Abnormal levels of antioxidant defenses in a large sample of patients with hypertensive disorders of pregnancy

The Change of Oxidative Stress in Maternal Blood During Pregnancy

Oxidative stress (OS) is a state in which the oxidative capacity exceeds the antioxidant capacity in vivo. OS is associated with various perinatal diseases. There have been few reports about OS during pregnancy, such as OS changes that occur during gestation, normal maternal OS dynamics, and OS levels in umbilical cord blood. We here examined the oxidative and antioxidant capacity in maternal blood as well as in umbilical cord vein blood during normal pregnancy. Pregnant women managed from early pregnancy to the postpartum period in our hospital, from April 2018 to March 2019, were included. We obtained maternal blood at 12, 24, and 36 weeks of gestation and obtained umbilical cord blood at delivery. The OS (derivatives of reactive oxygen metabolites [d-ROMs]) and antioxidant capacity (biological antioxidant potential [BAP]) of blood samples were measured. D-ROMs and BAP were compared across gestational weeks. Moreover, d-ROMs and BAP were compared between mothers with and without disease. We analyzed 100 pregnancies (651 specimens). Eleven patients developed hypertensive disorder of pregnancy (HDP)/preeclampsia (PE). The median maternal age was 35 years, and the median gestational age at delivery was 39 weeks. Thirty-one women had undergone fertility treatments. D-ROM values were significantly higher and BAP values were significantly lower in mid- and late pregnancy than in early pregnancy. D-ROM and BAP showed no significant differences between HDP/PE and non-hypertensive groups. During pregnancy, maternal OS increases, and antioxidant capacity decreases with advancing gestational age.

Antioxidant status in hypertensive disorders of pregnancy

Objective: Pregnancy can be associated with maternal hypertension leading to possible complications in pregnancy outcome. Antioxidant status may be proned to changes during pregnancy with hypertension. The aim of our study was to estimate antioxidant status through high-risk pregnancies.Methods: Seventy-nine pregnant women with high-risk for preeclampsia development were included and 46 of them developed some hypertensive disorder in pregnancy. Superoxide-dismutase (SOD) and paraoxonase 1 (PON1) activities and relative proportion of PON1 activiity on different HDL subclasses were determined in 1^st, 2^nd, and 3^rd trimester and prior to delivery.Results: SOD activity was significantly lower in 2^nd and 3^rd trimesters when compared to 1^st trimester (P˂0.001) whereas PON1 activity was significantly higher in 3^rd than in 1^st trimester (P˂0.05) in group of hypertensive women. This group had significantly higher SOD and PON1 activities and relative proportion of PON1 on HDL_3c subclasses in the 1^st trimester, significantly increased PON1 in the 3^rd trimester and prior to delivery and significantly higher PON1 activity on HDL_3c subclasses (P˂0.05) than nonhypertensive group. In 1^st trimester and prior to delivery, total PON1 activity and relative proportion of PON1 on HDL_3c subclasses exhibited significant ability to mark out hypertension in pregnancy (P˂0.05).Conclusions: SOD activity decreased whereas total PON1 activity increased during pregnancy with hypertension. Pregnant women with hypertension had higher activities of PON1 and SOD and relative proportion of PON1 on HDL_3c subclasses than nonhypertensive ones. PON1 activity and relative proportion of PON1 on HDL_3c subclasses exhibited significant association with hypertension in pregnancy.

Grape Seed Extract Polyphenols Improve Resistance Artery Function in Pregnant eNOS-/- Mice

Hypertension during pregnancy is a leading cause of maternal and fetal morbidity and mortality worldwide, increasing the risk of complications including preeclampsia, intracerebral hemorrhage and fetal growth restriction. Increased oxidative stress is known to contribute to poor vascular function; however, trials of antioxidant supplementation have raised concerns about fetal outcomes, including risk of low birthweight. Grape seed extract polyphenols (GSEP) have been suggested to promote cardiovascular protection, at least in part through antioxidant actions. We tested the hypothesis that administration of GSEP during pregnancy would reduce oxidative stress and improve resistance artery function with no detrimental effects on fetal growth, in an established model of maternal hypertension associated with vascular dysfunction, the endothelial NO synthase knockout (eNOS^-/-) mouse. Pregnant C57BL/6J (WT) and eNOS^-/- mice received either GSEP (200 mg/kg/day) or drinking water, between gestational (GD) day 10.5 and GD18.5. At GD17.5, maternal systolic blood pressure (SBP) was measured; at GD18.5, maternal malondialdehyde (MDA) concentrations, vascular function of aortic, mesenteric, uterine and posterior cerebral arteries was assessed, and fetal outcome evaluated. GSEP reduced maternal SBP (P < 0.01) and plasma MDA concentrations (P < 0.01) in eNOS^-/- mice. Whilst there was no effect of GSEP on vascular reactivity of aortas, GSEP improved endothelial-dependent relaxation in mesenteric and uterine arteries of eNOS^-/- mice (P < 0.05 and P < 0.001, respectively) and normalized lumen diameters of pressurized posterior cerebral arteries in eNOS^-/- mice (P < 0.001). Supplementation with GSEP had no effect in WT mice and did not affect fetal outcomes in either genotype. Our data suggest that GSEP improve resistance artery function, potentially through antioxidant actions, and provide a basis to further investigate these beneficial effects including in the prevention of intracerebral hemorrhage. Maternal supplementation with GSEP may be a safe intervention to improve outcomes in pregnancies associated with hypertension and vascular dysfunction.

