Augmented oxidative stress as well as antioxidant capacity in maternal circulation in preeclampsia

Dietary carotenoid intake and risk of developing preeclampsia: a hospital-based case-control study

Background

The effect of carotenoids on the risk of preeclampsia (PE) is uncertain. We aimed to examine the associations between the intake of dietary carotenoids and related compounds by pregnant women in China, and the risk of their developing PE.

Methods

Four hundred and forty PE cases and 440 age- (± 3 years), gestational age- (± 1 weeks) and gestational diabetes mellitus status- (yes/no) matched healthy controls were recruited from March 2016 to June 2019. Dietary intake of carotenoids was assessed using a 79-item validated food-frequency questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression.

Results

After adjusting for potential confounders, we found that the intake of total carotenoids, β-carotene, β-cryptoxanthin, lycopene, and lutein and zeaxanthin (lut-zea) were negatively associated with the odds of developing PE. Compared with the lowest quartile intake, the multivariate-adjusted OR (95% CI) of the highest quartile intake was 0.29 (0.16–0.54, P_trend <  0.001) for total carotenoids, 0.31 (0.16–0.58, P_trend <  0.001) for β-carotene, 0.50 (0.27–0.90, P_trend = 0.007) for β-cryptoxanthin, 0.55 (0.30–0.99, P_trend = 0.04) for lycopene and 0.32 (0.17–0.61, P_trend = 0.001) for lut-zea. However, no significant associations were observed between the risk of developing PE and α-carotene intake (OR = 0.75, 95% CI: 0.41–1.36, P_trend = 0.28). Moreover, similar negative associations were found for every one-standard-deviation increase in the intake of total carotenoids, β-carotene, β-cryptoxanthin, lycopene and lut-zea.

Conclusion

These results indicate that a high intake of total carotenoids, β-carotene, β-cryptoxanthin, lycopene and lut-zea may be associated with a low risk of developing PE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04737-5.

Preeclampsia and Gestational Hypertension: Biochemical and Antioxidant Features in Vitro Might Help Understand Different Outcomes

OBJECTIVE

 Gestational hypertension (GH) is characterized by increased blood pressure after the 20^th gestational week; the presence of proteinuria and/or signs of end-organ damage indicate preeclampsia (PE). Heme oxygenase-1 (HO-1) is an antioxidant enzyme with an important role in maintaining endothelial function, and induction of HO-1 by certain molecules shows potential in attenuating the condition's effects over endothelial tissue. HO-1 production can also be stimulated by potassium iodide (KI). Therefore, we evaluated the effects of KI over HO-1 expression in human umbilical vein endothelial cells (HUVECs) incubated with plasma from women diagnosed with GH or PE.

METHODS

 Human umbilical vein endothelial cells were incubated with a pool of plasma of healthy pregnant women (n = 12), pregnant women diagnosed with GH (n = 10) or preeclamptic women (n = 11) with or without the addition of KI for 24 hours to evaluate its effect on this enzyme expression. Analysis of variance was performed followed by Dunnet's test for multiple comparisons between groups only or between groups with addition of KI (p ≤ 0.05).

RESULTS

 KI solution (1,000 µM) reduced HO-1 in the gestational hypertension group (p = 0.0018) and cytotoxicity in the preeclamptic group (p = 0.0143); treatment with KI reduced plasma cytotoxicity but did not affect the preeclamptic group's HO-1 expression.

CONCLUSION

 Our findings suggest that KI alleviates oxidative stress leading to decreased HO-1 expression; plasma from preeclamptic women did not induce the enzyme's expression in HUVECs, and we hypothesize that this is possibly due to inhibitory post-transcriptional mechanisms in response to overexpression of this enzyme during early pregnancy.

SIRT1-dependent effects of resveratrol and grape juice in an in vitro model of preeclampsia

Preeclampsia (PE) is a multifactorial hypertensive disorder of pregnancy that is partly responsible for both maternal and fetal morbidity and mortality levels worldwide. It has been recently discovered that sirtuin-1 (SIRT1) is reduced in the circulation and in an in vitro model of PE. Therefore, in this study, we investigated the effects of trans-resveratrol, a potent antioxidant and activator of SIRT1, on oxidative stress and nitric oxide (NO) production in an in vitro model of PE compared to gestational hypertensive (GH) and healthy pregnant (HP) women. Furthermore, we also evaluated the effects of an acute intake of grape juice on women with PE to assess whether it could mimic in vitro trans-resveratrol supplementation. (1) In the GH group, resveratrol decreased intracellular reactive oxygen species (ROS) and increased their antioxidant capacity, while inhibiting SIRT1 reestablished previous levels. (2) In PE, inhibition of SIRT1 increased antioxidant activity. (3) Intracellular NO and supernatant nitrite levels were increased by inhibiting SIRT1 in the PE group. (4) Grape juice intake increased intracellular NO levels versus before grape juice intake control; however, the inhibition of SIRT1 before grape juice intake initially increased NO, but decreased it 1 h after grape juice intake. In conclusion, activating SIRT1 by using resveratrol alone may not be beneficial to women with PE, and GH and PE seem to have different responsive mechanisms to this molecule. Furthermore, grape juice intake seems to have different effects compared to resveratrol supplementation alone in this in vitro model of PE, demonstrating the potential of the combination of other biologically active molecules from grape juice over the SIRT1-eNOS-NO in PE treatment.

