Iron-induced Oxidative Stress Research Articles

A novel synthetic compound, deferiprone–resveratrol hybrid (DFP-RVT), promotes hepatoprotective effects and ameliorates iron-induced oxidative stress in iron-overloaded β-thalassemic mice

A high amount of iron in β-thalassemia patients can lead to oxidative stress and organ dysfunction, especially liver, the main iron accumulated organ. Iron catabolism causes the generation of reactive oxygen species (ROS), triggering liver inflammation, fibrosis, and cirrhosis. Deferiprone-resveratrol hybrid (DFP-RVT) is chemically synthesized by combining deferiprone (DFP) and resveratrol (RVT) which shows an iron-chelating property along with antioxidant activity. This study explored the hepatoprotective effect of DFP-RVT in iron overloaded β-knockout (BKO) thalassemic mice. The results revealed that DFP-RVT treatment improved liver function in iron-overloaded BKO mice by reducing liver enzymes and increasing hepcidin levels compared to iron overload control mice. Both DFP alone and DFP-RVT treatment groups demonstrated iron chelation effects by decreasing liver iron content (LIC), iron profiles, and iron deposition in the liver. Moreover, DFP-RVT powerfully showed antioxidant properties by decreasing liver and plasma thiobarbituric acid reactive substances (TBARs) and increasing reduced glutathione (GSH) and superoxide dismutase (SOD). Interestingly, transforming growth factor β1 (TGFβ1), which can contribute to chronic liver disease through liver injury, inflammation, fibrosis, and cirrhosis, is highly expressed in iron-overloaded mice. However, both DFP and DFP-RVT treatment significantly reduced TGFβ1 levels compared to the iron-overloaded group. Therefore, DFP-RVT could be a potent hepatoprotective compound through the mobilization of iron, reduction of ROS, improvement of liver enzymes, and alleviation of liver damage, potentially relieving liver dysfunction in iron-overloaded BKO mice.

Iron chelating, antioxidant, and anti-inflammatory properties of brazilin from Caesalpinia sappan Linn

BackgroundIron overload and inflammation are severe conditions that can lead to various chronic diseases. However, the current iron chelator drugs have their limitations. The phytochemical compounds from herbals, such as brazilin, the major active compound in Caesalpinia sappan Linn., have significant therapeutic potential in various chronic diseases. Our study was designed to examine the effect of brazilin on iron chelating properties, antioxidant activity in hepatocytes, and anti-inflammatory potential in macrophages. MethodsThis study focused on the isolation, purification, and evaluation of brazilin, the principal bioactive constituent found in C. sappan wood. Brazilin was extracted via methanol maceration followed by column chromatography purification. The purified compound was characterized using high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS). The antioxidant potential of brazilin was assessed by in vitro assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzthiazolin-6-sulfonic acid (ABTS), and ferric-reducing antioxidant power (FRAP). Furthermore, its cellular antioxidant activity was evaluated using hydrogen peroxide-induced oxidative stress in the hepatocellular carcinoma cell line (Huh-7). The iron-chelating capacity of brazilin was determined spectrophotometrically, and Job's plot method was used to elucidated the stoichiometry of the iron-brazilin complex formation. The anti-inflammatory properties of brazilin were investigated in lipopolysaccharide (LPS)-stimulated macrophages (RAW 264.7). Nitric oxide (NO) inhibition was quantified using the Griess reagent, while the expression levels of pro-inflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), were evaluated by RT-qPCR. ResultsThe results demonstrated that brazilin exhibited potent antioxidant activity in vitro and hepatocytes in a concentration-dependent manner. It also showed anti-inflammatory activity, in which NO production was significantly reduced and IL-6 and TNF-α expression in LPS-induced macrophages were repressed. Furthermore, it can bind ferric and ferrous ions. Brazilin acts as a bidentate iron chelator that forms a complex with iron in a 2:1 ratio, and two water molecules are used as additional chelators in this complex. ConclusionsOur findings have significant implications. Brazilin can potentially alleviate the harmful effects of iron-induced oxidative stress and inflammatory disorders.

Antioxidant Effects of Cactus Seed Oil against Iron-Induced Oxidative Stress in Mouse Liver, Brain and Kidney.

