Oxidative stress of the newborn in the pre- and postnatal period and the clinical utility of melatonin

Redox Regulation and the Autistic Spectrum: Role of Tryptophan Catabolites, Immuno-inflammation, Autoimmunity and the Amygdala

The autistic spectrum disorders (ASD) form a set of multi-faceted disorders with significant genetic, epigenetic and environmental determinants. Oxidative and nitrosative stress (O&NS), immuno-inflammatory pathways, mitochondrial dysfunction and dysregulation of the tryptophan catabolite (TRYCATs) pathway play significant interactive roles in driving the early developmental etiology and course of ASD. O&NS interactions with immuno-inflammatory pathways mediate their effects centrally via the regulation of astrocyte and microglia responses, including regional variations in TRYCATs produced. Here we review the nature of these interactions and propose an early developmental model whereby different ASD genetic susceptibilities interact with environmental and epigenetic processes, resulting in glia biasing the patterning of central interarea interactions. A role for decreased local melatonin and N-acetylserotonin production by immune and glia cells may be a significant treatment target.

Melatonin content of pepper and tomato fruits: effects of cultivar and solar radiation

We evaluated the effect of cultivar and solar radiation on the melatonin content of Capsicum annuum (pepper) and Solanum lycopersicum (tomato) fruits. The melatonin content of red pepper fruits ranged from 31 to 93ngg(-1) (dry weight). The melatonin content of tomato ranged from 7.5 to 250ngg(-1) (dry weight). We also studied the effect of ripeness on melatonin content and identified one group of pepper cultivars in which the melatonin content increased as the fruit ripened and another in which it decreased as the fruit ripened. Under shade conditions, the melatonin content in most of tomato cultivars tended to increase (up to 135%), whereas that of most pepper cultivars decreased (to 64%). Overall, the results also demonstrated that the melatonin content of the fruits was not related to carbon fluxes from leaves.

Neuroinflammation in ischemic brain injury as an adaptive process

Cerebral ischaemia triggers various physiological processes, some of which have been considered deleterious and others beneficial. These processes have been characterized in one influential model as being part of a transition from injury to repair processes. We argue that another important distinction is between dysregulated and regulated processes. Although intervening in the course of dysregulated processes may be neuroprotective, this is unlikely to be true for regulated processes. This is because from an evolutionary perspective, regulated complex processes that are conserved across many species are likely to be adaptive and provide a survival advantage. We argue that the neuroinflammatory cascade is an adaptive process in this sense, and contrast this with a currently popular theory which we term the maladaptive immune response theory. We review the evidence from clinical and preclinical pharmacology with respect to this theory, and deduced that the evidence is inconclusive at best, and probably falsifies the theory. We argue that this is why there are no anti-inflammatory treatments for cerebral ischaemia, despite 30 years of seemingly promising preclinical results. We therefore propose an opposing theory, which we call the adaptive immune response hypothesis.

Melatonin: its possible role in the management of viral infections--a brief review

Melatonin, a versatile molecule, is synthesized by the pineal gland but also by other organs, including gastrointestinal tract, retina, thymus, bone marrow, and by leukocytes. Besides playing an important role in various functions of the body, including sleep and circadian rhythm regulation, melatonin also shows immunoregulatory, free radical scavenger and antioxidant functions. Because of these latter characteristics melatonin has also been found to be effective in fighting viral infections in a variety of experimental animal and in vitro studies. These data suggest a possible therapeutic potential of melatonin in human virus-induced disorders.

Melatonin attenuates methamphetamine-induced disturbances in mitochondrial dynamics and degeneration in neuroblastoma SH-SY5Y cells

Methamphetamine (METH) is a psychostimulant drug that can cause toxicity and degeneration in the brain. The toxicity due to METH involves multiple pathways, including the mitochondrial-dependent death pathway. Several pieces of evidence have emphasized that the fragmentation of mitochondria into smaller structures plays some role in the cell-death process. In this study, we investigated the role of mitochondrial dynamics in METH-induced toxicity in human dopaminergic neuroblastoma SH-SY5Y cultured cell lines. In addition, the protective effect of melatonin against METH-induced toxicity was investigated. Our results show that METH significantly decreased cell viability and increased the levels of the mitochondrial fission protein, Fis1 and the Drp1 oligomer. However, the levels of the mitochondrial fusion proteins OPA1 and Mfn1 did not change in METH-treated cells. Melatonin can reverse the toxic effects of the METH-induced reduction in cell viability and the production of the Fis1 protein and the Drp1 oligomer. Moreover, the morphological alteration of mitochondria was investigated in METH-treated cells in the presence of melatonin using transmission electron microscopy (TEM). At 24 hr after METH exposure, typical cell shrinkage was observed in SH-SY5Y cells. Mitochondria were fragmented into small globular structures in a large proportion of METH-treated cells, but tubular networks of mitochondria were present in large proportions of control-untreated cells and METH-treated cells in the presence of melatonin. The results of the present study demonstrate the potential of melatonin to reduce cell death and restore mitochondrial function in neurons affected by METH-induced toxicity.

Phase I pilot clinical trial of antenatal maternally administered melatonin to decrease the level of oxidative stress in human pregnancies affected by pre-eclampsia (PAMPR): study protocol

INTRODUCTION

Pre-eclampsia is a common pregnancy condition affecting between 3% and 7% of women. Unfortunately, the exact pathophysiology of the disease is unknown and as such there are no effective treatments that exist notwithstanding prompt delivery of the fetus and culprit placenta. As many cases of pre-eclampsia occur in preterm pregnancies, it remains a significant cause of maternal and perinatal morbidity and mortality. Recently, in vitro and animal studies have highlighted the potential role of antioxidants in mitigating the effects of the disease. Melatonin is a naturally occurring antioxidant hormone and provides an excellent safety profile combined with ease of oral administration. We present the protocol for a phase I pilot clinical trial investigating the efficacy and side effects of maternal treatment with oral melatonin in pregnancies affected by preterm pre-eclampsia.

