Nutritional Modulation of Hepcidin in the Treatment of Various Anemic States

Iron metabolism and ferroptosis in health and diseases: The crucial role of mitochondria in metabolically active tissues

Iron is essential in various physiological processes, but its accumulation leads to oxidative stress and cell damage, thus iron homeostasis has to be tightly regulated. Ferroptosis is an iron-dependent non-apoptotic regulated cell death characterized by iron overload and reactive oxygen species accumulation. Mitochondria are organelles playing a crucial role in iron metabolism and involved in ferroptosis. MitoNEET, a protein of mitochondrial outer membrane, is a key element in this process. Ferroptosis, altering iron levels in several metabolically active organs, is linked to several non-communicable diseases. For example, iron overload in the liver leads to hepatic fibrosis and cirrhosis, accelerating non-alcholic fatty liver diseases progression, in the muscle cells contributes to oxidative damage leading to sarcopenia, and in the brain is associated to neurodegeneration. The aim of this review is to investigate the intricate balance of iron regulation focusing on the role of mitochondria and oxidative stress, and analyzing the ferroptosis implications in health and disease.

Impact of Vitamin A Deficiency on Iron Metabolism and Anemia: A Historical Perspective and Research Advances

Vitamin A deficiency (VAD) and iron deficiency anemia coexist around the world, particularly in children and women of reproductive age in low- and middle-income countries. Within this scenario, there is a known interaction between vitamin A and iron, and it has been postulated that lack of vitamin A impairs iron metabolism, leading to vitamin A deficiency anemia (VADA). Current animal, epidemiological, and clinical studies support this notion. The objective of this study was to review the current literature on proposed metabolic mechanisms regarding how VAD modulates iron metabolism leading to anemia. To attain this objective, a literature search was conducted of research publications in the related field, without date restriction, using PubMed, Scopus, Google Scholar, and the University of Illinois's reference system. The data support the essentiality of vitamin A for normal erythropoiesis. It indicates that, in VAD, iron mobilization is impaired, and that this mineral accumulates in the liver and spleen, making it less available for erythropoiesis. A triggering factor for the development of VADA seems to be inflammation and systemic infection, which release cytokines that upregulate the production of hepcidin by the liver. VAD may also increase hepcidin directly without the involvement of inflammation or infection. The elevated hepcidin, in turn, lowers circulating iron and sequesters iron in storage depots, downregulating erythropoietin, leading to inefficient erythropoiesis, decreased hemoglobin (Hb) production, and (subsequently) anemia. VAD may also impact the expression of iron regulatory protein 2 (IRP2), and thus affect intracellular iron metabolism gene expression. VADA is not due to iron deficiency, but to a redistribution of iron in the body. Understanding the mechanism of VADA will assist in designing more effective strategies for combating anemia worldwide.

Effect of dietary protein on serum hepcidin and iron in adults with obesity and insulin resistance: A randomized single blind clinical trial

BACKGROUND AND AIMS

Both obesity and iron deficiency are public health problems. The association between the two problems could be explained by chronic low-grade inflammation in obesity, which could stimulate hepcidin expression and modify iron concentration that the consumption of high-protein diets could prevent. Thus, this study aimed to compare the effects of high-protein diets with a predominance of animal or vegetable protein on serum hepcidin and iron concentrations in adults with obesity.

METHODS AND RESULTS

This randomized clinical trial involved adults with obesity and insulin resistance, who were assigned to either a high animal protein (AP) group or a high vegetable protein (VP) group for a one-month intervention. Both groups followed a calorie-restricted diet, reducing energy intake by 750 kcal/day. Baseline and final measurements included serum concentrations of hepcidin and iron, biochemical parameters, anthropometric data, and body composition. A total of 33 participants (63 % female) were included in the study. Significant weight loss was observed in both groups after the intervention. Adjusted for weight loss percentage, the AP group showed a significant increase in hepcidin concentration (from 22.3 ± 14.7 to 27.5 ± 19.5 ng/mL) compared to the VP group (from 17.9 ± 15.1 to 17.2 ± 10.1 ng/mL) (p < 0.01), with no changes in serum iron concentration. Additionally, the VP diet significantly reduced serum adiponectin (p = 0.04) and C-reactive protein (p = 0.03) levels.

CONCLUSIONS

In adults with obesity following the AP diet for one month, hepcidin levels increased without affecting serum iron concentrations.

TRIAL REGISTRATION

NCT03627104.

Dietary Artemisia arborescens Supplementation Effects on Growth, Oxidative Status, and Immunity of Gilthead Seabream (Sparus aurata L.)

Fish infectious diseases are one of the main constraints of the aquaculture sector. The use of medicinal plants provides a sustainable way of protection using safe, eco-friendly compounds in a more cost-effective way of treatment, compared to antibiotics. The aim of the present study is the assessment of Artemisia arborescens (AA) feed-supplementation effects on gilthead seabream (Sparus aurata). Fish with an average initial body weight of 109.43 ± 3.81 g, were divided into two groups based on AA feed composition (A25 and A50). Following two months of ad libitum feeding, the effect of diets on fish weight and length were measured. Fish serum and mucus were analyzed for non-specific immune parameters (nitric oxide, lysozyme, myeloperoxidase, protease-/anti-protease activity, and complement), antibody responses, oxidative stress (cytochrome P450 1A1, metallothionein), and metabolism markers (total protein, alkaline phosphatase, and glucose). Expression levels of antioxidants (sod1, gpx1), cytokines (il-1b, il-10, tfgb1, and tnfa), hepcidin, and heat shock protein grp75 genes were measured in spleen samples. A results analysis indicated that A. arborescens use as a feed supplement has a compromised positive effect on the growth performance, immune response, and blood parameters of gilthead seabream. Overall, the suitability of A. arborescens as an efficient food supplement for gilthead seabream health improvement was investigated, setting the basis for its application assessment in Mediterranean aquaculture.

Mechanisms of ferroptosis in nonalcoholic fatty liver disease and therapeutic effects of traditional Chinese medicine: a review

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive accumulation of fat in hepatocytes (nonalcoholic fatty liver (NAFL)), and lobular inflammation and hepatocyte damage (which characterize nonalcoholic steatohepatitis (NASH) are found in most patients). A subset of patients will gradually develop liver fibrosis, cirrhosis, and eventually hepatocellular carcinoma, which is a deadly disease that threatens human life worldwide. Ferroptosis, a novel nonapoptotic form of programmed cell death (PCD) characterized by iron-dependent accumulation of reactive oxygen radicals and lipid peroxides, is closely related to NAFLD. Traditional Chinese medicine (TCM) has unique advantages in the prevention and treatment of NAFLD due to its multicomponent, multipathway and multitarget characteristics. In this review, we discuss the effect of TCM on NAFLD by regulating ferroptosis, in order to provide reference for the further development and application of therapeutic drugs to treat NAFLD.