In recent times, exploring the protective potential of medicinal plants has attracted increasing attention. To fight reactive oxygen species (ROS), which are key players in hepatic, cerebral and renal diseases, scientists have directed their efforts towards identifying novel compounds with antioxidant effects. Due to its unique composition, significant attention has been given to Cactus Seed Oil (CSO). Iron, as a metal, can be a potent generator of reactive oxygen species, especially hydroxyl radicals, via the Fenton and Haber-Weiss reactions. Here, we employed ferrous sulfate (FeSO4) to induce oxidative stress and DNA damage in mice. Then, we used CSO and Colza oil (CO) and evaluated the levels of the antioxidants (superoxide dismutase [SOD], glutathione peroxidase [GPx] and glutathione [GSH]) as well as a metabolite marker for lipid peroxidation (malondialdehyde [MDA]) relating to the antioxidant balance in the liver, brain and kidney. In addition, we measured DNA damage levels in hepatic tissue and the effects of CSO on it. Our study found that iron-dependent GPx activity decreases in the liver and the kidney tissues. Additionally, while iron decreased SOD activity in the liver, it increased it in the kidney. Interestingly, iron treatment resulted in a significant increase in hepatic MDA levels. In contrast, in brain tissue, there was a significant decrease under iron treatment. In addition, we found varying protective effects of CSO in alleviating oxidative stress in the different tissues with ameliorating DNA damage after iron overload in a mouse liver model, adding compelling evidence to the protective potential of CSO.

Ferritin loss in astrocytes reduces spinal cord oxidative stress and demyelination in the experimental autoimmune encephalomyelitis (EAE) model.

Demyelinating diseases such as multiple sclerosis (MS) cause myelin degradation and oligodendrocyte death, resulting in the release of toxic iron and iron-induced oxidative stress. Astrocytes have a large capacity for iron transport and storage, however the role of astrocytic iron homeostasis in demyelinating disorders is not completely understood. Here we investigate whether astrocytic iron metabolism modulates neuroinflammation, oligodendrocyte survival, and oxidative stress following demyelination. To this aim, we conditionally knock out ferritin in astrocytes and induce experimental autoimmune encephalomyelitis (EAE), an autoimmune-mediated model of demyelination. Ferritin ablation in astrocytes reduced the severity of disease in both the acute and chronic phases. The day of onset, peak disease severity, and cumulative clinical score were all significantly reduced in ferritin KO animals. This corresponded to better performance on the rotarod and increased mobility in ferritin KO mice. Furthermore, the spinal cord of ferritin KO mice display decreased numbers of reactive astrocytes, activated microglia, and infiltrating lymphocytes. Correspondingly, the size of demyelinated lesions, iron accumulation, and oxidative stress were attenuated in the CNS of ferritin KO subjects, particularly in white matter regions of the spinal cord. Thus, deleting ferritin in astrocytes reduced neuroinflammation, oxidative stress, and myelin deterioration in EAE animals. Collectively, these findings suggest that iron storage in astrocytes is a potential therapeutic target to lessen CNS inflammation and myelin loss in autoimmune demyelinating diseases.

Evaluation of Unsaponifiable Fraction of Avocado Oil on Liver and Kidney Mitochondrial Function in Rats Fed a High-Fat and High-Carbohydrate Diet.

High-fat and high-carbohydrate (HF-HC) diets induce metabolic syndrome via mitochondrial dysfunction and oxidative stress. We have previously shown that this may be prevented by avocado oil, a source of bioactive molecules with antioxidant properties. However, it is unknown if these effects are mediated by the unsaponifiable fraction of avocado oil (UFAO). Thus, we tested if this fraction improves glucose metabolism, bioenergetics and oxidative stress in mitochondria from the kidney and liver of rats fed an HF-HC diet. We found that 12 weeks of an HF-HC diet impaired glucose utilization and increased insulin resistance, which was prevented by UFAO administration. The HF-HC diet decreased respiration, membrane potential and electron transport chain (ETC) function in liver and kidney mitochondria. These mitochondrial dysfunctions were prevented by UFAO intake. Unexpectedly, UFAO increased ROS levels in the mitochondria of control animals and did not decrease them in rats with an HF-HC diet; however, UFAO protects liver and kidney mitochondria from iron-induced oxidative stress. These findings suggest that impairments in glucose metabolism and mitochondrial function by an HF-HC diet may be prevented by UFAO, without decreasing ROS generation but protecting mitochondria from oxidative damage.

