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

Catalpol Inhibits Homocysteine-induced Oxidation and Inflammation via Inhibiting Nox4/NF-κB and GRP78/PERK Pathways in Human Aorta Endothelial Cells

Hyperhomocysteinemia (HHCY) has been recognized as an independent risk factor for atherosclerosis and plays a vital role in the development of atherosclerosis. Catalpol, an iridoid glucoside extracted from the root of Rehmannia glutinosa, can produce anti-inflammatory, anti-oxidant, anti-tumor, and dopaminergic neurons protecting effects. This study aimed to determine the protecting effects of catalpol against homocysteine (HCY)-induced injuries in human aortic endothelial cells (HAECs) and uncover the underlying mechanisms: 1. HAECs were cultured with different concentrations of HCY (3 mM) and catalpol (7.5 μΜ, 15 μΜ, 30 μΜ) for 24 h. (1) The level of MDA and GSH as well as LDH release was measured with colorimetric assay. (2) Reactive oxygen species (ROS) were detected by flow cytometry analysis. (3) Western blotting analysis was performed to detect the expression of Nox4, p22^phox, ICAM-1, MCP-1, VCAM-1, IκB, nucleus p65, p65 phosphorylation, caspase-3, −9, bax, bcl-2, and ER stress-related proteins. (4) The expressions of CHOP, ATF4 were measured by qRT-PCR. (5) Mitochondrial membrane potential in HCY-treated HAECs was measured by rhodamine 123 staining, and the samples were observed by confocal laser scanning microscopy. 2. DPI, PDTC, and TUDCA were used to determine the interaction among Nox4/ROS, NF-κB, and endoplasmic reticulum stress. 3. TUDCA or Nox4 siRNA were used to investigate whether the effect of catalpol inhibiting the over-production of ROS were associated with inhibiting ER stress and Nox4 expression. Catalpol significantly suppressed LDH release, MDA level, and the reduction of GSH. Catalpol reduced HCY-stimulated ROS over-generation, inhibited the NF-κB transcriptional activation as well as the protein over-expressions of Nox4, ICAM-1, VCAM-1, and MCP-1. Catalpol elevated bcl-2 protein expression and reduced bax, caspase-3, −9 protein expressions in the HCY-treated HAECs. Simultaneously, catalpol could also inhibit the activation of ER stress-associated sensors GRP78, IRE1α, ATF6, P-PERK, P-eIF2α, CHOP, and ATF4 induced by HCY. In addition, the extent of catalpol inhibiting ROS over-generation and NF-κB signaling pathway was reduced after inhibiting Nox4 or ER stress with DPI or TUDCA. The inhibitor of NF-κB PDTC also reduced the effects of catalpol inhibiting the expressions of Nox4 and GRP78. Furthermore, the effect of catalpol inhibiting the over-generation of ROS was reduced by Nox4 siRNA. Catalpol could ameliorate HCY-induced oxidation, cells apoptosis and inflammation in HAECs possibly by inhibiting Nox4/NF-κB and ER stress.

Presence of Telocytes in a Non-innervated Organ: The Placenta

This chapter discusses the relationship between failure in placentation and the subsequent alterations in the normal structure of the placenta. Interstitial Cajal-like cells (ICLC) were observed for the first time in the human placenta in 2007 and later were named telocytes. Strong evidence confirms that in the placental chorionic villi, TC are located strategically between the smooth muscle cells (SMC) of the fetal blood vessel wall and the stromal myofibroblasts. As the placenta is a non-innervated organ and considering the strategic position of telocytes in chorionic villi, it has been postulated that their function would be related to signal transduction mechanisms involved in the regulation of the blood flow in the fetal vessels, as well as in the shortening/lengthening of the chorionic villi providing the necessary rhythmicity to the process of maternal/fetal metabolic exchange. In this context, telocytes represent part of a functional triad: "SMC of fetal blood vessel-telocyte-myofibroblast." This triad takes part in the regulation of fetal growth and development via transport of nutrients and gases. This chapter also discusses the alterations in the metabolic maternal-fetal exchange, leading to intrauterine growth retardation and preeclampsia. Additionally, the apoptosis undergoing in the preeclamptic hypoxic placenta affects all the chorionic villi cells, including telocytes and myofibroblast, and not only trophoblast, as it has been so far considered. In consequence, we proposed that apoptosis affects the triad structure and alters the placental function, subsequently affecting the normal fetal growth and development.

