Lipid-soluble antioxidants and pregnancy: maternal serum levels of coenzyme Q10, alpha-tocopherol and gamma-tocopherol in preeclampsia and normal pregnancy

The role played by oral antioxidant therapies in preventing and treating preeclampsia: An updated meta-analysis

AIMS

Performing an up-to-date meta-analysis of oral antioxidant therapies and determining whether they are effective in preventing and/or treating preeclampsia (PE).

DATA SYNTHESIS

Search was performed in PubMed, CENTRAL, LILACS, Web of Science, and ScienceDirect databases. The risk of bias was assessed based on using Cochrane Collaboration's tool. A funnel plot was created, and Egger's and Peter's test was carried out to assess publication bias in the primary outcome of prevention studies. The overall quality of the evidence was assessed based on using the Grading of Recommendations Assessment, Developing and Evaluation (GRADE) tool; a formal protocol was published in the PROSPERO database (registration number CRD42022348992). In total, 32 studies were taken into consideration for analysis purposes; 22 studies focused on investigating preeclampsia prevention methods, whereas 10 focused on its treatment. Significant results associated with the incidence of preeclampsia were observed in prevention studies comprising 11,198 subjects and 1106 events in the control groups, as well as 11,156 subjects and 1048 events in the intervention groups (relative risk [RR]: 0.86, 95% confidence interval [CI]: [0.75, 0.99], P = 0.03; I² = 44%, P = 0.02). With respect to outcomes associated with treatment studies, only intrauterine growth restriction has shown significant effects. Egger's and Peter's test has evidenced publication bias. Six outcomes in prevention studies were classified as having low quality and two as having moderate quality, whereas all three outcomes assessed in treatment studies were classified as having moderate quality.

CONCLUSIONS

Antioxidant therapy has shown beneficial effects on preeclampsia prevention; moreover, the positive impact of this therapy on intrauterine growth restriction was observed during the disease treatment.

Modulation of NRF2/KEAP1 Signaling in Preeclampsia

Placentation is a key and tightly regulated process that ensures the normal development of the placenta and fetal growth. Preeclampsia (PE) is a hypertensive pregnancy-related disorder involving about 5-8% of all pregnancies and clinically characterized by de novo maternal hypertension and proteinuria. In addition, PE pregnancies are also characterized by increased oxidative stress and inflammation. The NRF2/KEAP1 signaling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. ROS activate NRF2, allowing its binding to the antioxidant response element (ARE) region present in the promoter of several antioxidant genes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase that neutralize ROS, protecting cells against oxidative stress damages. In this review, we analyze the current literature regarding the role of the NRF2/KEAP1 pathway in preeclamptic pregnancies, discussing the main cellular modulators of this pathway. Moreover, we also discuss the main natural and synthetic compounds that can regulate this pathway in in vivo and in vitro models.

A longitudinal epigenome-wide association study of preeclamptic and normotensive pregnancy

Background

While preeclampsia (PE) is a leading cause of pregnancy-related morbidity/mortality, its underlying mechanisms are not fully understood. DNA methylation (DNAm) is a dynamic regulator of gene expression that may offer insight into PE pathophysiology and/or serve as a biomarker (e.g., risk, subtype, a therapeutic response). This study's purpose was to evaluate for differences in blood-based DNAm across all trimesters between individuals eventually diagnosed with PE (cases) and individuals who remained normotensive throughout pregnancy, did not develop proteinuria, and birthed a normally grown infant (controls).

Results

In the discovery phase, longitudinal, genome-wide DNAm data were generated across three trimesters of pregnancy in 56 participants (n=28 cases, n=28 controls) individually matched on self-identified race, pre-pregnancy body mass index, smoking, and gestational age at sample collection. An epigenome-wide association study (EWAS) was conducted, using surrogate variable analysis to account for unwanted sources of variation. No CpGs met the genome-wide significance p value threshold of 9×10-8, but 16 CpGs (trimester 1: 5; trimester 2: 1; trimester 3: 10) met the suggestive significance threshold of 1×10-5. DNAm data were also evaluated for differentially methylated regions (DMRs) by PE status. Three DMRs in each trimester were significant after Bonferonni-adjustment. Since only third-trimester samples were available from an independent replication sample (n=64 cases, n=50 controls), the top suggestive hits from trimester 3 (cg16155413 and cg21882990 associated with TRAF3IP2-AS1/TRAF3IP2 genes, which also made up the top DMR) were carried forward for replication. During replication, DNAm data were also generated for validation purposes from discovery phase third trimester samples. While significant associations between DNAm and PE status were observed at both sites in the validation sample, no associations between DNAm and PE status were observed in the independent replication sample.

