الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
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Abstract
Aloin, a natural anthraquinone glycoside, is derived from the exudates of Aloe vera leaves. It was reported to possess different pharmacological activities, including anti-inflammatory and neuroprotective effects, antimicrobial, antioxidant potential with iron chelating activities and antitumor activity.
Anthracyclines have a high iron chelating activity and interfere with the homeostasis and trafficking of the cellular iron through different molecular mechanisms. Previously, aloin and doxorubicin were reported to induce erythropoiesis impairment demonstrated by the decline in red blood cells count, blood hemoglobin level and altering systemic iron homeostasis.
The current study was undertaken to investigate the impact of repeated aloin treatment on nonheme iron stores and metabolism in adult male rats, compared to doxorubicin as a reference anthracycline compound. Furthermore, the effect of iron supplementation to aloin- or doxorubicin-treated rats on modulation of perturbations in iron homeostasis was assessed.
To achieve the targets of the present study, a total number of 48 adult male Wistar rats were equally divided into six equal groups and had a free access to commercial diet (balanced to contain 35 mg elemental iron /kg diet) and tap water: group I (Control), group II (Fe); rats received a daily oral dose of carbonyl iron (20.56 mg elemental Fe/kg bw) for 2 consecutive weeks, group III (Doxo); rats received 3 i.p. injections of doxorubicin (2.5 mg/kg bw) per week for 2 consecutive weeks, group IV (Aloin); rats received 2 i.m. injections of aloin per week (50 mg/kg bw) for 2 consecutive weeks, group V (Doxo+Fe); rats received a daily oral dose of carbonyl iron (20.56 mg Fe/kg bw) along with 3 i.p. injections of doxorubicin per week for 2 consecutive weeks, and group VI (Aloin+Fe); rats received a daily oral dose of carbonyl iron along with 2 i.m. injections of aloin per week for 2 consecutive weeks.
Results obtained from this study demonstrate the following:
• Treatment of rats with doxorubicin or aloin produced a significantly marked reduction in the final body weights, compared to their initial body weights. Iron supplementation to doxorubicin-treated rats slightly ameliorated the decrease in the final body weight of rats, whereas administration of iron to aloin-treated rats caused a less pronounced decrease in the final body weight of rats, compared to their respective initial body weights.
• Treatment of normal rats with doxorubicin, either alone or with iron supplementation, significantly reduced the relative spleen weight, compared to the normal control group. On the other hand, treatment of normal rats with aloin caused a significant increase in the relative weights of liver, spleen and kidneys. However, iron supplementation to aloin-treated rats normalized the relative weights of the liver, spleen and kidneys.
• Treatment of normal rats with doxorubicin, a myelosuppressive agent, either alone or with iron supplementation showed a sharp immune suppression verified by the significant decrease of WBCs count. By contrast, treatment of normal rats with aloin either alone or with iron supplementation caused an enhanced immune response demonstrated by a significant increase of WBCs count.
• Treatment of male rats with doxorubicin caused a disruption in erythropoiesis and iron homeostasis represented by a marked reduction in red blood cells count, blood hemoglobin level, hematocrit value, serum iron level and percentage of transferrin saturation, whereas total and unsaturated iron binding capacities, were significantly elevated. Co-administration of iron along with doxorubicin demonstrated a significantly persistent decrease of red blood cell counts, hemoglobin concentration, as well as unsaturated iron binding capacity, whereas a dramatic increase of serum iron and transferrin saturation levels was observed.
• Treatment of rats with aloin produced a significant reduction in red blood cells count, hemoglobin concentration and hematocrit value, and by contrast a significant increase of serum iron level and transferrin saturation percent was observed. Daily oral administration of iron to aloin-treated rats gave rise to a significant increase of serum iron level, while red blood cells count, hemoglobin concentration, hematocrit value and percentage of transferrin saturation rebound to normal levels.
• Treatment of male rats with doxorubicin caused an iron overload in the liver and spleen, which was verified by histopathological examination. Iron supplementation to doxorubicin-treated animals brought about a decrease of non-heme iron content in the spleen, compared to doxorubicin-treated animals, and normal hepatic iron content, whereas the kidneys iron content was significantly increased almost equal to that recorded in rats treated with iron alone.
• Treatment of rats with aloin gave rise to a significant iron overload in the spleen, and a significant reduction in the hepatic and kidney iron contents. Iron supplementation to aloin-treated rats caused a significant increase of the non-heme iron content in the spleen, heart and kidneys, compared to normal controls.
• Treatment of normal rats with doxorubicin or aloin caused a significant increase of hepatic hepcidin level, while iron supplementation to aloin-treated rats normalized hepatic hepcidin level. Iron supplementation to doxorubicin-treated rats showed a persistent increase of hepatic hepcidin.
• Daily oral supplementation of iron to normal rats significantly downregulated mRNA expression of hepatic TfR-1 gene, and by contrast upregulated the mRNA expression of Ferr-H gene.
• Doxorubicin treatment per se caused a significant upregulation in mRNA expression of hepatic TfR-1 and Ferr-H genes. Doxorubicin administration along with oral iron supplementation augmented the hepatic Ferr-H gene expression, and by contrast significantly downregulated the hepatic TfR-1 gene expression.
• Treatment of male rats with aloin decreased mRNA expression of hepatic TfR-1 gene, and increased Ferr-H mRNA expression, compared to normal controls. More interestingly, supplementation of iron to aloin-treated rats normalized mRNA expression of TfR-1 and Ferr-H genes.
• Microscopical examination of the bone marrow smears from iron-treated rats showed a significant increase of iron particles deposition, whereas a significant reduction in iron particles was observed in rats treated with doxorubicin and/or iron-supplementation. On the other hand, the bone marrow smears from rats supplemented with iron and treated with aloin revealed an elevation in iron stores with dense clumps of iron particles.
• Histopathological examination of the liver sections from iron- treated rats showed numerous apoptotic figures and sedimentation of hemosiderin pigments in Kupffer cells, while the spleen sections showed expansion of extramedullary hematopoiesis and abundant macrophages with hemosiderin pigment.
• Histopathological examination of doxorubicin-treated rats showed various degenerative changes in the liver. Furthermore, splenic sections showed extensive hemorrhage and erythroid and myeloid precursors.
• Histopathological examination of the hepatic sections from rats supplemented with iron and treated with doxorubicin showed more severe alterations with newly formed bile cholangioles in the portal area, associated with macrophages infiltration. The spleen sections showed increased extramedullary hematopoiesis with a significant increase of erythroid and myeloid precursors.
• Histopathological examination of tissue sections from aloin-treated rats showed a non-remarkable histopathological alternation.
• Histopathological examination of the tissue sections from rats supplemented with iron and treated with aloin showed mild histopathological alterations, mild granular degeneration of hepatocytes, a few weakly stained Kupffer cells in the hepatic periportal area, an extramedullary hematopoiesis in spleen with expansion of the red pulp containing erythroid and myeloid cells in the spleen, as well as macrophages with blue hemosiderin pigment lower than other groups.