Maternal serum lipid levels, oxidative stress and antioxidant activity in pre-eclampsia patients from Southwest India

OBJECTIVE

A study was carried out to evaluate the effects of metabolic syndrome components and oxidative stress factors among preeclamptic women from South West India.

STUDY DESIGN

A case-control study was carried out by enrolling fifty pre-eclampsia cases and hundred low-risk pregnant women within the age group of 18-40 years, at 28-34 weeks of pregnancy. The fasting glucose level, fasting insulin level, insulin resistance, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), malondialdehyde, the ferric reducing ability of plasma (FRAP assay), cardiac output and aortic wall distensibility were measured.

MAIN OUTCOME MEASURES

There was a significant rise in the fasting blood glucose, fasting insulin, insulin resistance levels, total cholesterol, triglycerides, LDL, and antioxidant levels in pre-eclamptic women (p < 0.001). The cardiac output and aortic wall distensibility were observed to be low in the cases.

CONCLUSION

We conclude that abnormal lipid metabolism and high lipid peroxide concentrations observed in pre-eclampsia may result in oxidative stress and vascular dysfunction.

Health Effects of Carotenoids during Pregnancy and Lactation

Adequate nutrition is particularly important during pregnancy since it is needed not only for maintaining the health of the mother, but also determines the course of pregnancy and its outcome, fetus development as well as the child’s health after birth and during the later period of life. Data coming from epidemiological and interventions studies support the observation that carotenoids intake provide positive health effects in adults and the elderly population. These health effects are the result of their antioxidant and anti-inflammatory properties. Recent studies have also demonstrated the significant role of carotenoids during pregnancy and infancy. Some studies indicate a correlation between carotenoid status and lower risk of pregnancy pathologies induced by intensified oxidative stress, but results of these investigations are equivocal. Carotenoids have been well studied in relation to their beneficial role in the prevention of preeclampsia. It is currently hypothesized that carotenoids can play an important role in the prevention of preterm birth and intrauterine growth restriction. Carotenoid status in the newborn depends on the nutritional status of the mother, but little is known about the transfer of carotenoids from the mother to the fetus. Carotenoids are among the few nutrients found in breast milk, in which the levels are determined by the mother’s diet. Nutritional status of the newborn directly depends on its diet. Both mix feeding and artificial feeding may cause depletion of carotenoids since infant formulas contain only trace amounts of these compounds. Carotenoids, particularly lutein and zeaxanthin play a significant role in the development of vision and nervous system (among others, they are important for the development of retina as well as energy metabolism and brain electrical activity). Furthermore, more scientific evidence is emerging on the role of carotenoids in the prevention of disorders affecting preterm infants, who are susceptible to oxidative stress, particularly retinopathy of prematurity.

Classifying oxidative stress by F2-isoprostane levels across human diseases: A meta-analysis

The notion that oxidative stress plays a role in virtually every human disease and environmental exposure has become ingrained in everyday knowledge. However, mounting evidence regarding the lack of specificity of biomarkers traditionally used as indicators of oxidative stress in human disease and exposures now necessitates re-evaluation. To prioritize these re-evaluations, published literature was comprehensively analyzed in a meta-analysis to quantitatively classify the levels of systemic oxidative damage across human disease and in response to environmental exposures.

In this meta-analysis, the F₂-isoprostane, 8-iso-PGF_2α, was specifically chosen as the representative marker of oxidative damage. To combine published values across measurement methods and specimens, the standardized mean differences (Hedges’ g) in 8-iso-PGF_2α levels between affected and control populations were calculated.

The meta-analysis resulted in a classification of oxidative damage levels as measured by 8-iso-PGF_2α across 50 human health outcomes and exposures from 242 distinct publications. Relatively small increases in 8-iso-PGF_2α levels (g<0.8) were found in the following conditions: hypertension (g=0.4), metabolic syndrome (g=0.5), asthma (g=0.4), and tobacco smoking (g=0.7). In contrast, large increases in 8-iso-PGF_2α levels were observed in pathologies of the kidney, e.g., chronic renal insufficiency (g=1.9), obstructive sleep apnoea (g=1.1), and pre-eclampsia (g=1.1), as well as respiratory tract disorders, e.g., cystic fibrosis (g=2.3).