Conclusions

The discovery phase findings for cg16155413/cg21882990 (TRAF3IP2-AS1/TRAF3IP2) were validated with a new platform but were not replicated in an independent sample. Given the differences in participant characteristics between the discovery and replication samples, we cannot rule out important signals for these CpGs. Additional research is warranted for cg16155413/cg21882990, as well as top hits in trimesters 1-2 and significant DMRs that were not examined in the replication phase.

Influence of pregnancy and non-fasting conditions on the plasma metabolome in a rat prenatal toxicity study

The current parameters for determining maternal toxicity (e.g. clinical signs, food consumption, body weight development) lack specificity and may underestimate the extent of effects of test compounds on the dams. Previous reports have highlighted the use of plasma metabolomics for an improved and mechanism-based identification of maternal toxicity. To establish metabolite profiles of healthy pregnancies and evaluate the influence of food consumption as a confounding factor, metabolite profiling of rat plasma was performed by gas- and liquid-chromatography-tandem mass spectrometry techniques. Metabolite changes in response to pregnancy, food consumption prior to blood sampling (non-fasting) as well as the interaction of both conditions were studied. In dams, both conditions, non-fasting and pregnancy, had a marked influence on the plasma metabolome and resulted in distinct individual patterns of changed metabolites. Non-fasting was characterized by increased plasma concentrations of amino acids and diet related compounds and lower levels of ketone bodies. The metabolic profile of pregnant rats was characterized by lower amino acids and glucose levels and higher concentrations of plasma fatty acids, triglycerides and hormones, capturing the normal biochemical changes undergone during pregnancy. The establishment of metabolic profiles of pregnant non-fasted rats serves as a baseline to create metabolic fingerprints for prenatal and maternal toxicity studies.

Preconception tests at advanced maternal age

Pregnancies at an advanced reproductive age are increasingly common. However, the safety of pregnancy remains a concern as maternal age is a recognized independent factor for various obstetric complications. Also, age is a risk factor for most systematic health problems and older women are more likely to enter into pregnancy with pre-existing conditions. At the moment there is no separate, structured guidance on preconception tests at advanced maternal age. However, the preconceptual period offers an ideal window to recognize and address underlying health issues, social issues and harmful lifestyle behaviours in order to optimize maternal health ultimately reducing infertility, perinatal morbidity and mortality. Preconception tests should be clinically relevant aiming to identify risk factors and address them to predict and prevent infertility and pregnancy complications. The importance of preconception care is magnified for women of advanced age for whom the risks are higher and the potential benefits greater.

Coenzyme Q10: Clinical Applications in Cardiovascular Diseases

Coenzyme Q₁₀ (CoQ₁₀) is a ubiquitous factor present in cell membranes and mitochondria, both in its reduced (ubiquinol) and oxidized (ubiquinone) forms. Its levels are high in organs with high metabolism such as the heart, kidneys, and liver because it acts as an energy transfer molecule but could be reduced by aging, genetic factors, drugs (e.g., statins), cardiovascular (CV) diseases, degenerative muscle disorders, and neurodegenerative diseases. As CoQ₁₀ is endowed with significant antioxidant and anti-inflammatory features, useful to prevent free radical-induced damage and inflammatory signaling pathway activation, its depletion results in exacerbation of inflammatory processes. Therefore, exogenous CoQ₁₀ supplementation might be useful as an adjuvant in the treatment of cardiovascular diseases such as heart failure, atrial fibrillation, and myocardial infarction and in associated risk factors such as hypertension, insulin resistance, dyslipidemias, and obesity. This review aims to summarize the current evidences on the use of CoQ₁₀ supplementation as a therapeutic approach in cardiovascular diseases through the analysis of its clinical impact on patients' health and quality of life. A substantial reduction of inflammatory and oxidative stress markers has been observed in several randomized clinical trials (RCTs) focused on several of the abovementioned diseases, even if more RCTs, involving a larger number of patients, will be necessary to strengthen these interesting findings.