Hyperhomocysteinemia regulated SCF expression in cultured cardiomyocytes via modulation of NF-κB activities

Hyperhomocysteinemia (HHcy) is an important, independent risk factor for coronary artery disease, especially for the myocardial infarction. Our previous study has shown that myocardial stem cell factor (SCF) mediated cardiac stem cells migration, which was involved in cardiac repair. However, it is not clear regarding the action of HHcy on the expression of SCF in cardiomyocytes. In the present study, cultured neonatal rat cardiomyocytes were treated with 20, 50, or 100 μM homocysteine (Hcy) for 5 h. Results showed an significantly increase of SCF expression with 20-50 μM Hcy incubation, which matched with elevated nuclear factor-kappaB (NF-κB) activities. Treatment with NF-κB inhibitor N-acetylcysteine significantly inhibited the increase of SCF. Nevertheless, 100 μM Hcy markedly decreased the expression of SCF, which was in accordance with the suppression of NF-κB activities. The present study indicated that HHcy regulated the expression of SCF in a concentration-dependent manner via modulation of NF-κB activities. Thus, HHcy may increase the risk for cardiovascular diseases not only by causing endothelial dysfunction but also by directly exerting detrimental effects on cardiomyocytes.

Effects of vitamin C, vitamin E, and molecular hydrogen on the placental function in trophoblast cells

AIM

This study aimed to investigate the effects of three different antioxidants, namely vitamin C, vitamin E, and molecular hydrogen, on cytotrophoblasts in vitro.

METHODS

Two trophoblast cell lines, JAR and JEG-3, were exposed to different concentrations of vitamin C (0, 25, 50, 100, 500, 1,000, 5,000 μmol/L), vitamin E (0, 25, 50, 100, 500, 1,000, 5,000 μmol/L), and molecular hydrogen (0, 25, 50, 100, 500 μmol/L) for 48 h. The cell viability was detected using the MTS assay. The secretion of human chorionic gonadotropin (hCG) and the tumor necrosis factor-α (TNF-α) were assessed and the expression of TNF-α mRNA was observed by real-time RT-PCR.

RESULTS

Cell viability was significantly suppressed by 500 μmol/L vitamins C and E (P < 0.05), but not by 500 μmol/L molecular hydrogen (P > 0.05). The expression of TNF-α was increased by 100 μmol/L vitamin C and 50 μmol/L vitamins E, separately or combined (P < 0.05), but not by molecular hydrogen (0-500 μmol/L), as validated by real-time RT-PCR. But the secretion of hCG was both inhibited by 50-500 μmol/L molecular hydrogen and high levels of vitamin C and E, separately or combined.

CONCLUSION

High levels of antioxidant vitamins C and E may have significant detrimental effects on placental function, as reflected by decreased cell viability and secretion of hCG; and placental immunity, as reflected by increased production of TNF-a. Meanwhile hydrogen showed no such effects on cell proliferation and TNF-α expression, but it could affect the level of hCG, indicating hydrogen as a potential candidate of antioxidant in the management of preeclampsia (PE) should be further studied.

A putative role for telocytes in placental barrier impairment during preeclampsia

