Magnesium sulfate ameliorates maternal and fetal inflammation in a rat model of maternal infection

Effect of intra-operative Magnesium sulphate on the occurrence of post-operative delirium and insomnia in patients undergoing lumbar fixation: a randomized controlled trial

BACKGROUND

Over the last two decades, a large body of literature has focused on studying the prevalence and outcome of the postoperative delirium and sleep disturbance. The aim of this work was to evaluate the effect of intraoperative administration of Magnesium sulphate on the occurrence of post-operative delirium and insomnia in patients undergoing lumbar fixation.

METHODS

This prospective randomized controlled trial was carried out on 80 patients indicated for lumbar fixation; 40 of them received conventional general anesthesia with extra administration of intraoperative magnesium sulphate (Mg sulphate group), and the other 40 received conventional general anesthesia only (control group). Both groups were submitted to pre-operative assessment of depression using Beck Depression inventory (BDI) scale, pre-operative assessment of fatigue using a fatigue questionnaire, pre- and post-operative assessment of insomnia using Insomnia severity index (ISI), post-operative assessment of delirium using Memorial delirium assessment scale (MDAS), post-operative assessment of pain using Visual Analogue Scale (VAS), and pre- and post-operative Quantitative electroencephalography (QEEG).

RESULTS

Mg sulphate administration, age, pre-operative BDI, pre-operative ISI, and post-operative VAS were independent predictors of post-operative ISI (P-value < 0.001, 0.047, 0.021, < 0.001, and < 0.001 respectively). Age and post-operative VAS were independent predictors of post-operative MDAS (P-value = 0.008, 0.013 respectively). Mg sulphate administration and pre-operative ISI were independent predictors of post-operative VAS (P-value = 0.010, 0.006 respectively).

CONCLUSION

There was a significant relationship between intraoperative Mg sulphate administration and both post-operative insomnia and pain in unadjusted and adjusted analysis.

Magnesium sulfate and risk of hypoxic-ischemic encephalopathy in a high-risk cohort

BACKGROUND

Hypoxic-ischemic encephalopathy contributes to morbidity and mortality among neonates ≥36 weeks of gestation. Evidence of preventative antenatal treatment is limited. Magnesium sulfate has neuroprotective properties among preterm fetuses. Hypertensive disorders of pregnancy are a risk factor for hypoxic-ischemic encephalopathy, and magnesium sulfate is recommended for maternal seizure prophylaxis among patients with preeclampsia with severe features.

OBJECTIVE

(1) Determine trends in the incidence of hypertensive disorders of pregnancy, antenatal magnesium sulfate, and hypoxic-ischemic encephalopathy; (2) evaluate the association between hypertensive disorders of pregnancy and hypoxic-ischemic encephalopathy; and (3) evaluate if, among patients with hypertensive disorders of pregnancy, the odds of hypoxic-ischemic encephalopathy is mitigated by receipt of antenatal magnesium sulfate.

STUDY DESIGN

We analyzed a prospective cohort of live births ≥36 weeks of gestation between 2012 and 2018 within the California Perinatal Quality Care Collaborative registry, linked with the California Department of Health Care Access and Information files. We used Cochran-Armitage tests to assess trends in hypertensive disorders, encephalopathy diagnoses, and magnesium sulfate utilization and compared demographic factors between patients with or without hypertensive disorders of pregnancy or treatment with magnesium sulfate. Hierarchical logistic regression models were built to explore if hypertensive disorders of pregnancy were associated with any severity and moderate/severe hypoxic-ischemic encephalopathy. Separate hierarchical logistic regression models were built among those with hypertensive disorders of pregnancy to evaluate the association of magnesium sulfate with hypoxic-ischemic encephalopathy.

