The Protective Effects Of Genistin On Oxidative Injury Induced By Parenteral Iron

Background. Administration of parenteral iron has become a mainstay for treating anemia in patients with end-stage renal disease (ESRD). This practice is required in order to offset dialysis-related blood (iron) loss, and the need to optimize hematopoietic responsiveness to exogenous erythropoeitin (Epo) therapy. Currently employed parenteral iron formulation [e.g., iron dextran (FeD), iron sucrose (FeS), and iron gluconate (FeG)] has the potential to induce oxidative stress. When administered intravenously, these agents may induce free radical generation and lipid peroxidation, processes which can induce acute endothelial dysfunction. Additional support for the concept of iron-induced toxicity comes from a recent report which indicates that clinically achievable concentrations of FeG or FeS can impair polymorphonuclear cell (PMN)/transendothelial migration. This could contribute to infectious complications in dialysis patients. While the above evidence suggests potential acute toxicities, the long-term consequences of parenteral iron administration remain largely unknown. it is noteworthy that iron-mediated oxidative stress can contribute to both atherogenesis and chronic inflammation, each of which are leading causes of morbidity and mortality in ESRD patients.Furthermore, because Genistein (Gen), the major isoflavone aglycone, has strangely antioxidant effect, it is conceivable that it might contribute to protects against oxidative injury to endothelial cells and polymorphonuclear leukocyte. Therefore, this study sought to experimentally test this hypothesis.Methods. In vivo study, 71 MHD patients were enrolled and randomly divided into intravenous iron group (n=24) and oral iron group (n=27) and non-iron group (n=20).Their HCT, hemoglobin (Hb), serum iron (SI), serum ferrin (sf), TAST and their redox markers and biomarkers of inflammation were measured at the begin and the end of the study. These markers of oxidative stress include plasma and erythrocyte malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (Gpx), whole blood catalase (CAT). Biomarkers of inflammation include serum C-reactive protein (CRP), interleukin-10 (IL-1β), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α). 20 healthy volunteers were involved in this study as normal controls.In vitro study, Human umbilical vein endothelial cells (HUVEC) were isolated and harvested by collagenase treatment of umbilical cords, as described previously. HUVECs were cultured to the third generation. Then HUVSCs were cultured with iron dextran and Gen at different concentrations. Final, MTT and MDA, AOPP, CAT, SOD, GSH-px of endothelium cells were measured. NO in cell was examined in 2, 4 hours. After 4 hours, HUVECs were collected to isolate the total RNA. With eNOS special primer, RT-PCR was performed. PMN obtained from healthy adults were similarly incubated with iron dextran and Gen; the surface level of CD11b, CD62L was measured by Immunofluorescence flow cytometry.Resultes. in vivo study, at the end of the trial , plasma and erythrocyte MDA were elevated significantly and plasma and erythrocyte SOD,Gpx and whole blood CAT were decreased markedly, biomarkers of inflammation ( CRP, IL-10, TNF-a ) were significantly elevated in intravenous group (P<0.01 or P<0.05). The levels of plasma MDA were positively correlated to the levels of SF (r=o.7800.P< 0.01) and also positively correlated to the levels of serum TNF-α (r=o.5451.P<0.01) at the end of the trial. In vitro study, after endothelium cells were exposed to iron dextran with different concentrations, MTT, CAT, SOD, GSH-px was deseased significantly, MDA and AOPP was increased significantly, NO in HUVECs was reduced significantly compared with that in the control group. After PMN were exposed to Iron , a significant upregulation of the CD11b, and a downregulation of the CD62L were found. Gen pretreatment in different concentration, showed antioxidant effect, which can be concluded from the increasing in the vitality of antioxidant enzymes and the decreasing in MDA, AOPP. At the same time, genistein effected as antioxidation from 50μmol/L Genistein 200p mol/L had the strongest effect. Through Gen pretreatment HUVECs release NO was increased significantly, RT-PCR products showed that eNOS transcription was not affected. Through Gen pretreatment PMN CD11b reduced and CD62L increased...