The Potential protective role of astaxanthin on doxorubicin-induced cardiac toxicity in rats

Background and Aim of Work Doxorubicin (DOX) is one of the most commonly used effective anticancer drugs, through its inhibition of topoisomerase II, DNA replication and repair. In addition, DOX leads to generation of semiquinone free radicals and oxygen free radicals which attack DNA and oxidize DNA bases. However, the clinical use of doxorubicin is limited by its adverse effects such as cardiotoxicity, which is acute and occurs within 2-3 days of its administration. Recently, the potential health benefits of Astaxanthin were investigated, however, the protective effect of astaxanthin supplementation on cardiac dysfunction induced by Doxorubicin is not clearly investigated. The aim of the present study is directed to investigate the possible role of astaxanthin (xanthophyll carotenoid) in protection against DOX- induced cardiac toxicity, and to elucidate the underlying mechanism(s). Materials and Methods Animals used were 47 adult male albino rats, which were randomly allocated into four groups. Control group(C): received 0.1ml/100gm BW i.p. saline injections for 7 successive days. DOX-treated group: received 0.1ml/100gm BW i.p. saline injections for 7 successive days, followed by a single i.p. injection of DOX, 20 mg/kg i.p. on the 7th day. ATX-treated group: received 40mg/kg/day BW i.p. ATX injections for 7 successive days. ATX+DOX treated group: received 40mg/kg/day BW i.p. ATX injections for 7 successive days, followed by a single i.p. injection of DOX, 20 mg/kg i.p. on the 7th day. At the end of the study, the overnight fasted rats were subjected to final arterial blood pressure measurement. Rats were then weighed and anaesthetized with 40 mg/kg B.W i.p. thiopental sodium. Then, ECG was recorded, blood samples were collected from abdominal aorta and centrifuged. The resulting plasma was used for measurement of plasma cardiac Troponin I (cTnI) and plasma Cytochrome C. The heart was subjected to In vitro study of isolated hearts perfused in langendorff preparation. Hearts and ventricles were weighed. The left ventricle was then stored at -80οC for later determination of cardiac tissue iron. Statistical Analysis was made using 1-way ANOVA for difference between means of different groups. Ethics Committee The study protocol was approved by the Research Ethical Committee of Faculty o fMedicine Ain Shams University (Reference No. FWA00017585). Results The systolic blood pressure was increased significantly in the DOX treated group compared to the control group. All of the systolic, diastolic and mean arterial blood pressures were significantly decreased in the ATX +DOX treated group compared to the DOX treated group. Heart rate was significantly increased in the ATX +DOX treated group compared to the control group, and compared to the DOX treated group. PT and PT/LVW were significantly increased in the ATX +DOX group compared to both of the DOX group and the control group. In addition, PT and PT/LVW were significantly increased in the ATX-treated group compared to the DOX group. The TPT was prolonged in the DOX group compared to the control group and this prolongation was statistically significant in pre-ischemia and 5 minutes after reperfusion of the isolated hearts, and was significantly shortened in the ATX-treated group and ATX +DOX group compared to the DOX. Also, TPT was significantly shortened in the ATX-treated and in the in the ATX +DOX groups compared to the control group. HRT was significantly prolonged in the DOX group compared to the control group. However, HRT was significantly shortened in the ATX-treated and ATX +DOX groups compared to the DOX group, and in the ATX +DOX group compared to the control group. The MFR and MFR/LVW were significantly decreased in the DOX group compared to the control group. However, the MFR was significantly increased in each of the ATX-treated group and ATX +DOX group when each was compared to the DOX group. Moreover, MFR was significantly increased in the ATX +DOX group compared to the control group. Each of plasma cardiac Troponin, plasma Cytochrome C and Cardiac Tissue Iron were significantly increased in the DOX group compared to the control group, and all were significantly decreased in the ATX-treated group when compared to DOX group, and in the ATX +DOX group when compared to the DOX group. No significant changes were detected in body weight, heart weights and ECG parameters between the different studied groups. Conclusion Doxorubicin produces acute cardiotoxic effects and impairs systolic and diastolic cardiac functions, which is due to increased oxidative stress, mitochondrial instability and iron accumulation in the cardiac tissue. Astaxanthin exerts a major cardioprotective activities against DOXinduced cardiotoxicity, probably due to its major antioxidant and iron chelation properties.