In conclusion, we have established a quantitative classification for the level of 8-iso-PGF_2α generation in different human pathologies and exposures based on a comprehensive meta-analysis of published data. This analysis provides knowledge on the true involvement of oxidative damage across human health outcomes as well as utilizes past research to prioritize those conditions requiring further scrutiny on the mechanisms of biomarker generation.

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Oxidative damage is highly variable in human conditions as measured by F₂-isoprostanes.

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Respiratory tract and urogenital diseases have the highest F₂-isoprostanes.

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Cancer and cardiovascular diseases have surprisingly low F₂-isoprostanes.

Determination of glucose exchange rates and permeability of erythrocyte membrane in preeclampsia and subsequent oxidative stress-related protein damage using dynamic-19F-NMR

The cause of the pregnancy condition preeclampsia (PE) is thought to be endothelial dysfunction caused by oxidative stress. As abnormal glucose tolerance has also been associated with PE, we use a fluorinated-mimic of this metabolite to establish whether any oxidative damage to lipids and proteins in the erythrocyte membrane has increased cell membrane permeability. Data were acquired using ¹⁹F Dynamic-NMR (DNMR) to measure exchange of 3-fluoro-3-deoxyglucose (3-FDG) across the membrane of erythrocytes from 10 pregnant women (5 healthy control women, and 5 from women suffering from PE). Magnetisation transfer was measured using the 1D selective inversion and 2D EXSY pulse sequences, over a range of time delays. Integrated intensities from these experiments were used in matrix diagonalisation to estimate the values of the rate constants of exchange and membrane permeability. No significant differences were observed for the rate of exchange of 3-FDG and membrane permeability between healthy pregnant women and those suffering from PE, leading us to conclude that no oxidative damage had occurred at this carrier-protein site in the membrane.

Nicotinamide benefits both mothers and pups in two contrasting mouse models of preeclampsia

Preeclampsia (PE) complicates ∼5% of human pregnancies and is one of the leading causes of pregnancy-related maternal deaths. The only definitive treatment, induced delivery, invariably results in prematurity, and in severe early-onset cases may lead to fetal death. Many currently available antihypertensive drugs are teratogenic and therefore precluded from use. Nonteratogenic antihypertensives help control maternal blood pressure in PE, but results in preventing preterm delivery and correcting fetal growth restriction (FGR) that also occurs in PE have been disappointing. Here we show that dietary nicotinamide, a nonteratogenic amide of vitamin B₃, improves the maternal condition, prolongs pregnancies, and prevents FGR in two contrasting mouse models of PE. The first is caused by endotheliosis due to excess levels in the mothers of a soluble form of the receptor for vascular endothelial growth factor (VEGF), which binds to and inactivates VEGF. The second is caused by genetic absence of Ankiryn-repeat-and-SOCS-box-containing-protein 4, a factor that contributes to the differentiation of trophoblast stem cells into the giant trophoblast cells necessary for embryo implantation in mice; its absence leads to impaired placental development. In both models, fetal production of ATP is impaired and FGR is observed. We show here that nicotinamide decreases blood pressure and endotheliosis in the mothers, probably by inhibiting ADP ribosyl cyclase (ADPRC), and prevents FGR, probably by normalizing fetal ATP synthesis via the nucleotide salvage pathway. Because nicotinamide benefits both dams and pups, it merits evaluation for preventing or treating PE in humans.

Cytokines, angiogenic, and antiangiogenic factors and bioactive lipids in preeclampsia

