Iron-overloaded Rats Research Articles

Blockade of angiotensin AT1 receptors prevents arterial remodelling and stiffening in iron-overloaded rats.

Damage to the vasculature caused by chronic iron-overload in both humans and animal models, is characterized by endothelial dysfunction and reduced compliance. In vitro, blockade of the angiotensin II AT1 receptors reversed functional vascular changes induced by chronic iron-overload. In this study, the effect of chronic AT1 receptor blockade on aorta stiffening was assessed in iron-overloaded rats. Male Wistar rats were treated for 15 days with saline as control group, iron dextran 200 mg·kg-1 ·day-1 , 5 days a week (iron-overload group), losartan (20 mg·kg-1 ·day-1 in drinking water), and iron dextran plus losartan. Mechanical properties of the aorta were assessed in vivo. In vitro, aortic geometry and biochemical composition were assessed with morphometric and histological methods. Thoracoabdominal aortic pulse wave velocity (PWV) increased significantly, indicating a decrease in aortic compliance. Co-treatment with losartan prevented changes on PWV, β-index, and elastic modulus in iron-overloaded rats. This iron-related increase in PWV was not related to changes in aortic geometry and wall stress. but to increased elastic modulus/wall stress ratio, suggesting that a change in the composition of the wall was responsible for the stiffness. Losartan treatment also ameliorated the increase in aorta collagen content of the iron-overload group, without affecting circulating iron or vascular deposits. Losartan prevented the structural and functional indices of aortic stiffness in iron-overloaded rats, implying that inhibition of the renin-angiotensin system would limit the vascular remodelling in chronic iron-overload.

Krill oil alleviates oxidative stress, iron accumulation and fibrosis in the liver and spleen of iron-overload rats.

Krill oil (KO) is a recent supplement which is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These fatty acids are found in both krill oil and fish oil. In krill oil, they esterified to phospholipids, but in fish oil, they are esterified to triacylglycerols. The target of this study was to investigate whether KO could help against iron overload-induced toxicity in liver and spleen. Rats were randomly assigned into 3 categories: control rats, rats received iron in a drinking water for 8 weeks followed by either vehicle or KO (40 mg/kg) treatment for an extra 8 weeks. Extent of hepatic and splenic injury was assessed via biochemical, histopathological and immunohistochemical evaluations. KO effectively improved the microscopic features of liver and spleen. Moreover, it decreased the increased levels of serum transaminases, ALP, LDH, iron, and ferritin and increased albumin serum level as well. In addition, it restored the balance between oxidants and antioxidants in the hepatic and splenic tissues. Furthermore, it decreased HO-1 levels, upregulated the production of Nrf2, and limited the expression of MMP9. These findings altogether suggest that KO might be a new candidate for treatment of iron overload-induced toxicity. Graphical abstract Graphical abstract.

Renal clearable nanochelators for iron overload therapy

Iron chelators have been widely used to remove excess toxic iron from patients with secondary iron overload. However, small molecule-based iron chelators can cause adverse side effects such as infection, gastrointestinal bleeding, kidney failure, and liver fibrosis. Here we report renal clearable nanochelators for iron overload disorders. First, after a singledose intravenous injection, the nanochelator shows favorable pharmacokinetic properties, such as kidney-specific biodistribution and rapid renal excretion (>80% injected dose in 4 h), compared to native deferoxamine (DFO). Second, subcutaneous (SC) administration of nanochelators improves pharmacodynamics, as evidenced by a 7-fold increase in efficiency of urinary iron excretion compared to intravenous injection. Third, daily SC injections of the nanochelator for 5 days to iron overload mice and rats decrease iron levels in serum and liver. Furthermore, the nanochelator significantly reduces kidney damage caused by iron overload without demonstrating DFO’s own nephrotoxicity. This renal clearable nanochelator provides enhanced efficacy and safety.

Renoprotective Effects of Alpha Lipoic Acid on Iron Overload-Induced Kidney Injury in Rats by Suppressing NADPH Oxidase 4 and p38 MAPK Signaling.

