Vitamin E supplementation restores glutathione and malondialdehyde to normal concentrations in erythrocytes of type 1 diabetic children.

Abstract

OBJECTIVE -This study examined the relationship between cellular glutathione and vitamin E concentrations and the effect of vitamin E (␣-tocopherol) supplementation on glutathione and lipid peroxidation product concentrations in the erythrocytes of type 1 diabetic patients.RESEARCH DESIGN AND METHODS -We obtained written informed consent to participate in this study from diabetic patients (n = 29) and their age-matched nondiabetic siblings (n = 21) according to the guidelines of the Institutional Review Board on Human Experimentation. Diabetic patients were supplemented with a DL-␣-tocopherol (vitamin E) capsule (100 IU/ orally) or placebo for 3 months in a double-blind clinical trial. Fasting blood samples were collected from each diabetic patient before the start of and after the 3 months of vitamin E or placebo supplementation. Glutathione, malondialdehyde (which is a product of lipid peroxidation), and ␣-tocopherol were determined using high-performance liquid chromatography. A total of 5 diabetic patients were excluded after randomization from the data analyses. Data were analyzed statistically using a paired Student' s t test to compare 12 diabetic patients taking vitamin E with 12 diabetic patients receiving placebo supplementation and to compare diabetic patients with healthy nondiabetic subjects.RESULTS -Erythrocytes of diabetic patients had 21% higher (P Ͻ 0.001) malondialdehyde and 15% lower (P Ͻ 0.05) glutathione concentrations than healthy subjects. Vitamin E in erythrocytes had a significant correlation with the glutathione concentrations in the erythrocytes (r = 0.46, P Ͻ 0.02). Vitamin E supplementation increased glutathione concentrations by 9% (P Ͻ 0.01) and lowered concentrations of malondialdehyde by 23% (P Ͻ 0.001) and of HbA 1c by 16% (P Ͻ 0.02) in erythrocytes of diabetic patients. No differences were evident in these parameters before versus after placebo supplementation.CONCLUSIONS -Glutathione level is significantly related to vitamin E level, and supplementation with vitamin E (100 IU/day) significantly increases glutathione and lowers lipid peroxidation and HbA 1c concentrations in the erythrocytes of type 1 diabetic patients.

Effect of beef from grass or maize silage- and concentrate-fed cattle on lipid metabolism and antioxidative status of rats

“…The rats that were fed with grass-fed beef were characterized by a higher intake of α-tocopherol with the diet and, simultaneously, by a lower concentration of TBARS assayed in their plasma and liver. A relationship between α-tocopherol intake and lipid peroxidation has also observed by other authors (Jain et al, 2000;De Cabo et al 2006).…”

“…Activation of GPx in the serum of the rats that were fed the grass-fed meat may result from the availability of glutathione or selenium in the body, but also of other redox-related molecules that cooperate with glutathione (Miyamoto et al, 2003). According to Jain et al (2000), vitamin E may restore the glutathione concentration to typical values in human erythrocytes, which may explain our results and underscore that the activity of antioxidant enzymes is related to the availability of exogenous antioxidants in the organism.…”

Regulation of glutathione synthesis

“…Thus, glucocorticoids may exert different tissue-specific effects. With regards to relevance to human situation, lower levels of GSH in the erythrocytes of diabetic patients and increased susceptibility to oxidative stress of these cells have been reported (Yoshida et al, 1995;Jain et al, 2000). Recently, Kim et al confirmed the effect of insulin on GSH levels and GCLC expression in rat hepatocytes and found that of the signaling pathways activated by insulin, PI3K/Akt/p70S6K are involved in mediating the effect while ERK, JNK and p38 MAPK are not (Kim et al, 2004).…”

Study of Incubation Conditions for Erythrocytes Osmotic Fragility Testing in Dromedary Camel (Camelus dromedarius)

“…This extent is dependent on cell volume, surface area, and functional integrity of cell membranes. Since it can be followed by changes in absorbance at 540 nm, the EOF test was frequently applied to the diagnosis of hemolytic diseases and oxidant alterations leading to destruction of erythrocytes [1,2,3]. For example, road transportation to slaughterhouses associated to heat stress had been demonstrated to cause increase of hemolysis in pig [3], goat [4] and camel [5].…”