Influence of Selected Natural Antioxidants on Iron-Induced Enzymatic Alterations Related to Oxidative Stress

Iron is required in various biological processes of the cell, but excess iron causes oxidative stress. Oxidative stress can be prevented by antioxidants with free radical scavenging properties. Tannic acid and gallic acid are phenolic compounds with antioxidant properties found naturally in plants. In this study, the effects of gallic acid and tannic acid on iron-induced oxidative stress parameters were investigated in a fruit fly model. Effect of the compounds against iron-induced oxidative stress were evaluated by determining spectrophotometrically superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and acetylcholinesterase (AChE) enzyme activities, and levels of reduced glutathione (GSH) and malondialdehyde (MDA) in larvae (n: 10) and adults (n: 20) of wild type Oregon R strain of Drosophila melanogaster. Iron treatment decreased enzyme activities and GSH levels, but increased MDA levels. Co-treatment of these compounds with iron ameliorated iron-induced changes, especially in larvae. On the other hand, iron-induced decrease in AChE activity was increased in adults by treatment of these compounds with iron. The results showed that natural phenolic compounds have the potential to ameliorate iron-induced changes in oxidative stress parameters.

Could Alcohol-Related Cognitive Decline Be the Result of Iron-Induced Neuroinflammation?

Excessive and prolonged alcohol use can have long-term severe neurological consequences. The mechanisms involved may be complicated; however, new evidence seems to indicate the involvement of iron accumulation and neuroinflammation. Prolonged alcohol consumption has been linked to the accumulation of iron in specific regions of the brain. Evidence suggests that excess iron in the brain can trigger microglia activation in response. This activation leads to the release of pro-inflammatory cytokines and reactive oxygen species, which can cause damage to neurons and surrounding brain tissue. Additionally, iron-induced oxidative stress and inflammation can disrupt the blood-brain barrier, allowing immune cells from the periphery to infiltrate the brain. This infiltration can lead to further neuroinflammatory responses. Inflammation in the brain subsequently disrupts neuronal networks, impairs synaptic plasticity, and accelerates neuronal cell death. Consequently, cognitive functions such as memory, attention, and decision-making are compromised. Additionally, chronic neuroinflammation can hasten the development and progression of neurodegenerative diseases, further exacerbating cognitive impairment. Therefore, alcohol could act as a trigger for iron-induced neuroinflammation and cognitive decline. Overall, the mechanisms at play here seem to strongly link alcohol with cognitive decline, with neuroinflammation resulting from alcohol-induced iron accumulation playing a pivotal role.

Two 5-Methoxyindole Carboxylic Acid-Derived Hydrazones of Neuropharmacological Interest: Synthesis, Crystal Structure, and Chemiluminescent Study of Radical Scavenging Properties

Given the importance of molecular structure in pharmacological activity and interaction with biological receptors, we conducted a study on the 3,4-dihydroxybenzaldehyde hydrazone derivative of 5-methoxy-indole carboxylic acid (5MICA) and a newly synthesised analogue bearing a 2-methoxy-4-hydroxyphenyl ring using single-crystal X-ray diffraction. We studied the ability of the two compounds to scavenge hypochlorite ions using luminol-enhanced chemiluminescence and their potential to modulate oxidative damage induced by iron on the biologically significant molecules lecithin and deoxyribose in order to evaluate possible antioxidant and prooxidant effects. The X-ray study revealed highly conserved geometry and limited rotation and deformation freedom of the respective indole and phenyl fragments. Interestingly, a conformational difference between the two independent molecules in the asymmetric unit of 3b was found. The X-ray study revealed a combination of hydrogen bonding interactions, short contacts, and π–π stacking stabilizing the specific three-dimensional packing of the molecules of 3a and 3b in the crystal structures. The three-dimensional packing of the molecules of 3b produced a zigzag layering projected along the c-axis. Both compounds effectively decreased luminol-dependent chemiluminescence in model systems with KO2-produced superoxide. They displayed opposite effects when applied in a xanthine/xanthine oxidase system. The hydrazones of 5MICA do not trigger a prooxidant effect or subsequent toxicity under conditions of iron-induced oxidative stress. The 3,4-dihydroxy-substituted derivative demonstrated excellent radical scavenging properties in all model systems, making it the lead compound for the development of compounds with combined neuroprotective and antioxidant properties.