Preeclampsia is a low-grade systemic inflammatory condition in which oxidative stress and endothelial dysfunction occurs. Plasma levels of soluble receptor for vascular endothelial growth factor (VEGFR)-1, also known as sFlt1 (soluble fms-like tyrosine kinase 1), an antiangiogenic factor have been reported to be elevated in preeclampsia. It was reported that pregnant mice deficient in catechol-O-methyltransferase (COMT) activity show a preeclampsia-like phenotype due to a deficiency or absence of 2-methoxyoestradiol (2-ME), a natural metabolite of estradiol that is elevated during the third trimester of normal human pregnancy. Additionally, autoantibodies (AT1-AAs) that bind and activate the angiotensin II receptor type 1 a (AT1 receptor) also have a role in preeclampsia. None of these abnormalities are consistently seen in all the patients with preeclampsia and some of them are not specific to pregnancy. Preeclampsia could occur due to an imbalance between pro- and antiangiogenic factors. VEGF, an angiogenic factor, is necessary for the transport of polyunsaturated fatty acids (PUFAs) to endothelial cells. Hence reduced VEGF levels decrease the availability of PUFAs to endothelial cells. This leads to a decrease in the formation of anti-inflammatory and angiogenic factors: lipoxins, resolvins, protectins, and maresins from PUFAs. Lipoxins, resolvins, protectins, maresins, and PUFAs suppress insulin resistance; activation of leukocytes, platelets, and macrophages; production of interleukin-6 and tumor necrosis factor-α; and oxidative stress and endothelial dysfunction; and enhance production of prostacyclin and nitric oxide (NO). Estrogen enhances the formation of lipoxin A4 and NO. PUFAs also augment the production of NO and inhibit the activity of angiotensin-converting enzyme and antagonize the actions of angiotensin II. Thus, PUFAs can prevent activation of angiotensin II receptor type 1 a (AT1 receptor). Patients with preeclampsia have decreased plasma phospholipid concentrations of arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), the precursors of lipoxins (from AA), resolvins (from EPA and DHA), and protectins (from DHA) and prostaglandin E1 (PGE1 from DGLA: dihomo-γ-linolenic acid) and prostacyclin (PGI2 derived from AA). Based on these evidences, it is proposed that preeclampsia may occur due to deficiency of PUFAs and their anti-inflammatory products: lipoxins, resolvins, protectins, and maresins.

Evaluation of oxidative stress levels in the conjunctival epithelium of patients with or without dry eye, and dry eye patients treated with preservative-free hyaluronic acid 0.15 % and vitamin B12 eye drops

PURPOSE

Increased levels of oxidative stress have been seen in animal models of dry eye and in the conjunctival epithelial cells of patients with Sjögren's syndrome. The aims of this study were to compare the levels of oxidative stress in patients with dry eye and patients without dry eye and to evaluate the effects of treatment with preservative-free eye drops containing hyaluronic acid 0.15 % and vitamin B12 on oxidative stress and dry eye symptoms.

METHODS

Three cohorts of patients who were to undergo planned cataract surgery were enrolled: patients with dry eye randomized to either no treatment (n = 29) or treatment (n = 32) with hyaluronic acid/vitamin B12 eye drops, and patients without dry eye (n = 42). Patients were assessed by Schirmer's type I test, fluorescein clearance test (FCT), Break Up Time (BUT), and Ocular Surface Disease Index (OSDI). Lipid peroxidation, a marker of oxidative stress, was assessed by LP-CHOLOX test.

RESULTS

Compared with patients without dry eye, patients with dry eye had significantly increased levels of oxidative stress, higher OSDI and FCT scores, and significantly lower Schirmer's test and BUT scores. Treatment with eye drops containing hyaluronic acid 0.15 % and vitamin B12 was associated with significantly reduced levels of oxidative stress and OSDI and FCT scores and significantly increased Schirmer's test and BUT scores.

CONCLUSIONS

These findings indicate that oxidative stress is associated with dry eye and that hyaluronic acid/vitamin B12 eye drops may attenuate oxidative stress and inflammation, improving dry eye symptoms. Further study in controlled clinical trials is warranted.

Preeclampsia and future cardiovascular risk: are women and general practitioners aware of this relationship? The experience from a portuguese centre

Objective. To evaluate the impact of preeclampsia in the modification of lifestyle habits and decreasing cardiovascular risk factors in a population of women at least 6 months after having the diagnosis of preeclampsia. Methods. Cross-sectional observational study. Data included 141 cases of preeclampsia and chronic hypertension with superimposed preeclampsia on singleton births diagnosed in our institution between January 2010 and December 2013. From the cases diagnosed over 6 months a standardized questionnaire evaluating lifestyle changes was applied. Results. We reviewed 141 cases, of which 120 were diagnosed for more than 6 months. An overall participation rate in the questionnaire of 65% was yielded. A slight increase from the mean BMI before pregnancy was found. No statistical significant association was established between postpregnancy mean BMI, weight variation, and the frequency of aerobic exercise with the severity of preeclampsia. Only 28% of our cases were practising aerobic exercise at least weekly. The majority of women assessed blood pressure at least monthly (45/78), but only 25 assessed glycaemia at least once/year. Conclusion. This study shows that the majority of our patients and general practitioners do not take into consideration a previous pregnancy affected by preeclampsia as a risk factor for future cardiovascular disease.