Mitochondria and Coenzyme Q10 in the Pathogenesis of Preeclampsia

Hypertensive disorders during pregnancy constitute one of the main causes of maternal and perinatal morbidity and mortality across the world and particularly in developing countries such as Ecuador. However, despite its impact on public health, the primary pathophysiological processes involved are yet to be elucidated. It has been proposed, among other theories, that an abnormal placentation may induce an endothelial dysfunction, which is ultimately responsible for the final clinical manifestations. Mitochondria, particularly from trophoblastic cells, are responsible for the production of energy, which is extremely important for normal placentation. The malfunction in this supply of energy may produce higher levels of free radicals. In both production of energy and free radicals, coenzyme Q10 (CoQ10) plays a crucial role in electron transport. As such, the role of CoQ10 in the genesis and prevention of preeclampsia has become the focus of a number of research groups, including that of the authors. Developing an in-depth understanding of these mechanisms might allow us to design new and feasible strategies with which we can reduce preeclampsia, particularly in the Latin-American countries.

Vaginal lipidomics of women with vulvovaginal candidiasis and cytolytic vaginosis: A non-targeted LC-MS pilot study

Objective

To characterize the lipid profile in vaginal discharge of women with vulvovaginal candidiasis, cytolytic vaginosis, or no vaginal infection or dysbiosis.

Design

Cross-sectional study.

Setting

Genital Infections Ambulatory, Department of Tocogynecology, University of Campinas, Campinas, São Paulo–Brazil.

Sample

Twenty-four women were included in this study: eight with vulvovaginal candidiasis, eight with cytolytic vaginosis and eight with no vaginal infections or dysbiosis (control group).

Methods

The lipid profile in vaginal discharge of the different study groups was determined by liquid chromatography-mass spectrometry and further analyzed with MetaboAnalyst 3.0 platform.

Main outcome measures

Vaginal lipids concentration and its correlation with vulvovaginal candidiasis and cytolytic vaginosis.

Results

PCA, PLS-DA and hierarchical clustering analyses indicated 38 potential lipid biomarkers for the different groups, correlating with oxidative stress, inflammation, apoptosis and integrity of the vaginal epithelial tissue. Among these, greater concentrations were found for Glycochenodeoxycholic acid-7-sulfate, O-adipoylcarnitine, 1-eicosyl-2-heptadecanoyl-glycero-3-phosphoserine, undecanoic acid, formyl dodecanoate and lipoic acid in the vulvovaginal candidiasis group; N–(tetradecanoyl)-sphinganine, DL-PPMP, 1-oleoyl-cyclic phosphatidic, palmitic acid and 5-aminopentanoic acid in the cytolytic vaginosis group; and 1-nonadecanoyl-glycero-3-phosphate, eicosadienoic acid, 1-stearoyl-cyclic-phosphatidic acid, 1-(9Z,12Z-heptadecadienoyl)-glycero-3-phosphate, formyl 9Z-tetradecenoate and 7Z,10Z-hexadecadienoic acid in the control group.

Conclusions

Lipids related to oxidative stress and apoptosis were found in higher concentrations in women with vulvovaginal candidiasis and cytolytic vaginosis, while lipids related to epithelial tissue integrity were more pronounced in the control group. Furthermore, in women with cytolytic vaginosis, we observed higher concentrations of lipids related to bacterial overgrowth.

Plastoquinone and Ubiquinone in Plants: Biosynthesis, Physiological Function and Metabolic Engineering

