A randomized placebo-controlled clinical trial of oral green tea epigallocatechin 3-gallate on erythropoiesis and oxidative stress in transfusion-dependent β-thalassemia patients

β-Thalassemia patients suffer from ineffective erythropoiesis and increased red blood cell (RBC) hemolysis. Blood transfusion, erythropoietic enhancement, and antioxidant supplementation can ameliorate chronic anemia. Green tea extract (GTE) is comprised of catechin derivatives, of which epigallocatechin-3-gallate (EGCG) is the most abundant, presenting free-radical scavenging, iron-chelating, and erythropoiesis-protective effects. The present study aimed to evaluate the effects of GTE tablets on the primary outcome of erythropoiesis and oxidative stress parameters in transfusion-dependent β-thalassemia (TDT) patients. Twenty-seven TDT patients were randomly divided into placebo and GTE tablet (50 and 100 mg EGCG equivalent) groups and assigned to consume the product once daily for 60 days. Blood was collected for analysis of hematological, biochemical, and oxidative stress parameters. Accordingly, consumption of GTE tablets improved blood hemoglobin levels when compared with the placebo; however, there were more responders to the GTE tablets. Interestingly, amounts of nonheme iron in RBC membranes tended to decrease in both GTE tablet groups when compared with the placebo. Importantly, consumption of GTE tablets lowered plasma levels of erythroferrone (p < 0.05) and reduced bilirubin non-significantly and dose-independently. Thus, GTE tablets could improve RBC hemolysis and modulate erythropoiesis regulators in transfusion-dependent thalassemia patients.

Protection of Iron-Induced Oxidative Damage in Neuroblastoma (SH-SY5Y) Cells by Combination of 1-(N-Acetyl-6-aminohexyl)-3-hydroxy-2-methylpyridin-4-one and Green Tea Extract

Iron is a crucial trace element and essential for many cellular processes; however, excessive iron accumulation can induce oxidative stress and cell damage. Neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease, have been associated with altered iron homoeostasis causing altered iron distribution and accumulation in brain tissue. This study aims to investigate the protective effect of 1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methylpyridin-4-one (CM1) in combination with green tea extract (GTE) on iron-induced oxidative stress in neuroblastoma (SH-SY5Y) cells. Cells were cultured in medium with or without ferric chloride loading. Their viability and mitochondrial activity were assessed using MTT and JC-1 staining methods. Levels of the cellular labile iron pool (LIP), reactive oxygen species (ROS), and lipid-peroxidation products were determined using calcein acetoxymethyl ester, 2',7'-dichlorohydrofluorescein diacetate, and TBARS-based assays, respectively. The viability of iron-loaded cells was found to be significantly increased after treatment with CM1 (10 µM) for 24 h. CM1 co-treatment with GTE resulted in a greater protective effect than their monotherapy. Combination of CM1 and GTE also reduced mitochondrial disruption and LIP content and ROS and TBARS production. In conclusion, the combination of CM1 and GTE exhibits protection against iron-induced oxidative stress in neuroblastoma cells.

Polymeric nanocarriers for the treatment of systemic iron overload

Desferrioxamine (DFO), deferiprone (L1) and desferasirox (ICL-670) are clinically approved iron chelators used to treat secondary iron overload. Although iron chelators have been utilized since the 1960s and there has been much improvement in available therapy, there is still the need for new drug candidates due to limited long-term efficacy and drug toxicity. Moreover, all currently approved iron chelators are of low molecular weight (MW) (<600 Da) and the objectives reported for the "ideal" chelator of low MW, including possessing the ability to promote iron excretion without causing toxic side effects, has proven difficult to realize in practice. With prolonged iron chelator use, patients may develop toxicities or become insensitive. In contrast, the limited research that has been geared towards developing higher MW, polymeric, long circulating iron chelators has shown promise. The inherent potential of polymeric iron chelators toward longer plasma half-lives and reduction in toxicity provides optimism and may be a significant addition to the currently available low MW iron chelators. This article reviews knowledge pertaining to this theme, highlights some unique advantages that these nanomedicines have in treating systemic iron overload as well as their potential utility in the treatment of other disease states.