Assessment of oxidative status markers and NO bioavailability in hypertensive disorders of pregnancy

The systemic oxidative status in hypertensives disorders of pregnancy (HDP) and its association with endothelial dysfunction is controversial. In the present study, we evaluated systemic plasma levels of oxidative stress markers (TBARS (thiobarbituric acid-reactive substances) and carbonyl) and total antioxidant status (FRAP (ferric reducing ability of plasma (ferric reducing/antioxidant power) and reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide))), as well as assessed the impact these markers have on nitric oxide (NO) status in healthy pregnant (HP, n=38), gestational hypertensive (GH, n=33) and preeclamptic pregnant women (PE, n=28). We found similar values of TBARS among all groups, and reduced carbonyl levels in HDP between the PE and GH. Conversely, significant increases in plasma activity of antioxidant status were observed in the GH and PE groups compared to the HP group (using both MTT or FRAP method). Importantly, HDP present significantly lower nitrite levels compared to HP women. In Conclusion, our findings show a compensatory antioxidant mechanism against reactive oxygen species (ROS) generation in HDP, which is not associated with nitrite levels restoration.

Oxidative stress in pathological pregnancies

Oxidative stress (OS) plays a role in pregnancy at risk of pre-eclampsia, diabetes and premature labour. We measured three markers of OS: total antioxidant capacity (TAC), thiolyte capacity and pro-oxidant capacity in 45 women: 15 normal pregnancies, 17 pathological pregnancies (pre-eclampsia and pregestational diabetes) and 13 delivered pre-term. Plasma TAC (μmol/ml) values in patients with pathological pregnancies (235.67 ± 70.08) (p(1) = 0.0086) and pre-term labour (243.51 ± 50.52) (p(2) = 0.0479) were significantly reduced as compared with the controls (306.78 ± 70.08). Thiolyte capacity (μmol/ml) in the pathological pregnancies (326.03 ± 78.24) (p(3) = 0.0029) and in pre-term labour (335.94 ± 76.63) (p(4) = 0.0084) groups were significantly reduced compared with the control group (417.48 ± 39.76) (p < 0.05). Pro-oxidant capacity (mg/100 ml) in the pathological pregnancies (94.11 ± 26.13) (p(5) = 0.00034) and in pre-term labour (87.18 ± 20.28) (p(6) = 0.00044) groups were significantly higher compared with the controls (60.27 ± 6.33). Elevated OS values were seen in pathological pregnancies. This supports the important role of OS in diseases in pregnancy, particularly pre-eclampsia, diabetes and pre-term birth.

Is there a role for isofurans and neuroprostanes in pre-eclampsia and normal pregnancy?

Pre-eclampsia is a complex disorder of pregnancy that adversely affects the mother and baby. Arachidonic acid and docosahexaenoic acid are essential for fetal development and can undergo free radical oxidation to F(2)-isoprostanes (F(2)-IsoPs) and isofurans (IsoFs); and F(4)-neuroprostanes (F(4)-NeuroPs), respectively. These metabolites may be relevant to pre-eclampsia and fetal development. We examined IsoFs, F(4)-NeuroPs, and F(2)-IsoPs in maternal plasma and cord blood plasma of 23 women with pre-eclampsia and 21 normal pregnancies. Women with pre-eclampsia had significantly elevated maternal IsoFs and F(4)-NeuroPs, but not F(2)-IsoPs. Cord blood F(4)-NeuroPs were elevated among neonates of women with pre-eclampsia. In women with pre-eclampsia, birth weight was predicted by gestation at delivery. The latter was also true in normal pregnancy, but birth weight was negatively related to maternal F(2)-IsoPs, IsoFs, and F(4)-NeuroPs. We have shown that in women with pre-eclampsia, IsoFs and F(4)-NeuroPs are elevated, and cord blood F(4)-NeuroPs are increased. The inverse relationship between maternal F(2)-IsoPs, IsoFs, and F(4)-NeuroPs and birth weight may be relevant as predictors of low birth weight in normal pregnancy. Future studies should examine whether these markers in maternal blood at early stages of pregnancy relate to subsequent maternal, fetal, and neonatal complications.

Serum derivative of reactive oxygen metabolites (d-ROMs) in pediatric hemato-oncological patients with neutropenic fever

BACKGROUND

Early markers for predicting the severity of neutropenic fever (NF) in patients with hemato-oncological patients have not yet been established. Reactive oxygen species are known to play an important role in the antimicrobial function of neutrophils. The aim of this study was to determine the serum levels of derivatives of reactive oxygen metabolites (d-ROMs) and the biological antioxidant potential (BAP) levels in these patients, and to investigate the associations between these levels and the severity of NF.

PROCEDURE

Twenty-seven pediatric hemato-oncological patients were enroled in this prospective study. Their median age was 10 years (range 1-19). Laboratory samples for C-reactive protein (CRP), d-ROMs, and BAP were collected at the onset of NF. The Free Radical Analytical System 4(R) was used to measure levels of d-ROMs and BAP.

