX-2, and nitrotyrosine, which were overexpressed in DN rats. Immunohistochemistry showed that the mechanism of deferiprone action may involve regulation of MMP-9 and TIMP-1. Decreased MMP-9 expression and increased TIMP-1 expression in DN rats were significantly promoted and inhibited by deferiprone, respectively.

CONCLUSION

Iron chelation by oral deferiprone has a renoprotective effect in DN rats by relieving oxidative stress, inflammation, and fibrosis, which is related to the cytokines NF-κB, MCP-1, MMP-9, TIMP-1, COX-2, and nitrotyrosine.

Targeting deoxyhypusine hydroxylase activity impairs cap-independent translation initiation driven by the 5'untranslated region of the HIV-1, HTLV-1, and MMTV mRNAs

Replication of the human immunodeficiency virus type 1 (HIV-1) is dependent on eIF5A hypusination. Hypusine is formed post-translationally on the eIF5A precursor by two consecutive enzymatic steps; a reversible reaction involving the enzyme deoxyhypusine synthase (DHS) and an irreversible step involving the enzyme deoxyhypusine hydroxylase (DOHH). In this study we explored the effect of inhibiting DOHH activity and therefore eIF5A hypusination, on HIV-1 gene expression. Results show that the expression of proteins from an HIV-1 molecular clone is reduced when DOHH activity is inhibited by Deferiprone (DFP) or Ciclopirox (CPX). Next we evaluated the requirement of DOHH activity for internal ribosome entry site (IRES)-mediated translation initiation driven by the 5'untranslated region (5'UTR) of the full length HIV-1 mRNA. Results show that HIV-1 IRES activity relies on DOHH protein concentration and enzymatic activity. Similar results were obtained for IRES-dependent translation initiation mediated by 5'UTR of the human T-cell lymphotropic virus type 1 (HTLV-1) and the mouse mammary tumor virus (MMTV) mRNAs. Interestingly, activity of the poliovirus IRES, was less sensitive to the targeting of DOHH suggesting that not all viral IRESs are equally dependent on the cellular concentration or the activity of DOHH. In summary we present evidence indicating that the cellular concentration of DOHH and its enzymatic activity play a role in HIV-1, HTLV-1 and MMTV IRES-mediated translation initiation.

Comparative study of the protective effect between deferoxamine and deferiprone on chronic iron overload induced cardiotoxicity in rats

Patients with iron overload frequently suffer from hemochromatosis of major organs, such as the heart and liver. Heart affection is the most common cause of death in patients with iron overload. Although the beneficial effects of deferoxamine (DFO) on iron-associated mortality are well documented, the role of deferiprone in the management of transfusional iron overload is controversial. The aim of this study was to compare the protective effect of iron chelators (DFO and deferiprone) individually and in combination with the anti-oxidant (vitamin C) in the prevention of myocardial damage. Sixty albino rats were divided into six groups: two control groups (noniron-loaded and iron-loaded) and four iron-loaded groups classified as follows: DFO group, DFO combined with vitamin C group, deferiprone group and deferiprone combined with vitamin C group. Heart tissue and blood samples were taken for histopathological examination of the heart, determination of total iron-binding capacity, 8-OH-deoxyguanosine (8-OH-dG), myocardial lipid peroxidation and glutathione (GSH) content. Less histopathological cardiac changes and a significant decrease in all biochemical parameters, except myocardial GSH, were observed in the deferiprone group. The addition of vitamin C improves the biochemical and histopathological changes in comparison to those rats administered DFO or deferiprone individually.

Drug-Based Lead Discovery: The Novel Ablative Antiretroviral Profile of Deferiprone in HIV-1-Infected Cells and in HIV-Infected Treatment-Naive Subjects of a Double-Blind, Placebo-Controlled, Randomized Exploratory Trial