We aimed to investigate the protective effect of alpha lipoic acid (ALA), a powerful antioxidant, against oxidative kidney damage induced by iron overload in rats. Male Wistar albino rats were separated into groups: control (n = 7), ALA (100mg/kg (n = 7), iron sucrose (IS) (40mg/kg) (n = 7), and IS + ALA (40mg/kg IS administration followed by 100mg/kg ALA) (n = 7). IS and ALA were injected weekly for 4weeks via the tail vein. Blood and kidneys were collected at sacrification on day 29. Serum creatinine and iron levels were analyzed. Tubular injury and iron deposits were evaluated histopathologically. Additionally, iron, malondialdehyde (MDA), superoxide dismutase (SOD), catalase, and glutathione (GSH) levels and mRNA expressions of the subunits of NADPH oxidase, known as NOX4 and p22phox, tumor necrosis factor (TNF)-α, kidney injury molecule-1 (KIM-1), and also p38 MAPK signaling in the kidneys, were evaluated biochemically. In the IS group, serum creatinine and iron level, tubular dilation, and loss of brush border in the kidneys were significantly higher than those of the control. Although those changes were reduced by ALA, the differences were not statistically significant. However, ALA reduced significantly MDA level and increased SOD activity in the kidney during IS administration. ALA also significantly reduced mRNA expressions of NOX4 and p22phox induced by IS, which was parallel to significant decreases of TNF-α and KIM-1 mRNA expressions. Moreover, ALA could suppress the activation of p38 MAPK during IS administration. In conclusion, ALA may be an effective strategy to attenuate in IS-induced oxidative kidney injury.

Iron-induced oxidative stress contributes to α-synuclein phosphorylation and up-regulation via polo-like kinase 2 and casein kinase 2

α-Synuclein plays a central role in synucleinopathies pathogenesis such as Parkinson's disease (PD). Phosphorylation is the most common and important protein modification linked to α-synuclein pathologies. There is mounting evidence suggested iron and α-synuclein are closely related in PD. We previously reported iron up-regulated α-synuclein mRNA levels and induced α-synuclein aggregation. In the present study, we aimed to investigate whether and how phosphorylation was involved in iron-induced α-synuclein regulations. The results showed that iron could induce pS129 α-synuclein (phosphorylation at Ser129) and α-synuclein upregulation in the substantia nigra of iron-overloaded rats and iron-treated SH-SY5Y cells, accompanied by the elevated levels of polo-like kinase 2 (PLK2) and casein kinase 2 (CK2). Over-expression of CK2 or PLK2 induced pS129 α-synuclein up-regulation and inhibitors of CK2 or PLK2 could suppress iron-induced α-synuclein phosphorylation. Antioxidant NAC could fully block iron-induced upregulation of CK2, PLK2 and pS129 α-synuclein levels, indicating oxidative stress plays a critical role in iron-induced α-synuclein phosphorylation. However, iron-induced α-synuclein up-regulation could only be partially blocked by CK2/PLK2 inhibitor or NAC. These findings demonstrate that iron-induced oxidative stress is largely responsible for α-synuclein phosphorylation and upregulation via CK2 and PLK2, and α-synuclein upregulation is not fully phosphorylation-dependent.

Mangiferin and mangiferin-containing leaf extract from Mangifera foetida L for therapeutic attenuation of experimentally induced iron overload in a rat model

Introduction: Thalassemia is a hereditary anemia usually treated with regular blood transfusions, which can result in elevated levels of total iron in the body. As soon as the capacity of iron-regulating proteins (e.g., ferritin, transferrin) are used up, free plasma iron increases generating reactive oxygen species (ROS), leading to oxidative stress. Hence, blood transfusions should be accompanied by iron-chelating therapy, e.g., deferiprone (DFP). The purpose of this study was to evaluate the effect of mangiferin (M) and an aqueous leaf extract of Mangifera foetida L (EMF) as alternative iron-chelating antioxidants in an animal model. Methods: Thirty male Sprague Dawley rats were randomly divided into 5 equal groups: normal control, iron overload (IO), IO+DFP, IO+M, and IO+EMF. Iron overload was induced by intraperitoneal iron dextran injection with a total dose of 90 mg/mouse (15 mg Fe/mouse every 3-4 days for 3 weeks) followed by oral administration of DFP 462.5 mg/kg, mangiferin 75 mg/kg, or EMF 2.930 g/kg for 7 days. Results: Body weight (BW) increased in all groups during the 4 weeks of experiment, except for the IO group. As expected, DFP decreased significantly the total plasma iron and increased iron excretion via urine in iron-overloaded rats (positive control), mangiferin and EMF had similar – although slightly smaller – effects than DFP. The antioxidant activity of M and EMF were stronger compared to DFP as determined by plasma superoxide dismutase (SOD) activity. Conclusion: Mangiferin and EMF have iron-chelating and antioxidant effects and might be used for the treatment of iron overload in the body.