METHODS AND ANALYSIS

We propose undertaking a single-arm open label clinical trial recruiting 20 women with preterm pre-eclampsia (24(+0)-35(+6) weeks). We will take baseline measurements of maternal and fetal well-being, levels of oxidative stress, ultrasound Doppler studies and other biomarkers of pre-eclampsia. Women will then be given oral melatonin (10 mg) three times daily until delivery. The primary outcome will be time interval between diagnosis and delivery compared to historical controls. Secondary outcomes will compare the baseline measurements previously mentioned with twice-weekly measurements during treatment and then 6 weeks postpartum.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from Monash Health Human Research Ethics Committee B (HREC 13076B). Data will be presented at international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12613000476730 (ANZCTR).

Designing artificial environments for preterm infants based on circadian studies on pregnant uterus

Using uterine explants from Per1::Luc rats and in situ hybridization, we recently reported that the circadian property of the molecular clock in the uterus and placenta is stably maintained from non-pregnancy, right through to the end stage of pregnancy under regular light-dark (LD) cycles. Despite long-lasting increases in progesterone during gestation and an increase in estrogen before delivery, the uterus keeps a stable Per1::Luc rhythm throughout the pregnancy. The study suggests the importance of stable circadian environments for fetuses to achieve sound physiology and intrauterine development. This idea is also supported by epidemiological and animal studies, in which pregnant females exposed to repeated shifting of the LD cycles have increased rates of reproductive abnormalities and adverse pregnancy outcomes. Leading from this, we introduced artificial circadian environments with controlled lighting conditions to human preterm infants by developing and utilizing a specific light filter which takes advantage of the unique characteristics of infants' developing visual photoreceptors. In spite of growing evidence of the physiological benefits of nighttime exposure to darkness for infant development, many Japanese Neonatal Intensive Care Units (NICUs) still prefer to maintain constant light in preparation for any possible emergencies concerning infants in incubators. To protect infants from the negative effects of constant light on their development in the NICU, we have developed a new device similar to a magic mirror, by which preterm infants can be shielded from exposure to their visible wavelengths of light even in the constant light conditions of the NICU while simultaneously allowing medical care staff to visually monitor preterm infants adequately. The device leads to significantly increased infant activity during daytime than during night time and better weight gains.

The role of melatonin in the cells of the innate immunity: a review

Melatonin is the major secretory product synthesized and secreted by the pineal gland and shows both a wide distribution within phylogenetically distant organisms from bacteria to humans and a great functional versatility. In recent years, a considerable amount of experimental evidence has accumulated showing a relationship between the nervous, endocrine, and immune systems. The molecular basis of the communication between these systems is the use of a common chemical language. In this framework, currently melatonin is considered one of the members of the neuroendocrine-immunological network. A number of in vivo and in vitro studies have documented that melatonin plays a fundamental role in neuroimmunomodulation. Based on the information published, it is clear that the majority of the present data in the literature relate to lymphocytes; thus, they have been rather thoroughly investigated, and several reviews have been published related to the mechanisms of action and the effects of melatonin on lymphocytes. However, few studies concerning the effects of melatonin on cells belonging to the innate immunity have been reported. Innate immunity provides the early line of defense against microbes and consists of both cellular and biochemical mechanisms. In this review, we have focused on the role of melatonin in the innate immunity. More specifically, we summarize the effects and action mechanisms of melatonin in the different cells that belong to or participate in the innate immunity, such as monocytes-macrophages, dendritic cells, neutrophils, eosinophils, basophils, mast cells, and natural killer cells.

Melatonin ameliorates cognitive impairment induced by sleep deprivation in rats: role of oxidative stress, BDNF and CaMKII

Sleep deprivation (SD) has been shown to induce oxidative stress which causes cognitive impairment. Melatonin, an endogenous potent antioxidant, protects neurons from oxidative stress in many disease models. The present study investigated the effect of melatonin against SD-induced cognitive impairment and attempted to define the possible mechanisms involved. SD was induced in rats using modified multiple platform model. Melatonin (15 mg/kg) was administered to the rats via intraperitoneal injection. The open field test and Morris water maze were used to evaluate cognitive ability. The cerebral cortex (CC) and hippocampus were dissected and homogenized. Nitric oxide (NO) and malondialdehyde (MDA) levels and the superoxide dismutase (SOD) enzyme activity of hippocampal and cortical tissues (10% wet weight per volume) were performed to determine the level of oxidative stress. The expression of brain-derived neurotrophic factor (BDNF) and calcium-calmodulin dependent kinase II (CaMKII) proteins in CC and hippocampus was assayed by means of immunohistochemistry. The results revealed that SD impairs cognitive ability, while melatonin treatment prevented these changes. In addition, melatonin reversed SD-induced changes in NO, MDA and SOD in both of the CC and hippocampus. The results of immunoreactivity showed that SD decreased gray values of BDNF and CaMKII in CC and hippocamal CA1, CA3 and dentate gyrus regions, whereas melatonin improved the gray values. In conclusion, our results suggest that melatonin prevents cognitive impairment induced by SD. The possible mechanism may be attributed to its ability to reduce oxidative stress and increase the levels of CaMKII and BDNF in CC and hippocampus.

Modulation by melatonin of the pathogenesis of inflammatory autoimmune diseases

Melatonin is the major secretory product of the pineal gland during the night and has multiple activities including the regulation of circadian and seasonal rhythms, and antioxidant and anti-inflammatory effects. It also possesses the ability to modulate immune responses by regulation of the T helper 1/2 balance and cytokine production. Autoimmune diseases, which result from the activation of immune cells by autoantigens released from normal tissues, affect around 5% of the population. Activation of autoantigen-specific immune cells leads to subsequent damage of target tissues by these activated cells. Melatonin therapy has been investigated in several animal models of autoimmune disease, where it has a beneficial effect in a number of models excepting rheumatoid arthritis, and has been evaluated in clinical autoimmune diseases including rheumatoid arthritis and ulcerative colitis. This review summarizes and highlights the role and the modulatory effects of melatonin in several inflammatory autoimmune diseases including multiple sclerosis, systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes mellitus, and inflammatory bowel disease.

Prolonging in utero-like oxygenation after birth diminishes oxidative stress in the lung and brain of mice pups

Background

Fetal-to-neonatal transition is associated with oxidative stress. In preterm infants, immaturity of the antioxidant system favours supplemental oxygen-derived morbidity and mortality.

Objectives

To assess if prolonging in utero-like oxygenation during the fetal-to-neonatal transition limits oxidative stress in the lung and brain, improving postnatal adaptation of mice pups.