Plastoquinone (PQ) and ubiquinone (UQ) are two important prenylquinones, functioning as electron transporters in the electron transport chain of oxygenic photosynthesis and the aerobic respiratory chain, respectively, and play indispensable roles in plant growth and development through participating in the biosynthesis and metabolism of important chemical compounds, acting as antioxidants, being involved in plant response to stress, and regulating gene expression and cell signal transduction. UQ, particularly UQ₁₀, has also been widely used in people's life. It is effective in treating cardiovascular diseases, chronic gingivitis and periodontitis, and shows favorable impact on cancer treatment and human reproductive health. PQ and UQ are made up of an active benzoquinone ring attached to a polyisoprenoid side chain. Biosynthesis of PQ and UQ is very complicated with more than thirty five enzymes involved. Their synthetic pathways can be generally divided into two stages. The first stage leads to the biosynthesis of precursors of benzene quinone ring and prenyl side chain. The benzene quinone ring for UQ is synthesized from tyrosine or phenylalanine, whereas the ring for PQ is derived from tyrosine. The prenyl side chains of PQ and UQ are derived from glyceraldehyde 3-phosphate and pyruvate through the 2-C-methyl-D-erythritol 4-phosphate pathway and/or acetyl-CoA and acetoacetyl-CoA through the mevalonate pathway. The second stage includes the condensation of ring and side chain and subsequent modification. Homogentisate solanesyltransferase, 4-hydroxybenzoate polyprenyl diphosphate transferase and a series of benzene quinone ring modification enzymes are involved in this stage. PQ exists in plants, while UQ widely presents in plants, animals and microbes. Many enzymes and their encoding genes involved in PQ and UQ biosynthesis have been intensively studied recently. Metabolic engineering of UQ₁₀ in plants, such as rice and tobacco, has also been tested. In this review, we summarize and discuss recent research progresses in the biosynthetic pathways of PQ and UQ and enzymes and their encoding genes involved in side chain elongation and in the second stage of PQ and UQ biosynthesis. Physiological functions of PQ and UQ played in plants as well as the practical application and metabolic engineering of PQ and UQ are also included.

Effects of lifestyle factors on urinary oxidative stress and serum antioxidant markers in pregnant Japanese women: A cohort study

Oxidative stress plays a major pathological role in pregnancy-related complications. Although oxidative stress is induced by exogenous toxins in association with a poor lifestyle in normal subjects, there is little information on the factors altering oxidative stress and antioxidant levels during pregnancy. The purpose of this study was to determine the relationship between lifestyle factors and oxidative stress/antioxidant levels during each trimester and 1-month postpartum. This prospective cohort study followed 54 healthy women through pregnancy; first, second, and third trimester and 1-month postpartum. Participants were administered a questionnaire on characteristics and lifestyle factors. Morning blood and urine samples were obtained to measure urinary biopyrrins and serum coenzyme Q10 (CoQ10) levels. The levels of urinary biopyrrins and serum CoQ10 increased significantly throughout pregnancy, with peak values registered during the third trimester. Higher biopyrrin levels were significantly associated with non-consumption of morning meal during the first trimester, smoking during the third trimester and 1-month postpartum, alcohol consumption during the third trimester, high food-based polyunsaturated fatty acid intake during the third trimester, and poor mental health scores during the first and third trimesters. Higher CoQ10 levels were significantly associated with no smoking during pregnancy and at 1-month postpartum, and with a high frequency of exercise during the third trimester and 1-month postpartum. Thus, pregnancy represents a state of oxidative stress, which can be counterbalanced by increased levels of antioxidants, such as CoQ10. We speculate that certain lifestyle choices such as avoiding smoking can reduce oxidative stress and increase antioxidant levels during pregnancy.

First-trimester plasma tocopherols are associated with risk of miscarriage in rural Bangladesh

BACKGROUND

Tocopherols were discovered for their role in animal reproduction, but little is known about the contribution of deficiencies of vitamin E to human pregnancy loss.

OBJECTIVE

We sought to determine whether higher first-trimester concentrations of α-tocopherol and γ-tocopherol were associated with reduced odds of miscarriage (pregnancy losses <24 wk of gestation) in women in rural Bangladesh.

DESIGN

A case-cohort study in 1605 pregnant Bangladeshi women [median (IQR) gestational age: 10 wk (8-13 wk)] who participated in a placebo-controlled vitamin A- or β-carotene-supplementation trial was done to assess ORs of miscarriage in women with low α-tocopherol (<12.0 μmol/L) and γ-tocopherol (<0.81 μmol/L; upper tertile cutoff of the γ-tocopherol distribution in women who did not miscarry).