Exenatide reduces oxidative stress and cell death in testis in iron overload rat model.

Glucagon-like peptide-1 (GLP-1) has been demonstrated to affect the oxidative stress status in several in vitro, in vivo and clinical studies. The aim of the present study was to evaluate the effect of a GLP-1 analogue, exenatide, on oxidative stress parameters and apoptotic markers in testicular cells in an iron overload rat model. To obtain this model, the animals were randomly divided into three groups (n=6/group). Rats in the control group received intraperitoneal injections of saline. Intraperitoneal iron dextran (60 mg/kg/day) was given to Group FE for 5 days a week for 4 weeks. The third group (Group Fe +E) was given subcutaneous injections of 10 µg/kg exenatide in two divided doses for 4 weeks in addition to iron dextran. Testes of all rats were immediately removed for immunohistochemical staining and to measure the malondialdehyde level and superoxide dismutase enzyme activity. A significant reduction was observed in caspase-8 and −3 enzyme staining in testicular stromal and endothelial cells in exenatide injected iron overloaded rats when compared with controls. Oxidative stress markers malondialdehyde levels and superoxide dismutase enzyme activities were also significantly lower in exenatide-injected rats when compared with controls. These findings indicate that exenatide may be protective against the harmful effects of iron accumulation in testis. Further studies are required to evaluate how exenatide reduces oxidative stress and cell death in iron overloaded testis tissue.

Hepcidin Attenuates the Secondary Neuronal Injury after Intracerebral Hemorrhage in Rats

Iron plays a key role in secondary neuronal injury after intracerebral hemorrhage (ICH), and hepcidin is able to reduce brain iron in iron-overloaded rats by down-regulating iron transport proteins. These led us to hypothesize that hepcidin might reduce iron-mediated neurotoxicity by inhibiting iron accumulation in ICH brain. Here, we tested our hypothesis in 510 rats and demonstrated for the first time that hepcidin could significantly suppress the ICH-induced increase in iron and ferritin in brain tissues and cerebrospinal fluid by inhibiting expression of iron transport proteins, increase neuronal survival by attenuating ICH-induced apoptosis, neurodegeneration and brain edema, as well as effectively improve ICH-induced behavioral and cognitive deficit in rats. We concluded that hepcidin could effectively attenuate iron-mediated secondary neuronal injury after ICH in rats. This naturally existing protein which is biodegradable, nontoxic, and non-immunogenic can potentially be developed into a therapeutic drug for the treatment of ICH patients. Funding: The studies were supported by the National Natural Science Foundation of China (NSFC31330035-ZMQ, NSFC31571195-ZMQ), the Competitive Earmarked Grants of The Hong Kong Research Grants Council (GRF14111815-KY, GRF 14167817-KY, GRF14107616-KY), Hong Kong Health & Medical Research Fund (HMRF: 03141436-KY), Hong Kong Innovation and Technology Fund (ITS/163/16-KY), and the National 973 Programs (2014CB541604-ZMQ). Conflict of interest: The authors declare that they have no conflict of interest. Ethical Approval Statement: The Health Department of Hong Kong and Shanghai Government and the Animal Research Ethics Committee of The Chinese University of Hong Kong and Fudan University approved the experimental procedures of this study and the care and handling of the animals were in accord with National Institutes of Health guidelines.