RESULTS

A total 36 NF episodes were evaluated. Levels of d-ROMs in NF patients with systemic inflammatory response syndrome (SIRS, n = 7) were significantly lower than those in subjects without SIRS (n = 29; 197.6 vs. 314.1 U.CARR, P = 0.017). There were no statistically significant differences in CRP, BAP, WBC count, or neutrophil count at the onset. The peak levels of CRP were significantly higher in patients with SIRS than in those without SIRS (23.9 vs. 6.1 mg/dl, P = 0.0003).

CONCLUSION

Patients with low level of d-ROMs at the onset of NF should be observed stringently since they possibly have severe NF.

Plasma sFlt-1-to-PlGF ratio is correlated with inflammatory but not with oxidative stress in Chinese preeclamptic women

PURPOSE

Considerable interest has been focused on angiogenic factors and angiogenic imbalance in the field of pre-eclampsia (PE), owing to its gaining role in the development of PE. This study was addressed to investigate the associations of sFlt-1-to-PlGF plasma ratios with oxidative stress assessed by the level of 8-isoprostane, and inflammation measured by the level of high-sensitive C-reactive protein (hs-CRP), and adipocytokines.

METHODS

A total of 83 patients with PE including 47 mild PE (MPE) and 36 severe PE (SPE) and 50 age-matched normotensive subjects in the third trimester of pregnancy were examined. Measurements included body mass index (BMI), systolic and diastolic blood pressure (BP) levels, plasma concentrations of hs-CRP, 8-isoprostane, adiponectin, and leptin.

RESULTS

Subjects with PE had higher levels of sFlt-1/PlGF (P < 0.01), hs-CRP (P < 0.01), 8-isoprostane and leptin (both P < 0.01) and lower adiponectin (P < 0.01) than did normotensive control subjects. Significant positive correlations were found between plasma sFlt-1/PlGF and hs-CRP (r = 0.437, P < 0.01) or leptin (r = 0.656, P < 0.01). A weak inverse correlation emerged between sFlt-1/PlGF and adiponectin (r = -0.306, P < 0.01). When a multiple regression analysis was performed, with sFlt-1/PlGF as a dependent variable and all the other parameters as independent variables, sFlt-1/PlGF maintain a significant relationship with leptin (beta = 0.219, P < 0.05) and with hs-CRP (beta = 0.295, P < 0.01) as well as with systolic BP(beta = 0.446, P < 0.05).

CONCLUSIONS

In Chinese preeclamptic women, plasma sFlt-1-to-PlGF ratio is correlated with inflammatory and adipocytokines but not with oxidative stress.

Aromatic amino acid biomarkers of preeclampsia--a nuclear magnetic resonance investigation

OBJECTIVES

There is conflicting literature regarding the correlation between aromatic amino acid concentrations and the occurrence of preeclampsia (PE). The object of this study was to test whether these molecules could enable discrimination between healthy and preeclamptic pregnancies when detected using (1)H nuclear magnetic resonance spectroscopy.

METHODS

Plasma samples from 11 normotensive and 11 preeclamptic pregnant women were analyzed using (1)H-NMR. The the aromatic region of the spectrum was divided into regions of uniform size. The area of each region was subjected to principal component analysis.

RESULTS

A distinction was made between normal and preeclamptic pregnancies on the basis of histidine, tyrosine, and phenylalanine concentrations. The concentration of histidine was significantly higher in the plasma of patients with PE than in that of normotensive women (p = 0.003).

CONCLUSION

(1)H-NMR-based analysis of biofluids is capable of differentiating between patients with and without preeclampsia.

Post-delivery oxidative stress in women with preeclampsia or IUGR

AIM

To compare oxidative stress in patients with preeclampsia (PE) or intrauterine growth restriction (IUGR) vs. normal pregnancy (controls) during 48 h after delivery.

STUDY DESIGN

Women with singleton pregnancies were recruited immediately after delivery (gestational age >26.0 weeks). Women with PE or IUGR were matched with healthy controls by age, BMI, gestational age and delivery mode. Venous blood samples and urine samples were tested for oxidative stress products 24 h and 48 h after delivery.

RESULTS

Plasma malondialdehyde (MDA) concentration 24 h after delivery was significantly higher in subjects with PE or IUGR (3.41+/-1.14 micromol/L, n=20) than in controls (2.91+/-0.82 micromol/L, n=38) (P=0.04). Urine iPF(2alpha)-VI declined from 24 to 48 h after delivery significantly in controls (P=0.006) and not in subjects with PE or IUGR (P=0.71).

CONCLUSION

Of the markers tested only MDA is indicating higher oxidative stress in women with PE/IUGR than in normal pregnancy and only at 24 h after delivery. No consistent pattern of change in the oxidative stress markers exists between 24-48 h after delivery.

