Antioxidant status and lipid peroxidation in hemodialysis patients undergoing erythropoietin and erythropoietin-vitamin E combined therapy

Abstract

In this study, plasma and red blood cell (RBC) antioxidant status and plasma lipid peroxidation were investigated in 46 hemodialysis patients. In addition, the effect of erythropoietin (EPO) and EPO-vitamin E combination therapy on plasma and RBC antioxidant status, and plasma lipid peroxidation were examined. There were 10 healthy subjects in the control group and 10 hemodialysis patients in the untreated group. The third group included 36 hemodialysis patients that were given EPO (100 U/kg) for 3 months, 3 times per week. The fourth group included 36 hemodialysis-patients from the EPO group that were given EPO at a 50% decreased dose + vitamin E (300 mg/day) for 3 months. MDA levels in the untreated group, the EPO group and the EPO + vitamin E groups were found to be higher than the control group (p < 0.001, in both). Furthermore, MDA levels in both of the treatment groups were lower when compared to the untreated group (p < 0.001, in both). Plasma vitamin E levels in the untreated, the EPO group and EPO + vitamin E groups were lower than the control group (p < 0. 001). In contrast, plasma vitamin E levels in the treatment groups were higher in comparison with the control group (p < 0.05). SOD activities in the untreated, the EPO group and the EPO + vitamin E groups were found to be lower than the control group (p < 0.001). SOD activities in the treatment groups were higher than the control group (p<0.001). The SOD activities in the EPO+vitamin E group increased when compared to the EPO group (p < 0.001). CAT activities in the untreated, the EPO group and the EPO + vitamin E groups were found to be lower than the control group (p < 0.001 in untreated and EPO groups, p <0.01 in EPO+ vitamin E group). CAT activities in EPO and EPO+ vitamin E groups were increased when compared to the untreated group (p < 0.01). In conclusion, our findings have shown that antioxidant status decreased and lipid peroxidation increased in hemodialysis patients. EPO has an antioxidant effect on the RBC and plasma antioxidant status, and plasma lipid peroxidation. These effects were moderately increased by the combination of vitamin E and EPO.

Modulation of Antioxidant Enzyme Expression and Activity by Paraquat in Renal Epithelial NRK-52E Cells

“…Increased superoxide anion generation due to paraquat and its contribution to paraquat toxicity have been documented over many years (Inal et al, 1999;Mimc-Oka et al, 1999;Modlinger et al, 2004;Sindhu et al, 2005) and in this study, its role including that of hydroxyl radical in the development of renocytotoxicity was confirmed in vitro. As expected, the paraquat-induced increase in the generation of superoxide anions and hydroxyl radicals was significantly reduced by superoxide dismutase and catalase respectively.…”

“…Antioxidant enzyme activities are also altered in chronic renal failure (CRF) in which oxidative stress also plays an important part (Modlinger et al, 2004), however, as with diabetic conditions, the true effects are still unclear. Specifically, CAT activity has been found to be down-regulated (Inal et al, 1999;Mimc-Oka et al, 1999;Sindhu et al, 2005) or unaffected (Sommerburg et al, 2002). GSH-Px activity has also been reported to be unaffected in CRF (Sindhu et al, 2005).…”

Effects of α-Tocopherol and Mixed Tocopherol Supplementation on Markers of Oxidative Stress and Inflammation in Type 2 Diabetes

“…Using erythrocyte SOD and GPx activity as markers, we also showed that there was no perturbation of 2 of the major endogenous antioxidant defense systems. Previous studies have shown that ␣T supplementation at 300 mg or 600 mg/day for Ն3 months increased erythrocyte antioxidant enzyme activities in hemodialysis patients (30,31 ). The difference in study populations and duration of tocopherol supplementation may account for the different observations.…”

Assessment of microvascular reactivity and oxidative stress in hypertensive adolescents and hemodialysis patients

“…Despite a transient increase in the levels of oxidative markers after the initiation of ESA therapy [60] (preventable with simultaneous vitamin E administration [61]), long-term ESA treatment is thought to have antioxidant effects [62][63][64][65][66], though the mechanisms have not been well established [67]. These mechanisms are suggested to include elevated expressions of the enzymes SOD, CAT, GPx [62][63][64][65] and heme oxygenase-1 [66], and attenuated lipid peroxidation [64,65].…”

“…These mechanisms are suggested to include elevated expressions of the enzymes SOD, CAT, GPx [62][63][64][65] and heme oxygenase-1 [66], and attenuated lipid peroxidation [64,65]. Factors associated with the reduction of iron-dependent oxidative injury [68] and the correction of anemia [65,69] may also play roles in the improvement of oxidative stress.…”