Chronic iron overload induces vascular dysfunction in resistance pulmonary arteries associated with right ventricular remodeling in rats

Although iron excess is toxic to the vasculature and even that pulmonary hypertension has been reported in this scenario, the role of iron overload per se remains to be clarified. This study aimed to test the effects of chronic iron-overload in rats on the morphophysiology of resistance pulmonary arteries (RPA) and right ventricle (RV) remodeling. Rats were injected with saline or iron-dextran (10, 100 and 200 mg/kg/day i.p.) for 28 days. Our results indicated increased circulating iron with significant lung deposits. Moreover, rats treated with the highest dose exhibited RV dysfunction and hypertrophy; inward remodeling and increased vasoconstriction of the RPA. Vascular hyperreactivity was accompanied by reduced nitric oxide (NO), and was reversed by incubation with Dimethylsulfoxide, Catalase and Tempol. The NADPH oxidase subunit gp91phox was increased due to iron-overload, and incubation with angiotensin II type-1 receptor (AT1) antagonist losartan not only reduced oxidative stress but also restored vascular function. Thus, we concluded that AT1 pathway plays a role in pulmonary vascular dysfunction by increasing oxidative stress and reducing NO bioavailability, thereby contributing to vascular remodeling and pulmonary hypertension of iron-overload. This finding should instigate future studies on the beneficial impacts of in vivo blockade of AT1 receptor under iron overload.

The Effects of Chronic Iron Overload in Rats with Acute Acetaminophen Overdose.

Rats are resistant to acetaminophen (APAP) hepatotoxicity. In this study, we evaluated whether by augmentation of the hepatic oxidative stress, through the induction of hepatic iron overload (IO), it will be feasible to overcome the resistance of rats to the toxic effects of APAP. Rats with no or increased hepatic IO. Providing iron by diet induced hepatocellular IO, while parenteral iron administration induced combined hepatocellular and sinusoidal cell IO. APAP administration to rats with no IO caused an increase in hepatic oxidative stress and a decrease in the hepatic antioxidative markers but no hepatic cell damage. APAP administration to rats with hepatocellular IO further amplified the hepatic oxidative stress but induced only hepatocyte feathery degeneration without any increase in serum aminotransaminases. APAP administration to rats with combined hepatocellular and sinusoidal cell IO caused an unexpected decrease in hepatic oxidative stress and increase in the hepatic antioxidative markers and no hepatic cell damage. No hepatic expression of activated c-jun-N-terminal kinase was detected in any of the rats. The hepatic distribution of iron may affect its oxidative/antioxidative milieu. Augmentation of hepatic oxidative stress did not increase the rats' vulnerability to APAP.

The effect of different digoxin concentrations on heart tissue and antioxidant status in iron-overloaded rats.

BACKGROUNDThalassaemia is a hereditary disorder and has an economic burden on patients and the government. The most prevalent complication in these patients is iron overload which is followed by cardiomyopathy. Digoxin is considered as a treatment against heart failure in thalassaemia. The present study evaluated the effect of two digoxin concentrations on iron content and antioxidative defense in cardiac tissue of iron-overloaded rats.METHODSThe study was conducted on 48 rats which were divided into 6 groups. Group 1 was the control group and did not receive any treatment and group 2 was the iron overload group. In addition groups 3 and 4 were the digoxin control groups which received 1 and 5 mg/kg/day of digoxin, respectively. Groups 5 and 6 received 1 and 5 mg/kg/day of digoxin plus iron-dextran, respectively. After 1 month, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPX), and total antioxidant status (TAS) were assessed in cardiac tissues.RESULTSCo-administration of iron-dextran and digoxin (1 and 5 mg/kg/day) significantly increased SOD and TAS levels (P < 0.0010) and reduced MDA (P < 0.0010) in heart tissue compared to control and iron overload groups. GPX levels significantly reduced in groups 5 and 6 (iron + digoxin 1 (P < 0.0500) and iron + digoxin 5) (P < 0.0010) compared to the iron control group.CONCLUSIONDigoxin remarkably facilitates iron uptake by cardiomyocytes by affecting other channels such as L-type and T-type Ca2+ channels (LTCC and TTCC). Digoxin administration in the iron-overloaded rat model deteriorated antioxidative parameters and increased iron entry into heart tissue at higher doses. Therefore, in patients with beta thalassaemia major, digoxin must be administered with great care and serum iron and ferritin must be regularly monitored.