Material and methods

Inspiratory oxygen fraction (FiO₂) in pregnant mice was reduced from 21% (room air) to 14% (hypoxia) 8–12 h prior to delivery and reset to 21% 6–8 h after birth. The control group was kept at 21% during the procedure. Reduced (GSH) and oxidized (GSSG) glutathione and its precursors [γ-glutamyl cysteine (γ-GC) and L-cysteine (CySH)] content and expression of several redox-sensitive genes were evaluated in newborn lung and brain tissue 1 (P1) and 7 (P7) days after birth.

Results

As compared with control animals, the GSH/GSSG ratio was increased in the hypoxic group at P1 and P7 in the lung, and at P7 in the brain. In the hypoxic group a significant increase in the mRNA levels of NAD(P)H:quinone oxidoreductase 1 (noq1), Sulfiredoxin 1 (srnx1) and Glutathione Peroxidase 1 (gpx) was found in lung tissue at P1, as well as a significant increase in gpx in brain tissue at P7.

Conclusions

Delaying the increase in tissue oxygenation to occur after birth reduces short-and-long-term oxidative stress in the lung. Similar yet more subtle effects were found in the brain. Apparently, the fetal-to-neonatal transition under hypoxic conditions appears to have protective qualities.

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The present study describes a mouse model meant to study redox biology of the fetal-to-neonatal transition under hypoxia.

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Lung protection against oxidative stress was induced at day 1 after birth.

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Improvement in lung and brain redox environments 7 days after birth was observed.

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Changes detected in lung and brain were subtle, however significant, under physiologic conditions.

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The applicability of our model under pathophysiologic conditions (e.g. postnatal hyperoxia) should be tested.

Autism risk factors: genes, environment, and gene-environment interactions

The aim of this review is to summarize the key findings from genetic and epidemiological research, which show that autism is a complex disorder resulting from the combination of genetic and environmental factors. Remarkable advances in the knowledge of genetic causes of autism have resulted from the great efforts made in the field of genetics. The identification of specific alleles contributing to the autism spectrum has supplied important pieces for the autism puzzle. However, many questions remain unanswered, and new questions are raised by recent results. Moreover, given the amount of evidence supporting a significant contribution of environmental factors to autism risk, it is now clear that the search for environmental factors should be reinforced. One aspect of this search that has been neglected so far is the study of interactions between genes and environmental factors.

Total oxidant, antioxidant, and paraoxonase levels in babies born to pre-eclamptic mothers

AIM

The aim of this study was to investigate the oxidant-antioxidant status in babies born to pre-eclamptic mothers (BBPM).

MATERIAL AND METHODS

The paraoxonase (PON)-1, total antioxidant status (TAS), and total oxidant status (TOS) levels were measured in the cord blood and venous blood (7th day) of BBPM (n = 31) and babies born to normotensive mothers (n = 25).

RESULTS

The PON-1 and TOS levels in the cord blood and venous blood on the 7th day were not significantly different between the two groups; however, the cord blood TAS levels were higher in BBPM (P = 0.001), and the TAS levels in the venous blood were higher in the control group (P = 0.021). Furthermore, the cord blood PON-1 levels of babies born to severely pre-eclamptic mothers (n = 18) were higher than those of babies born to moderately pre-eclamptic mothers (n = 13) (P = 0.042). There were no differences in the cord blood TAS and TOS levels and venous blood PON-1, TAS, and TOS levels between babies born to severely and moderately pre-eclamptic mothers.

CONCLUSION

The increased TAS levels found in the cord blood of BBPM indicate that the fetus is protected against oxidative damage caused by increased oxidative stress in the mother. To the best of our knowledge, this is the first study in the published work investigating PON-1 levels in BBPM.

Peripheral reproductive organ health and melatonin: ready for prime time

Melatonin has a wide variety of beneficial actions at the level of the gonads and their adnexa. Some actions are mediated via its classic membrane melatonin receptors while others seem to be receptor-independent. This review summarizes many of the published reports which confirm that melatonin, which is produced in the ovary, aids in advancing follicular maturation and preserving the integrity of the ovum prior to and at the time of ovulation. Likewise, when ova are collected for in vitro fertilization-embryo transfer, treating them with melatonin improves implantation and pregnancy rates. Melatonin synthesis as well as its receptors have also been identified in the placenta. In this organ, melatonin seems to be of particular importance for the maintenance of the optimal turnover of cells in the villous trophoblast via its ability to regulate apoptosis. For male gametes, melatonin has also proven useful in protecting them from oxidative damage and preserving their viability. Incubation of ejaculated animal sperm improves their motility and prolongs their viability. For human sperm as well, melatonin is also a valuable agent for protecting them from free radical damage. In general, the direct actions of melatonin on the gonads and adnexa of mammals indicate it is an important agent for maintaining optimal reproductive physiology.

Roles of melatonin in fetal programming in compromised pregnancies

Compromised pregnancies such as those associated with gestational diabetes mellitus, intrauterine growth retardation, preeclampsia, maternal undernutrition, and maternal stress may negatively affect fetal development. Such pregnancies may induce oxidative stress to the fetus and alter fetal development through the epigenetic process that may affect development at a later stage. Melatonin is an oxidant scavenger that reverses oxidative stress during the prenatal period. Moreover, the role of melatonin in epigenetic modifications in the field of developmental programming has been studied extensively. Here, we describe the physiological function of melatonin in pregnancy and discuss the roles of melatonin in fetal programming in compromised pregnancies, focusing on its involvement in redox and epigenetic mechanisms.

Efficacy of melatonin in the treatment of endometriosis: a phase II, randomized, double-blind, placebo-controlled trial

Endometriosis-associated chronic pelvic pain (EACPP) presents with an intense inflammatory reaction. Melatonin has emerged as an important analgesic, antioxidant, and antiinflammatory agent. This trial investigates the effects of melatonin compared with a placebo on EACPP, brain-derived neurotrophic factor (BDNF) level, and sleep quality. Forty females, aged 18 to 45 years, were randomized into the placebo (n = 20) or melatonin (10 mg) (n = 20) treatment groups for a period of 8 weeks. There was a significant interaction (time vs group) regarding the main outcomes of the pain scores as indexed by the visual analogue scale on daily pain, dysmenorrhea, dysuria, and dyschezia (analysis of variance, P < 0.01 for all analyses). Post hoc analysis showed that compared with placebo, the treatment reduced daily pain scores by 39.80% (95% confidence interval [CI] 12.88-43.01%) and dysmenorrhea by 38.01% (95% CI 15.96-49.15%). Melatonin improved sleep quality, reduced the risk of using an analgesic by 80%, and reduced BNDF levels independently of its effect on pain. This study provides additional evidence regarding the analgesic effects of melatonin on EACPP and melatonin's ability to improve sleep quality. Additionally, the study revealed that melatonin modulates the secretion of BDNF and pain through distinct mechanisms.