Preeclampsia (PE) is a major health problem occurring in pregnant women and the principal cause of maternal morbidity and perinatal mortality. It is characterized by alteration of the extravilli trophoblast cell migration toward the endometrial spiral arteries with a concomitant reduction in maternal blood flow in the placenta. This result in a state of ischemia-hypoxia which triggers an oxidative stress stage with production of reactive oxygen species. A cascade of cellular and molecular events leads then to endothelial dysfunction, transduction pathway signal disruption and induction of apoptosis and necrosis mechanisms and therefore a significant reduction in the amount of nutrients required for normal fetal development. Placental anchoring chorionic and stem villi present a skeleton of myofibroblasts arranged in parallel disposition to its longitudinal axis. The intraplacental blood volume is controlled by the contraction/relaxation of these myofibroblasts, promoting the delivery of nutrients and metabolites to the fetus. Recently, a new mesodermal originated cell type has been described in the villous stroma, the so named "telocytes". These cells are strategically located between the smooth muscle cells of the blood vessel wall and the myofibroblasts, and it is reasonable to hypothesize that they may play a pacemaker role, as in the intestine. This study provide new information supporting the notion that the occurrence of oxidative stress in PE is not only related to endothelial dysfunction and apoptosis of the trophoblast cells, but also involves telocytes and its putative role in the regulation of fetal blood flow and the intra-placental blood volume. Some ideas aimed at dilucidating the relationship between placental failure and the behavior of telocytes in pathological organs in adulthood, are also discussed.

Impaired renal function and increased urinary isoprostane excretion in Ghanaian women with pre-eclampsia

Background

The cause of pre-eclampsia remains largely unknown, but oxidative stress (an imbalance favoring oxidant over antioxidant forces) has been implicated in contributing to the clinical symptoms of hypertension and proteinuria. Assessment of oxidative stress in pre-eclampsia using urinary isoprostane has produced conflicting results, and it is likely that renal function may affect isoprostane excretion. The aim of this study was to determine the role of oxidative stress in the pathophysiology of pre-eclampsia and to assess the effect of renal function on isoprostane excretion in pre-eclampsia in the Ghanaian population.

Methods

This was a case-controlled study, comprising 103 pre-eclamptic women and 107 normal pregnant controls and conducted at the Korle-Bu Teaching Hospital between December 2006 and May 2007. The study participants were enrolled in the study after meeting the inclusion criteria and signing their written informed consent. Oxidative stress was determined by measuring urinary excretion of isoprostane and total antioxidant capacity using an enzyme-linked immunosorbent assay technique. Renal function was assessed by calculating the estimated glomerular filtration rate using the Modification of Diet in Renal Disease formula.

Results

The pre-eclampsia group had significantly (P = 0.0006) higher urinary isoprostane excretion (2.81 ± 0.14 ng/mg creatinine) than the control group (2.01 ± 0.18 ng/mg creatinine) and a significantly (P = 0.0008) lower total antioxidant power (1.68 ± 0.05 mM) than the control group (1.89 ± 0.04 mM). Urinary isoprostane excretion showed a positive correlation with both mean arterial pressure (r = 0.261) and microalbuminuria (r = 0.510) in the pre-eclampsia cases. The pre-eclampsia group had a significantly lower estimated glomerular filtration rate than the control group (P < 0.001), indicating more renal impairment.

Conclusion

The increased urinary excretion of isoprostanes and decreased total antioxidant power in the in pre-eclampsia group suggest increased production of oxidants and depletion and/or reduction of maternal antioxidants. Increased oxidative stress may be important in the pathophysiology of pre-eclampsia by contributing to endothelial dysfunction, proteinuria, and hypertension.

Analysis of the original causes of placental oxidative stress in normal pregnancy and pre-eclampsia: a hypothesis

Pre-eclampsia (PE) and eclampsia remain enigmatic despite intensive research. Growing evidence suggests that placental oxidative stress (OS) is involved in the etiopathogenesis of pre-eclampsia. Reduced perfusion as a result of abnormal placentation was proposed to be responsible for placental OS in PE. However, placental OS was also observed in normal pregnancy. The exact differences and correlation of placental OS in PE and normal pregnancy remain elusive. In this review, we attempted to link both normal pregnancy and PE on the causes of placental OS and proposed a hypothesis that placental OS in normal pregnancy, plus the exploration of other placental and/or maternal factors, could provide a novel explanation of that in PE. We concluded that pregnancy, placental abnormality and preexisting maternal constitutional conditions are three principle factors that could contribute to placental OS in PE. The specific causes in each clinical case could be heterogeneous, which requires individual analysis.