RESULTS

Among 44,314 unique infants, the diagnosis of hypoxic-ischemic encephalopathy, maternal hypertensive disorders of pregnancy, and the use of magnesium sulfate increased over time. Compared with patients with hypertensive disorders of pregnancy alone, patients with hypertensive disorders treated with magnesium sulfate represented a high-risk population. They were more likely to be publicly insured, born between 36 and 38 weeks of gestation, be small for gestational age, have lower Apgar scores, require a higher level of resuscitation at delivery, have prolonged rupture of membranes, experience preterm labor and fetal distress, and undergo operative delivery (all P<.002). Hypertensive disorders of pregnancy were associated with hypoxic-ischemic encephalopathy (adjusted odds ratio, 1.26 [95% confidence interval, 1.13-1.40]; P<.001) and specifically moderate/severe hypoxic-ischemic encephalopathy (adjusted odds ratio, 1.26 [95% confidence interval, 1.11-1.42]; P<.001). Among patients with hypertensive disorders of pregnancy, treatment with magnesium sulfate was associated with 29% reduction in the odds of neonatal hypoxic-ischemic encephalopathy (adjusted odds ratio, 0.71 [95% confidence interval, 0.52-0.97]; P=.03) and a 37% reduction in the odds of moderate/severe neonatal hypoxic-ischemic encephalopathy (adjusted odds ratio, 0.63 [95% confidence interval, 0.42-0.94]; P=.03).

CONCLUSION

Hypertensive disorders of pregnancy are associated with hypoxic-ischemic encephalopathy and, specifically, moderate/severe disease. Among people with hypertensive disorders, receipt of antenatal magnesium sulfate is associated with a significant reduction in the odds of hypoxic-ischemic encephalopathy and moderate/severe disease in a neonatal cohort admitted to neonatal intensive care unit at ≥36 weeks of gestation. The findings of this observational study cannot prove causality and are intended to generate hypotheses for future clinical trials on magnesium sulfate in term infants.

Intra-amniotic inflammation in the mid-trimester of pregnancy is a risk factor for neuropsychological disorders in childhood

OBJECTIVES

Intra-amniotic inflammation is a subclinical condition frequently caused by either microbial invasion of the amniotic cavity or sterile inflammatory stimuli, e.g., alarmins. An accumulating body of evidence supports a role for maternal immune activation in the genesis of fetal neuroinflammation and the occurrence of neurodevelopmental disorders such as cerebral palsy, schizophrenia, and autism. The objective of this study was to determine whether fetal exposure to mid-trimester intra-amniotic inflammation is associated with neurodevelopmental disorders in children eight to 12 years of age.

METHODS

This is a retrospective case-control study comprising 20 children with evidence of prenatal exposure to intra-amniotic inflammation in the mid-trimester and 20 controls matched for gestational age at amniocentesis and at delivery. Amniotic fluid samples were tested for concentrations of interleukin-6 and C-X-C motif chemokine ligand 10, for bacteria by culture and molecular microbiologic methods as well as by polymerase chain reaction for eight viruses. Neuropsychological testing of children, performed by two experienced psychologists, assessed cognitive and behavioral domains. Neuropsychological dysfunction was defined as the presence of an abnormal score (<2 standard deviations) on at least two cognitive tasks.

RESULTS

Neuropsychological dysfunction was present in 45% (9/20) of children exposed to intra-amniotic inflammation but in only 10% (2/20) of those in the control group (p=0.03). The relative risk (RR) of neuropsychological dysfunction conferred by amniotic fluid inflammation remained significant after adjusting for gestational age at delivery [aRR=4.5 (1.07-16.7)]. Of the 11 children diagnosed with neuropsychological dysfunction, nine were delivered at term and eight of them had mothers with intra-amniotic inflammation. Children exposed to intra-amniotic inflammation were found to have abnormalities in neuropsychological tasks evaluating complex skills, e.g., auditory attention, executive functions, and social skills, whereas the domains of reasoning, language, and memory were not affected in the cases and controls.

