LIPID PEROXIDATION AND ANTIOXIDANT STATUS IN SS-Thalassemia

Abstract

Autoxidation of globin chains and iron overload are the suggested mechanisms for the increased oxidative stress in beta-thalassemia. The aim of this study was to evaluate the extend of lipid peroxidation and antioxidant status of patients with beta-thalassemia and iron deficiency anemia (IDA) and compare the results with healthy subjects. Oxidant and antioxidant status of the children with beta-thalassemia major (n = 22) and iron deficiency anemia (n = 19) were studied. Healthy controls (n = 14) were age and sex matched. Fresh anticoagulated venous blood samples were obtained from all children. Conjugated diene (CD) and thiobarbituric acid-reactive (TBARS) substances were analyzed to indicate the oxidative parameters, whereas the erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured to show the antioxidant status of the children. Plasma TBARS and CD concentrations were elevated in beta-thalassemia compared to IDA. When compared to the controls, elevation in TBARS was significant. In the iron-deficiency group both TBARS and CD levels were decreased compared to the controls. SOD and GPx activities were increased in the beta-thalassemia group. SOD in beta-thalassemia was higher than both IDA and the controls and GPx activity was higher than the IDA group. In vivo lipid peroxidation was increased in children with beta-thalassemia major. This leads to a compensatory increase in antioxidant enzymes, whereas IDA does not lead to lipid peroxidation with a normal antioxidant enzyme activity.

Invited Review: Oxidation of Biological Systems: Oxidative Stress Phenomena, Antioxidants, Redox Reactions, and Methods for Their Quantification

“…Lipids (100,169) All cellular membranes are especially vulnerable to oxidation due to their high concentrations of unsaturated fatty acid. The damage to lipids, usually called lipid peroxidation, occurs in 3 stages.…”

Oxidant and antioxidant status in beta thalassemia major patients Beta talasemi major hastalarinda oksidan ve antioksidan düzeyleri

“…Increased ESOD activities were found in the patients with beta-thalassemia by the investigators previously (12,16). Both beta-thalassemia and accompanying iron overload lead in vivo lipid peroxidation and the compensatory increase in the antioxidant enzyme levels of SOD and glutathione peroxidase (GPx) (12). The significant increased catalytic activities of SOD and GPx in beta-thalassemic erythrocytes were found when compared with healty subjects and beta-thalassemic carriers (17).…”

“…ESOD is a preventive antioxidant. Increased ESOD activities were found in the patients with beta-thalassemia by the investigators previously (12,16). Both beta-thalassemia and accompanying iron overload lead in vivo lipid peroxidation and the compensatory increase in the antioxidant enzyme levels of SOD and glutathione peroxidase (GPx) (12).…”

“…There is extensive evidence of in vivo oxidative damage as well as enhanced sensitivity to exogenous oxidant stress in red cells of beta-thalassemia (3). It has been postulated that the biochemical and metabolic changes of beta-thalassemic red blood cells (RBC) are associated with a constant oxidative stress within the cell caused by precipitation of excess alpha-globin chains, iron decompartimentalization, and release of free iron (2,3) Increased plasma malonyldialdehyde (MDA) level, which is measured by the thiobarbituric acid reaction substance (TBARS) methods, was found in beta-thalassemia patients (12,13). MDA is a good indicator of oxidative damage.…”

Evaluation of serum antioxidant enzymes in β- thalassemia major patients

“…While all of the above enzymes play important roles in the modulation of oxidative stress, the primary role in the metabolism of superoxide anion radical is exerted by superoxide dismutase 4 . Antioxidants are protective agents that have inactivated ROS and play an essential role in protection of the cells from oxidative damage 5 . They include several agents such as enzymes (glutathione peroxidase, superoxide dismutase, catalase), large molecules (ferritin, albumin), small molecules (uric acid, glutathione, bilirubin, ascorbic acid, α-tocopherol, and vitamin E) and some essential trace elements such zinc, copper and selenium 6 .…”