Comparative study of oxidative stress in maternal blood with that of cord blood and maternal milk

OBJECTIVE

Oxidative stress has been implicated in pregnancy-induced hypertension and preeclampsia. There is still some debate over whether this is confined to the placenta or occurs in the maternal circulation. This study was designed to investigate this question by comparing parameters of oxidative stress in samples of maternal blood and cord blood taken from normotensive and hypertensive pregnant women. A further aim was to compare these parameters in maternal milk from the two populations.

STUDY DESIGN

Forty-six hypertensive (31 preeclamptic and 15 chronic hypertensive) and 60 normotensive pregnant women were recruited. Antecubital blood was collected from each woman before and after delivery, cord blood just after delivery, and maternal milk for the first 3 days postpartum. Total antioxidant capacity, total peroxides and sulphydryl concentration were measured and total antioxidant capacity calculated for each specimen.

RESULTS

For all specimens (maternal blood plasma, cord blood plasma, maternal milk) total antioxidant capacity and sulphydryl concentration were significantly lower in the hypertensive women than in the normotensive, while total peroxide and oxidative stress index were significantly higher.

CONCLUSION

These results support the association between hypertension in pregnancy and oxidative stress and the view that this occurs throughout the maternal circulation. They show further that oxidative stress may be transmitted from mother to newborn in maternal milk. Supplementation with antioxidants could, in view of our findings, possibly provide protection to the mother and fetus and also, through transmission in maternal milk, to the newborn.

Protective effects of hydrogen-rich saline in preeclampsia rat model

Hydrogen has been reported as a novel antioxidant to selectively reduce levels of toxic reactive-oxygen species (ROS). We investigated the effects of hydrogen-rich saline on the prevention of oxidative injuries in N(omega)-nitro-L-arginine methyl ester (L-NAME) induced rat model of preeclampsia (PE). Sprague-Dawley rats (n = 50) were randomized into five groups: non-pregnant; normal pregnancy; pregnancy + hydrogen saline, 5 ml/kg, intraperitoneal (i.p.); pregnancy + L-NAME, 60 mg/kg (i.p.); pregnancy + L-NAME + hydrogen saline rats. Terminations of pregnancy were performed on day 22 of gestation, when the placentas and kidneys were microscopically inspected; tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and malonyldialdehyde (MDA) were assessed; and the mean systolic BP, level of proteinuria, resorptions, and pups birth weights were recorded. It was found that the pups of hypertensive gravid rats treated with hydrogen-rich saline presented fewer number of resorptions than those of the group of pregnancy + L-NAME, 60 mg/kg i.p. (P < 0.05). Additionally, hydrogen-rich saline treatment decreased the blood and placental MDA, proteinuria and the pro-inflammatory cytokine TNF-α, IL-1β in the placental tissues compared with those in L-NAME-treated rats (all P < 0.05). The mean systolic BP showed no significant difference except on day 22 of gestation (P < 0.05). The preventive administration of hydrogen significantly attenuated the severity of PE, which might be ascribed to a reduction in inflammation response and oxidative stress. It could be concluded that hydrogen can be an effective antioxidant in the management of PE.

Effects of antioxidant vitamins on newborn and placental traits in gestations at high altitude: comparative study in high and low altitude native sheep

The present study evaluated the hypothesis that the effects of hypoxia on sheep pregnancies at high altitude (HA) are mediated by oxidative stress and that antioxidant vitamins may prevent these effects. Both HA native and newcomer ewes were maintained at an altitude of 3,589 m during mating and pregnancy. Control low altitude (LA) native ewes were maintained at sea level. Half of each group received daily oral supplements of vitamins C (500 mg) and E (350 IU) during mating and gestation. Near term, maternal plasma vitamin levels and oxidative stress biomarkers were measured. At delivery, lambs were weighed and measured, and placentas were recovered for macroscopic and microscopic evaluation. Vitamin concentrations in supplemented ewes were two- or threefold greater than in non-supplemented ewes. Plasma carbonyls and malondialdehyde in non-supplemented ewes were consistent with a state of oxidative stress, which was prevented by vitamin supplementation. Vitamin supplementation increased lamb birthweight and cotyledon number in both HA native and newcomer ewes, although placental weight and cotyledon surface were diminished. Placentas from vitamin-supplemented HA ewes were similar to those from ewes at sea level, making these placental traits (weight, number and diameter of cotyledons) similar to those from ewes at sea level. Vitamin supplementation had no effect on LA pregnancies. In conclusion, supplementation with vitamins C and E during pregnancy at HA prevents oxidative stress, improving pregnancy outcomes.