CONCLUSIONS

Asymptomatic sterile intra-amniotic inflammation in the mid-trimester of pregnancy, followed by a term birth, can still confer to the offspring a substantial risk for neurodevelopmental disorders in childhood. Early recognition and treatment of maternal immune activation in pregnancy may be a strategy for the prevention of subsequent neurodevelopmental disorders in offspring.

Long-term effects of prophylactic MgSO4 in maternal immune activation rodent model at adolescence and adulthood

The effects of MgSO₄ as an anti-inflammatory agent in pregnant women have been investigated in the last few years. Infections can cause an inflammatory reaction involving the placenta membranes and amniotic cavity. They may have short-term effects on the mother and her fetuses, like preterm birth, cerebral palsy, and developmental delay. Despite the alleged advantages of MgSO₄ as a neuroprotective agent in the preterm brain, the long-term molecular and behavioral function of MgSO₄ has not been fully elucidated. Here, we investigated the long-term effect of antenatal MgSO₄ , during late gestation, on offspring's behavior focusing on cognitive function, motor activity, and social cognition in adolescence and adulthood, and explored its influence on brain gene expression (e.g., ErbB signaling, pro-inflammatory, and dopaminergic markers) in adulthood. A significant abnormal exploratory behavior of offspring of MgSO₄ -treated dams was found compared to the control group in both adolescence and adulthood. Furthermore, we found that adult females exposed to MgSO₄ under inflammation displayed working and recognition memory impairment. A reduction in IL-6 expression was detected in the prefrontal cortex, and hippocampus specimens derived from LPS-Mg-treated group. In contrast, an imbalanced expression of dopamine 1 and 2 receptors was detected only in prefrontal cortex specimens. Besides, we found that MgSO₄ ameliorated the overexpression of the Nrg1 and Erbb4 receptors induced by LPS in the hippocampus. Thus, MgSO₄ treatment for preventing brain injuries can adversely affect offspring cognition behavior later in life, depending on the sex and age of the offspring.

Combined Use of Magnesium Sulfate and Fingolimod for Antenatal Neuroprotection against Inflammation-Mediated Experimental Preterm Brain Injury in a Rat Model

BackgroundWe compared the neuroprotective effects of Fingolimod (fng), a neuroprotective and anti-inflammatory drug, with that of magnesium sulfate (MgSO4), alone and in combination, in fetal rat whose mothers were exposed to endotoxin.MethodSeven groups of pregnant rats (28 total) were evaluated at 0.8 gestation - Group1 - saline only; 2 - endotoxin only; 3 - endotoxin + MgSO4; 4 - endotoxin + fng; 5 - endotoxin + MgSO4 + fng; 6 - saline + fng; 7 - saline + MgSO4 + fng. Preterm labor was induced 4 h after intraperitoneal endotoxin administration. Fetal brain samples were examined immunohistochemically using S100β, IL-6, and IL-10.ResultsEndotoxin caused increased expression of S100β, IL-6, and IL-10. Compared with MgSO4 alone, combined treatment was associated with lower expression of IL-10, IL-6 and S100 β.ConclusionFng decreases inflammatory markers after in-utero exposure to endotoxin, has a synergistic effect combined with MgSO4, and may be a candidate neuroprotective drug for inflammation-induced preterm brain injury.

Impact of tocolysis-intent magnesium sulfate and beta-adrenergic agonists on perinatal brain damage in infants born between 28-36 weeks' gestation

AIMS

Magnesium sulfate has neuroprotective effects in preterm infants. Whether other antepartum treatments interfere with the neuroprotective actions is not well known. This study aims to explore the impacts of antenatal administration of Magnesium sulfate or beta-2 adrenergic agonists as tocolytic agents on the developing brain in premature infants.

