Attenuation of oxidative stress-induced changes in thalassemic erythrocytes by vitamin E

The oxidative stress status of the transfusion-dependent Ebeta- and beta-thalassemia patients were studied before and after treatment with vitamin E for a period of four weeks. The level of cellular vitamin antioxidants viz. ascorbic acid and vitamin E in the thalassemia patients were found to be considerably lower compared to normal subjects. The activities of enzymatic antioxidants viz. catalase, glutathione peroxidase and glutathione reductase were found to be drastically reduced in untreated Ebeta- and beta-thalassemic patients when compared to normal subjects. However, the activity of superoxide dis-mutase was found to be increased in both types of untreated thalassemic patients when compared to normal individuals. An increase in superoxide dismutase and a decrease in catalase activity reflects the presence of a severe oxidative stress situation in the erythrocytes of the untreated transfusion dependent Ebeta- and beta-thalassemia patients. Changes in erythrocyte membrane protein pattern in untreated Ebeta- and beta-thalassemia patients when compared to normal erythrocyte further confirm the presence of continued oxidative stress in the ailing thalassemic erythrocytes. All these changes in the antioxidant status as well as the changes in the erythrocyte membrane proteins are ameliorated to considerable extent when the transfusion-dependent Ebeta- and beta-thalassemia patients were treated with vitamin E at a dose of 10 mg/kg/day for a period of four weeks. The patients during the treatment period did not exhibit any side effects and gained in body weight indicating a healthy status. The present study reveals that the lipophilic antioxidant vitamin E could be useful in the management of transfusion-dependant Ebeta- and beta-thalassemia patients.

Effect of endotoxin on protein degradation and lipid peroxidation of erythrocytes

Sepsis has often been associated with infection due to endotoxin (LPS) produced from gram-negative bacteria. Microcirculatory failure is one of the ultimate causes of septic shock. We studied the effect of endotoxin on the protein breakdown and lipid peroxidation of erythrocyte. In vivo (20 ug LPS/100 g) studies in rats showed increased tyrosine production from erythrocyte, as an index of protein degradation in erythrocyte. In vitro studies using 25 microg to 250 microg LPS per ml also showed similar type of increased effect of endotoxin in protein degradation. Washed erythrocyte devoid of plasma and leucocytes did not show any increased effect after endotoxin treatment. Lipid peroxidation was also increased after endotoxin treatment. However, protein degradation was more prominent than lipid peroxidation. We concluded therefore that the protein degradation and lipid peroxidation of erythrocytes caused by endotoxin are probably related to the production of septic shock.