F2-isoprostanes in human health and diseases: from molecular mechanisms to clinical implications

Oxidative stress is implicated as one of the major underlying mechanisms behind many acute and chronic diseases, and involved in normal aging. However, the measurement of free radicals or their end products is complicated. Thus, proof of association of free radicals in pathologic conditions has been absent. Isoprostanes are prostaglandin-like bioactive compounds that are biosynthesized in vivo independent of cyclooxygenases, principally through free-radical catalyzation of arachidonic acid. Isoprostanes are now considered to be reliable biomarkers of oxidative stress, as evidenced by an autonomous study organized recently by the National Institutes of Health (NIH) in the United States. A number of these compounds have potent biologic activities such as vasoconstrictive and certain inflammatory properties. Isoprostanes are involved in many human diseases. Additionally, elevated levels of F(2)-isoprostanes have been seen in normal human pregnancy and after intake of some fatty acids, but their physiologic assignments have not yet been distinctive. This evidence indicates that measurement of bioactive F(2)-isoprostanes in body fluids offers a unique noninvasive analytic utensil to study the role of free radicals in physiology, oxidative stress-related diseases, experimental acute or chronic inflammatory conditions, and also in the assessment of various antioxidants, radical scavengers, and drugs.

Reactive oxygen species and anti-oxidant defences in swine follicular fluids

A growing body of evidence indicates that the pro-oxidant/anti-oxidant balance inside the ovarian follicle plays an important role in folliculogenesis. Therefore, the aim of the present study was to assess the redox status of follicular fluids collected from different-sized swine follicles. We quantified the most important reactive oxygen species (ROS), namely superoxide anion (O2–), hydrogen peroxide and hydroperoxides (ROOH); in addition, we examined the activity of the detoxifying enzymes superoxide dismutase, catalase (CAT) and glutathione peroxidase and the total non-enzymatic antioxidant capacity as determined by the ferric-reducing anti-oxidant power assay. Our data demonstrate that oxidative stress does not affect follicle growth because O2– levels do not change during follicle development, whereas concentrations of H2O2 and ROOH are reduced (P < 0.05). Surprisingly, all non-enzymatic and enzymatic scavengers examined in the present study, except for CAT, demonstrated reduced activity during follicle development (P < 0.05). Taken together, these results suggest that other factors could be involved in ROS detoxification during follicle development.

Plasma from women with preeclampsia has a low lipid and ketone body content--a nuclear magnetic resonance study

OBJECTIVE

Using (1)H-nuclear magnetic resonance spectroscopy and chemometrics, we sought to establish the metabolic profile for preeclampsia and to identify biomarkers that would permit a distinction between women with a normal pregnancy and those suffering from preeclampsia.

METHODS

Plasma samples from 11 normotensive pregnant women and 11 women with preeclampsia were analyzed. Principal component analysis was applied to differentiate between the two groups of patients.

RESULTS

Lipid concentrations were found to be significantly lower in the plasma of patients suffering from preeclampsia than those in normotensive pregnant women (p = 0.031). There is also evidence to suggest that ketone body constituents may contribute to the discrimination.

CONCLUSION

(1)H-nuclear magnetic resonance-based metabolic profiling can detect patients with preeclampsia.

Homocysteine, cysteine, and related metabolites in maternal and fetal plasma in preeclampsia

Homocysteine is associated with endothelial dysfunction and cardiovascular disease, and elevated concentrations of homocysteine have been found in preeclampsia. The purpose of this study was to investigate maternal and fetal concentrations of total homocysteine and related metabolites (including cysteine, choline, and betaine), and possible associations with infant birth weight. Women with preeclampsia (n=47) and controls (n=51), who underwent cesarean section, were included. Maternal plasma, umbilical vein, and artery plasma were analyzed. Median concentrations of homocysteine, cysteine, choline, and betaine were significantly higher in women with preeclampsia than controls, both in maternal and fetal plasma. There were no differences in folate and vitamin B12 concentrations between the groups, neither for maternal nor fetal samples. Maternal homocysteine concentration was a negative predictor for birth weight only in the preeclampsia group. Elevated homocysteine and cysteine concentration in maternal circulation in preeclampsia is reflected in the fetal circulation. The clinical significance of elevated homocysteine and cysteine concentrations in maternal and fetal compartments in preeclampsia remain to be explored, both regarding fetal growth and development of disease later in life.

Circulating concentrations of soluble endoglin (CD105) in fetal and maternal serum and in amniotic fluid in preeclampsia

OBJECTIVE

We explored whether concentrations of soluble endoglin in fetal serum and amniotic fluid and in maternal serum were elevated in preeclampsia.

STUDY DESIGN

Umbilical vein serum, amniotic fluid, and maternal serum from 42 preeclamptic and 43 uncomplicated pregnancies that were delivered by cesarean section were analyzed by enzyme-linked immunosorbent assay for soluble endoglin.