RESULTS

In all women, plasma α- and γ-tocopherol concentrations were low [median (IQR): 10.04 μmol/L (8.07-12.35 μmol/L) and 0.66 μmol/L (0.50-0.95 μmol/L), respectively]. In a logistic regression analysis that was adjusted for cholesterol and the other tocopherol, low α-tocopherol was associated with an OR of 1.83 (95% CI: 1.04, 3.20), whereas a low γ-tocopherol concentration was associated with an OR of 0.62 (95% CI: 0.41, 0.93) for miscarriage. Subgroup analyses revealed that opposing ORs were evident only in women with BMI (in kg/m(2)) ≥18.5 and serum ferritin concentration ≤150 μg/L, although low BMI and elevated ferritin conferred stronger risk of miscarriage.

CONCLUSIONS

In pregnant women in rural Bangladesh, low plasma α-tocopherol was associated with increased risk of miscarriage, and low γ-tocopherol was associated with decreased risk of miscarriage. Maternal vitamin E status in the first trimester may influence risk of early pregnancy loss. The JiVitA-1 study, from which data for this report were derived, was registered at clinicaltrials.gov as NCT00198822.

Maternal plasma and amniotic fluid coenzyme Q10 levels in preterm and term gestations: a pilot study

OBJECTIVE

To measure maternal plasma and amniotic fluid coenzyme Q10 (CoQ10) levels in preterm and term gestations.

STUDY DESIGN

This pilot study comprised a convenience sample of 72 women admitted for labor with singleton live gestations and intact membranes (preterm n = 27 and term n = 45).

RESULTS

Median [interquartile range] maternal plasma CoQ10 levels did not differ among the studied women (preterm, 0.47 [0.12] vs. term, 0.47 [0.23] mmol/L, p = 0.90). Overall CoQ10 amniotic fluid levels were nearly tenfold lower than those found in maternal plasma, with a significant lower level observed among those delivering preterm (0.050 [0.05] vs. 0.062 [0.04] mmol/L, p = 0.007). Multiple linear regression analysis controlling for several covariates determined a significant correlation between amniotic fluid CoQ10 levels and neonatal gestational age.

CONCLUSION

This is the first study to assess CoQ10 levels in amniotic fluid during pregnancy in which levels were significantly lower among those delivering preterm. More research is warranted in this regard.

Ubiquinol-10 and ubiquinone-10 levels in umbilical cord blood of healthy foetuses and the venous blood of their mothers

Despite their being good markers of oxidative stress for clinical use, little is known about ubiquinol-10 (reduced coenzyme Q10) and ubiquinone-10 (oxidized coenzyme Q10) levels in foetuses and their mothers. This study investigates oxidative stress in 10 healthy maternal venous, umbilical arterial and venous bloods after vaginal delivery by measuring ubiquinol-10 and ubiquinone-10 levels. Serum ubiquinol-10 and ubiquinone-10 levels were measured by HPLC with a highly sensitive electrochemical detector. Maternal venous ubiquinol-10 and ubiquinone-10 levels were significantly higher than umbilical arterial and venous levels (all p < 0.001). However, the ubiquinone-10/total coenzyme Q10 (CoQ10) ratio, which reflects the redox status, was significantly higher in umbilical arterial and umbilical venous blood compared to maternal venous blood (all p < 0.001). The ubiquinone-10/total CoQ10 ratio was higher in umbilical arterial than in umbilical venous blood (p < 0.01). The present study demonstrated that foetuses were under higher oxidative stress than their mothers.

Effects of oral, vaginal, and transdermal hormonal contraception on serum levels of coenzyme q(10), vitamin e, and total antioxidant activity

The use of the transdermal contraceptive patch is associated with greater bioavailability of ethinyl estradiol (EE) compared with contraceptive vaginal ring or oral contraceptives (OC). We compared the influences of three contraceptive methods (OC, vaginal ring, and transdermal patch) on serum levels of coenzyme Q(10), alpha-tocopherol, gamma-tocopherol and total antioxidant capacity in premenopausal women. Blood samples from 30 premenopausal women who used hormonal contraception for at least 4 months were collected. Forty subjects who did not use any contraception were studied as control. Serum levels of coenzyme Q(10), alpha-tocopherol and gamma-tocopherol were measured by high-pressure liquid chromatography. Serum samples were also assayed for total antioxidant capacity (TAOC). Serum levels of coenzyme Q(10) and alpha-tocopherol were found to be significantly lower (P < .05) in all three contraceptive users compared with controls. Contraceptive patch users had the lowest levels of coenzyme Q(10) levels compared with normal subjects. Serum TAOC levels were significantly lower (P < .05) among the contraceptive user groups. Alterations in coenzyme Q(10) and alpha-tocopherol induced by hormonal contraception and the potential effect(s) of exogenous ovarian hormones should be taken into consideration in future antioxidant research.

