Nitric oxide and antioxidant enzymes in venous and cord blood of late preterm and term omani mothers

Role of Oxidative Stress and DNA Damage on Preterm Birth Outcome

Background: Preterm birth (PTB) poses a significant global health challenge and focused research is vital for improving maternal and neonatal health outcomes. The purpose of this study was to determine the effect of oxidative stress (OS) and DNA damage on PTB. Methods: There were two groups: (a) cases consisting of mothers with PTB (<37 weeks of gestation, n = 100) and (b) controls consisting of mothers with term birth (>37 weeks of gestation, n = 100). Women with vaginal infection, non-cephalic presentation, multiple gestations, fetal anomalies, Cesarean delivery, pregnancy with Mullerian anomalies, or preeclampsia were excluded from the study. OS analysis was conducted by measuring levels of superoxide dismutase (SOD), catalase (CAT), lipid peroxidation (LPO), and total protein and DNA damage were evaluated by CBMN-Cyt assay. Statistical analysis was performed using students' t-test and one-way ANOVA. Results: Low levels of antioxidants SOD and CAT (p < .0001), and total protein (p < .0001), besides high malondialdehyde (byproduct of LPO) (p < .0001) were observed in the PTB group. Moreover, high frequencies of micronuclei (p < .0001) and nucleoplasmic buds (p < .01) were detected in the PTB mothers compared to term birth mothers, while no significance was observed in the nucleoplasmic bridge frequencies. Conclusion: When the body's immune system and antioxidants fail to cope up with the generated OS, it can lead to PTB. Along with other body tests, OS markers and CBMN-Cyt tests have the potential to be used in diagnostics for early warning as well as monitoring and advising mothers for a better pregnancy outcome.

Disrupted Balance of the Oxidant-Antioxidant System in the Pathophysiology of Female Reproduction: Oxidative Stress and Adverse Pregnancy Outcomes

The significance of oxidative stress in the pathophysiology of male reproductive processes has been closely studied in the last two decades. Recently, it has become clear that oxidative stress can lead to numerous pathological conditions during female reproductive processes as well, contributing to the development of endometriosis, polycystic ovary syndrome and various forms of infertility. During pregnancy, physiological generation of reactive oxygen species (ROS) occurs in association with several developmental processes including oocyte maturation and implantation. An overproduction of ROS can lead to disturbances in fetal development and increases the risk for missed abortion, intrauterine growth restriction, pre-eclampsia, premature delivery and gestational diabetes. Our review focuses on the etiological role of the disrupted oxidant-antioxidant system during human gestation as it relates to adverse pregnancy outcomes.

Status of Oxidative Stress during Low-Risk Labour: Preliminary Data

Pregnancy and childbirth are associated with the forming of reactive oxygen species that generate oxidative stress. Oxidative stress is a factor that may adversely affect the development of the fetus and the course of labour. Monitoring the parameters of oxidative stress can be used to assess the risk of health issues in the course of pregnancy and the condition of the newborn. Therefore, the analysis of oxidative stress in the physiological course of labour is the basis for understanding the role of oxidative stress in the pathogenesis of miscarriages and neonatal health circumstances. The study aimed to assess oxidative stress of mother-child pairs in the venous blood and umbilical cord blood at the time of physiological labour. One hundred and sixty-eight mother-child pairs were recruited to donate the mother’s venous blood in the first stage of labour and the venous umbilical cord blood after the newborn’s birth. Total antioxidant status (TAS), the activity of superoxide dismutase (SOD) with cofactors (Zn, Cu, Mn) and the activity of glutathione peroxidase (GPx) were analysed in venous blood plasma and umbilical cord blood. TAS value (p = 0.034), GPx activity (p < 0.001) and Zn concentration (p = 0.007) were significantly lower in maternal blood plasma as compared to neonatal umbilical cord blood. However, the activity of SOD (p = 0.013) and the concentration of Cu (p < 0.001) were significantly higher in the blood of mothers than of new-borns. The concentration of Mn in the plasma of the mother’s blood and the umbilical cord blood of the newborns was similar. Our research indicates higher levels of antioxidant enzyme (GPx) and total antioxidant potential (TAS) in umbilical cord blood compared to maternal blood, which may suggest depletion of redox reserves in women’s blood during labour.