Oxidative Stress Markers Differ in Two Placental Dysfunction Pathologies: Pregnancy-Induced Hypertension and Intrauterine Growth Restriction

Aim

Pregnancy-induced hypertension (PIH) and intrauterine growth restriction (IUGR) are both multisystemic disorders of pregnancy that cause perinatal morbidity and mortality. Recently, researchers focused on the role of oxidative stress (OS) as a pathophysiological mechanism in the development of these pathologies. The aim of this study was to compare OS in placental-related pathologies (PIH and IUGR) and uncomplicated pregnancies. We also investigated which salivary OS markers reflect systemic oxidative status and which only reflect the state of the oral cavity. Material and Methods. A total of 104 pregnant women (n = 104; 27 with PIH, 30 with IUGR, and 47 controls) were evaluated. Malondialdehyde (MDA), total antioxidant capacity (ORAC), aldehyde dehydrogenase (ALDH), and activity of glutathione peroxidase (GPx) and glutathione transferase (GST) in plasma/whole blood and/or saliva were analysed. Dietary nutrient intake was calculated using a Semiquantitative Food Frequency Questionnaire (SFFQ). Oral health was assessed to eliminate patients with bleeding, severe periodontitis, and other dental pathologies.

Results

In the IUGR group, increased concentration of ORAC was observed both in saliva and plasma. Also, lower plasma levels of MDA in IUGR compared to the control group was detected. No sign of oxidative stress was confirmed in the PIH group. The examined groups did not differ regarding diet and markers of inflammation. ORAC in saliva was correlated with its level in plasma. No such correlations for MDA were observed. In the IUGR group, there were no differences in OS markers in plasma, but there was a lower ALDH level in the blood compared to the control group. It confirms OS occurrence in IUGR. In IUGR, a higher activity of salivary ALDH was probably due to worse oral health.

Conclusion

Oxidative stress differs between IUGR and PIH groups: the presence of oxidative stress was confirmed only in the IUGR group. Salivary ORAC can be used to estimate ORAC in plasma. The activity of salivary ALDH reflects the state of the oral cavity.

Increased Oxidatively Modified Forms of Albumin in Association with Decreased Total Antioxidant Activity in Different Types of Hypertensive Disorders of Pregnancy

Protein oxidation has been demonstrated in preeclampsia, but this finding has not been established in other hypertensive disorders in pregnancy (HDP). The present study comparatively evaluated ischemia modified albumin (IMA) and advanced oxidation protein products (AOPP) in different HDP and investigated their association with total antioxidant activity (AOA) and total thiols. There was a significant increase in AOPP and IMA, a significant decrease in AOA, total thiols and albumin in every HDP compared to controls. Among HDP groups, eclampsia patients showed more significant change in each of the parameter. IMA and AOPP were negatively associated with AOA in every HDP and with total thiols only in eclampsia. The present study supports the hypothesis of oxidative stress, as evidenced by increased protein oxidation, decreased antioxidant status and significant negative association between protein oxidation and AOA in every HDP. The imbalance of prooxidants and antioxidants was further augmented in eclampsia.

The Relationship of Restless Legs Syndrome to History of Pregnancy-Induced Hypertension

BACKGROUND

Restless legs syndrome (RLS), a burdensome sleep disorder, has been associated with cardiovascular disease (CVD), hypertension, diabetes, and related disorders. However, the relationship of RLS to history of pregnancy-induced hypertension (PIH), a predictor of subsequent CVD, diabetes, and associated conditions, remains little explored. In this study, we investigated the relationship of RLS to history of PIH in a sample of primary care patients.

METHODS

Participants were women aged ≥40 years drawn from an anonymous survey study of West Virginia primary care patients. Data collected included detailed information on demographics, lifestyle factors, sleep patterns, and reproductive/medical history; the survey also included an RLS diagnostic questionnaire. Women who were pregnant or unsure about their pregnancy status were excluded from the analyses.

RESULTS

Of the 498 participants in the final analytic sample, 24.5% met diagnostic criteria for RLS (17.9% with symptoms ≥once/week, 11.9% with symptoms ≥3 times/week); 73 (16.5% of parous women) reported a history of PIH, defined as physician-diagnosed preeclampsia or gestational hypertension. After adjustment for demographics, lifestyle characteristics, obesity, reproductive history, health conditions, and other factors, those reporting a history of PIH were approximately twice as likely to meet criteria for RLS (odds ratio [OR] = 1.9; 95% confidence interval [CI] = 1.1, 3.6). These associations increased in magnitude with increasing symptom frequency (adjusted OR for RLS with symptoms ≥3 times/week = 3.8; CI 1.9, 7.6; p for trend = 0.003).