Coenzyme Q10 supplementation during pregnancy reduces the risk of pre-eclampsia

OBJECTIVE

To assess whether supplementation with Coenzyme Q10 (CoQ10) during pregnancy reduces the risk of pre-eclampsia.

METHODS

Women at increased risk of pre-eclampsia were enrolled in a randomized, double-blind, placebo-controlled trial. Women were assigned to receive 200 mg of CoQ10 or placebo daily from 20 weeks of pregnancy until delivery. The primary outcome was rate of pre-eclampsia. Statistical analyses were by intention-to-treat.

RESULTS

Of the 235 women enrolled in the trial, 118 were randomized to receive CoQ10 and 117 received a placebo. A total of 197 (83.8%) women were followed-up. The overall rate of pre-eclampsia was 20% (n=47). Thirty women (25.6%) in the placebo group developed pre-eclampsia compared with 17 women (14.4%) in the CoQ10 group, and this reduction was significant (P=0.035) (relative risk [RR] 0.56; 95% confidence interval [CI], 0.33-0.96).

CONCLUSION

Supplementation with CoQ10 reduces the risk of developing pre-eclampsia in women at risk for the condition.

Coenzyme Q10 levels in women with preeclampsia living at different altitudes

BACKGROUND

Preeclampsia is a common disorder of pregnancy exhibiting abnormal plasma and placental coenzyme Q10 (CoQ10) levels when compared to normal pregnancies.

OBJECTIVE

To evaluate CoQ10 levels both in plasma and placenta among normal pregnant (n = 60) and preeclamptic (n = 63) primigravid women and determine the effect of high or low altitude residency.

STUDY DESIGN

CoQ10 was determined using High Performance Liquid Chromatography (HPLC) technique and group comparisons were performed.

RESULTS

Preeclamptic women living at high altitude displayed significantly lower CoQ10 plasma levels (0.64 +/- 0.23 vs. 0.82 +/- 0.46 micromol/L, p = 0.05). No differences were found in CoQ10 plasma levels among women living at sea level. Interestingly, plasma CoQ10 levels at low altitude in normal pregnancies were significantly lower than high altitude normal pregnancies. Compared to normal pregnancies, preeclamptic women displayed higher placental CoQ10 content, which was only significant among those living at sea level (0.120 +/- 0.07 vs. 0.076 +/- 0.04 ng/mg protein, p < 0.005). Normal pregnant women living at high altitude displayed higher placental CoQ10 content when compared to those residing at sea level (p < 0.0005).

CONCLUSION

Women suffering from preeclampsia (high or low altitude) display high placental CoQ10 content, with significant low plasma CoQ10 levels among those residing in high altitude. More research is warranted to establish the cause-effect relationship between CoQ10 levels and preeclampsia.

The NADPH- and iron-dependent lipid peroxidation in human placental microsomes

In pregnant females, placenta is the most important source of lipid hydroperoxides and other reactive oxygen species (ROS). The increased production of lipid peroxides is often linked to preeclampsia. In our study, we revealed that NADPH- and iron-dependent lipid peroxidation in human placental microsomes (HPM) occurred. In the presence of Fe2+ ion, HPM produced small amounts of thiobarbituric acid-reactive substances (TBARS) - a final product of lipid peroxidation. NADPH caused a strong increase of iron stimulated TBARS formation. TBARS formation was inhibited by superoxide dismutase, butylated hydroxytoluene and alpha-tocopherol but not by mannitol or catalase. TBARS and superoxide radical production was inhibited in similar manner by cytochrome P450 inhibitors. The results obtained led us to the following conclusions: (1) microsomal lipid peroxidation next to mitochondrial lipid peroxidation may by an important source of lipid hydroperoxides in blood during pregnancy and (2) superoxide radical released by microsomal cytochrome P450 is an important factor in NADPH- and iron-dependent lipid peroxidation in HPM.