Markers of Oxidative Stress in Obstetrics and Gynaecology-A Systematic Literature Review

Oxidative stress has been implicated in many diseases, including reproductive and pregnancy disorders, from subfertility to maternal vascular disease or preterm labour. There is, however, discrepancy within the standardized markers of oxidative stress in obstetrics and gynaecology in clinical studies. This review aims to present the scope of markers used between 2012 and 2022 to describe oxidative stress with regard to reproduction, pregnancy, and pregnancy-related issues. Despite the abundance of evidence, there is no consensus on the set of standardised markers of oxidative stress which poses a challenge to achieve universal consensus in order to appropriately triangulate the results.

Impaired Antioxidant Defence Status Is Associated With Metabolic-Inflammatory Risk Factors in Preterm Children With Extrauterine Growth Restriction: The BIORICA Cohort Study

Introduction: An impaired antioxidant status has been described during foetal growth restriction (FGR). Similarly, the antioxidant defence system can be compromised in preterm children with extrauterine growth restriction (EUGR). The aim of this prospective study was to evaluate the antioxidant status in prepubertal children with a history of prematurity without FGR, with and without EUGR, compared to a healthy group. Methods: In total, 211 children were recruited and classified into three groups: 38 with a history of prematurity and EUGR; 50 with a history of prematurity and adequate extrauterine growth (AEUG); and 123 control children born at term. Catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR) activities were assessed in lysed erythrocytes with spectrophotometric methods. Plasma levels of the antioxidants α-tocopherol, retinol and β-carotene were determined through solvent extraction and ultra-high-pressure liquid chromatography coupled to mass spectrometry. Results: Children with the antecedent of EUGR and prematurity had lower CAT activity than the other two groups and lower GPx activity than the control children. Lower SOD, GPx and GR activities were observed in the AEUG group compared to the controls. However, higher concentrations of α-tocopherol and β-carotene were found in the EUGR group compared to the other groups; retinol levels were also higher in EUGR than in AEUG children. In EUGR and AEUG children, enzymatic antioxidant activities and plasma antioxidants were associated with metabolic syndrome components and pro-inflammatory biomarkers. Conclusions: This study reveals, for the first time, that the EUGR condition and prematurity appear to be linked to an impairment of the antioxidant defence status, which might condition an increased risk of adverse metabolic outcomes later in life.

Oxidative Stress in Pregnant Women Between 12 and 20 Weeks of Gestation and Preterm Birth

BACKGROUND

A known relationship exists between oxidative stress and preterm birth (PTB). However, few studies have measured oxidative stress prospectively in early or midpregnancy, and no studies have used electron paramagnetic resonance (EPR) spectroscopy prospectively to predict PTB.

OBJECTIVE

The purpose of this study was to identify predictive relationships between antioxidants and reactive oxygen species (ROS), specifically, superoxide (O2), peroxynitrite (OONO), and hydroxyl radical (OH), using EPR spectroscopy, measured between 12 and 20 weeks of gestation and compare with the incidence of PTB.

METHODS

Blood was obtained from pregnant women (n = 140) recruited from a tertiary perinatal center. Whole blood was analyzed directly for ROS, O2, OONO, and OH using EPR spectroscopy. Red blood cell lysate was used to measure antioxidants. PTB was defined as parturition at <37 weeks of gestation.

RESULTS

No differences were found between ROS, O2, OONO, or OH with the incidence of PTB. Catalase activity, glutathione, and reduced/oxidized glutathione ratio were significantly lower with PTB. Logistic regression suggests decreased catalase activity in pregnant women is associated with increased odds of delivering prematurely.

DISCUSSION

We prospectively compared antioxidants and specific ROS using EPR spectroscopy in pregnant women between 12 and 20 weeks of gestation with the incidence of PTB. Results are minimal but do suggest that antioxidants-specifically decreased catalase activity-in early pregnancy may be associated with PTB; however, these findings should be cautiously interpreted and may not have clinical significance.