Dietary Supplementation of Calendula officinalis Counteracts the Oxidative Stress and Liver Damage Resulted from Aflatoxin

This study was conducted to evaluate the total phenolic compounds, the antioxidant properties, and the hepatorenoprotective potential of Calendula officinalis extract against aflatoxins (AFs-) induced liver damage. Six groups of male Sprague-Dawley rats were treated for 6 weeks included the control; the group fed AFs-contaminated diet (2.5 mg/kg diet); the groups treated orally with Calendula extract at low (CA1) and high (CA2) doses (500 and 1000 mg/kg b.w); the groups treated orally with CA1 and CA2 one week before and during AFs treatment for other five weeks. The results showed that the ethanol extract contained higher phenolic compounds and posses higher 1,1-diphenyl 1-2-picryl hydrazyl (DPPH) radical scavenging activity than the aqueous extract. Animals fed AFs-contaminated diet showed significant disturbances in serum biochemical parameters, inflammatory cytokines, and the histological and histochemical pictures of the liver accompanied by a significant increase in malondialdehyde (MDA) and a significant decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPx) in liver. Calendula extract succeeded to improve the biochemical parameters, inflammatory cytokines, decreased the oxidative stress, and improved the histological pictures in the liver of rats fed AFs-contaminated diet in a dose-dependent manner. It could be concluded that Calendula extract has potential hepatoprotective effects against AFs due to its antioxidant properties and radical scavenging activity.

Pulmonary innate immune response and melatonin receptors in the perinatal stress

Objective. To analyze the cytokines of the innate immune pulmonary response and the capacity for local response to melatonin according to the perinatal stress. Methods. 49 cases of pediatric autopsies were evaluated, divided according to cause of death, perinatal stress, gestational age, and birth weight. The percentages of IL-6, C-reactive protein (CRP), IL-1β, TNF-α, and melatonin receptor were evaluated by immunohistochemistry. Results. The IL-6 expression was higher in the children showing chronic stress, anoxia, and infection. The IL-6 expression showed a progressive increase according to the relation between weight and GA. There was no significant difference in the expression of IL-1β and TNF-α. The CRP expression was higher in the cases showing chronic stress and premature cases. The expression of melatonin receptors was significantly higher in the cases showing chronic stress, being more evident in the cases showing infection. Conclusion. The cause of death and the type of stress influence the expression in situ of melatonin and cytokines of the innate immune pulmonary response. The evaluation of IL-6 and CRP may contribute to the understanding of the evolution of neonates with chronic stress. The greater sensitivity of the lung to melatonin in these cases may indicate an attempt at controlling the immunological response, in an attempt to diminish the harmful effects of stress.

Birth weight of Korean infants is affected by the interaction of maternal iron intake and GSTM1 polymorphism

Excessive iron consumption during pregnancy can lead to increased oxidative stress in the maternal body, which may result in adverse pregnancy outcomes. Glutathione S-transferases (GSTs) originate from a superfamily of detoxifying enzymes that play a role in reducing xenobiotic compounds and oxidative stress. The aim of this study was to determine the relationship among GST gene expression, maternal iron intake during pregnancy, and neonatal birth weight. The study participants were 1087 Korean gravidas and their newborns recruited for the Mothers and Children's Environmental Health study between 2006 and 2010. A 24-h dietary recall interview was conducted to estimate iron intake; additional intake through nutritional supplements was thoroughly investigated. Deletion polymorphisms of GSTM1 and GSTT1 were genotyped using PCR. Dietary iron consumption during pregnancy was positively associated with birth weight in pregnant women who were GSTM1-present after adjustment for the following covariates: maternal age, prepregnancy BMI, mother's education level, log-transformed urinary cotinine level, infant gender, gestational age at term, log-transformed energy intake, parity, and the use of folic acid supplements (P < 0.05). There were interactions between the GSTM1 genotype and iron intakes from animal foods (P < 0.05), diet (P < 0.05), and diet with supplements (P < 0.05). No relationship was found between maternal iron intake and birth weight for the GSTT1 polymorphism. This study demonstrates that increased iron consumption during pregnancy may improve infant birth weight for mothers who are GSTM1-present, but it might not be beneficial for mothers with the GSTM1-null genotype.

Postpartum depression: psychoneuroimmunological underpinnings and treatment

Postpartum depression (PPD) is common, occurring in 10%-15% of women. Due to concerns about teratogenicity of medications in the suckling infant, the treatment of PPD has often been restricted to psychotherapy. We review here the biological underpinnings to PPD, suggesting a powerful role for the tryptophan catabolites, indoleamine 2,3-dixoygenase, serotonin, and autoimmunity in mediating the consequences of immuno-inflammation and oxidative and nitrosative stress. It is suggested that the increased inflammatory potential, the decreases in endogenous anti-inflammatory compounds together with decreased omega-3 poly-unsaturated fatty acids, in the postnatal period cause an inflammatory environment. The latter may result in the utilization of peripheral inflammatory products, especially kynurenine, in driving the central processes producing postnatal depression. The pharmacological treatment of PPD is placed in this context, and recommendations for more refined and safer treatments are made, including the better utilization of the antidepressant, and the anti-inflammatory and antioxidant effects of melatonin.

Comparison of melatonin and oxytocin in the prevention of critical illness polyneuropathy in rats with experimentally induced sepsis

BACKGROUND

Critical illness polyneuropathy is an acute neuromuscular disorder of critically ill patients and is characterized by limb and respiratory muscle weakness. The purpose of the study was to evaluate the neuroprotective effects of melatonin (MEL) and oxytocin (OT) on the early stage of sepsis by recording compound muscle action potentials and measuring plasma tumor necrosis factor (TNF)-α levels, lipid peroxidation (malondialdehyde; MDA), and total antioxidant capacity.