Effects of menstrual cycle and oral contraceptive use on serum levels of lipid-soluble antioxidants

OBJECTIVE

The purpose of this study was to examine the influence of menstrual cycle and oral contraceptive use on serum levels of lipid-soluble antioxidants.

STUDY DESIGN

In this cross-section study, nonfasting blood samples were collected twice from 10 healthy premenopausal women during the follicular phase (between days 8 and 11) and the luteal phase (between days 18 and 22) of their same menstrual cycle. In addition, blood samples from 15 premenopausal women who used oral contraceptive for at least 6 months and 40 women who did not use oral contraceptive were collected randomly at any day of the menstrual cycle. Serum levels of coenzyme Q10, alpha-tocopherol, gamma-tocopherol, beta-carotene, alpha-carotene, and lycopene were determined using high pressure liquid chromatography.

RESULTS

Serum coenzyme Q10 and alpha-tocopherol levels were significantly lower during the follicular phase compared with the luteal phase of the same menstrual cycle (P < .05). Oral contraceptive use also significantly decreased coenzyme Q10 and alpha-tocopherol (P < .001). Other antioxidant levels were comparable.

CONCLUSION

Alterations in coenzyme Q10 and alpha-tocopherol levels during the menstrual cycle and in oral contraceptive users should be taken into consideration, concerning the future antioxidant research in premenopausal women. Further studies are needed to investigate the potential role of endogenous and exogenous ovarian hormones on oxidative stress in women.

The role of placental oxidative stress and lipid peroxidation in preeclampsia

Preeclampsia is a complex multisystem disorder exclusively seen in human species that is characterized by hypertension and proteinuria. This disorder has the highest maternal and fetal morbidity and mortality of all pregnancy-related complications. Growing evidence suggests that placental oxidative stress is involved in the etiopathogenesis of preeclampsia. Reduced perfusion as a result of abnormal placentation leads to ischemia reperfusion injury to the placenta. Placental oxidative stress, which results from the ischemia reperfusion injury, is being increasingly reported to be involved in the etiopathogenesis of preeclampsia. It has been proposed as a promoter of lipid peroxidation and the endothelial cell dysfunction that is commonly seen in this condition. Although preeclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity, there is no consensus regarding causality of lipid peroxidation in preeclampsia. In this article, we address the question of the biologic association of lipid peroxidation and preeclampsia. Lipid peroxidation and leukocyte activation may play a pivotal role in endothelial cell dysfunction. We also review the different factors that have been proposed to cause endothelial cell dysfunction in preeclampsia, trials investigating the role of antioxidant supplementation in preeclampsia, and the lack of consensus among the trials. Additional longitudinal studies are necessary to determine if the various oxidative stress biomarkers estimated early in pregnancy can be narrowed to a single marker for predicting preeclampsia.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to recall that placental oxidative stress is involved in the etiopathogenesis of preeclampsia, state that placental oxidative stress results from ischemic reperfusion injury, and explain that ischemic reperfusion injury is a promoter of lipid peroxidation and endothelial cell dysfunction seen in preeclampsia.

Pathophysiological basis for the prophylaxis of preeclampsia through early supplementation with antioxidant vitamins

Preeclampsia (PE) is a multisystem disorder that remains a major cause of maternal and foetal morbidity and death. To date, no treatment has been found that prevents the development of the disease. Endothelial dysfunction is considered to underlie its clinical manifestations, such as maternal hypertension, proteinuria, and edema; however, the precise biochemical pathways involved remain unclear. A current hypothesis invokes the occurrence of oxidative stress as pathogenically important, as suggested by the fact that in PE, the placental and circulating levels of lipid peroxidation products (F2-isoprostanes and malondialdehyde [MDA]) are increased and endothelial cells are activated. A potential mechanism for endothelial dysfunction may occur via nuclear transcription factor kappa B (NF-kappaB) activation by oxidative stress. Alternatively, the idea that the antiangiogenic placental soluble fms-like tyrosine kinase 1 factor (sFlt1) is involved in the pathogenesis of this disease is just emerging; however, other pathophysiological events seem to precede its increased production. This review is focused on evidence providing a pathophysiological basis for the beneficial effect of early antioxidant therapy in the prevention of PE, mainly supported by the biological effects of vitamins C and E.