The role of mangiferin in the prevention of liver Fe accumulation and fibrosis in experimentally induced iron overload in rats

The role of mangiferin in the prevention of liver Fe accumulation and fibrosis in experimentally induced iron overload in rats

A combination of an iron chelator with an antioxidant exerts greater efficacy on cardioprotection than monotherapy in iron-overload thalassemic mice

Many recent studies have shown that antioxidant compounds decrease cardiac oxidative stress, decrease cardiac iron deposition, and improve cardiac dysfunction in iron-overload induced cardiomyopathy in animal models. Interestingly, a therapy including the combination of the iron chelator deferiprone (DFP) plus the antioxidant N-acetylcysteine (NAC) has been shown to significantly decrease oxidative stress and restore heart and brain function in iron-overloaded rats. However, the cardioprotective effects of this combined DFP and NAC treatment in thalassemic mice have not been investigated. We hypothesised that the combination of DFP and NAC exerts better cardioprotection than monotherapy via decreasing cardiac iron accumulation, oxidative stress, and apoptosis in thalassemic mice. The iron-overload condition was induced in heterozygous βKO HT and wild-type mice by instigating high iron diet consumption (FE) for three months. Then, iron chelator DFP (75 mg/kg/day twice a day), antioxidant NAC (100 mg/kg/day once a day), and combined DFP plus NAC were fed via oral gavage for one month with continuous iron feeding. Left ventricular (LV) function, heart rate variability (HRV), apoptosis, and cardiac iron accumulation were determined. Chronic iron-overload in mice led to increased cardiac iron deposition, oxidative stress, apoptosis, and impaired LV function and HRV. Although DFP and NAC showed similar cardioprotective efficacy, combined DFP plus NAC exerted greater efficacy in reducing both cardiac iron deposition and cellular apoptosis than monotherapy. In conclusion, combined iron chelator and NAC treatment exert the greatest cardioprotective efficacy when compared with either of the monotherapies in iron-overload thalassemic mice.

The Effect of Sappan Wood Extract (Caesalpinia sappan), Wheat grass and Vitamin E Treatment on the Liver Structure of Iron overload of Rat (Rattus norvegicus)

This research was carried out to detect the effect of Sappan Wood Extract (Caesalpinia sappan), Wheat grass and Vitamin E Treatment on the liver structure of iron overload rat (Rattus norvegicus).The method of experimental used Completely Random Design (CRD in triple repetition. The treatment had been carried out orally. Iron dextran with total dose of 1.5 g kg-1 of body were given to rat on the first, fourth, seventh, ten and thirteenth day. Sappan Wood Extract (Caesalpinia sappan)200 mg kg-1 bw, 400 mg kg-1 bw, Wheat grass extract 100 mg kg-1 bw and Vitamin E 60 mg kg-1 bw were given to rat everyday for 15 days. At the seventeenth, rat were killed and their liver were taken. The observed parameters are morphological abnormality including the colour, the contour, ratio between liver weight and body weight as well as histological destruction. The result showed iron dextran treatment was proved the abnormality on morphological and histological desruction. Futhermore, Sappan Wood Extract (Caesalpinia sappan), Wheat grass and Vitamin E Treatment can decrease the morphological abnormality and the liver histological destructionon of iron overload rat. Keywords: Sappan Wood Extract, Wheat grass, Vitamin E, Iron, Morphological abnormality, Histological destruction

Green tea activity and iron overload induced molecular fibrogenesis of rat liver.