MATERIALS AND METHODS

One hundred adult male Sprague-Dawley rats were included in the study. The cecal ligation and puncture (CLP) procedure was performed to induce the sepsis model. MEL (10, 20, and 40 mg/kg), OT (0.4, 0.8, and 1.6 mg/kg), and a combination of MEL (20 mg/kg) and OT (0.8 mg/kg) were administered intraperitoneally in the first hour of surgery. Electromyography (EMG) studies were achieved 24 h after CLP surgery and then blood samples were collected for biochemical measurements.

RESULTS

EMG findings revealed that compound muscle action potential amplitude was significantly decreased and distal latency was prolonged in the CLP group compared with the sham group (P < 0.05 and P < 0.0005). Moreover, the animals that received CLP surgery showed significantly higher TNF-α and MDA levels and lower total antioxidant capacity values than the sham group. The administration of MEL and OT to rats significantly abolished the EMG alterations and suppressed oxidative stress and TNF-α release in CLP-induced rats.

CONCLUSIONS

The inflammatory processes and imbalance in oxidative/antioxidative status play important roles in the pathogenesis of critical illness polyneuropathy. We suggest that both oxytocin and melatonin may have beneficial effects against sepsis-induced polyneuropathy in critical illness.

Risk factors for developing transient neonatal cholestasis

OBJECTIVES

To describe the incidence and the characteristics of neonatal cholestasis in a cohort of patients with known risk factors and to investigate additional risk factors.

METHODS

A prospective observational study conducted between April 2008 and 2009 involved all neonates admitted in the neonatal ward. They were divided into high- and low-risk groups for cholestasis. The high-risk group included preterm birth <34  weeks of gestation, small for gestational age (SGA), parenteral nutrition (PN) >7 days, abdomino-pelvic or thoracic surgery. Bilirubinemia was weekly measured in the high-risk group.

RESULTS

Of the 460 newborns studied, 234 were included in the high-risk group and 226 in the low-risk group. Cholestasis developed in 32 patients (13.7%) in the high-risk group at mean (SD) age of 14.7 (12.9) days; all were receiving PN. None of the patients in the low-risk group developed cholestasis. An analysis was carried out in the 207 patients in the high-risk group who received PN. The odds ratio (OR) for developing cholestasis was 2.3 [1.1-5.0] and 5.6 [2.5-12.5] for SGA or surgical patients, respectively. Cholestasis was associated with neonatal severe conditions, longer PN duration, and more intravenous macronutrients' intakes. In multivariate analysis, SGA and neonatal surgery were strong independent risk factors for cholestasis, with OR (95% confidence interval [95% CI]) of 4.4 [1.6-12.5] and 4.6 [1.7-12.3], respectively.

CONCLUSIONS

Transient neonatal cholestasis is a complication of PN. SGA and neonatal surgery are additional risk factors. There is no evidence to limit intravenous protein intakes in preterm.

In vivo and in vitro evaluation of the use of a newly developed melatonin loaded emulsion combined with UV filters as a protective agent against skin irradiation

BACKGROUND

Melatonin has attracted attention because of their high antioxidant and anticarcinogenic activity. Otherwise, the use of sunscreens is recommended for patients after chemotherapy and radiotherapy treatments or to prevent UV radiation-induced skin damages that may result in pre-cancerous and cancerous skin lesions.

OBJECTIVE

To evaluate the beneficial influence of melatonin in topical sunscreen emulsions combined with three common ultraviolet filters.

METHODS

After the formulation characterization in terms of rheology, stability studies were performed. Release studies let us to evaluate its mechanism of delivery and ex vivo permeation study through human skin, the amount of melatonin retained. The antioxidant activity assay was also carried out, and finally the in vivo photoprotective effect in rats was tested as transepidermal water loss and erythema formation.

RESULTS

The rheological behaviour of formulations was pseudoplastic fluid, all emulsions had good physical stability. Release studies showed a trend of enhancement in melatonin release from emulsions incorporating UV filters and followed a Weibull model. Melatonin permeation was higher from the emulsion containing melatonin combined with a mixture of three ultraviolet filters (MMIX) formulation. Equally this formulation exhibited the highest radical scavenging activity. Finally the photoprotective assay showed that only skin areas treated with this formulation were statistically equivalent to the unirradiated control area.

CONCLUSION

MMIX formulation would be a promising formulation for preventing the undesirable adverse effects of UV skin irradiation because melatonin not only acts as a potent antioxidant itself, but also is capable of activating an endogenous enzymatic protective system against oxidative stress.

Therapeutic role of toll-like receptor modification in cardiovascular dysfunction

Toll-like receptors (TLR) are key pattern recognition receptors in the innate immune system. The TLR-mediated immune response against pathogens is usually protective however inappropriate TLR activation may lead to excessive tissue damage. It is well recognised that TLRs respond to a variety of endogenous as well as exogenous ligands. By responding to endogenous ligands that are exposed during cellular damage, TLRs have been implicated in a range of pathological conditions associated with cardiovascular dysfunction. Increasing knowledge on the mechanisms involved in TLR signalling has encouraged the exploration of therapeutic pharmacological modulation of TLR activation in conditions such as atherosclerosis, ischaemic heart disease, heart failure and ischaemic reperfusion injury. The aim of this review is to explore the translational potentials of TLR modification in cardiovascular dysfunction, where these agents have been studied.

Melatonin-induced autophagy is associated with degradation of MyoD protein in C2C12 myoblast cells

MyoD is a muscle-specific transcriptional factor that acts as a master switch for skeletal muscle differentiation. This protein regulates myoblast proliferation and myogenic differentiation and is also a short-lived regulatory protein that is degraded by the ubiquitin system. However, the lysosomal pathway of MyoD protein degradation remains unknown. In this study, we sought to determine whether melatonin (1, 2mm)-induced autophagy causes the degradation of MyoD protein in C2C12 myoblast cells. Melatonin induced a significant increase in expression of the microtubule-associated protein 1 light chain 3 (LC3)-II and Beclin-1 proteins in a dose-dependent manner. Melatonin treatment also significantly increased p-ERK, Ras, and p-Akt expressions in a dose-dependent manner. However, Bax expression was high compared with the absence of melatonin treatment, and Bcl-2 expression was high in the 0.1-0.5mm melatonin treatments and low in the 1 and 2mm melatonin treatments. Under the same conditions, cytosolic MyoD protein was significantly decreased in a dose-dependent manner and completely eliminated by 36hr. This decrease in MyoD protein involved ubiquitin-mediated proteasomal activity with proteasome inhibitor MG132 or autophagy-dependent lysosomal degradation with lysosomal inhibitor bafilomycin A1 (Baf-A1). In the same condition, phosphorylation of the mammalian target of rapamycin, p-mTOR, and p-S6K expression with Baf-A1 or Baf-A1-plus melatonin treatment were significantly decreased compared with the levels after treatment with melatonin only. Together, these results suggest that melatonin (1, 2mm)-induced autophagy results in partial lysosomal degradation of MyoD protein in C2C12 myoblast cells.