Antiretrovirals suppress HIV-1 production yet spare the sites of HIV-1 production, the HIV-1 DNA-harboring cells that evade immune detection and enable viral resistance on-drug and viral rebound off-drug. Therapeutic ablation of pathogenic cells markedly improves the outcome of many diseases. We extend this strategy to HIV-1 infection. Using drug-based lead discovery, we report the concentration threshold-dependent antiretroviral action of the medicinal chelator deferiprone and validate preclinical findings by a proof-of-concept double-blind trial. In isolate-infected primary cultures, supra-threshold concentrations during deferiprone monotherapy caused decline of HIV-1 RNA and HIV-1 DNA; did not allow viral breakthrough for up to 35 days on-drug, indicating resiliency against viral resistance; and prevented, for at least 87 days off-drug, viral rebound. Displaying a steep dose-effect curve, deferiprone produced infection-independent deficiency of hydroxylated hypusyl-eIF5A. However, unhydroxylated deoxyhypusyl-eIF5A accumulated particularly in HIV-infected cells; they preferentially underwent apoptotic DNA fragmentation. Since the threshold, ascertained at about 150 μM, is achievable in deferiprone-treated patients, we proceeded from cell culture directly to an exploratory trial. HIV-1 RNA was measured after 7 days on-drug and after 28 and 56 days off-drug. Subjects who attained supra-threshold concentrations in serum and completed the protocol of 17 oral doses, experienced a zidovudine-like decline of HIV-1 RNA on-drug that was maintained off-drug without statistically significant rebound for 8 weeks, over 670 times the drug's half-life and thus clearance from circulation. The uniform deferiprone threshold is in agreement with mapping of, and crystallographic 3D-data on, the active site of deoxyhypusyl hydroxylase (DOHH), the eIF5A-hydroxylating enzyme. We propose that deficiency of hypusine-containing eIF5A impedes the translation of mRNAs encoding proline cluster ('polyproline')-containing proteins, exemplified by Gag/p24, and facilitated by the excess of deoxyhypusine-containing eIF5A, releases the innate apoptotic defense of HIV-infected cells from viral blockade, thus depleting the cellular reservoir of HIV-1 DNA that drives breakthrough and rebound.

TRIAL REGISTRATION

ClinicalTrial.gov NCT02191657.

Mineral Levels in Thalassaemia Major Patients Using Different Iron Chelators

The goal of the present study was to determine the levels of minerals in chronically transfused thalassaemic patients living in Antalya, Turkey and to determine mineral levels in groups using different iron chelators. Three iron chelators deferoxamine, deferiprone and deferasirox have been used to remove iron from patients' tissues. There were contradictory results in the literature about minerals including selenium, zinc, copper, and magnesium in thalassaemia major patients. Blood samples from the 60 thalassaemia major patients (the deferoxamine group, n = 19; the deferiprone group, n = 20 and the deferasirox group, n = 21) and the controls (n = 20) were collected. Levels of selenium, zinc, copper, magnesium, and iron were measured, and all of them except iron showed no significant difference between the controls and the patients regardless of chelator type. Serum copper levels in the deferasirox group were lower than those in the control and deferoxamine groups, and serum magnesium levels in the deferasirox group were higher than those in the control, deferoxamine and deferiprone groups. Iron levels in the patient groups were higher than those in the control group, and iron levels showed a significant correlation with selenium and magnesium levels. Different values of minerals in thalassaemia major patients may be the result of different dietary intake, chelator type, or regional differences in where patients live. That is why minerals may be measured in thalassaemia major patients at intervals, and deficient minerals should be replaced. Being careful about levels of copper and magnesium in thalassaemia major patients using deferasirox seems to be beneficial.

Efficient attenuation of Friedreich's ataxia (FRDA) cardiomyopathy by modulation of iron homeostasis-human induced pluripotent stem cell (hiPSC) as a drug screening platform for FRDA

BACKGROUND

Friedreich's ataxia (FRDA), a recessive neurodegenerative disorder commonly associated with hypertrophic cardiomyopathy, is caused by silencing of the frataxin (FXN) gene encoding the mitochondrial protein involved in iron-sulfur cluster biosynthesis.

METHODS

Application of our previously established FRDA human induced pluripotent stem cell (hiPSC) derived cardiomyocytes model as a platform to assess the efficacy of treatment with either the antioxidant coenzyme Q10 analog, idebenone (IDE) or the iron chelator, deferiprone (DFP), which are both under clinical trial.