Selenium supplementation and the incidence of preeclampsia in pregnant Iranian women: a randomized, double-blind, placebo-controlled pilot trial

OBJECTIVE

Recent studies have reported that antioxidant status, including serum selenium concentrations, is altered in women who develop preeclampsia. We wished to examine the effects of selenium supplementation in the prevention of preeclampsia in high-risk pregnant women.

DESIGN

We carried out a randomized, double-blind, placebo-controlled pilot trial. A total of 166 primigravid pregnant women, who were in the first trimester of pregnancy, were randomized to receive 100 microg of selenium (n = 83; dropouts, n = 22) or a placebo (n = 83; dropouts, n = 19) per day until delivery. The incidence of preeclampsia, serum selenium concentrations, lipid profile and high-sensitivity C-reactive protein status were evaluated at baseline and at the end of the study.

RESULTS

Supplementation with selenium was not associated with any reported major side effects and was associated with a significant increase in mean serum selenium concentrations at term (p < 0.001). In contrast, mean serum selenium concentrations remained unchanged in the control group (p = 0.63). The incidence of preeclampsia was lower in the selenium group (n = 0) than in the control group (n = 3), although this was not statistically significant (p > 0.05). After treatment, systolic and diastolic blood pressure, serum total cholesterol, triglycerides, low-density and high-density lipoprotein cholesterol, and high-sensitivity C-reactive protein were significantly increased in both groups compared with pretreatment levels (p < 0.05).

CONCLUSION

Our findings indicate that selenium supplementation in pregnant women may be associated with a lower frequency of preeclampsia.

Urine iodine levels in preeclamptic and normal pregnant women

The aim of this study was to investigate the urine iodine concentration in women with severe preeclampsia and in healthy women in Erzurum, Turkey. Urine specimens were obtained from 40 severe preeclampsia and 18 healthy pregnant women. Urinary iodine levels were determined by the Foss method based on the Sandell-Kolthoff reaction. The urinary iodine level for women with severe preeclampsia was 4.25 +/- 2.7 microg/dL, lower than 20.89 +/- 6.4 microg/dL of urinary iodine for healthy pregnant women (p < 0.001). Blood magnesium concentration was found to be 1.63 +/- 0.05 mg/dL for women with severe preeclampsia, which is lower than that of healthy pregnant women (1.87 +/- 0.05 mg/dL; p < 0.001). There was a positive correlation between urinary iodine level and blood magnesium level in pregnant women with preeclampsia (Pearson correlation coefficient = 0.43; p < 0.01). However, there was no correlation between urinary iodine level and blood magnesium level in healthy pregnant women. There was no difference in thyroid hormone levels (T4, TSH, FT4) between women with severe preeclampsia and healthy pregnant women. However, there was a difference in T3 thyroid hormone levels between women with severe preeclampsia (1.86 +/- 0.4 microg/dL) and healthy pregnant women (1.45 +/- 0.3 microg/dL; p < 0.001). There was also a difference in FT3 between women with severe preeclampsia (2.77 +/- 0.4 pg/mL) and healthy pregnant women (2.41 +/- 0.5 microg/dL; p < 0.01). Urinary iodine excretion is currently the most convenient laboratory marker of iodine deficiency. The method is useful for the rapid and low-cost assessment of iodine deficiency. Our results suggested that urinary iodine concentration might be a useful marker for prediagnosing preeclamptic women. In addition, iodine supplementation may also be considered for preeclamptic therapy.