3-(4-methoxyphenyl) acrylic acid halts redox imbalance and modulate purinergic enzyme activity in iron-induced testicular injury

Abstract Various derivatives of cinnamic acid have been reported to possess significant activities such as antioxidant and hepatoprotective, and neuroprotective activities. Interestingly, testicular toxicity has been linked to several causes, with oxidative damage being one of the pathophysiological mechanisms. 3-(4-methoxyphenyl) acrylic acid (1), a derivative of cinnamic acid, was synthesized and then investigated for its effects on iron-induced testicular injury and oxidative stress via ex vivo and in silico studies, respectively. Evaluations were done on KAD-1’s FRAP, DPPH free radical scavenging activity, and iron chelating potential. Through the ex vivo incubation of tissue supernatant and 0.1 mM FeSO4 for 30 min at 37 °C with different concentration of 1, oxidative testicular damage treatments were induced. The scavenging property of 1 increases significantly (p < 0.05) as the concentration increases when compared with the standard quercetin. The MDA, CAT, ATPase, and ENTPDase activities were reduced when testicular damage was induced (p < 0.05). The group treated with 30 mg/mL had the highest level of MDA. A significant rise in GSH level and activity of SOD were observed. The result obtained indicated that 1 has the potential to prevent oxidative testicular toxicity, as evidenced by its capacity to control nucleotide hydrolysis and reduce oxidative stress. Overall, the results of this experimental study point to some possible uses of 3-(4-methoxyphenyl) acrylic acid (1) in the prevention of oxidative testicular dysfunction. Therefore, 3-(4-methoxyphenyl) acrylic acid (1) would be a good product in developing a medication to alleviate male infertility.

Abstract A014: Role of stromal CD10 expression in progression of endometrial and endometriosis-associated cancers

Abstract Endometriosis-associated carcinomas (EACs) and endometrial malignancies have many commonalities yet their pathophysiology, particularly those with high-risk histology such as clear cell, is understudied. EACs are histologically and clinically distinct from other gynecological cancers due to their unique origin within endometriosis. The endometriotic microenvironment is uniquely hypoxic with high levels of iron due to recurrent menstrual cycling, and this iron-rich microenvironment has been linked to promoting carcinogenesis through iron-induced oxidative stress. However, the mechanism by which the endometriotic microenvironment contributes to EAC tumorigenesis and how this compares with endometrial cancer is unknown. Most of our current knowledge of EACs is built on either epidemiologic analyses or correlative studies. Additionally, most studies of the endometriotic microenvironment primarily focus on the epithelial component while the role of the stroma has been largely unexplored. Mesenchymal stem cells (MSC) are a critical component of the stromal microenvironment. Recently, we identified a key role of endometriosis derived MSCs (enMSCs) in altering ovarian clear cell carcinoma iron regulation. Interestingly, enMSCs resemble the primary endometrium derived MSCs, which suggested their role in endometrial cancer. This stromal subset is characterized by the loss of surface CD10 expression. It is known that cancer cells, particularly clear cell carcinoma (CCC), have a unique requirement for high levels of iron. We hypothesize that CD10 negative enMSCs promote growth of EAC and endometrial cancer through iron regulation. MSCs were isolated from primary human benign endometriosis, benign endometrium, or endometrial cancer. Flow cytometry was used to measure surface CD10 expression. We investigated the role of CD10 negative enMSCs on CCC iron regulation. Our results showed that CD10 negative enMSCs promote CCC growth by exporting iron through the upregulation of Hephaestin (HEPH) and Ferroportin (FPO) which then led to increase labile iron pool (LIP) in CCC cells. However, increasing the LIP does not occur with iron supplementation alone, this indicates the critical role of CD10 negative enMSCs in regulating iron handling in CCC cells. Additionally, our data showed that CD10 negative enMSCs alter the balance of Ferritin L and Ferritin H- the main iron storage proteins- in CCC cells. Mechanistically, our preliminary data showed that CD10 negative enMSCs directly donate Ferritin L into CCC cells. Further, CD10 negative enMSCs enhance Ferritin H degradation through the upregulation of ferritinophagy in CCC cells. In conclusion, our results indicate there is a sub-population of enMSCs, marked by the loss of CD10 expression, that enhances EAC and endometrial cancer cell growth through iron regulation. This highlights the existence of a tumor-promoting stromal cell within both the endometrium and endometriosis which can be capitalized on as an “Achilles' heel” to uncover novel treatment targets for EAC and endometrial cancer. Citation Format: Huda I. Atiya, Lan G. Coffman. Role of stromal CD10 expression in progression of endometrial and endometriosis-associated cancers [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr A014.