RESULTS

DFP was able to more significantly suppress synthesis of reactive oxygen species (ROS) than IDE at the dosages of 25 μM and 10nM respectively which agreed with the reduced rate of intracellular accumulation of iron by DFP treatment from 25 to 50 μM. With regard to cardiac electrical-contraction (EC) coupling function, decay velocity of calcium handling kinetics in FRDA-hiPSC-cardiomyocytes was significantly improved by DFP treatment but not by IDE. Further mechanistic studies revealed that DFP also modulated iron induced mitochondrial stress as reflected by mitochondria network disorganization and decline level of respiratory chain protein, succinate dehydrogenase (CxII) and cytochrome c oxidase (COXIV). In addition, iron-response protein (IRP-1) regulatory loop was overridden by DFP as reflected by resumed level of ferritin (FTH) back to basal level and the attenuated transferrin receptor (TSFR) mRNA level suppression thereby reducing further iron uptake.

CONCLUSIONS

DFP modulated iron homeostasis in FRDA-hiPSC-cardiomyocytes and effectively relieved stress-stimulation related to cardiomyopathy. The resuming of redox condition led to the significantly improved cardiac prime events, cardiac electrical-coupling during contraction.

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

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.

Sensorineural hearing loss in β-thalassemia patients treated with iron chelation

The predictive value of pure-tone audiometry (PTA) in the early detection of ototoxicity has been questioned, particularly in the higher frequencies. Otoacoustic emissions testing appears to be more sensitive to cochlear insult than conventional PTA. We conducted a cross-sectional descriptive study to compare the efficacy of distortion-product otoacoustic emissions (DPOAE) testing with that of PTA as a method of audiologic monitoring. Our study group was made up of 159 patients (318 ears)-69 males (43.4%) and 90 females (56.6%), aged 5 to 61 years (mean: 23.59 ± 12.55). All patients had been diagnosed with either β-thalassemia major (BTM) or β-thalassemia intermedia (BTI), and all had received at least 1 year of treatment within the previous year with an iron chelator-either deferasirox, desferrioxamine (deferoxamine in the United States), deferiprone, or a combination of desferrioxamine and deferiprone. PTA and DPOAE evaluations were performed by the same audiologist using the same audiometer for all patients. In the right ears, the overall incidence of ototoxicity as manifested by sensorineural hearing loss was 39.0% on PTA and 22.0% on DPOAE testing; in the left ears, the corresponding figures were 27.7 and 19.5%, respectively. There were no statistically significant differences in the incidence of ototoxicity between the BTM and BTI groups with any of the four different drug regimens on PTA (p = 0.765, p = 0.378, p = 0.265, and p = 0.579, respectively) or on DPOAE testing (p = 0.890, p = 0.263, p = 0.390, and p = 0.340, respectively). Based on these data, we found no significant difference between PTA and DPOAE testing in their ability to detect ototoxicity. We conclude that periodic testing with both PTA and DPOAE is necessary for patients with suspected β-thalassemia in order arrive at a prompt diagnosis and initiate timely management.

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

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 <1,250 μM had no effect, whereas DFP at 2,500 μM increased biofilms forming in A. fumigatus or preformed biofilms (P < 0.01). DFP at 156 to 2,500 μM inhibited biofilm formation (P < 0.01 to 0.001) in a dose-responsive manner. Biofilm formation with 625 μM DFP plus any concentration of FeCl3 was lower than that in the controls (P < 0.05 to 0.001). FeCl3 at ≥625 μM reversed the DFP inhibitory effect (P < 0.05 to 0.01), but the reversal was incomplete compared to the controls (P < 0.05 to 0.01). For preformed biofilms, DFP in the range of ≥625 to 1,250 μM was inhibitory compared to the controls (P < 0.01 to 0.001). FeCl3 at ≥625 μM overcame inhibition by 625 μM DFP (P < 0.001). FeCl3 alone at ≥156 μM stimulated biofilm formation (P < 0.05 to 0.001). Preformed A. fumigatus biofilm increased with 2,500 μM FeCl3 only (P < 0.05). In a strain survey, various susceptibilities of 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.

