Eltrombopag (ELT) is a thrombopoietin receptor agonist reported to decrease labile iron in leukemia cells. Here we examine the previously undescribed iron(III)-coordinating and cellular iron-mobilizing properties of ELT. We find a high binding constant for iron(III) (log β=35). Clinically achievable concentrations (1 µM) progressively mobilized cellular iron from hepatocyte, cardiomyocyte, and pancreatic cell lines, rapidly decreasing intracellular reactive oxygen species (ROS) and also restoring insulin secretion in pancreatic cells. Decrements in cellular ferritin paralleled total cellular iron removal, particularly in hepatocytes. Iron mobilization from cardiomyocytes exceeded that obtained with deferiprone, desferrioxamine, or deferasirox at similar iron-binding equivalents. When combined with these chelators, ELT enhanced cellular iron mobilization more than additive (synergistic) with deferasirox. Iron-binding speciation plots are consistent with ELT donating iron to deferasirox at clinically relevant concentrations. ELT scavenges iron citrate species faster than deferasirox, but rapidly donates the chelated iron to deferasirox, consistent with a shuttling mechanism. Shuttling is also suggested by enhanced cellular iron mobilization by ELT when combined with the otherwise ineffective extracellular hydroxypyridinone chelator, CP40. We conclude that ELT is a powerful iron chelator that decreases cellular iron and further enhances iron mobilization when combined with clinically available chelators.

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Malaria i a serious health problem caused by Plasmodium spp. that can be treated by an anti-folate pyrimethamine (PYR) drug. Deferiprone (DFP) is an oral iron chelator used for the treatment of iron overload and has been recognized for its potential anti-malarial activity. Deferiprone–resveratrol hybrids (DFP-RVT) have been synthesized to present therapeutic efficacy at a level which is superior to DFP. We have focused on determining the lipophilicity, toxicity and inhibitory effects on P. falciparum growth and the iron-chelating activity of labile iron pools (LIPs) by DFP-RVT. According to our findings, DFP-RVT was more lipophilic than DFP (p < 0.05) and nontoxic to blood mononuclear cells. Potency for the inhibition of P. falciparum was PYR > DFP-RVT > DFP in the 3D7 strain (IC50 = 0.05, 16.82 and 47.67 µM, respectively) and DFP-RVT > DFP > PYR in the K1 strain (IC50 = 13.38, 42.02 and 105.61 µM, respectively). The combined treatment of DFP-RVT with PYR additionally enhanced the PYR activity in both strains. DFP-RVT dose-dependently lowered LIP levels in PRBCs and was observed to be more effective than DFP at equal concentrations. Thus, the DFP-RVT hybrid should be considered a candidate as an adjuvant anti-malarial drug through the deprivation of cellular iron.

The most important cause of death in β-thalassemia major patients is organ dysfunction due to iron deposits.

Iron is essential for all organisms including fast-dividing malarial parasites. Inversely, iron chelators can inhibit parasite growth through the inhibition of DNA synthesis and can ameliorate oxidative cell damage. Deferiprone (DFP)-resveratrol (RVT) hybrid (DFP-RVT) is a lipophilic anti-oxidative, iron-chelating agent that has displayed potent neuroprotective and anti-plasmodium activities in vitro. The goal of this work was to investigate the inhibitory effects of DFP-RVT on parasite growth and oxidative stress levels during malaria infections. Mice were intraperitoneally infected with P. berghei and orally administered with DFP, DFP-RVT and pyrimethamine for 4 d. The percentage of parasitemia was determined using Giemsa’s staining/microscopic examination. Amounts of the lipid-peroxidation product, thiobarbituric acid-reactive substance (TBARS), were determined in both plasma and liver tissue. In our findings, DFP-RVT exhibited a greater potent inhibitory effect and revealed an improvement in anemia and liver damage in infected mice than DFP. To this point, the anti-malarial activity was found to be associated with anti-RBC hemolysis and the liver weight index. In addition, plasma and liver TBARS levels in the DFP-RVT-treated mice were lower than those in DFP-treated mice. Thus, DFP-RVT could exert anti-plasmodium, anti-hemolysis and anti-lipid peroxidation activities to a better degree than DFP in P. berghei-infected mice.