Iron overload toxicity was shown to associate with chronic liver diseases which lead to hepatic fibrosis and subsequently the progression to cancer through oxidative stress and apoptotic pathways. Green tea potential activity as chelating, anti-oxidative, or anti-apoptotic mechanisms against metal toxicity was poorly clarified. Here, we are trying to evaluate the anti-oxidant and anti-apoptotic properties of green tea in the regulation of serum hepcidin levels, reduction in iron overloads, and improve of liver fibrosis in iron overloaded experimental rats. Three groups of male adult rats were randomly classified into three groups and treated as follows: control rats, iron treated rats for two months in drinking water followed by either vehicle or green tea extract (AGTE; 100 mg/kg) treatment for 2 more months. Thereafter, we studied the effects of AGTE on iron overload-induced lipid peroxidation, anti-oxidant depletion, liver cell injury and apoptosis. Treatment of iron-overloaded rats with AGTE resulted in marked decreases in iron accumulation within liver, depletion in serum ferritin, and hepcidin levels. Iron-overloaded rats had significant increase in malonyldialdehyde (MDA), a marker of lipid peroxidation and nitric oxide (NO) in liver when compared to control group. Also, significant change in cytochrome c and DNA content as apoptotic markers were reported in iron treated rats. The effects of iron overload on lipid peroxidation, NO levels, cytochrome c and DNA content were significantly reduced by the intervention treatment with AGTE (P < 0.001). Furthermore, the endogenous anti-oxidant capacities/levels (TAC) in liver were also significantly decreased in chronic iron overload and administration of AGTE restored the decrease in the hepatic antioxidant activities/levels. Also, hepatic hepcidin was shown to be significantly correlated with oxidative and apoptotic relating biomarkers as well as an improvement in liver fibrosis of iron treated rats following AGTE treatment. In-vitro analysis showed that, the improvement in iron toxicity of the liver depend mainly on antioxidant and protective ability of green tea polyphenolic compounds especiallyepigallocatechin-3-gallate (EGCG). Our study showed that green tea extract (GTE) ameliorates iron overload induced hepatotoxicity, apoptosis and oxidative stress in rat liver via inhibition of hepatic iron accumulation; improve of liver antioxidant capacity, and down regulation of serum hepcidin as well as reduction in the release of apoptotic relating proteins.

Chronic iron overload induces functional and structural vascular changes in small resistance arteries via NADPH oxidase-dependent O2[rad]− production

Iron overload leads to excessive free radical formation and induces cardiovascular dysfunction. Thus, our aim was to investigate the structural and endothelial modulation of vascular tone induced by chronic iron overload in mesenteric arteries. Rats were divided into two groups: the control (vehicle) group and the group treated with iron dextran for 28days (100mg/kg, 5days a week). Chronic iron overload altered the following morpho-physiological parameters of third-order mesenteric resistance arteries: decreased lumen and external diameters; increased wall/lumen ratio and wall thickness; decreased distensibility and increased stiffness; and increased pulse wave velocity. Additionally, iron overload increased the vasoconstrictor response in mesenteric arterial rings in vitro but did not affect the relaxation induced by acetylcholine and sodium nitroprusside. It is suggested that iron overload reduces nitric oxide bioavailability by increasing free radicals, because L-NAME did not shift the concentration-response curve to phenylephrine, but L-NAME plus superoxide dismutase shifted the curve to the left. In vitro assays with DAF-2 and DHE indicated reduced NO production and increased superoxide anion (O2−) generation in the iron-overloaded group. Furthermore, tiron, catalase, apocynin and losartan induced reduced reactivity only in iron-overloaded rats. Moreover, increased ACE activity was observed in the mesenteric resistance arteries of iron-overloaded rats accompanied by an increase in gp91phox, catalase, ERK1/2 and eNOS protein expression. In conclusion, these findings show that chronic iron overload induces structural and functional changes in resistance arteries, most likely due to a decrease in NO bioavailability resulting from an increase in O2− production by NADPH oxidase.

Hepcidin Protects Neuron from Hemin-Mediated Injury by Reducing Iron.

Hemin plays a key role in mediating secondary neuronal injury after intracerebral hemorrhage (ICH) and the cell toxicity of hemin is thought to be due to iron that is liberated when hemin is degraded. In a recent study, we demonstrated the iron regulatory hormone hepcidin reduces brain iron in iron-overloaded rats. Therefore, we hypothesized that hepcidin might be able to reduce iron and then protect neurons from hemin or iron-mediated neurotoxicity in hemin-treated neuronal cells. Here, we tested the hypothesis and demonstrated that ad-hepcidin and hepcidin peptide both have the ability to suppress the hemin-induced increase in LDH release and apoptotic cell numbers, to reduce cell iron and ferritin contents, and to inhibit expression of transferrin receptor 1, divalent metal transporter 1, and ferroportin 1 in hemin-treated neurons. We conclude that hepcidin protects neuron from hemin-mediated injury by reducing iron via inhibition of expression of iron transport proteins.

Evaluation of iron chelating and antioxidant potential of Epilobium hirsutum for the management of iron overload disease.