Evidence Suggesting a Role of Iron in a Mouse Model of Nephrogenic Systemic Fibrosis

Nephrogenic systemic fibrosis is associated with gadolinium contrast exposure in patients with reduced kidney function and carries high morbidity and mortality. We have previously demonstrated that gadolinium contrast agents induce in vivo systemic iron mobilization and in vitro differentiation of peripheral blood mononuclear cells into ferroportin (iron exporter)-expressing fibrocytic cells. In the present study we examined the role of iron in a mouse model of nephrogenic systemic fibrosis. Chronic kidney disease was induced in 8-week-old male Balb/C mice with a two-step 5/6 nephrectomy surgery. Five groups of mice were studied: control (n = 5), sham surgery control (n = 5), chronic kidney disease control (n = 4), chronic kidney disease injected with 0.5 mmol/kg body weight of Omniscan 3 days per week, for a total of 10 injections (n = 8), and chronic kidney disease with Omniscan plus deferiprone, 125 mg/kg, in drinking water (n = 9). Deferiprone was continued for 16 weeks until the end of the experiment. Mice with chronic kidney disease injected with Omniscan developed skin changes characteristic of nephrogenic systemic fibrosis including hair loss, reddening, ulceration, and skin tightening by 10 to 16 weeks. Histopathological sections demonstrated dermal fibrosis with increased skin thickness (0.25±0.06 mm, sham; 0.34±+0.3 mm, Omniscan-injected). Additionally, we observed an increase in tissue infiltration of ferroportin-expressing, fibrocyte-like cells accompanied by tissue iron accumulation in the skin of the Omniscan-treated mice. The deferiprone-treated group had significantly decreased skin thickness (p<0.05) and significantly decreased dermal fibrosis compared to the Omniscan-only group. In addition, iron chelation prevented tissue infiltration of ferroportin-expressing, fibrocyte-like cells. Our in vitro experiments demonstrated that exposure to Omniscan resulted in the release of catalytic iron and this was prevented by the iron chelator deferiprone. Deferiprone inhibited the differentiation of human peripheral blood mononuclear cells into ferroportin-expressing cells by immunohistochemical staining and western blot analysis. Our studies support an important role of iron in the pathophysiology of gadolinium chelate toxicity and nephrogenic systemic fibrosis.

A Speciation Study on the Perturbing Effects of Iron Chelators on the Homeostasis of Essential Metal Ions

A number of reports have appeared in literature calling attention to the depletion of essential metal ions during chelation therapy on β-thalassaemia patients. We present a speciation study to determine how the iron chelators used in therapy interfere with the homeostatic equilibria of essential metal ions. This work includes a thorough analysis of the pharmacokinetic properties of the chelating agents currently in clinical use, of the amounts of iron, copper and zinc available in plasma for chelation, and of all the implied complex formation constants. The results of the study show that a significant amount of essential metal ions is complexed whenever the chelating agent concentration exceeds the amount necessary to coordinate all disposable iron--a frequently occurring situation during chelation therapy. On the contrary, copper and zinc do not interfere with iron chelation, except for a possible influence of copper on iron speciation during deferiprone treatment.

Novel aberrant genetic and epigenetic events in Friedreich's ataxia

It is generally accepted that Friedreich's ataxia (FRDA) is caused by a deficiency in frataxin expression, a mitochondrial protein involved in iron homeostasis, which mainly affects the brain, dorsal root ganglia of the spinal cord, heart and in certain cases the pancreas. However, there is little knowledge as to other possible genes that may be affected in this disorder, and which can contribute to its complexity. In the current study we compared human periodontal ligament cells gene expression of healthy individuals and FRDA patients. The expression of active-caspase 3, as well as other apoptosis-related genes, was increased in the FRDA cells. Furthermore, iron-sulphur cluster genes, as well as oxidative stress-related genes were overexpressed in FRDA. Moreover, brain-derived neurotrophic factor, neuregulin 1 and miR-132 were all upregulated. These three genes are capable of regulating the expression of each other. Interestingly, when the cells from FRDA patients were co-cultured in the presence of idebenone and deferiprone, caspase expression decreased while antioxidant gene expression, as well as frataxin expression, increased. Regarding epigenetic mechanisms, the frataxin gene was hypermethylated, compared to the healthy counterparts, in the upstream GAA repetitive region. Of the three DNA methyltransferases, DNMT1 but not DNMT3׳s gene expression was higher in FRDA cells. In conclusion, our data show that FRDA cells present altered expression of genes related to cell cycle, oxidative stress and iron homeostasis which may be implicated in the increased apoptotic levels. Also, the altered expression is in a certain degree normalized in the presence of idebenone and deferiprone.