Melatonin inhibits IL1β-induced MMP9 expression and activity in human umbilical vein endothelial cells by suppressing NF-κB activation

Matrix metalloproteinases (MMPs) have been involved in inflammatory and degradative processes in pathologic conditions. The purpose of this study was to investigate the protective effect of melatonin in human umbilical vein endothelial cell (HUVEC) monolayer permeability and the regulation of MMP9 induced by interleukin 1β (IL1β (IL1B)) in HUVECs. Protection studies were carried out with melatonin, a well-known antioxidant and antiinflammatory molecule. MMP9 expression was increased with IL1β induction in HUVECs. Melatonin showed a barrier-protective role by downregulation of MMP9 and upregulation of tissue inhibitor of metalloproteinase-1 expression in HUVECs. Meanwhile, melatonin also decreased sodium fluorescein permeability and counteracted the downregulation of vascular endothelial cadherin and occludin expression in HUVECs. During inflammatory stimulus, nuclear factor-κB (NF-κB) plays a significant role in regulating MMP genes expression, thus the function of NF-κB in HUVECs' barrier disruption was investigated. IL1β induced nuclear translocation of NF-κB in HUVECs and regulated MMP9 expression. However, NF-κB translocation into the nucleus was inhibited significantly by melatonin. Our results show that melatonin decreases the permeability of monolayer endothelial cell induced by IL1β. At the same time, melatonin decreased the expression and activity of MMP9 by a NF-κB-dependent pathway in HUVECs induced by IL1β.

Melatonin and oral cavity

While initially the oral cavity was considered to be mainly a source of various bacteria, their toxins and antigens, recent studies showed that it may also be a location of oxidative stress and periodontal inflammation. Accordingly, this paper focuses on the involvement of melatonin in oxidative stress diseases of oral cavity as well as on potential therapeutic implications of melatonin in dental disorders. Melatonin has immunomodulatory and antioxidant activities, stimulates the proliferation of collagen and osseous tissue, and acts as a protector against cellular degeneration associated with aging and toxin exposure. Arising out of its antioxidant actions, melatonin protects against inflammatory processes and cellular damage caused by the toxic derivates of oxygen. As a result of these actions, melatonin may be useful as a coadjuvant in the treatment of certain conditions of the oral cavity. However, the most important effect of melatonin seems to result from its potent antioxidant, immunomodulatory, protective, and anticancer properties. Thus, melatonin could be used therapeutically for instance, locally, in the oral cavity damage of mechanical, bacterial, fungal, or viral origin, in postsurgical wounds caused by tooth extractions and other oral surgeries. Additionally, it can help bone formation in various autoimmunological disorders such as Sjorgen syndrome, in periodontal diseases, in toxic effects of dental materials, in dental implants, and in oral cancers.

Melatonin utility in neonates and children

Melatonin (N-acetyl-5-methoxytryptamine) is an endogenously produced indoleamine secreted by the pineal gland and the secretion is suppressed by light. Melatonin is a highly effective antioxidant, free radical scavenger, and has anti-inflammatory effect. Plenty of evidence supports the utility of melatonin in adults for cancer, neurodegenerative disorders, and aging. In children and neonates, melatonin has been used widely, including for respiratory distress syndrome, bronchopulmonary dysplasia, periventricular leukomalacia (PVL), hypoxia-ischemia encephalopathy and sepsis. In addition, melatonin can be used in childhood sleep and seizure disorders, and in neonates and children receiving surgery. This review article discusses the utility of melatonin in neonates and children.

Antioxidant therapies: a potential role in perinatal medicine

Pregnancies complicated by impaired placentation, acute severe reductions in oxygen supply to the fetus, or intrauterine infection are associated with oxidative stress to the mother and developing baby. Such oxidative stress is characterized as an upregulation in the production of oxidative or nitrative free radicals and a concomitant decrease in the availability of antioxidant species, thereby creating a state of fetoplacental oxidative imbalance. Recently, there has been a good deal of interest in the potential for the use of antioxidant therapies in the perinatal period to protect the fetus, particularly the developing brain, against oxidative stress in complications of pregnancy and birth. This review will examine why the immature brain is particularly susceptible to oxidative imbalance and will provide discussion on antioxidant treatments currently receiving attention in the adult and perinatal literature - allopurinol, melatonin, α-lipoic acid, and vitamins C and E. In addition, we aim to address the interaction between oxidative stress and the fetal inflammatory response, an interaction that may be vital when proposing antioxidant or other neuroprotective strategies.

Melatonin prevents down-regulation of astrocytic phosphoprotein PEA-15 in ischemic brain injury

Melatonin functions as a free-radical scavenger and has a neuroprotective effect against ischemic brain damage. PEA-15 (phosphoprotein enriched in astrocytes 15) regulates various cellular processes including cell proliferation and apoptosis. In this study, we investigated whether melatonin regulates the levels of PEA-15 and the two phosphorylated forms of PEA-15 (Ser 104 and Ser 116) in a middle cerebral artery occlusion (MCAO)-induced injury model and neuronal cells exposed to glutamate. Adult male rats were treated with vehicle or melatonin (5 mg/kg) prior to MCAO, and cerebral cortex tissues were collected 24 h after MCAO. PEA-15 levels after ischemic brain injury were monitored using a proteomic approach. Melatonin pretreatment prevented the ischemic injury-induced reduction in PEA-15 levels. Moreover, Western blot analysis demonstrated that melatonin attenuated the ischemic injury-induced reduction in PEA-15, phospho-PEA-15 (Ser 104), and phospho-PEA-15 (Ser 116) levels. Neuronal cells exposed to glutamate showed decreased expression of PEA-15, phospho-PEA-15 (Ser 104), and phospho-PEA-15 (Ser 116), while melatonin pretreatment prevented the glutamate toxicity-induced decreases in the levels of these proteins. The reduction in the levels of phospho-PEA-15 proteins indicates the inhibition of anti-apoptotic function of PEA-15. Together, in vivo and in vitro results suggest that melatonin protects neurons against ischemic injury by maintaining levels of phospho-PEA-15 proteins.