Oxidative Stress and Preterm Birth: An Integrative Review

BACKGROUND

A variety of methods and measures have been used to quantify oxidative stress in clinical studies related to preterm birth (PTB), and studies have reported conflicting findings. No integrative reviews have been conducted.

OBJECTIVE

To describe specific molecules used as markers of oxidative stress and methods to measure these molecules and to review the literature for associations between oxidative stress and PTB specific to these molecules.

METHOD

Systematic literature searches were conducted in June 2015 and updated in 2017 in databases from the Biomedical Reference Collection: Basic Edition, including MEDLINE and clinicaltrials.gov . Articles were included if they described original research published after 2009 and compared PTB or preterm premature rupture of membranes with term birth (TB).

RESULTS

Abstracts ( n = 3,107) were reviewed for inclusion/exclusion criteria. Of these, 308 were full-text reviewed, and 30 articles were included in this review. All were identified as nonexperimental. The most common measurements of oxidative stress were quantification of total oxidant or antioxidant status or lipid peroxidation. Studies measuring reactive oxygen species or by-products of oxidative stress reported higher levels of these molecules for preterm specimens compared to TB specimens. Studies measuring antioxidants reported lower levels for these molecules in PTB specimens. Few of the studies had inconclusive findings.

DISCUSSION

Findings suggest that an imbalance between oxidants and antioxidants may be associated with PTB. The measurements and findings to date limit interpretation and understanding. Research using multidimensional methods and multidisciplinary teams are necessary to advance research and practice.

Nrf2 regulates gene-environment interactions in an animal model of intrauterine inflammation: Implications for preterm birth and prematurity

Preterm birth (PTB) is the leading cause of neonatal mortality, and surviving infants are at increased risk for lifelong disabilities. Intrauterine inflammation is an etiological factor that drives PTB, and oxidative stress is associated with PTB. Nuclear erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that is the key regulator of the response to oxidative and inflammatory stress. Here, we used the established mouse model of intrauterine inflammation-induced PTB to determine whether Nrf2 is a modifier of susceptibility to PTB and prematurity-related morbidity and mortality in the offspring. We determined that Nr2-deficient (Nrf2^−/−) mice exhibited a greater sensitivity to intrauterine inflammation, as indicated by decreased time to delivery, reduced birthweight, and 100% mortality. Placentas from preterm Nrf2^−/− mice showed elevated levels of markers of inflammation, oxidative stress, and cell death, and transcriptomic analysis identified numerous key signaling pathways that were differentially expressed between wild-type (WT) and Nrf2^−/− mice in both preterm and control samples. Thus, Nrf2 could be a critical factor for gene-environment interactions that may determine susceptibility to PTB. Further studies are needed to determine if Nrf2 is a viable therapeutic target in women who are at risk for PTB and associated complications in the affected offspring.

Nitric oxide and antioxidant enzyme levels in blood of respiratory distress syndrome--Egyptian preterms and their mothers

BACKGROUND

The mechanisms of tissue injury in respiratory distress syndrome (RDS) have not been completely elucidated but the involvement of oxidative damage due to reactive oxygen species (ROS) is important in the pathogenesis of preterm labor and RDS.

OBJECTIVES

To assess the oxidative status in preterms with and without RDS and in their mothers.

PATIENTS AND METHODS

Measuring and comparing concentrations of serum nitric oxide (NO), and erythrocytic activities of some antioxidant enzymes in blood of 20 preterms with RDS and 20 preterms without and their mothers, respectively.

RESULTS

Our results confirm significant elevation of mean levels of serum NO and reduced mean levels of erythrocytic activities of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT), in RDS preterms and their mothers compared with controls and their mothers. A significant positive correlations were found between maternal and preterm serum NO (r=0.3 & 0.6) and erythrocytic activity of SOD (r=0.5 & 0.4) for RDS and control groups, respectively. In addition, a significant negative correlations were found between NO and SOD in all groups.

CONCLUSIONS

The existence of oxygen metabolites and lipid peroxidation was significantly more obvious in RDS preterms and in their mothers than those without.