Deferiprone, a non-toxic reagent for determination of iron in samples via sequential injection analysis

We present for the first time the use of deferiprone as a non-toxic complexing agent for the determination of iron by sequential injection analysis in pharmaceuticals and food samples. The method was based on the reaction of Fe(III) and deferiprone in phosphate buffer at pH 7.5 to give a Fe(III)-deferiprone complex, which showed a maximum absorption at 460nm. Under the optimum conditions, the linearity range for iron determination was found over the range of 0.05-3.0μgmL(-1) with a correlation coefficient (r(2)) of 0.9993. The limit of detection and limit of quantitation were 0.032μgmL(-1) and 0.055μgmL(-1), respectively. The relative standard deviation (%RSD) of the method was less than 5.0% (n=11), and the percentage recovery was found in the range of 96.0-104.0%. The proposed method was satisfactorily applied for the determination of Fe(III) in pharmaceuticals, water and food samples with a sampling rate of 60h(-1).

Inhibition of Fe(2+)- and Fe(3+)- induced hydroxyl radical production by the iron-chelating drug deferiprone

Deferiprone (L1) is an effective iron-chelating drug that is widely used for the treatment of iron-overload diseases. It is known that in aqueous solutions Fe(2+) and Fe(3+) ions can produce hydroxyl radicals via Fenton and photo-Fenton reactions. Although previous studies with Fe(2+) have reported ferroxidase activity by L1 followed by the formation of Fe(3+) chelate complexes and potential inhibition of Fenton reaction, no detailed data are available on the molecular antioxidant mechanisms involved. Similarly, in vitro studies have also shown that L1-Fe(3+) complexes exhibit intense absorption bands up to 800nm and might be potential sources of phototoxicity. In this study we have applied an EPR spin trapping technique to answer two questions: (1) does L1 inhibit the Fenton reaction catalyzed by Fe(2+) and Fe(3+) ions and (2) does UV-Vis irradiation of the L1-Fe(3+) complex result in the formation of reactive oxygen species. PBN and TMIO spin traps were used for detection of oxygen free radicals, and TEMP was used to trap singlet oxygen if it was formed via energy transfer from L1 in the triplet excited state. It was demonstrated that irradiation of Fe(3+) aqua complexes by UV and visible light in the presence of spin traps results in the appearance of an EPR signal of the OH spin adduct (TMIO-OH, a(N)=14.15G, a(H)=16.25G; PBN-OH, a(N)=16.0G, a(H)=2.7G). The presence of L1 completely inhibited the OH radical production. The mechanism of OH spin adduct formation was confirmed by the detection of methyl radicals in the presence of dimethyl sulfoxide. No formation of singlet oxygen was detected under irradiation of L1 or its iron complexes. Furthermore, the interaction of L1 with Fe(2+) ions completely inhibited hydroxyl radical production in the presence of hydrogen peroxide. These findings confirm an antioxidant targeting potential of L1 in diseases related to oxidative damage.

Chelation in metal intoxication--Principles and paradigms

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 new oral iron antidotes deferiprone and desferasirox have entered into the clinical arena. Comparisons of these agents and deferoxamine infusions are in progress. General principles for research and development of new chelators are briefly outlined in this review.

Combined chelation therapy with daily oral deferiprone and twice-weekly subcutaneous infusion of desferrioxamine in children with β-thalassemia: 3-year experience

OBJECTIVE

To study the efficacy of combined treatment with oral and subcutaneous iron chelators.

MATERIAL AND METHODS

50-100 mg/kg/day of oral deferiprone (DFP) combined with 40 mg/kg/dose s.c. desferrioxamine (DFO) twice weekly were given to transfusion-dependent β-thalassemia children.