Coenzyme Q10 is increased in placenta and cord blood during preeclampsia

Preeclampsia is a common (approximately 7% of all pregnancies) disorder of pregnancy in which the normal hemodynamic response to pregnancy is compromised. Despite many years of intensive research, the pathogenesis of preeclampsia is still not fully understood. The objective of the present study was to investigate the levels of coenzyme Q(10) (CoQ(10)) in placental tissue compared to maternal and umbilical cord levels both during normal pregnancy and in those complicated with preeclampsia. Pregnant women (n = 30) and women with preeclampsia (n = 30) were included. Maternal, newborn cord blood levels and placental content of coenzyme Q(10) were measured by high performance liquid chromatography (HPLC). Plasma coenzyme Q(10) levels were significantly higher in normal pregnant women than in women with preeclampsia. CoQ(10) content in placenta from women with preeclampsia (mean 0.28 SEM 0.11 nmol/mg protein) was significantly higher compared to normal pregnancy (mean 0.09 SEM 0.01 nmol/mg protein; p = 0.05). Levels of CoQ(10) in cord blood from normal pregnant women (mean 0.30 SEM 0.05 micromol/l) were significantly lower than in preeclamptic women (mean 4.03 SEM 2.38 micromol/l). In conclusion, these data indicate a possible involvement of CoQ(10) in preeclampsia that might bear deep physiopathological significance and deserve to be further elucidated.

Placental CoQ10 levels in HELLP syndrome

Oxidative stress is considered a key factor in HELLP syndrome, a severe complication of preeclampsia in pregnancy. In the present study we analysed the content of Coenzyme Q(10) (CoQ(10)), a fundamental component of the mitochondrial respiratory chain and recognized lipophilic antioxidant, in placentas from women affected by HELLP syndrome and compared them with the relative controls. Twenty-eight patients with HELLP syndrome and twenty-eight age-matched healthy pregnant controls were enrolled. Two aliquots of placental tissue were taken immediately after delivery and placed into liquid nitrogen. Thawed samples were homogenised by Ultra-Turrax; total protein and CoQ(10) concentration were thereafter analysed. CoQ(10) concentration was 0.162 +/- 0.07 microg/mg protein in HELLP syndrome versus 0.87 +/- 0.003 microg/mg protein in controls, the difference being highly significant. A positive correlation, within the placentas from HELLP, was found between the weight of the new-born and CoQ(10)/protein ratio. A significant positive correlation was also present between CoQ(10)/protein ratio and Apgar at 1st and 5th minute as well as between CoQ(10)/protein ratio and the median cerebral artery pulsatility index. The increase in placental CoQ(10) in this syndrome might derive from a compensatory mechanism in a situation of increased oxidative stress.

Age-related changes in plasma coenzyme Q10 concentrations and redox state in apparently healthy children and adults

BACKGROUND

Coenzyme Q10 (CoQ) is an endogenous enzyme cofactor, which may provide protective benefits as an antioxidant. Because age-related CoQ changes and deficiency states have been described, there is a need to establish normal ranges in healthy children. The objectives of this study are to determine if age-related differences in reduced CoQ (ubiquinol), oxidized CoQ (ubiquinone), and CoQ redox state exist in childhood, and to establish reference intervals for these analytes in healthy children.

METHODS

Apparently healthy children (n=68) were selected from individuals with no history of current acute illness, medically diagnosed disease, or current medication treatment. Self-reported healthy adults (n=106) were selected from the ongoing Princeton Follow-up Study in greater Cincinnati. Participants were assessed for lipid profiles, ubiquinol concentration, ubiquinone concentration, total CoQ concentration, and CoQ redox ratio.

RESULTS

Mean total CoQ and ubiquinol concentrations are similar in younger children (0.2-7.6 years) and adults (29-78 years); however, lipid-adjusted total CoQ concentrations are significantly increased in younger children. Also CoQ redox ratio is significantly increased in younger and older children compared with adults.

CONCLUSIONS

Elevated CoQ and redox ratios in children may be an indication of oxidative stress effects, which are associated with early development of coronary heart disease.