Oxidative stress is closely related to clinical severity of pre-eclampsia

Abstract

Pre-eclampsia is a hypertensive disorder of pregnancy in which enzymatic antioxidant defenses fail and tissues are injured. This prospective case-control study evaluated whether pre-eclamptic women and their newborns show higher degrees of oxidative stress than normal pregnancies and sought to determine if this stress is related to clinical severity. Forty-four pre-eclamptic and thirty healthy pregnant women attending two hospitals in Valparaíso, Chile, were studied. The following plasmatic variables of antioxidant capacity were evaluated: glutathione peroxidase activity (GPx), total antioxidant capacity measured by oxidation of ABTS substrate (2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid), and superoxide dismutase activity (SOD). malondialdehide (MDA) was measured to evaluate lipoperoxidation. The evaluation was performed at diagnosis of pre-eclampsia, delivery, 30 days and 120 days post delivery. Newborns were studied at delivery through umbilical cord blood samples. Our analysis shows that antioxidant enzyme activity (SOD, GPx, ABTS) was significantly decreased, while lipoperoxidation (MDA) was increased in both pre-eclamptic groups compared to normal pregnant women (p<0.01). Statistically significant difference was found between mild and severe pre-eclamptic groups (p<0.01), for all biochemical markers studied. Therefore, the clinical severity of this pathology is closely related to the degree of oxidative stress.

Evaluation of Oxidative Stress and Antioxidant Defence in Subjects of Preeclampsia

“…In India, studies conducted by Adiga, Patil et al [5] and Krishna Menon S [6] at different institutes showed significant elevations in the levels of malondialdehyde in preeclampsia compared to normal pregnancy and nonpregnant females. Outside India also, various studies like those by Elesa Llusla [7], Madazli R et al, and Chamy et al [8] have all found significantly increased MDA levels in preeclampsia as compared to normal pregnancy and also in pregnancy as such compared to non-pregnant females.…”

Placental Anti-Oxidant Gene Polymorphisms, Enzyme Activity, and Oxidative Stress in Preeclampsia

“…The two hallmark symptoms are hypertension and proteinuria, complicating at least 5% of pregnancies and are usually resolved upon delivery of the placenta. Preeclampsia has been closely associated with oxidative stress in a number of studies [1][2][3][4]. The mechanism of oxidative stress associated hypertension has been continuously evolving with the popular theme of endothelial dysfunction [5,6].…”

Alterations of antioxidant enzymes in preeclampsia

“…Similar to our study decreased activity of catalase was noted by others. 6,13,14 Catalase is the enzyme which protects the cells from the accumulation of hydrogen peroxide by dismutating it to water and oxygen or by using it as an oxidant in which it works as peroxidase. 14,15 In contrast to our study, few others reported increased activity of catalase enzyme in preeclampsia.…”

“…14,19,20 In contrast to our study, a decrease in GPx activity in preeclampsia was noted by others. 5,6,17 Glutathione peroxidase (GPx), an oxidative stress inducible enzyme plays a significant role in the peroxyl scavenging mechanism and in maintaining functional integration of the cell membranes. 21 The rise in the activity of this antioxidant enzyme could be due to its induction to counter the effect of increased oxidative stress.…”

“…There are conflicting reports on activities of the antioxidant enzymes like Glutathione Peroxidase (GPx), catalase in preeclampsia. Some studies have shown an increase in the activity of glutathione peroxidase, 3,4 whereas few studies reported a reduction in its activity [5][6][7] in preeclampsia. Similarly, the activity of catalase has been reported to increase, 7 or decrease 8 in preeclampsia.…”