RESULTS

Enrolled patients (9 with β-thalassemia major and 33 with β-thalassemia hemoglobin E), ranging from 3 to 18 years in age, were divided into 3 groups; group 1 ferritin ≥1,000-2,500 ng/ml (n = 10), group 2 ferritin >2,500-4,000 ng/ml (n = 23) and group 3 ferritin >4,000 ng/ml (n = 9). Of the 42 patients, 28 reached the 36-month follow-up. Ten patients whose ferritin declined <15% while receiving 100 mg/kg/day of DFP were considered nonresponders. The median age and previous transfusion duration before enrollment were significantly higher in nonresponders than responders (p = 0.04 and 0.003, respectively). The responders exhibited a significant fall in median ferritin levels from 2,954.6 to 936.6 ng/ml (p < 0.001). Time to a significant decrease in serum ferritin among responders was 6 months. In 13 patients, 16 episodes of adverse events occurred: hemophagocytosis with cytopenia (n = 1), neutropenia (n = 2), thrombocytopenia (n = 2), elevated alanine aminotransferase (n = 5), elevated serum creatinine (n = 1), proteinuria (n = 1) and gastrointestinal discomfort (n = 4).

CONCLUSION

Combination therapy with daily oral DFP and subcutaneous DFO twice weekly is a safe and effective alternative to chelation monotherapy in β-thalassemia children.

Combined versus monotherapy or concurrent therapy for treatment of thalassaemia

A combined deferasirox (DFX) and deferiprone (DFP) treatment protocol for relieving thalassemia patients' iron-overload was designed and the pharmacokinetic study was performed by LC-MS/MS. For this open-label, randomized trial, eight patients were recruited and randomly allocated to different treatment regimens: (A) monotherapy with single oral dose of DFX 30 mg/kg, (B) monotherapy with DFP 80 mg/kg/day, twice daily, (C) combined therapy with DFX and DFP (DFX 30 mg/kg for first dose, DFP 40 mg/kg 7 hours later, and DFP 40 mg/kg after another 7 h) and (D) concurrent therapy with DFX 30 mg/kg and DFP 80 mg/kg. Descriptive statistics evaluated pharmacokinetic parameters, AUC0-t, AUC0-inf, Cmax, Tmax, T1/2 and MRT. A positive pharmacokinetic drug interaction was observed in combined therapy. In case of DFX, combined therapy tallied about 2-fold larger than monotherapy in AUC, 1.5-fold larger in Cmax, 1 h longer in Tmax, but 1 h shorter in T1/2. Regarding DFP, most such parameters of combined therapy concurred with monotherapy. Conversely, negative drug interaction was observed in concurrent therapy. With DFX, concurrent therapy attained 1.2- to 2.2-fold lower than monotherapy in AUC0-t and Cmax, 0.6-h shorter in Tmax, and 3-fold longer in T1/2. With DFP, concurrent therapy proved approximately 2-fold larger than monotherapy in AUC and Cmax, 2.5-fold longer in T1/2, and 1.4-fold longer in MRT. Follow-up of subjects' clinical examinations and subjective symptoms showed no adverse events. Our findings showed the combined therapy had advantages, safe, convenient and painless for patients, over the existing concurrent therapy with deferoxamine (DFO) and DFX.

Comparison of deferiprone and deferrioxamine for the treatment of transfusional iron overload in children with beta thalassemia major

BACKGROUND

Thalassemia major is the most common genetic disorder in Pakistan. The study was done to compare the efficacy and safety of the deferiprone with deferrioxamine for the treatment of iron overload in children with thalassemia major.

METHODS

This randomized controlled trail was conducted at thalassemia blood transfusion unit of Allied Hospital, Faisalabad (AHF)/District Headquarter Hospital (DHQ), Faisalabad. Thalassemia-Unit Hilal-e-Ahmar, Alizeb Foundation and Blood Bank Services Faisalabad from November 2010 to December 2011.Children with beta thalassemia major of age more than 2 years and less than 16 years with transfusion iron over load were randomly allocated to one of the two groups each comprising of 67 patients. One group received deferiprone given at a daily dose of 75mg/kg in three divided doses orally while the other group received deferrioxamine at dose 50 mg/kg/24hrs for 5 days/week as parental infusion. Changes in the serum ferritin level were assessed. Cardiac function and toxicity were also examined.

RESULTS

Serum ferritin was significantly reduced after 1 year in both treatment arms (p=0.01). Neutropenia observed in 13 (19.40%) non-splenectomized patients taking deferiprone. Transient elevations in ALT were observed in 3 (4.47%) children taking deferiprone. Left ventricular ejection fraction (LVEF) remained in normal range in both treatment arm but has decreased significantly in Deferrioxamine group compliance. Compliance was better in deferiprone as compared to deferrioxamine. Discontinuing percentage 2 (3%) vs 9 (13.43%).