Polymeric nanocarriers for the treatment of systemic iron overload

Desferrioxamine (DFO), deferiprone (L1) and desferasirox (ICL-670) are clinically approved iron chelators used to treat secondary iron overload. Although iron chelators have been utilized since the 1960s and there has been much improvement in available therapy, there is still the need for new drug candidates due to limited long-term efficacy and drug toxicity. Moreover, all currently approved iron chelators are of low molecular weight (MW) (<600 Da) and the objectives reported for the “ideal” chelator of low MW, including possessing the ability to promote iron excretion without causing toxic side effects, has proven difficult to realize in practice. With prolonged iron chelator use, patients may develop toxicities or become insensitive. In contrast, the limited research that has been geared towards developing higher MW, polymeric, long circulating iron chelators has shown promise. The inherent potential of polymeric iron chelators toward longer plasma half-lives and reduction in toxicity provides optimism and may be a significant addition to the currently available low MW iron chelators. This article reviews knowledge pertaining to this theme, highlights some unique advantages that these nanomedicines have in treating systemic iron overload as well as their potential utility in the treatment of other disease states.

Effect of a novel oral active iron chelator: 1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methylpyridin-4-one (CM1) in iron-overloaded and non-overloaded mice

OBJECTIVE

To evaluate efficacy and toxicity of a novel orally active bidentate iron chelator, 1-(N-acetyl-6-aminohexyl)-3-hydroxy-2-methylpyridin-4-one (CM1) in mice under normal and iron overload conditions.

METHODS

Wild type C57BL/6 mice were fed with normal and 0.2% (w/w) ferrocene-supplemented (Fe) diets, respectively for 240 d and orally given the CM1 (50, 100 and 200 mg/kg) for 180 d. Blood iron profiles, hematological indices, liver enzymes and histopathology were determined.

RESULTS

CM1 treatment lowered plasma levels of labile plasma iron and non-transferrin bound iron, but not ferritin in the Fe-fed mice. However, the treatment did not impact blood hemoglobin level, white blood cell and platelet numbers in both normal diet and Fe diet-fed mice. Interestingly, CM1 treatment did not markedly elevate plasma aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase activities in the normal diet-fed mice but it tended to increase the levels of the liver enzymes slightly in the Fe-fed mice. Hematoxylin and eosin staining result showed no abnormal pathological changes in heart, liver and spleen tissues.

CONCLUSIONS

It is clear that CM1 would not be toxic to bone marrow and liver cells under normal and iron-overload conditions.

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

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-loaded β-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 overload β-thalassemic mice.

Iron distribution and histopathological characterization of the liver and heart of β-thalassemic mice with parenteral iron overload: Effects of deferoxamine and deferiprone

The liver and heart are the major target organs for iron accumulation and iron toxicity in β-thalassemia. To mimic the phenomenon of heavy iron overload resulting from repeated blood transfusions, a total of 180 mg of iron dextran was intraperitoneally injected into C57BL/6J mice (WT) and heterozygous β-globin knockout mice ((mu)β(th-3/+), BKO). The effects of deferiprone and deferoxamine in this model were investigated. The iron was distributed homogenously throughout the 4 liver lobes (left, caudate, right and median) and was present in hepatocytes, Kupffer cells and the sinusoidal space. Iron accumulation in phagocytic macrophages, recruitment of hepatic lymphocytes and nucleus membrane degeneration were observed as a result of iron overload in the WT and BKO mice. However, the expansion of hepatic extramedullary hematopoiesis was observed only in the BKO mice with iron overload. In the heart, the iron accumulated in the cardiac interstitium and myocytes, and moderate hypertrophy of the myocardial fibers and cardiac myocyte degeneration were observed. Although the total liver iron was not significantly altered by iron chelation therapy, image analysis demonstrated a difference in the efficacies of two iron chelators. The major site of chelation was the extracellular compartment, but treatment with deferiprone also resulted in intracellular iron chelation. Interestingly, iron chelators reversed the pathological changes resulting from iron overload in WT and BKO mice despite being used for only a short treatment period. We suggest that some of these effects may be secondary to the anti-inflammatory activity of the chelators.