Increased susceptibility of microcytic red blood cells to in vitro oxidative stress

Abstract

Oxidative damage to erythrocytes in thalassaemia has been related to generation of free radicals by an excess of denaturated α‐ or β‐globin chains, intracellular iron overload and low concentration of normal haemoglobin (HGB). Two good indicators of such oxidative damage are the high red blood cell (RBC) malonyldialdehyde (MDA) production detected following exogenous oxidant stress and the decrease of pyrimidine 5′‐nucleotidase (P5N), the most sensitive enzyme to SH‐group damage in vivo. Conflicting data, however, have so far accumulated in the literature concerning differences in oxidative damage between the different forms of thalassaemia and iron deficiency anaemia (IDA). In the present study, oxidative susceptibility, as defined by the production of MDA in vitro and antioxidant capacity, as measured by the activity of RBC glutathione peroxidase (GPx), superoxide dismutase (SOD) and by reduced glutathione (GSH), have been studied in microcytic RBCs from patients with β‐thalassaemia trait, Spanish (δβ)°‐thalassaemia heterozygotes (δβ‐thalassaemia trait) and iron deficiency anaemia (IDA). The results are consistent with the existence of significant differences in the severity and pattern of oxidative stress susceptibility between β‐thalassaemia trait (increased MDA production and higher SOD and GPx activities) and the other two forms of microcytosis (δβ thalassaemia trait and IDA). Furthermore, the finding of normal P5′N activity in δβ thalassaemia trait, gives further support to the less intense peroxidative environment of RBCs in this form of thalassaemia when compared to β‐thalassaemia trait, characterized by acquired RBC P5′N deficiency due to oxidative damage.

Prolidase activity and oxidative status in patients with thalassemia major

“…A study investigated oxidative status in thalassemia major subjects, where a significantly increased oxidative stress compared to other forms of microcytic anemias including d thalassemia major and iron deficiency anemia was detected (44). In respect of increased TOS and OSI, our findings were consistent with that study (44).…”

Oxidative status in iron‐deficiency anemia

“…In the literature (9,14,19), microcytic red blood cells had higher susceptibility to oxidant and high malonyldialdehyde production. Similarly, our results indicated that blood ROS concentrations were higher in patients with IDA than controls.…”

Extract from Conyza canadensis as a modulator of plasma protein oxidation induced by peroxynitrite in vitro

“…Free radical action and lipid peroxidation have been suggested as potentially important causative agents of aging and several types of human diseases [24]. Reactive oxygen species (ROS) have been implicated in damage to erythrocytes in patients with β-thalassemia, sickle cell anemia, glucose-6-phosphate dehydrogenase deficiency and other hemoglobinopathies [25,26]. Aqueous extracts of Conyza canadensis interact in some way with the biological membranes.…”