CONCLUSION

Deferiprone is a highly efficacious and safe chelation therapy for patients with thalassemia major who are non-compliant to Deferrioxamine. Deferiprone have an efficacy profile comparable to standard Deferrioxamine.

Protective effects of desferrioxamine and deferiprone on the spleen tissue of aluminum intoxicated mice: A Fourier transform infrared spectroscopy study

The present study was designed to examine the protective effects of the chelating agents desferrioxamine (DFO) and deferiprone (DFP) in aluminum intoxicated spleen tissue of mice by Fourier transform infrared (FTIR) spectroscopy. The finding revealed the alterations on the major biochemical constituents, such as lipids, proteins, phosphodiester and nucleic acids of the spleen tissue of mice at molecular level. The significant decreased in the peak areas of asymmetric and symmetric mode of the phosphodiester groups from control to aluminum intoxicated, but improved it by DFP and DFO+DFP treatments respectively for nearer control value. The bands ratio at I1081/I1232 significantly decreased from control to aluminum, but enhanced it by DFP and DFO+DFP respectively. This result suggests that DFO and DFP are the phosphodiesterase inhibitor, recovered from chronic growth of diseases in the spleen. Amide I and amide II peak area values decreased from control to aluminum intoxicated spleen tissue, but treated with DFP and DFO+DFP significantly improved. This result suggests an alteration in the protein profile. The absence of Olefinic=CH stretching in aluminum intoxicated spleen suggests an altered lipid levels. Concentrations of trace elements were found by ICP-OES. Histopathological findings confirmed the biochemical observations of this study. The results of the FTIR study were found to be in agreement with biochemical studies and demonstrated that FTIR can be used successfully applied to toxicological studies at molecular level.

Studies the alterations of biochemical and mineral contents in bone tissue of mus musculus due to aluminum toxicity and the protective action of desferrioxamine and deferiprone by FTIR, ICP-OES, SEM and XRD techniques

The present study has attempt to analyze the changes in the biochemical and mineral contents of aluminum intoxicated bone and determine the protective action of desferrioxamine (DFO) and deferiprone (DFP) by using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), and scanning electron microscopy (SEM) techniques for four groups of animals such as control (Group I), aluminum intoxicated (Group II), Al+DFP (Group III) and Al+DFO+DFP (Group IV) treated groups respectively. The FTIR spectra of the aluminum intoxicated bone showed significant alteration in the biochemical constituents. The bands ratio at I1400/I877 significantly decreased from control to aluminum, but enhanced it by Al+DFP to Al+DFO+DFP treated bone tissue for treatments of 16 weeks. This result suggests that DFO and DFP are the carbonate inhibitor, recovered from chronic growth of bone diseases and pathologies. The alteration of proteins profile indicated by Amide I and Amide II, where peak area values decreased from control to aluminum respectively, but enhanced by treated with DFP (p.o.) and DFO+DFP (i.p.) respectively. The XRD analysis showed a decrease in crystallinity due to aluminum toxicity. Further, the Ca, Mg, and P contents of the aluminum exposed bone were less than those of the control group, and enhanced by treatments with DFO and DFP. The concentrations of trace elements were found by ICP-OES. Therefore, present study suggests that due to aluminum toxicity severe loss of bone minerals, decrease in the biochemical constituents and changes in the surface morphology.

[In vitro interaction of deferiprone with cellular membrane transporters of hOCTs and hOAT1]

OBJECTIVE

To develop a LC-MS/MS method for determination of deferiprone in cell lysate and to study the potential interaction between deferiprone and hOCTs or hOAT1 transporters in vitro.

METHODS

The determination was performed on an Agilent Eclipse Plus C18 column(3.5 μm, 2.1 mm×50 mm).The gradient mobile phase was composed of solvent A:0.1% formic acid in water, and B:0.1% formic acid in acetonitrile. The mass spectrometer with an electrospray interface was operated in positive ion mode with multiple reaction monitoring (MRM) scan mode monitored the ion pair of deferiprone at m/z 140→96, or phenacetin at m/z 180→110. The effects of deferiprone on the accumulation of typical substrates of hOCTs and hOAT1 were evaluated by MDCK-hOCTs and MDCK-hOAT1 cells respectively. The accumulation of deferiprone was also investigated in MDCK-hOCTs cells and mock cells with or without typical inhibitors.