An Experimental Model for Iron Deficiency Anemia in Sows and Offspring Induced by Blood Removal during Gestation

Anemia is a common condition in sow herds. We aimed to study the effects of severe iron deficiency during gestation on sow and piglet health outcomes with an experimental model for blood-removal-induced iron deficiency anemia. In total, 18 multiparous sows (8 in trial I and 10 in trial II) were allocated to either a blood removal group or a control group. Hematologic parameters were monitored at regular intervals and the tissue iron concentrations were measured for the sows and newborn piglets after farrowing. In trial I, the mean liver iron content was reduced to 46.7 µg/g in the blood removal sows compared to 252.6 µg/g in the controls (p < 0.001). In trial II, sows in the blood removal group had lower iron content in the liver (147.8 µg/g), kidney (46.3 µg/g) and spleen (326.5 µg/g) compared to the control sows (323.2 µg/g, 81.3 µg/g and 728.9 µg/g, respectively; p = 0.009, 0.016, 0.01, respectively). In trial I, piglets from sows in the blood removal group had significantly decreased hematocrit (Hct), red blood cells (RBC) and a tendency for reduced hemoglobin (Hb) compared to the control piglets. We established a blood removal model that resulted in mild- to severe degrees of sow anemia and reduced tissue iron stores at farrowing.

Biobehavioral correlates of an fMRI index of striatal tissue iron in depressed patients

Dopaminergic function is a critical transdiagnostic neurophysiological dimension with broad relevance in psychiatry. Normalized T2*-weighted (nT2*w) imaging has been previously investigated as a method to quantify biological properties of tissue in the striatum (e.g., tissue iron), providing a widely available, in vivo marker with potential relevance to dopaminergic function; but no prior study to our knowledge has examined this neuroimaging marker in clinical depression. In a treatment-seeking, clinically depressed sample (n = 110), we quantified tissue iron (nT2*w) in striatal regions. We assessed test-retest reliability and correlated values with dimensional features across levels of analysis, including demographic/biological (sex, age, Body Mass Index), neuroanatomical (hippocampal atrophy, which was quantified using a recently validated machine-learning algorithm), and performance-based (Affective Go/NoGo task performance) indices with relevance to depressive neurocognition. Across patients, decreased tissue iron concentration (as indexed by higher nT2*w) in striatal regions correlated with indices of decreased cognitive-affective function on the Affective Go/NoGo task. Greater caudate nT2*w also correlated with greater hippocampal atrophy. Striatal tissue iron concentrations were robustly lower in female patients than males but gender differences did not explain relations with other neurocognitive variables. A widely available fMRI index of striatal tissue properties, which exhibited strong psychometric properties and can be readily quantified from most fMRI datasets irrespective of study-specific features such as task design, showed relevance to multiple biobehavioral markers of pathophysiology in the context of moderate-to-severe, treatment-resistant depression. Striatal tissue iron may play a role in dimensional and subgroup-specific features of depression, with implications for future research on depression heterogeneity.

Biodegradable Zinc Oxide Nanoparticles Doped with Iron as Carriers of Exogenous Iron in the Living Organism

Iron plays an important role in various crucial processes in the body and its deficiency is considered currently as a serious health problem. Thus, iron supplementation strategies for both humans and animals need to be effective and safe. According to our previous studies, zinc-based nanoparticles provide safe, biodegradable, fast and efficient transport system of orally given substances to the tissues. In the current manuscript we present results of a study aimed at investigation of the ZnO nanoparticle-based Fe supplementation system (average size 100 × 250 nm). Nanostructures were orally (gavage) administered to adult mice. Animals were sacrificed at different time points with collection of blood and internal organs for analyses (tissue iron concentration, hepatic level of hepcidin, blood parameters, liver and spleen levels of ferritin, histopathology). Initial experiment was performed to compare the biological effect of doping type (Fe3+ doping vs. a mixture of Fe3+ and Fe2+). Then, the effect of acute/chronic exposure models was determined. The increase in ferritin, along with improved, crucial hematological parameters and lack of the influence on hepcidin expression indicated the chronic application of Fe3+,2+ doped ZnO nanostructures to be the most effective among tested.