Role of nutrition in the risk of preeclampsia

Preeclampsia (PE) accounts for about one-quarter of the cases of maternal mortality and ranks second among the causes of pregnancy-associated maternal deaths in Canada and worldwide. The identification of an effective strategy to prevent PE is a priority and a challenge for research in obstetrics. Progress has been hampered by inadequate understanding of the underlying etiology of the disease. The role of maternal diet in the etiology of PE has recently received increased attention. The objective of this paper is to provide an overview of the literature concerning 1) the current understanding of the pathogenesis of PE, 2) the biological plausibility and potential mechanisms underlying the associations between maternal dietary exposures, nutrition, and the risk of PE, and 3) the epidemiological findings of maternal nutrient intake in relation to the risk of PE.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Iodine and magnesium levels in maternal and umbilical cord blood of preeclamptic and normal pregnant women

The objective of this study was to investigate the relationship between preeclampsia and iodine levels and magnesium concentration in the blood of subjects in the northeast Anatolia region where iodine deficiency is common. Blood specimens were obtained from 24 preeclamptic and 16 healthy pregnant women. Iodine levels in blood were determined by the Foss method based on the Sandell-Kolthoff reaction. Serum protein-bound iodine (PBI) levels and magnesium concentration in maternal blood were lower in patients with severe preeclampsia compared to normal pregnant women (8.46 +/- 1.22 vs. 11.46 +/- 1.71 microg/dL, p < 0.001, 1.63 +/- 0.05 vs. 1.86 +/- 0.05 mg/dL, p < 0.001, respectively). Serum PBI levels and magnesium concentration in umbilical cord blood were higher in patients with severe preeclampsia than in normal pregnant women (8.84 +/- 1.9 vs. 7.33 +/- 1.07 microg/dL, p < 0.05, 2.48 +/- 0.03 vs. 2.02 +/- 0.01 mg/dL, p < 0.001, respectively). There was a positive correlation between the serum PBI levels in maternal blood and magnesium concentration in maternal blood in patients with severe preeclampsia (r = 0.41, p < 0.05). Thus, iodine may be one factor contributing to the pathophysiology of preeclampsia. Iodine supplementation may be effective therapy in preeclamptic in pregnant women.

Role of vitamins C and e in regulating antioxidant and pro-oxidant markers in preeclampsia

We compared three groups of pregnant women: placebo with normotensive women, group A which included preeclamptics, and group B which comprised preeclamptics who were supplemented their diets with vitamins C and E. MDA increased from 6.22 ± 2.8 (placebo) to 8.48 ± 1.2 (A) and 8.02 ± 1.8 nmol/gHb (B). NO concentrations were enhanced from 19.3 ± 4.2 (P) to 23.8 ± 6.4 (A) and 24.1 ± 5.4 µmol/L (B). GSH contents were decreased from 10.42 ± 2.81 (P) to 8.02 ± 2.92 (A) and 9.39 ± 1.02 µmol/g Hb (B), whereas GSSG concentrations increased from 0.98 ± 0.28 (P) to 1.24 ± 0.29 (A) and 1.08 ± 0.12 µmol/g Hb (B). SOD activity decreased 23% in A and 14% in B; GRx decreased 27% in A and 5.5% in B; GPx decreased 12% in A and 9.6% in B. Catalase activity, however, increased 27% in A and 29% in B as compared to control. Thus, we conclude that the use of vitamins C and E should be considered for the control of certain important biochemical indices during the development of preeclampsia; however, further studies are needed to develop methods for the prevention of preeclampsia in women at high risk.

The role of antioxidant vitamins in hypertensive disorders of pregnancy

Preeclampsia (PE) is an important and a leading cause of both maternal morbidity and adverse perinatal outcomes. Despite progress in perinatal medicine for patients with an established diagnosis of PE, a therapeutic approach other than termination of pregnancy was unsuccessful. Women predisposed to PE begin pregnancy with a certain degree of endothelial dysfunction, a lesion that precedes shallow placentation. The proposed sequence of events comprises endothelial dysfunction, defective trophoblast invasion, and consequential impaired placental perfusion, immune maladaptation and inflammation. The possible link between these could be oxidative stress by excessive production of reactive oxygen species coupled with inadequate or overwhelmed antioxidant defense mechanisms. These defense mechanisms, involving antioxidant vitamins and enzyme systems, may restrain the extent of damage caused by oxidative stress. Markers of oxidative stress in women with established PE were confirmed. Accordingly, these findings support an expected beneficial effect of antioxidant therapy in the prevention of PE and other pregnancy-related disorders. Numerous studies have been carried out in order to investigate this possible and simple prophylactic and/or therapeutic approach in prevention of oxidative stress and eventual reduction of PE and its perinatal complications. In this review the role of vitamin antioxidants in prevention and treatment of PE is discussed. Despite the logic behind using antioxidant vitamins, the data, thus far, are at best conflicting.