Redox-active iron generates reactive oxygen species that can cause oxidative organ dysfunction. Thus, the anti-oxidative systems in the body and certain dietary antioxidants, such as anthocyanins, are needed to control oxidative stress. We aimed to investigate the effects of dielectric barrier discharge (DBD) plasma technology in the preparation of Riceberry™ rice flour (PRBF) on iron-induced oxidative stress in mice. PRBF using plasma technology was rich in anthocyanins, mainly cyanidine-3-glucoside and peonidine-3-glucoside. PRBF (5 mg AE/mg) lowered WBC numbers in iron dextran (FeDex)-loaded mice and served as evidence of the reversal of erythrocyte superoxide dismutase activity, plasma total antioxidant capacity, and plasma and liver thiobarbituric acid-reactive substances in the loading mice. Consequently, the PRBF treatment was observed to be more effective than NAC treatment. PRBF would be a powerful supplementary and therapeutic antioxidant product that is understood to be more potent than NAC in ameliorating the effects of iron-induced oxidative stress.

Iron-deficiency anemia (IDA) is the major cause of anemia in developing countries commonly associated with poor nutrition, pregnancy, celiac disease, hook-worm infestation and aging process. Iron fortification in staple food is recommended to help preventing IDA; however, the iron dosing may cause adverse effects and oxidative damage to the gut lumen resulting in gastrointestinal irritation and poor absorption. The Thai Sinlek rice (Oryza sativaL.) (IR) was developed as a new crossbreed of Jasmine (Hom nin) rice and white (Hom Mali 105) rice (WR) and is abundant with iron, phenolic compounds, tocopherols and tocotrienols. Previously, the consumption of IR drink (14.7 mg/100-mL serving/d) for 1 month significantly increased levels of hemoglobin (Hb) and tended to increase levels of serum iron (SI) and transferrin saturation (TS) in anemic elderly subjects. However, the nutraceutical effect of IR from iron fortification together with potential oxidative effects have not been properly tested in an animal model. To prepare the functional IR, we digested IR grains with a-amylase and dried the hydrolysate by using lyophilization technique. Iron content of the hydrolysate was determined using ferrozine colorimetric and inductively coupled plasma-mass spectrometry (ICP-MS) methods. IR hydrolysate was found to contain 13.9 mg iron/g dry weight compared with 1.94 mg iron/g in white rice (WR). Antioxidant activity was assayed using 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid radical (ABTS*) decolorizing method,and anti-hemolysis activity was determined using 2,2-azobis(2-amidinopropane) dihydrochloride radical (AAPH*) induced red blood cells (RBC) method as shown in Figure 1. The IR hydrolysate has higher antioxidant and anti-hemolysis activities in a dose dependent manner compared to the WR hydrolysate and controls (PBS). HPLC analysis also showed some amounts of phenolic compounds, g-oryzanol, tocopherols and tocotrienols in the IR hydrolysate (data not shown). To assess luminal absorptivity of iron, two Wistar rats were fed once with the IR hydrolysate (500 mg/kg body weight) and collected blood samples at different time points for 24 h. The finding reveals an increment of serum iron (SI) and transferrin saturation (TS) levels at 5 h and the maximum levels at 15 h (Figure 2). Finally, to study nutraceutical effects of the IR hydrolysate, Wistar rats (5 males, 5 females) were fed with the IR (50, 100 and 200 mg/kg) for 3 months and sacrificed for blood collection and analysis. Hematological parameters were determined using an automated Coulter cell counter (Table 1). The treatment with the IR at 50 mg/kg was found to increase significantly levels of RBC parameters e.g., Hb, hematocrit (Hct), red blood cell counts (RBC) and mean corpuscular volume (MCV) and total white blood count compared to higher dosing of the IR and control with deionized water (DI). In the highest IR dose (200 mg/kg), Hb, Hct and RBC were lowest suggesting a potential iron related toxicity probably on chronic intestinal inflammation. Our finding highlights that the optimal use of the IR should balance between the benefit from iron fortification to enhance hematopoiesis by preventing IDA against the risk of iron toxicity from dosing due to excessive free iron species and redox activity generation. Disclosures No relevant conflicts of interest to declare.