Relation Between Tissue Iron Content and Polarization of Macrophages in Diabetic Ulcer and the Transitional Zone of Diabetic Ulcers with Major Amputation

Most diabetic lower-limb amputations probably result from combinations of contributing causes rather than from unitary causes. Iron-induced damage might modulate the development of chronic diabetes complications. In this study, the relationship between tissue iron levels and polarization of macrophages in induction of angiogenesis was investigated in diabetic ulcer samples and the transitional zone of diabetic ulcers. Patients with diabetic ulcers who underwent amputation were included. The transitional zone of diabetic ulcers, from the same diabetic patients, was used as a control group. After tissue preparation, Perls Prussian blue staining and immunohistochemistry for CD11c, CD163, and CD68 markers were done. Vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF), Tie2, and protein kinase B (also known as AKT) transcription of genes were measured by real-time polymerase chain reaction. For statistical analysis, we used independent samples t-test or its nonparametric equivalents, Mann–Whitney U test was used for quantitative variables, and chi-square (or Fisher's exact test) for qualitative variables. According to the results, the ratio of M2 to M1 macrophages was decreased in ulcers tissue compared to the transitional zone of diabetic ulcers. The expression of angiogenesis-related genes was increased due to hypoxia induction such as HIF and VEGF in ulcer tissue ( P < .0001), but the expression of vascular stability-related genes such as Tie2 was decreased ( P < .0001).In amputated diabetic ulcers, the polarization of macrophages is toward the classic type, but no connection was found in terms of tissue iron and help in the polarization of macrophages.

Myeloid specific deletion of ferroportin impairs macrophage bioenergetics but is disconnected from systemic insulin action in adult mice

Tissue iron overload is associated with insulin resistance and mitochondrial dysfunction in rodents and humans; however, the mechanisms or cell types that mediate this phenotype are not completely understood. Macrophages (Mɸ)s are known to contribute to iron handling; thus, we hypothesized that perturbed iron handling by Mɸs impairs mitochondrial energetics and evokes systemic insulin resistance in mice. Male and female mice with myeloid targeted (LysMCre) deletion of the canonical iron exporter, ferroportin (Fpn, encoded by Slc40a1), floxed littermates and C57BL/6J wild-type mice were used to test our hypotheses. Myeloid-targeted deletion of Fpn evoked multi-tissue iron accumulation and reduced mitochondrial respiration in bone marrow-derived Mɸs, liver leukocytes, and Mɸ-enriched populations from adipose tissue (AT). In addition, a single bolus of exogenous iron administered to C57BL/6J mice phenocopied the loss of Fpn, resulting in a reduction in maximal and mitochondrial reserve capacity in Mɸ-enriched cellular fractions from liver and AT. In vivo exogenous iron chelation restored mitochondrial reserve capacity in liver leukocytes from Fpn LysMCre mice, but had no effect in AT myeloid populations. However, despite the impairments in mitochondrial respiration, neither loss of myeloid-specific Fpn, nor exogenous iron overload, perturbed glucose homeostasis or systemic insulin action in lean or obese mice; whereas, aging coupled with lifelong loss of Fpn unmasked glucose intolerance. Together these data demonstrate that iron handling is critical for the maintenance of macrophage mitochondrial function but perturbing myeloid iron flux via the loss of Fpn action is not sufficient to evoke systemic insulin resistance in young adult mice. These findings also suggest that if Mɸs are capable of storing iron properly, they have a pronounced ability to withstand iron excess without evoking overt collateral damage and associated insulin resistance that may be age dependent.

Upregulation of Local Hepcidin Contributes to Iron Accumulation in Alzheimer’s Disease Brains

Background: Accumulation of iron is a consistent feature of Alzheimer’s disease (AD) brains. The underlying cause, however, remains debatable. Objective: To explore whether local hepcidin synthesized by brain cells contributes to iron accumulation in AD brains. Methods: Brain tissue from the cingulate cortex of 33 cases of AD pre-assigned to Braak stage I-VI, 6 cases of non-dementia, and 15 cases of non-AD dementia were analyzed for transcriptional upregulation of hepcidin by RT-qPCR and RT-PCR. Change in the expression of ferritin, ferroportin (Fpn), microglial activation marker Iba1, IL-6, and TGFβ2 was determined by western blotting. Total tissue iron was determined by colorimetry. Results: Significant transcriptional upregulation of hepcidin was observed in Braak stage III-VI relative to Braak stage I and II, non-AD dementia, and non-dementia samples. Ferritin was increased in Braak stage V, and a significant increase in tissue iron was evident in Braak stage III-VI. The expression of Iba1 and IL-6 was also increased in Braak stage III-VI relative to Braak stage I and II and non-AD dementia samples. Amyloid-β plaques were absent in most Braak stage I and II samples, and present in Braak stage III-VI samples with few exceptions. Conclusion: These observations suggest that upregulation of brain hepcidin is mediated by IL-6, a known transcriptional activator of hepcidin. The consequent downregulation of Fpn on neuronal and other cells results in accumulation of iron in AD brains. The increase in hepcidin is disease-specific, and increases with disease progression, implicating AD-specific pathology in the accumulation of iron.