RESULTS

The standard curve was linear over the range of 5-300 nmol/L. The assay recovery of deferiprone was above 94%, and the intra-day precision (RSD) was less than 2.0%. The accumulation of MPP(+) in MDCK-hOCTs cells with 300 μmol/L deferiprone were 73.5%, 87.1% and 70.4%, respectively. The uptake of deferiprone in MDCK-hOCTs and mock cells did not show significant difference. Deferiprone of 100 μmol/L did not significantly affect the accumulation of 6-CF in MDCK-hOAT1 cell.

CONCLUSION

The method is sensitivity and suitable for the determination of deferiprone in cell lysate. Deferiprone can significantly inhibit hOCT1 and hOCT3, but has no effects on hOCT2 and hOAT1. hOCTs may not play a major role in the transport of deferiprone.

FTIR study of protective action of deferoxamine and deferiprone on the kidney tissues of aluminum loaded mice

The present study was designed to evaluate the FTIR spectra of the aluminum exposed kidney tissues and recovered by chelating agents DFO and DFP then showed significant alteration on the major biochemical constituents such as lipids, proteins and glycogen at molecular level. The significant increased in the peak area of glycogen from 0.006±0.001 to 0.187±0.032 may be the interruption of aluminum in the calcium metabolism and the reduced level of calcium. The peak area value of amide A significantly decreased from control (4.931±1.446) to aluminum (1.234±0.052), but improved by DFP and DFO+DFP from 2.658±0.153 to 3.252±0.070 respectively. Amide I and amide II peak area values also decreased from 1.690±0.133 to 0.811±0.192 and 1.158±0.050 to 0.489±0.047 but treated with DFP and DFO+DFP significantly improved. This result suggests an alteration in the protein profile. The absence of Olefinic=CH stretching band, C=O stretching of triglycerides and ring breathing mode in the DNA bases in aluminum exposure kidney suggests an altered lipid levels. Treated with DFP and DFO+DFP mice were considerably increased in lipid peroxidative markers. Further, assessed the activities of enzymatic antioxidants and measured the levels of nonenzymatic antioxidants. Concentrations of trace elements were found by ICP-OES. Histopathology of chelating agents treated kidney showed reduced renal damage in aluminum induced mice. Thus, histopathological findings confirmed the biochemical observations of this study. This results demonstrated that FTIR spectroscopy can be successfully applied to toxicological and biotoxicology studies.

FT-Raman study of deferoxamine and deferiprone exhibits potent amelioration of structural changes in the liver tissues of mice due to aluminum exposure

The present study inform the alterations on major biochemical constituents such as lipids, proteins, nucleic acids and glycogen along with phosphodiester linkages, tryptophan bands, tyrosine doublet, disulfide bridge conformations, aliphatic hydrophobic residue, and salt bridges in liver tissues of mice using Fourier transform Raman spectroscopy. In amide I, amide II and amide III, the area value significant decrease due structural alteration in the protein, glycogen and triglycerides levels but chelating agents DFP and DFO upturned it. Morphology changes by aluminium induced alterations and recovery by chelating agents within liver tissues known by histopathological examination. Concentrations of trace elements were found by ICP-OES. FT-Raman study was revealed to be in agreement with biochemical studies and demonstrate that it can successfully specify the molecular alteration in liver tissues. The tyrosyl doublet ratio I899/I831 decreases more in aluminum intoxicated tissues but treatment with DFP and DFO+DFP brings back to nearer control value. This indicates more variation in the hydrogen bonding of the phenolic hydroxyl group due to aluminum poisoning. The decreased Raman intensity ratio (I3220/I3400) observed in the aluminum induced tissues suggests a decreased water domain size, which could be interpreted in terms of weaker hydrogen-bonded molecular species of water in the aluminum intoxicated liver tissues. Finally, FT-Raman spectroscopy might be a useful tool for obtained successfully to indicate the molecular level changes.