Abstract TMP114: The Role of Iron Mediated Oxidative Stress and Lipid Peroxidation in the Development of Intracranial Aneurysm Rupture

Introduction: Iron is an essential element for vascular wall maintenance. However, iron deposition in the vascular wall may cause oxidative stress, which can attack DNA, proteins, and lipid membranes via the Fenton/Haber-Weiss reaction. Iron-induced oxidative stress triggers lipid oxidation, inflammation, endothelial cell activation and intracranial aneurysmal formation, growth, and rupture. Subarachnoid hemorrhage from intracranial aneurysm rupture results in significant morbidity and mortality. This study used a mouse model of intracranial aneurysm to evaluate the effect of dietary iron restriction on aneurysm formation and rupture. Methods: Intracranial aneurysms were induced using deoxycorticosterone acetate-salt-induced hypertension and a single injection of elastase into the cerebrospinal fluid of the basal cistern. Mice were fed an iron-restricted diet or a normal diet. Aneurysm rupture was detected by neurological symptoms, while the presence of intracranial aneurysm with subarachnoid hemorrhage was confirmed by post-mortem examination. Results: The aneurysmal rupture rate was significantly lower in iron-restricted diet mice (37%) compared with normal diet mice (76%; p < 0.05). Serum oxidative stress, iron accumulation, macrophage infiltration, and 8-hydroxy-2′-deoxyguanosine in the vascular wall were lower in iron-restricted diet mice ( p < 0.01). The areas of iron positivity were similar to the areas of CD68 positivity and 8-hydroxy-2′-deoxyguanosine in both normal diet and iron-restricted diet mice aneurysms. Conclusions: Compared with a normal diet, an iron-restricted diet reduced the incidence of intracranial aneurysmal rupture in mice via inhibition of iron accumulation in the aneurysmal wall. Iron may be a potential therapeutic target to prevent intracranial aneurysm rupture. Long-term iron restriction may be required to affect aneurysm formationrupture.

The Effect of Oral Iron Chelator Deferiprone on Iron Overload and Oxidative Stress in Patients with Myelodysplastic Syndromes: A Study by the Israeli MDS Working Group

Background: Most patients with lower risk myelodysplastic neoplasms or syndromes (MDSs) become RBC transfusion-dependent, resulting in iron overload, which is associated with an increased oxidative stress state. Iron-chelation therapy is applied to attenuate the toxic effects of this state. Deferiprone (DFP) is an oral iron chelator, which is not commonly used in this patient population, due to safety concerns, mainly agranulocytosis. The purpose of this study was to assess the effect of DFP, on oxidative stress parameters in iron-overloaded RBC transfusion-dependent patients with lower risk MDSs. Methods: Adult lower risk MDS patients with a cumulative transfusion burden of >20 red blood cell units and evidence of iron overload (serum ferritin >1,000 ng/mL) were included in this study. DFP was administered (100 mg/kg/day) for 4 months. Blood samples for oxidative stress parameters and iron overload parameters were done at baseline and monthly: reactive oxygen species (ROS), phosphatidylserine, reduced glutathione, membrane lipid peroxidation, serum ferritin, and cellular labile iron pool. The primary efficacy variable was ROS. Tolerability and side effects were recorded as well. A paired t test was applied for statistical analyses. Results: Eighteen patients were treated with DFP. ROS significantly decreased in all cell lineages: median decrease of 58.6% in RBC, 33.3% in PMN, and 39.8% in platelets (p < 0.01 for all). Other oxidative stress markers improved: phosphatidylserine decreased by 57.95%, lipid peroxidase decreased by 141.3%, and reduced gluthathione increased by 72.8% (p < 0.01 for all). The iron-overload marker and cellular labile iron pool decreased by 35% in RBCs, 44.3% in PMN, and 46.3% in platelets (p < 0.01 for all). No significant changes were observed in SF levels. There were no events of agranulocytosis. All AEs were grades 1–2. Conclusions: Herein, we showed preliminary evidence that DFP decreases iron-induced oxidative stress in MDS patients with a good tolerability profile (albeit a short follow-up period). No cases of severe neutropenia or agranulocytosis were reported. The future challenge is to prove that reduction in iron toxicity will eventually be translated into a clinically meaningful improvement.