Melatonin ameliorates necrotizing enterocolitis in a neonatal rat model

INTRODUCTION

We designed the present study to evaluate the efficacy of melatonin (M) on the severity of necrotizing enterocolitis (NEC) in a neonatal rat model.

MATERIALS AND METHODS

Immediately after birth, pups were weighed and randomized into 3 groups: NEC, NEC + M, and control. Necrotizing enterocolitis was induced by enteral formula feeding and exposure to hypoxia after cold stress at 4°C and oxygen. The NEC + M group received 10 mg/kg M daily for 3 days after the first day of the NEC procedure. The pups were killed on the fourth day, and their intestinal tissues were harvested for biochemical and histopathologic analysis. Blood samples were also obtained from the pups.

RESULTS

The mortality rate and weight loss were highest in the NEC group. Malondialdehyde and protein carbonyl content were significantly increased, whereas superoxide dismutase and glutathione peroxidase were decreased in the NEC-treated pups. Melatonin prevented these changes, with these values being similar to control levels in the NEC + M group. Nitrate plus nitrite levels and serum tumor necrosis factor α and interleukin-1β were increased in the NEC group, and histopathologic injury score in the NEC group was significantly higher than that in the NEC + M group.

CONCLUSION

Melatonin significantly reduced the severity of NEC in our study.

Melatonin's stimulatory effect on adult hippocampal neurogenesis in mice persists after ovariectomy

In this study, we examined whether melatonin treatment would increase new cell formation in the hippocampus in ovariectomized (OVX) mice. Chronic exogenous melatonin administration increased bromodeoxyuridine (BrdU) (OVX-sham 72 ± 3.2 versus OVX-mel 122 ± 12.0; P < 0.05) and doublecortin (DCX) (OVX-sham 88 ± 3.1 versus OVX-mel 176 ± 9.9; P < 0.05) immunoreactive cells in the hippocampus of ovariectomized mice. This neuronal development was correlated with synaptic plasticity, identified using the Golgi impregnation method to quantify dendritic spines in mouse dentate gyrus (DG). Finally, the antidepressant-like state of the animals was evaluated by the tail suspension test. The results indicate that melatonin acts on birth, survival, and differentiation of new neurons in the hippocampus, stimulates maturation of spines, and exerts an antidepressant-like action under estrogen-deprived conditions, in both a strain- and gender-independent manner, suggesting that this indoleamine may be useful in improving brain functions.

The biological basis of injury and neuroprotection in the fetal and neonatal brain

A compromised intrauterine environment that delivers low levels of oxygen and/or nutrients, or is infected or inflammatory, can result in fetal brain injury, abnormal brain development and in cases of chronic compromise, intrauterine growth restriction. Preterm birth can also be associated with injury to the developing brain and affect the normal trajectory of brain growth. This review will focus on the effects that episodes of perinatal hypoxia (acute, chronic, associated with inflammation or as an antecedent of preterm birth) can have on the developing brain. In animal models of these conditions we have found that relatively brief (acute) periods of fetal hypoxemia can have significant effects on the fetal brain, for example death of susceptible neuronal populations (cerebellum, hippocampus, cortex) and cerebral white matter damage. Chronic placental insufficiency which includes fetal hypoxemia, nutrient restriction and altered endocrine status can result in fetal growth restriction and long-term deficits in neural connectivity in addition to altered postnatal function, for example in the auditory and visual systems. Maternal/fetal inflammation can result in fetal brain damage, particularly but not exclusively in the white matter; injury is more pronounced when associated with fetal hypoxemia. In the baboon, in which the normal trajectory of growth is affected by preterm birth, there is a direct correlation between a higher flux in oxygen saturation and a greater extent of neuropathological damage. Currently, the only established therapy for neonatal encephalopathy in full term neonates is moderate hypothermia although this only offers some protection to moderately but not severely affected brains. There is no accepted therapy for injured preterm brains. Consequently the search for more efficacious treatments continues; we discuss neuroprotective agents (erythropoietin, N-acetyl cysteine, melatonin, creatine, neurosteroids) which we have trialed in appropriate animal models. The possibility of combining hypothermia with such agents or growth factors is now being considered. A deeper understanding of causal pathways in brain injury is essential for the development of efficacious strategies for neuroprotection.

Melatonin prevents hepatic injury-induced decrease in Akt downstream targets phosphorylations

Melatonin is a potent scavenger of reactive oxygen species and a strong antioxidant. Melatonin exerts protective effects against damage by the enhancing the Akt signal pathway, thus regulating apoptotic cell death. Akt phosphorylates pro-apoptotic proteins such as Bad and FoxO1 and inhibits the pro-apoptotic functions of these proteins. This study investigated the protective effects of melatonin through Akt and its downstream targets, Bad and FoxO1, in hepatic ischemia-reperfusion (I/R) damage. Adult mice were subjected to 1 h of hepatic ischemia and 3 h of reperfusion. Hepatic ischemia was induced by occlusions of the hepatic artery, portal vein, and bile duct. Melatonin (10 mg/kg, i.p.) or vehicle was administrated 15 min prior to ischemia and just before reperfusion. Serum aspartate aminotransferase and alanine aminotransferase levels were higher in I/R group than in sham-operated group. Melatonin attenuated increases in these levels. Moreover, melatonin attenuates injury-induced increases in positive TUNEL staining in hepatic tissues. Hepatic I/R injury induced reductions in the Akt up-stream target, PDK1 phosphorylation. The levels of phospho-Akt, phospho-Bad, and phospho-FoxO1 were decreased in vehicle-treated animals. However, melatonin prevented hepatic I/R injury-induced decreases in these proteins levels. Moreover, the interaction levels between phospho-Bad and 14-3-3 and between phospho-FoxO1 and 14-3-3 are reduced in vehicle-treated animals, and melatonin attenuated decreases in the binding levels of these proteins. 14-3-3 exerts an anti-apoptotic function by sequestration of Bad and FoxO1. These findings suggest that melatonin exerts protective effects in case of hepatic I/R damage by maintaining the binding of phospho-Bad and 14-3-3 and the binding of phospho-FoxO1 and 14-3-3, thus preventing activation of apoptotic cell death.

