Alcohol intake and iron overload: another role for hepcidin?

Dual nature of ferritin for hematologic, liver functional, and metabolic parameters in older diabetic patients

This study explored the association between ferritin with hematologic, liver functional, and metabolic parameters in older diabetic patients. A total of 210 diabetic patients aged 65 or older were classified into four groups according to the reference range of serum ferritin. Demographic variables and health-related lifestyle factors were obtained through the utilization of a standardized questionnaire. Anthropometric measures, blood pressure, hematology test, and biochemical assessment were also performed. Among all patients, 29.5% had anemia. The percentage of anemia in groups low ferritin (< 40 μg/L), lower side within the reference range (40-120 μg/L), higher side within the reference range (121-200 μg/L), and high ferritin levels (> 200 μg/L) were 50.0, 27.7, 20.5, and 24.2% (P = 0.025), respectively. Low ferritin levels had a higher risk of anemia and a high red blood cell distribution width (RDW). High ferritin levels were associated with a higher risk of high glutamate pyruvate transaminase, obesity, high fasting blood glucose (FBG), and high postprandial blood glucose. The higher side within the reference range of ferritin also showed a higher risk of high FBG and high glycated hemoglobin. Nevertheless, there was no significant association between ferritin and inflammation marker, serum lipids or blood pressure. Overall, ferritin demonstrates a dual nature in older diabetic patients: low ferritin levels are linked to anemia or elevated RDW, while high levels are linked to obesity, increased liver enzymes, and worse glycemia control.

The relation of toddy (palm wine) intake to amoebic liver abscess in a predominantly toddy-drinking population: a cross-sectional study

The role of toddy (palm wine) as an independent risk factor for amoebic liver abscess (ALA) is not clear. In a cross-sectional study, the clinico-demographic profiles of inpatients with ALA were examined. Microscopy examination of toddy (n = 43) samples was performed. A total of 198 patients with ALA were enrolled, most of whom were: admitted during the May-August months (48%); chronic alcoholic (85% [70% toddy]); malnourished (85%); and of low socioeconomic status (88%). Clinical and laboratory parameters were comparable between toddy and distilled alcohol drinkers. None of the toddy samples revealed presence of cysts and trophozoites of Entamoeba histolytica.

Systemic iron homeostasis

The iron hormone hepcidin and its receptor and cellular iron exporter ferroportin control the major fluxes of iron into blood plasma: intestinal iron absorption, the delivery of recycled iron from macrophages, and the release of stored iron from hepatocytes. Because iron losses are comparatively very small, iron absorption and its regulation by hepcidin and ferroportin determine total body iron content. Hepcidin is in turn feedback-regulated by plasma iron concentration and iron stores, and negatively regulated by the activity of erythrocyte precursors, the dominant consumers of iron. Hepcidin and ferroportin also play a role in host defense and inflammation, and hepcidin synthesis is induced by inflammatory signals including interleukin-6 and activin B. This review summarizes and discusses recent progress in molecular characterization of systemic iron homeostasis and its disorders, and identifies areas for further investigation.

Quercetin protects rat hepatocytes from oxidative damage induced by ethanol and iron by maintaining intercellular liable iron pool

Accumulating evidence has shown that ethanol-induced iron overload plays a crucial role in the development and progression of alcoholic liver disease. We designed the present study to investigate the potential protective effect of quercetin, a naturally occurring iron-chelating antioxidant on alcoholic iron overload and oxidative stress. Ethanol-incubated (100 mmol/L) rat primary hepatocytes were co-treated by quercetin (100 µmol/L) and different dose of ferric nitrilotriacetate (Fe-NTA) for 24 h. When the hepatic enzyme releases in the culture medium, redox status of hepatocytes and the intercellular labile iron pool (LIP) level were assayed. Our data showed that Fe-NTA dose dependently induced cellular leakage of aspartate transaminase and lactate dehydrogenase, glutathione depletion, superoxide dismutase inactivation, and overproduction of malondialdehyde) and reactive oxygen species (ROS) of intact and especially ethanol-incubated hepatocytes. The oxidative damage resulted from ethanol, Fe-NTA, and especially their combined treatment was substantially alleviated by quercetin, accompanying the corresponding normalization of intercellular LIP level. Iron in excess, thus, may aggravate ethanol hepatotoxicity through Fenton-active LIP, and quercetin attenuated ethanol-induced iron and oxidative stress. To maintain intercellular LIP contributes to the hepatoprotective effect of quercetin besides its direct ROS-quenching activity.

Mammalian iron metabolism

ABSTRACT Iron is an essential transition metal for mammalian cellular and tissue viability. It is critical to supplying oxygen through heme, the mitochondrial respiratory chain, and enzymes such as ribonucleotide reductase. Mammalian organisms have evolved with the means of regulating the metabolism of iron, because if left unregulated, the resulting excess amounts of iron may induce chronic toxicities affecting multiple organ systems. Several homeostatic mechanisms exist to control the amount of intestinal dietary iron uptake, cellular iron uptake, distribution, and export. Within these processes, numerous molecular participants have been identified because of advancements in basic cell biology and efforts in disease-based research of iron storage abnormalities. For example, dietary iron uptake across the intestinal duodenal mucosa is mediated by an intramembrane divalent metal transporter 1 (DMT1), and cellular iron efflux involves ferroportin, the only known iron exporter. In addition to duodenal enterocytes, ferroportin is present in other cell types, and exports iron into plasma. Ferroportin was recently discovered to be regulated by the expression of the circulating hormone hepcidin, a small peptide synthesized in hepatocytes. These recent studies on the role of hepcidin in the regulation of dietary, cellular, and extracellular iron have led to a better understanding of the pathways by which iron balance in humans is influenced, especially its involvement in human genetic diseases of iron overload. Other important molecular pathways include iron binding to transferrin in the bloodstream for cellular delivery through the plasma membrane transferrin receptor (TfR1). In the cytosol, iron regulatory proteins 1 and 2 (IRP1 and IRP2) play a prominent role in sensing the presence of iron in order to posttranscriptionally regulate the expression of TfR1 and ferritin, two important participants in iron metabolism. From a toxicological standpoint, posttranscriptional regulation of these genes aids in the sequestration, control, and hence prevention of cytotoxic effects from free-floating nontransferrin-bound iron. Given the importance of dietary iron in normal physiology, its potential to induce chronic toxicity, and recent discoveries in the regulation of human iron metabolism by hepcidin, this review will address the regulatory mechanisms of normal iron metabolism in mammals with emphasis on dietary exposure. It is the goal of this review that this information may provide in a concise format our current understanding of major pathways and mechanisms involved in mammalian iron metabolism, which is a basis for control of iron toxicity. Such a discussion is intended to facilitate the identification of deficiencies so that future metabolic or toxicological studies may be appropriately focused. A better knowledge of iron metabolism from normal to pathophysiological conditions will ultimately broaden the spectrum of the usefulness of this information in biomedical and toxicological sciences for improving and protecting human health.