CONCLUSIONS

History of PIH was strongly and positively related to current RLS in this study of primary care patients; these findings further support a possible role for metabolic dysregulation in RLS etiology.

A possible protective role of Nrf2 in preeclampsia

Excess release of reactive oxygen species (ROS) is a major cause of oxidative stress. This disturbance has been implicated as a cause of preeclampsia, a pregnancy-related disorder characterized by hypertension and proteinuria. Increased oxidative stress leads to trophoblast apoptosis/necrosis and alters the balance between pro- and anti-angiogenic factors, resulting in generalized maternal endothelial dysfunction. Trials using antioxidants have significantly failed to improve the condition of, or in any way protect, the mother from the life-threatening complications of this syndrome. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a potent transcription activator that regulates the expression of a multitude of genes that encode detoxification enzymes and anti-oxidative proteins. Recent discussion on evidence of a link between Nrf2 and vascular angiogenic balance has focussed on the downstream target protein, heme oxygenase-1 (HO-1). HO-1 metabolizes heme to biliverdin, iron and carbon monoxide (CO). HO-1/CO protects against hypertensive cardiovascular disease and contributes to the sustained health of the vascular system. In one animal model, sFlt-1 (soluble fms-like tyrosine kinase-1) has induced blood pressure elevation, but the induction of HO-1 attenuated the hypertensive response in the pregnant animals. The special conditions under which Nrf2 participates in the pathogenesis of preeclampsia are still unclear, as is whether Nrf2 attenuates or stimulates the processes involved in this syndrome. In this review, we summarize recent theories about how Nrf2 is involved in the pathogenesis of preeclampsia and present the reasons for considering Nrf2 as a therapeutic target for the treatment of preeclampsia.

New Insights into the Pathogenesis of Preeclampsia - The Role of Nrf2 Activators and their Potential Therapeutic Impact

Preeclampsia (PE), characterized by proteinuric hypertension and occurring in 2-3 % of all pregnancies, is one of the leading causes of maternal, fetal and neonatal morbidity and mortality. The etiology of PE still remains unclear and current treatments for this devastating disorder are still limited to symptomatic therapies. Placental oxidative stress may be a key intermediate step in the pathogenesis of PE; it has been related to excessive secretion of multiple antiangiogenic factors, mainly soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng). The nuclear factor-erythroid 2-like 2 (Nrf2) pathway is one of the most important systems that enhance cellular protection against oxidative stress. Nrf2 serves as a master transcriptional regulator of the basal and inducible expression of a multitude of genes encoding detoxification enzymes and antioxidative proteins. Evidence for a link between Nrf2 and restoring the balance between pro- and antiangiogenic factors mainly through its downstream target protein heme oxygenase-1 (HO-1) has lately been discussed. HO-1 metabolizes heme to biliverdin, iron and carbon monoxide (CO). CO enhances vascular endothelial growth factor (VEGF) synthesis in vascular smooth muscle and promotes its relaxation and hence vasodilatation. In addition, HO-1 has been shown in vitro to inhibit the production of sFlt-1. A recent animal study demonstrated that the induction of HO-1 in a mouse model of PE attenuates the induced hypertension in pregnant mice. This provides compelling evidence for the protective role of Nrf2/HO-1 in pregnancy and identifies this pathway as a target to treat women with PE. We summarize the recent findings on the involvement of Nrf2 in the pathogenesis of PE, and provide an overview of the possible beneficial effects of Nrf2 inducers in PE.

Evaluation of oxidative stress and antioxidant status in diabetic and hypertensive women during labor

Pregnancy in insulin-dependent diabetes mellitus is associated with a greater incidence of fetal abnormality. Animal studies suggested that increased free-radical production and antioxidant depletion may contribute to this risk. The objective of this work was to evaluate oxidative stress and antioxidant capacity in hypertensive, diabetics, and healthy control women during labor. Simultaneous determination of antioxidant enzymes activities, namely glutathione peroxidase (GSH-Px), glutathione reductase (GSH-red), superoxide dismutase (SOD), total antioxidant, and lipid peroxides measured as thiobarbituric acid-reactive substances (TBARS) levels, were carried out in maternal plasma during labor. Plasma GSH-Px activity was found to be significantly increased as it doubled in hypertensive, and diabetic women when compared with healthy control women (P < 0.05). In contrast, plasma SOD activity was significantly decreased in both groups when compared to the control group (P < 0.05). No significant differences were detected in GSH-Red activity between diabetic, hypertensive and control groups. Alterations in antioxidant enzyme activities were accompanied by a significant increase in the levels of plasma lipid peroxides in hypertensive and diabetic women during labor. Plasma levels of total antioxidants were significantly increased in diabetic women as compared with the control group. Based on our results, it may be concluded that enhanced generation of oxidative stress causes alteration of antioxidant capacity in diabetic and hypertensive women during labor. Alterations in antioxidant and prooxidant components may result in various complications including peroxidation of vital body molecules which may be regarded as an increased risk factor for pregnant women as well as the fetus.