Perspectives on the use of melatonin to reduce cytotoxic and genotoxic effects of methacrylate-based dental materials

Melatonin (5-methoxy-N-acetyltryptamine), an indoleamine produced in the pineal gland and many other organs, displays a wide spectrum of protective effects against cell injury of various origins. Contemporary dental restorative materials mainly consist of methacrylate polymers with some additives. However, because of the incompleteness of polymerization process in situ as well as mechanical shearing and enzymatic degradation, methacrylate monomers are released from the restoration into the oral cavity and the pulp, from where they gain access to other tissues and organs. Such monomers have displayed toxic properties in many in vivo and in vitro studies, including cytotoxicity and genotoxicity and a considerable portion of these effects is underlined by the oxidative action of these compounds. As melatonin shows biocompatibility with the oral cavity and displays antioxidative properties, it may be considered as a protective agent against harmful effects of methacrylate monomers derived from dental restorations. Melatonin decreases cytotoxic and genotoxic effects of methacrylate monomers used in dentistry, and it does not influence the bond strength of dental composites. This opens a new possible application of melatonin to improve properties of biomaterials used in dentistry.

Melatonin as a natural ally against oxidative stress: a physicochemical examination

Oxidative stress has been proven to be related to the onset of a large number of health disorders. This chemical stress is triggered by an excess of free radicals, which are generated in cells because of a wide variety of exogenous and endogenous processes. Therefore, finding strategies for efficiently detoxifying free radicals has become a subject of a great interest, from both an academic and practical points of view. Melatonin is a ubiquitous and versatile molecule that exhibits most of the desirable characteristics of a good antioxidant. The amount of data gathered so far regarding the protective action of melatonin against oxidative stress is overwhelming. However, rather little is known concerning the chemical mechanisms involved in this activity. This review summarizes the current progress in understanding the physicochemical insights related to the free radical-scavenging activity of melatonin. Thus far, there is a general agreement that electron transfer and hydrogen transfer are the main mechanisms involved in the reactions of melatonin with free radicals. However, the relative importance of other mechanisms is also analyzed. The chemical nature of the reacting free radical also has an influence on the relative importance of the different mechanisms of these reactions. Therefore, this point has also been discussed in detail in the current review. Based on the available data, it is concluded that melatonin efficiently protects against oxidative stress by a variety of mechanisms. Moreover, it is proposed that even though it has been referred to as the chemical expression of darkness, perhaps it could also be referred to as the chemical light of health.

Sphingosine kinase 1 pathway is involved in melatonin-induced HIF-1α inactivation in hypoxic PC-3 prostate cancer cells

Sphingosine kinase 1 (SPHK1) is a newly discovered modulator of hypoxia inducible factor 1α (HIF-1α) with various biological activities such as cell growth, survival, invasion, angiogenesis, and carcinogenesis. Thus, in the present study, the biological mechanisms of melatonin were elucidated in association with SPHK1 pathway in PC-3 prostate cancer cells under hypoxia. Melatonin inhibited the stability of HIF-1α in a time- and concentration- dependent manners. Also, melatonin decreased SPHK1 activity in PC-3 cells during hypoxia. Furthermore, melatonin suppressed AKT/glycogen synthase kinase-3β (GSK-3β) signaling pathway, which stabilizes HIF-1α via inhibition of von Hippel-Lindau tumor suppressor protein. Consistently, siRNA-SPHK1 and sphingosine kinase inhibitor (SKI) effectively blocked the expression of HIF-1α, phospho-AKT and vascular endothelial growth factor (VEGF) production in PC-3 cells under hypoxia, suggesting the role of SPHK1 in melatonin-inhibited HIF-1α accumulation. Moreover, reactive oxygen species (ROS) scavenger N-acteylcysteine enhanced melatonin-inhibited HIF-1α expression and SPHK1 activity. Overall, our findings suggest that melatonin suppresses HIF-1α accumulation via inhibition of SPHK1 pathway and ROS generation in PC-3 cells under hypoxia.

Upregulation of collagenase-1 and -3 in indomethacin-induced gastric ulcer in diabetic rats: role of melatonin

Collagenases are key proteases involved in inflammation and injury. We addressed whether collagenases have an association with the susceptibility of gastric injury under diabetes as well as the effect of melatonin on collagenases in ulcerated gastric tissues. Diabetes was induced in rats by a single dose of streptozotocin (STZ) followed by gastric ulceration using indomethacin, and melatonin's action was studied by its application prior to indomethacin exposure. Ulcer indices and damage were elevated significantly in gastric tissues of diabetic compared with nondiabetic rats. Melatonin reversed the effect of indomethacin during protection of gastric ulcers in diabetic rats. Matrix metalloproteinase (MMP)-13 (i.e., collagenase-3) was upregulated in diabetic gastric mucosa and enhanced further upon ulceration while melatonin ameliorated their activity. In addition, gastric tissues showed enhanced expression of both MMP-1 (i.e., collagenases-1) and -13 significantly in diabetic rats compared with nondiabetic animals and more so during ulceration while tissue inhibitors of metalloproteinase-1 (TIMP-1) showed an opposite trend. MMP-2 activities exhibited a ∼50% downregulation during gastric ulceration which were rescued by melatonin. Moreover, increased expression of both MMP-1 and -13 was mediated by activator protein-1 activation via extracellular signal-regulated kinase 1/2 which were parallel to upregulation of tumor necrosis factor-α, interleukin-1β, and heat shock protein-70 during ulceration. Melatonin arrested collagenase expression by downregulation of these signaling molecules thereby halting the progression of the disease. We conclude that diabetic gastric tissues are susceptible to ulceration and associated with MMP-1 and -13 upregulation in indomethacin-induced injury. Additionally, melatonin protects the gastric damage under diabetes via regulation of both MMP-1 and -13.

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.