Sonneratia apetala (Buch.-Ham.) Fruit Extracts Ameliorate Iron Overload and Iron-Induced Oxidative Stress in Mice.

Iron overload results in oxidative damage to various biomolecules including DNA, proteins and lipids which ultimately leads to cell death. The Sonneratia apetala fruit contains a high content of antioxidants and displays several bioactive properties. Therefore, the powder of the S. apetala fruit was successively fractionated into n-hexane (Hex), chloroform (Chl), and methanol (Met) fractions to evaluate their efficiency in ameliorating iron overload. In vitro, a colorimetric method was used to assess the Fe-chelating activity of the fractions using ferrozine. The fractions were also used in vivo to examine their efficacy in ameliorating iron overload and iron-induced oxidative stress in mice induced by intraperitoneal injection of ferric carboxymaltose at 100 mg/kg body weight (bw). Among the fractions, Met showed the highest Fe-chelation ability with an inhibitory concentration 50 of 165 μg/mL followed by Hex (270 μg/mL), and Chl (418 μg/mL). In vivo, the results showed a significantly (P<0.05) lower iron profile (iron and ferritin concentrations in serum and liver tissue and total iron-binding capacity of serum) in the Met and the Hex treated mice groups than in the iron-overloaded group. Met at 1,000 μg/kg bw completely ameliorated iron overload in the blood and the liver tissue of mice. At this concentration, Met also prevented iron-induced oxidative stress in the liver tissue of iron-overloaded mice by restoring reducing power, total antioxidant capacity, and total protein. Thus, the S. apetala fruit, especially its Met fraction can be used in treating iron overload and associated toxicity.

Kaempferol stimulation of autophagy regulates the ferroptosis under the oxidative stress as mediated with AMP-activated protein kinase

Recent studies have highlighted the positive effects of Kaempferol (KP), including its anti-inflammatory and antioxidant properties. However, its impact on oxidative damage induced by heavy metals and pro-inflammatory mediators, such as arachidonic acid (AA), has not yet been identified. Our objective was to specifically evaluate liver damage due to AA + iron-induced oxidative stress, both in vitro and in vivo. In HepG2 cells, KP activated the AMP-activated protein kinase (AMPK), suggesting a hepatoprotective effect through AMPK inhibition, as assessed by immunoblot and FACS analysis (EC50 = 10 μM). KP also stimulated autophagy, a degradation process that eliminates aged, damaged, and unnecessary components, via mTOR inhibition and ULK1 phosphorylation. This activation was further validated by the upregulation of autophagy-related genes (ATG5) and Beclin-1, along with the conversion of LC3BI to LC3BII. Ferroptosis, a non-apoptotic type of cell death characterized by oxidative stress from the production of reactive oxygen species (ROS) and excessive iron accumulation, was linked to the activation of autophagy, as confirmed through the protein expression of deferoxamine (DFO) and ferrostatin-1 (Fer-1), the representative ferroptosis inhibitors (positive controls). In mice, oral administration of KP demonstrated protective effects against CCl4-induced hepatotoxicity. In conclusion, KP provides hepatoprotective effects against oxidative stress induced by AA + iron treatment in vitro and CCl4 treatment in vivo.

Antioxidant Effects of Argan Oil and Olive Oil against Iron-Induced Oxidative Stress: In Vivo and In Vitro Approaches.