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.

Decrease in oxidative stress through supplementation of vitamins C and E is associated with a reduction in blood pressure in patients with essential hypertension

Oxidative stress has been associated with mechanisms of EH (essential hypertension). The aim of the present study was to test the hypothesis that the antioxidant properties of vitamins C and E are associated with a decrease in BP (blood pressure) in patients with EH. A randomized double-blind placebo-controlled clinical trial was conducted in 110 men with grade 1 EH (35-60 years of age without obesity, dyslipidaemia and diabetes mellitus, non-smokers, not undergoing vigorous physical exercise, without the use of any medication and/or high consumption of fruit and vegetables). Participants were randomly assigned to receive either vitamins C+E [vitamin C (1 g/day) plus vitamin E (400 international units/day)] or placebo for 8 weeks. Measurements included 24 h ambulatory BP and blood analysis of oxidative-stress-related parameters in erythrocytes (GSH/GSSH ratio, antioxidant enzymes and malondialdehyde) and plasma [FRAP (ferric reducing ability of plasma)], and levels of 8-isoprostane, vitamins C and E were measured at baseline and after treatment. Following administration of vitamins C+E, patients with EH had significantly lower systolic BP, diastolic BP and mean arterial BP and higher erythrocyte and serum antioxidant capacity compared with either placebo-treated patients with EH or the patients with EH at baseline prior to treatment. BP correlated positively with plasma 8-isoprostane levels and negatively with plasma FRAP levels in the vitamins C+E- and placebo-treated groups. In conclusion, the present study supports the view that oxidative stress is involved in the pathogenesis of EH, and that enhancement of antioxidant status by supplementation with vitamins C and E in patients with EH is associated with lower BP. This suggests intervention with antioxidants as an adjunct therapy for hypertension.

Prediction of pre-eclampsia in early pregnancy

Pre-eclampsia is a multisystem disorder of pregnancy, usually characterized by the appearance of high blood pressure and the excretion of protein in the urine of a previously healthy woman. Symptoms and signs vary in intensity from woman to woman; from a borderline rise in blood pressure, to convulsions (eclampsia), stroke and death. The disease remits following removal of the placenta and so the mainstay of current treatment is timely delivery. A pathophysiological framework of the disease has been established, beginning with failures in placental development, inducing oxidative stress and release of compounds that lead to endothelial activation, vasoconstriction and glomerular endotheliosis. A combination of epidemiological, biophysical and biochemical tests now allow most patients at-risk to be identified by midpregnancy, whilst minimizing false-positive prediction. It is hoped that earlier classification of patients at-risk of the disease, on the basis of pathophysiological changes, will enable specific therapies to be developed targeting these changes.

The association of exposure to cadmium through cigarette smoke with pregnancy-induced hypertension in a selenium deficient population

Oxidative stress has been postulated as major contributor to endothelial dysfunction and pregnancy-induced hypertension. We have examined the association of exposure to cadmium through cigarette smoke with hypertension disorders during pregnancy in the selenium deficient population. Markers of lipid peroxidation and antioxidative defense were measured and correlated with cadmium blood concentration in normotensive and hypertensive pregnant smokers and nonsmokers. We have observed significantly higher blood Cd in hypertensive smokers and significant differences in all other parameters. Se concentrations were lower in smokers, both in normotensive and hypertensive group as well as values of nonenzymatic (Zn, Cu, and glutathione) and enzymatic (superoxide dismutase, glutathione peroxidase, and glutathione reductase) parameters of antioxidative defense. Results of the study indicate that exposure to cadmium through cigarette smoke in pregnant women, living in Se deficient areas is associated with significantly higher cadmium concentrations and lower levels of enzymatic and nonenzymatic antioxidants and that it can be considered as a risk factor for pregnancy-induced hypertension. Selenium supplementation should be considered for recommendation in such condition.