The present study deals with the investigation of iron chelating and antioxidant potential of Epilobium hirsutum in iron-overloaded rats. Iron overload was induced by 6 IP injections of Iron dextran (12.5mg/100g) administered uniformly over a period of 30 days. Different fractions of E. hirsutum were given orally and deferoxamine (DFO) subcutaneously for 30 days. The extent of iron chelation and various biochemical parameters were estimated on 15th and 30th day of treatment. In-vitro study was assessed by EDTA and DFO method; the results exhibited a dose-dependant iron chelation. The methanolic fraction of methanolic extract (MFME) and methanolic fraction of aqueous extract (MFAE) of E. hirsutum showed significant (p<0.01) iron chelating and antioxidant potential as compared to disease control (DC) rats. The animals treated with MFME and MFAE of E. hirsutum showed significant (p<0.01) vital organ protection as compared to DC rats. The animals treated for longer duration (30th day) reveals better iron chelation potential than shorter ones (15th day). Superior iron chelation was seen at higher dose (300mg/kg) as compared to lower dose (150mg/kg). Taken into an account, our result reveals the reversible iron chelating and antioxidant ability of E. hirsutum and gives some evidence for its possible mechanism via excretion of iron in urine and feces.

Restoring the impaired cardiac calcium homeostasis and cardiac function in iron overload rats by the combined deferiprone and N-acetyl cysteine

Intracellular calcium [Ca2+]i dysregulation plays an important role in the pathophysiology of iron overload cardiomyopathy. Although either iron chelators or antioxidants provide cardioprotection, a comparison of the efficacy of deferoxamine (DFO), deferiprone (DFP), deferasirox (DFX), N-acetyl cysteine (NAC) or a combination of DFP plus NAC on cardiac [Ca2+]i homeostasis in chronic iron overload has never been investigated. Male Wistar rats were fed with either a normal diet or a high iron (HFe) diet for 4 months. At 2 months, HFe rats were divided into 6 groups and treated with either a vehicle, DFO (25 mg/kg/day), DFP (75 mg/kg/day), DFX (20 mg/kg/day), NAC (100 mg/kg/day), or combined DFP plus NAC. At 4 months, the number of cardiac T-type calcium channels was increased, whereas cardiac sarcoplasmic-endoplasmic reticulum Ca2+ ATPase (SERCA) was decreased, leading to cardiac iron overload and impaired cardiac [Ca2+]i homeostasis. All pharmacological interventions restored SERCA levels. Although DFO, DFP, DFX or NAC alone shared similar efficacy in improving cardiac [Ca2+]i homeostasis, only DFP + NAC restored cardiac [Ca2+]i homeostasis, leading to restoring left ventricular function in the HFe-fed rats. Thus, the combined DFP + NAC was more effective than any monotherapy in restoring cardiac [Ca2+]i homeostasis, leading to restored myocardial contractility in iron-overloaded rats.

Chronic iron overload induces gender-dependent changes in iron homeostasis, lipid peroxidation and clinical course of experimental autoimmune encephalomyelitis

To analyze iron- and gender-dependent mechanisms possibly involved in pathogenesis of multiple sclerosis (MS) in this study we evaluated the effects of iron overload (IO) on iron status and lipid peroxidation processes (LPO) in tissues of female and male DA rats during chronic relapsing experimental autoimmune encephalomyelitis, a well-established MS animal model.Rats were treated by iron sucrose (75mg/kg bw/day) or with saline solution during two weeks before the sensitization with bovine brain homogenate in complete Freund's adjuvant. Clinical signs of EAE were monitored during 29 days. Serum and tissues of CNS and liver were sampled before immunization and at day 13th post immunization (during acute phase of EAE). The determination of ferritin, iron, malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) and evaluation of histopathology were performed by ELISA, ICP spectrometry and immunohistochemistry.Results showed that IO in female EAE rats accelerated the onset of disease. In contrast, in male rats it accelerated the progression of disease and increased the mortality rate. During acute phase of EAE female IO rats sequestered more Fe in the liver, spinal cord and in the brain and produced more ferritin than male EAE rats. Male rats, however, reacted on IO by higher production of MDA or 4-HNE in the neural tissues and showed greater signs of plaque formation and gliosis in spinal cord.The data point to sexual dimorphism in mechanisms that regulate peripheral and brain iron homeostasis and imply that men and women during MS might be differentially vulnerable to exogenous iron overload.