RESULTS

Median maternal serum and amniotic fluid soluble endoglin concentrations were elevated in preeclampsia, compared with control pregnancies (66.9 ng/mL vs 15.1 ng/mL; P < .001, and 1.9 ng/mL vs 0.6 ng/mL; P < .001). Low concentrations of soluble endoglin were found in fetal circulation, which did not differ between preeclampsia and control pregnancies (5.0 ng/mL vs 4.7 ng/mL; P = .2). Maternal serum soluble endoglin levels correlated with circulating soluble fms-like tyrosine kinase 1 concentrations.

CONCLUSION

We confirmed elevated soluble endoglin in maternal circulation in preeclampsia, which correlated with soluble fms-like tyrosine kinase 1 concentrations and soluble fms-like tyrosine kinase 1/placental growth factor ratio. The fetus appears not to contribute to elevated circulating maternal soluble endoglin concentrations in preeclampsia.

Oxidative stress markers and antioxidant status after oral iron supplementation to very low birth weight infants

OBJECTIVE

To evaluate whether our current practice of giving iron 18 mg daily to 6-week-old infants with very low birth weight (VLBW) was associated with increased oxidative stress markers or decreased antioxidant status.

STUDY DESIGN

The study was a prospective observational study of 21 healthy VLBW infants (born at gestational age <32 weeks, birth weight <1500 g). Blood and urine were sampled twice before starting iron supplementation at 6 weeks postnatal age and after 1 week of iron supplementation at age 7 weeks. Urine 8-isoprostane was analyzed by gas chromatography-mass spectrometry and plasma total hydroperoxides were measured. Antioxidant status was assessed by ascorbic acid (vitamin C), alpha-tocopherol (vitamin E), ferric-reducing ability of plasma, and plasma glutathione.

RESULTS

After 1 week of iron supplementation, no significant changes in urine 8-isoprostane or plasma total hydroperoxides were seen, and plasma antioxidants were largely unchanged.

CONCLUSIONS

Markers of oxidative stress in urine and plasma antioxidant status in healthy VLBW infants fed human milk remained unchanged after high-dose oral iron supplementation.

Acute atherosis in decidual tissue: not associated with systemic oxidative stress in preeclampsia

The aim of this study was to explore a possible association between the presence of decidual acute atherosis, maternal hyperlipidaemia and oxidative stress in the maternal circulation in preeclamptic and uneventful pregnancies. Decidual tissue was harvested by a vacuum suction technique following delivery of the baby and placenta in 102 caesarean deliveries. Maternal plasma lipid profile and concentration of 8-isoprostane, a marker of oxidative stress, was analysed. Acute atherosis was present in 42% of the preeclamptic patients with identified spiral arteries. CD68 positive foam cells were found in the spiral artery walls in 14% of the normal pregnancies. We have previously demonstrated an elevated plasma level of 8-isoprostane in the preeclampsia group, as compared to the uneventful pregnancy group (218 vs. 354 pg/mL, p=0.02). Presence of acute atherosis was, however, not associated with an elevated level of oxidative stress in the maternal circulation, measured as 8-isoprostane. In conclusion, the presence of decidual vascular changes in the form of acute atherosis is not necessarily paralleled by hyperlipidaemia or augmented oxidative stress in the maternal systemic circulation. This study adds to the notion of preeclampsia being a multifactorial disease with a variety of clinical forms.

Oxidative stress and antioxidant status in fetal circulation in preeclampsia

Preeclampsia is associated with oxidative stress in maternal circulation. The purpose of this study was to explore oxidative stress and antioxidants in the fetal circulation in preeclampsia. Women with preeclampsia (n = 19) or uncomplicated pregnancies (n = 33) delivered by cesarean section were included. Blood was sampled separately from the umbilical vein and artery. 8-Iso-prostaglandin F(2alpha) (8-isoprostane), a stable product of lipid peroxidation, is a reliable marker of oxidative stress. Concentration of total 8-isoprostane in cord plasma was analyzed by gas chromatography-mass spectrometry. Antioxidant status was evaluated measuring ferric reducing ability of plasma and vitamin E. There was no difference between preeclampsia and control groups regarding median plasma concentration of 8-isoprostane in umbilical vein (955 versus 780 pg/mL, p = 0.41) or in umbilical artery (233 versus 276 pg/mL, p = 0.65). Concentration of 8-isoprostane was much higher in plasma from the umbilical vein than artery, suggesting placenta as the source of 8-isoprostane. Median ferric reducing ability of plasma concentration was higher in preeclampsia than in controls, both in the umbilical vein and artery. Median vitamin E concentration in the umbilical vein was higher in preeclampsia, but no difference was found in the umbilical artery. In conclusion, no evidence of increased oxidative stress, evaluated by 8-isoprostane concentration, was found in fetal circulation in preeclampsia.