Placental tissue iodine level and blood magnesium concentration in pre-eclamptic and normal pregnancy

OBJECTIVE

To assess iodine concentration in the placental tissue and magnesium concentration in the blood of women with severe pre-eclampsia in northeast Anatolia and compare these values with those of healthy pregnant women from the same region.

METHODS

Placental tissue and blood specimens were obtained from 20 severely pre-eclamptic and 15 healthy pregnant women. Iodine levels in placental tissue were determined by the Foss method based on the Sandell-Kolthoff reaction.

RESULTS

Placental tissue iodine levels were lower in women with severe pre-eclampsia than in healthy pregnant women (4.30+/-1.36 ng of iodine/mg protein vs. 7.71+/-2.84 ng of iodine/mg tissue protein; P<0.001), as were blood magnesium levels (1.63+/-0.05 mg/dL vs. 1.87+/-0.05 mg/dL; P<0.001). There was a positive correlation between placental tissue iodine levels and blood magnesium levels in women with severe pre-eclampsia (r=0.55, P<0.05), but no such correlation was observed in healthy pregnant women (r=0.23, P=0.41).

CONCLUSION

Magnesium assimilation is known to be defective when iodine levels are insufficient. In northeast Anatolia, where iodine deficiency is common, clinical trials of iodine supplementation should be considered for pre-eclamptic therapy.

Clinical pharmacology and therapeutic use of antioxidant vitamins

The clinical use of antioxidants has gained considerable interest during the last decade. It was suggested from epidemiological studies that diets high in fruits and vegetables might help decrease the risk of cardiovascular disease. Therefore, supplements of vitamins C and E were applied through protocols aimed to prevent diseases such as atherosclerosis, preeclampsia or hypertension, thought to be mediated by oxidative stress. Despite the biological properties of these vitamins could account for an effective protection, as shown by several clinical and experimental studies, their efficacy remains controversial in the light of some recent clinical trials and meta-analyses. However, the methodology of these studies, criteria for selection of patients, the uncertain extent of progression of the disease when initiating supplementation, the lack of mechanistic studies containing basic scientific aspects, such as the bioavailability, pharmacokinetic properties, and the nature of the antioxidant sources of vitamins, could account for the inconsistency of the various clinical trials and meta-analyses assessing the efficacy of these vitamins to prevent human diseases. This review presents a survey of the clinical use of antioxidant vitamins E and C, proposing study models based on the biological effects of these compounds likely to counteract the pathophysiological mechanisms able to explain the structural and functional organ damage.

Placental tissue cyclo-oxygenase 1 and 2 in pre-eclamptic and normal pregnancy

OBJECTIVE

To investigate the activities of the 2 isoforms of prostaglandin synthetic enzyme cyclo-oxygenase (COX), COX-1 and COX-2, in the placental tissue of women with pre-eclampsia and healthy pregnant women. The relationship between placental lipid peroxidation and the activities of COX-1 and COX-2 was also investigated.

METHODS

Tissue specimens were obtained from pre-eclamptic women (20 had severe pre-eclampsia and 38 had mild pre-eclampsia) and 27 healthy pregnant women who underwent cesarean section before the onset of labor. Malondialdehyde (MDA) levels and COX-1 and COX-2 activities were measured in placental tissue homogenates.

RESULTS

Mean activities for COX-1 and COX-2 were significantly lower in women with severe pre-eclampsia than in healthy controls (P<0.05 and P<0.01, respectively). COX-1 and COX-2 activities were also lower in women with mild pre-eclampsia than in healthy controls, but the difference was of borderline significance (P=0.049 and P=0.059, respectively). The mean placental MDA level was significantly higher in pregnant women with severe and mild pre-eclampsia than in healthy pregnant women (P<0.01 for both). The correlation analysis showed significant negative correlations between MDA and COX-1 (r=-0.44, P<0.001) and MDA and COX-2 (r=-0.45, P<0.001) in the placental tissue of women with pre-eclampsia.

CONCLUSION

These results suggest that COX-1 and COX-2 activities are decreased in the placental tissue of women with pre-eclampsia, probably by oxidative stress.