Assessment of iron status and interplay between lipid peroxidation and antioxidant capacity in common hemoglobin variants in Osun State, southwestern Nigeria.

Hemoglobin (Hb) and iron are prooxidants in nature and sources of free radicals in the biological system of all Hb phenotypes. Recent evidence linked abnormal hemoglobin S and C (HbSC) in sickle cell disease (SCD) to various complications in multiple oxidative processes. However, similar studies in relation to abnormal Hb traits are sparse. Besides, reports on activities of antioxidant enzymes and iron status in SCDs are still contradictory. This study assessed the interplay between lipid peroxidation and antioxidant defense capacity in various Hb variants. We enrolled 193 participants with different Hb phenotypes. They were consecutive patients with sickle cell anemia (HbSS, n = 32) and hemoglobin SC (HbSC) disease (n = 28) regularly followed up in a steady state. Other participants were subjects with abnormal Hb traits (HbAS, n = 50; HbAC, n = 33) and normal controls (HbAA, n = 50). The hematocrit (Hct) level, hemoglobin (Hb) concentration, iron status, and biochemical parameters including malondialdehyde (MDA), total antioxidant status (TAS), superoxide dismutase (SOD), and glutathione peroxidase (GPx) enzymes were investigated simultaneously. The MDA and SOD levels were significantly higher (P < 0.05) in Hb variants in order of HbSS>HbSC>HbAC>HbAS when compared with controls. Conversely, GPx and TAS levels showed significant reductions (P < 0.05). Similarly, Hct, Hb, and iron concentrations showed significant reductions (P < 0.05) sequentially following HbAC > HbAS > HbSC > HbSS compared with controls. The results suggest that both SCDs and the carriers were relatively more vulnerable to systemic oxidative stress against normal phenotype, and may be owing to ineffective antioxidant mechanisms needed for keeping spontaneous generations of free radicals in control without necessarily iron-mediated.

Plasma Malondialdehyde (MDA): An Indication of Liver Damage in Women with Pre-Eclamsia.

BACKGROUND: One of the features associated with pre-eclampsia is elevated liver transaminases. The reason this happens has not been fully described. However, the hepatocytes are not known to be spared by free radical injury. This study was conducted to examine the relationship between product of free radical injury (malondialdehyde) and transaminases in pre-eclamptic women. PATIENTS AND METHODS: A total of 98 and 115 pre-eclamptic and apparently normal pregnant women were selected from the booking clinic of Ladoke Akintola University of Technology Teaching Hospital, Osogbo. Non-pregnant women were selected from volunteered members of staff. Malondialdehyde (MDA), aspartate transaminase (AST) and alanine transaminase (ALT) analyses were determined on collected venous blood sample. Statistical analyses of variables were done using SPSS 17 taking level of significance to be p<0.05. RESULTS: Subjects with plasma AST between 10 and 20U/L had mean plasma MDA of 0.92µmol/l whereas those with plasma levels greater than 41U/L had mean plasma MDA of 4.72µmol/l. Similarly, Subjects with plasma ALT between 10 and 20U/L had mean plasma MDA of 0.86µmol/l, and subjects with plasma ALT greater than 51 U/L had mean plasma MDA of 4.71µmol/l. Positive correlation was observed between AST and ALT(r=0.79; p=0.047), between AST and MDA(r=0.690; p=0.061) as well as between ALT and MDA(r=0.571; p=0.049). CONCLUSION: The elevated liver enzymes seen in women with pre-eclampsia may be due to free radical injury to the liver. Pre-eclamptic women without free radical injury did not have elevated transaminases.

Free radical attack on membrane lipid and antioxidant vitamins in the course of pre-eclamptic pregnancy.

BACKGROUND: Despite the volume of knowledge and daily reports on pre-eclampsia, its pathogenesis is still yet to be ascertained. Oxidative stress (oxidant (free radical) in excess of antioxidant) injury is one of the recently suggested pathogenetic mechanisms. This study, however, was designed to determine second and third trimesters of plasma malondialdehyde (product of free radical attack on membrane lipid) and vitamins C and E in pre-eclamptic Nigerian women. SUBJECTS AND METHODS: A Total of 100 subjects, each for pre-eclamptic, apparently normal and non-pregnant women qualified for the study. Venous blood samples were taken in the second and third trimesters of pregnancy and at the point of contact for non-pregnant women. Variables were analyzed using SPSS version 16, taking level of significance to be 0.05. RESULTS: Plasma malondialdehyde in the third trimester of normal pregnancy (2.03±0.71µmol/l) was found to be significantly higher than the one in the second trimester (1.65±0.62µmol/l) (p<0.0001). For pre-eclamptic subjects, the malondialdehyde in the third trimester (3.13±0.61µmol/l) was also higher than the malondialdehyde in the second trimester (3.00±1.21µmol/l). The mean vitamin C values for subjects with normal pregnancy were similar in the second and third trimesters (38.25±19.66 vs. 38.66±19.40; p=0.882). For subjects with pre-eclampsia, the mean Vit C values were also similar in the 2(nd) and 3(rd) trimesters (35.05±18.37 vs. 37.20±24.44µmol/l; p=0.175). Mean vitamin E values in the second and third trimesters were also similar for subjects with normal pregnancy (28.62±13.85 vs. 28.50±13.35µmol/l; p=0.950). A similar finding was observed in pre-eclamptic subjects (25.09±12.79 vs. 28.00±14.83µmol/l; p=0.067). CONCLUSION: There was an increased product of membrane lipid attack (malondialdehyde) with no change in plasma levels of vitamins C and E as pregnancy advances into the third trimester of both normal and pre-eclamptic pregnancies. Antioxidant vitamins may not be useful in stopping the progression of free radical attack on membrane lipid to control pre-eclampsia.