Recently, the study of the protective powers of medicinal plants has become the focus of several studies. Attention has been focused on the identification of new molecules with antioxidant and chelating properties to counter reactive oxygen species (ROS) involved as key elements in several pathologies. Considerable attention is given to argan oil (AO) and olive oil (OO) due to their particular composition and preventive properties. Our study aimed to determine the content of AO and OO on phenolic compounds, chlorophylls, and carotenoid pigments and their antioxidant potential by FRAP and DPPH tests. Thus, several metallic elements can induce oxidative stress, as a consequence of the formation of ROS. Iron is one of these metal ions, which participates in the generation of free radicals, especially OH from H2O2 via the Fenton reaction, initiating oxidative stress. To study the antioxidant potential of AO and OO, we evaluated their preventives effects against oxidative stress induced by ferrous sulfate (FeSO4) in the protozoan Tetrahymena pyriformis and mice. Then, we evaluated the activities of the enzymatic (superoxide dismutase (SOD), glutathione peroxidase (GPx)) and metabolite markers (lipid peroxidation (MDA) and glutathione (GSH)) of the antioxidant balance. The results of the antioxidant compounds show that both oils contain phenolic compounds and pigments. Moreover, AO and OO exhibit antioxidant potential across FRAP and DPPH assays. On the other hand, the results in Tetrahymena pyriformis and mice show a variation in the level of iron-changed SOD and GPx activities and MDA and GSH levels. By contrast, treating Tetrahymena pyriformis and mice with argan and olive oils shows significant prevention in the SOD and GPx activities. These results reveal that the iron-changed ROS imbalance can be counteracted by AO and OO, which is probably related to their composition, especially their high content of polyphenols, sterols, and tocopherols, which is underlined by their antioxidant activities.

Ferulic acid protects HepG2 cells and mouse liver from iron-induced damage

Liver as iron storage organ is particularly susceptible to oxidative stress-induced injury from excess iron. Thus, antioxidant therapies are often used to reverse oxidative damage and protect cells and tissues. This study investigated the protective effects of phenolic acids; ferulic acid (FA) and its metabolite, ferulic acid 4-O-sulfate disodium salt (FAS) against oxidative stress under iron overload conditions in mouse and HepG2 cells. Cells were exposed to FA or FAS and then treated with iron-induced oxidative stress complex of 50 μmol/L FAC and 20 μmol/L of 8-hydroxyquinoline 8HQ (8HQ-FAC). Iron dextran was injected intraperitoneally on alternate days for 10 days to induce the iron overload condition in BALB/c mice. The study revealed that the phenolic acids were protective against ROS production, lipid peroxidation and antioxidant depletion in HepG2 cells and liver tissues of BALB/c mice during iron-induced oxidative stress. The protective function of phenolic acids was achieved by the transcriptional activation of nuclear factor erythroid-2-related factor 2 (Nrf2) to regulate antioxidant genes. In conclusion, the study provides evidence that FA has the potential as a therapeutic agent against iron-related diseases such as T2D.

Effect of iron on rat serum melatonin levels under different light/dark cycle patterns

Exposure to constant light or darkness for long periods has diverse effects on circadian physiology. Iron (Fe) overloading promotes oxidative stress and causes alterations in cellular structure and function in animals and humans. The aim of this study is to evaluate the interactions among serum melatonin (ML), photoperiod manipulation, and Fe overloading in rats. The results showed that constant darkness exposure for 15 days significantly increased serum ML levels (up to 22%) while the constant light exposure failed to reduce the serum ML level compared to the normal light/dark cycle treated rats. The lost serum ML level usually from the pineal gland under the long term of constant light exposure may be compensated by ML generated by other organs which adapted to the situation. Also, Fe overloading decreased ML production due to this molecule being consumed to scavenge the free radicals induced by the Fe overloading. In addition, we observed interactions among constant light or darkness exposure, Fe overloading and serum ML level. Overall, our results support the hypothesis of ML as scavenging molecule; it may be an effective therapeutic tool in iron-induced oxidative stress.

Heme-deficient primitive red blood cells induce HSPC ferroptosis by altering iron homeostasis during zebrafish embryogenesis.

The crosstalk between hematopoietic lineages is important for developmental hematopoiesis. However, the role of primitive red blood cells (RBCs) in the formation of definitive hematopoietic stem and progenitor cells (HSPCs) is largely unknown. Primitive RBC deficiencies in mammals always lead to early embryonic lethality, but zebrafish lines with RBC deficiencies can survive to larval stage. By taking advantage of a zebrafish model, we find that the survival of nascent HSPCs is impaired in alas2- or alad-deficient embryos with aberrant heme biosynthesis in RBCs. Heme-deficient primitive RBCs induce ferroptosis of HSPCs through the disruption of iron homeostasis. Mechanistically, heme-deficient primitive RBCs cause blood iron-overload via Slc40a1, and an HSPC iron sensor, Tfr1b, mediates excessive iron absorption. Thus, iron-induced oxidative stress stimulates the lipid peroxidation, which directly leads to HSPC ferroptosis. Anti-ferroptotic treatments efficiently reverse HSPC defects in alas2 or alad mutants. HSPC transplantation assay reveals that the attenuated erythroid reconstitution efficiency may result from the ferroptosis of erythrocyte-biased HSPCs. Together, these results illustrate that heme-deficient primitive RBCs are detrimental to HSPC production and may provide potential implications for iron dysregulation-induced hematological malignancies.

Effect of diabetic macular oedema on serum iron status indicators

ABSTRACT Clinical relevance The role of subclinical inflammation in the pathophysiology of diabetic macular oedema (DME), which is known to be quite complex, is of much interest. Serum ferritin level, which is an indicator of body iron stores, is both an inflammatory marker for various neurodegenerative diseases and an important indicator in the evaluation of iron-induced oxidative stress. Background Iron metabolism indicators play a role in the formation and development of diabetic retinopathy, which is known to be associated with subclinical inflammation, and may also play a role in the pathogenesis of DME. The aim of this study was to investigate the role of serum iron metabolism markers in the pathogenesis of DME. Materials and methods The files of all nonproliferative diabetic retinopathy (NPDR) patients who were scheduled for the first intravitreal injection for DME in the eye clinic between January 2019 and January 2020 were reviewed retrospectively. By examining the files of all diabetes mellitus patients who attended the outpatient eye clinic on the same dates, those without retinopathy and those with NPDR but not DME were recorded. All results, including a comprehensive ophthalmological examination, laboratory data of fasting blood tests, and an internal medicine outpatient examination were collected for analysis. Results Of the 157 participants, 44 were NPDR patients with oedema, 50 were NPDR patients without oedema, and 63 were patients without retinopathy. There was a significant difference between the groups in respect of creatinine, high-density lipoprotein, mean corpuscular volume, serum iron and ferritin, total iron binding capacity and transferrin saturation (p < 0.050). Ferritin values were found to be significantly higher in patients with macular oedema. Other iron status markers were found to be significantly lower (p < 0.050). Conclusion Evaluation of serum iron status indicators in the routine follow-up of diabetic patients may be of diagnostic and/or prognostic benefit in terms of DME.

The expression of ceruloplasmin in astrocytes is essential for postnatal myelination and myelin maintenance in the adult brain.

Ceruloplasmin (Cp) is a ferroxidase enzyme that is essential for cell iron efflux. The absence of this protein in humans and rodents produces progressive neurodegeneration with brain iron accumulation. Astrocytes express high levels of Cp and iron efflux from these cells has been shown to be central for oligodendrocyte maturation and myelination. To explore the role of astrocytic Cp in brain development and aging we generated a specific conditional KO mouse for Cp in astrocytes (Cp cKO). Deletion of Cp in astrocytes during the first postnatal week induced hypomyelination and a significant delay in oligodendrocyte maturation. This abnormal myelin synthesis was exacerbated throughout the first two postnatal months and accompanied by a reduction in oligodendrocyte iron content, as well as an increase in brain oxidative stress. In contrast to young animals, deletion of astrocytic Cp at 8 months of age engendered iron accumulation in several brain areas and neurodegeneration in cortical regions. Aged Cp cKO mice also showed myelin loss and oxidative stress in oligodendrocytes and neurons, and at 18 months of age, developed abnormal behavioral profiles, including deficits in locomotion and short-term memory. In summary, our results demonstrate that iron efflux-mediated by astrocytic Cp-is essential for both early oligodendrocyte maturation and myelin integrity in the mature brain. Additionally, our data suggest that astrocytic Cp activity is central to prevent iron accumulation and iron-induced oxidative stress in the aging CNS.