METHODS

This is a retrospective cohort study in four tertiary perinatal centers in Japan. We collected data of pregnant women and infants born between 28 and 36 weeks for tocolytic agents, gestational age, sex, antenatal corticosteroid, fetal growth restriction, pathological chorioamnionitis, low umbilical arterial pH values (<7.1), multiple pregnancy, mode of delivery and institutions after excluding clinical chorioamnionitis, non-reassuring fetal status or major anomalies. Tocolytic agents were categorized into four groups: no-tocolysis, magnesium sulfate, beta-2 adrenergic agonists and the combination of them. We conducted multiple comparisons with multivariate analyses using generalized linear regression models to compare the prevalence of a poor perinatal outcome defined as infant's death, brain damage, particularly cerebral palsy and developmental delay.

RESULTS

Among 1083 infants, 39% were no-tocolysis, 47% were magnesium sulfate, 41% were beta-2 adrenergic agonists and 27% were combination group, including the duplication. The incidence of poor perinatal outcome was decreased by magnesium sulfate (OR 0.27, 95% CI 0.10-0.72), but not changed significantly by beta-2 adrenergic agonists (OR 1.28, 95% CI 0.63-2.59) or the combination group (OR 2.24, 95% CI 0.67-7.54), compared with the no-tocolysis.

CONCLUSION

The combination therapy for tocolysis with beta-2 adrenergic agonists diminished the magnesium sulfate neuroprotective action after adjusting for covariables.

Short-Term Effect of MgSO4 on the Expression of NRG-ErbB, Dopamine, GABA, and Glutamate Systems in the Fetal Rat Brain

MgSO₄ has been used for the past two decades as neuroprotective treatment in a variety of preterm conditions. Despite the putative advantages of MgSO₄ as a neuroprotective agent in the preterm brain, the short- and long-term molecular function of MgSO₄ as a neuroprotective agent has not been fully elucidated. Neuregulin (NRG1)-ErbB4 signaling plays a critical role in embryonic brain development, in the biology of dopaminergic, GABAergic, and glutamatergic systems. We hypothesize that this pathway may be associated with the neuroprotective role of MgSO₄. The current study aims to investigate the ability of MgSO₄ to modulate the normal developing expression pattern of selected genes related to the NRG1-ErbB, dopaminergic, GABAergic, and glutamatergic systems. We demonstrate that overall short-term treatment of dam rats with MgSO₄ affects the expression of fetal brain NRG1, NRG3, ErbB4, GAD67, tyrosine hydroxylase (TH), dopamine D₂ and D₁ receptors, GluN1, and GluN2B. More specifically, the administration of MgSO₄ alters the expression of NRG-ErbB, GAD67, TH, and D2R at early gestation day 16 (GD16) regardless of the activation of the maternal immune system by lipopolysaccharide (LPS). Our data suggest that MgSO₄ treatment may affect the expression of major neuronal systems and pathways mostly at an early gestation day. These changes might be an initial clue (foundation stone) in the molecular mechanism that underlies the beneficial effect of MgSO₄ as a neuroprotective agent for the developmental brain.

Short-term effects of early initiation of magnesium infusion combined with cooling after hypoxia-ischemia in term piglets

BACKGROUND

Neuroprotection from therapeutic hypothermia (HT) is incomplete, therefore additional strategies are necessary to improve long-term outcomes. We assessed the neuroprotective efficacy of magnesium sulfate (MgSO₄) bolus and infusion over 48 h plus HT in a piglet model of term neonatal encephalopathy (NE).

METHODS

Fifteen newborn piglets were randomized following hypoxia-ischemia (HI) to: (i) MgSO₄ 180 mg/kg bolus and 8 mg/kg/h infusion with HT (Mg+HT) or (ii) HT and saline 0.5 ml/h (HT). Treatments were initiated 1 h post-HI; HT administered for 12 h (33.5 °C). HI was performed by transient carotid occlusion and inhalation of 6% O₂ for 20-25 min. Primary outcomes included aEEG, magnetic resonance spectroscopy (MRS) at 24, and 48 h, and immunohistochemistry.

RESULTS

MgSO₄ bolus and infusion was well tolerated (no hypotension) and doubled serum magnesium (0.72 vs 1.52 mmol/L) with modest (16%) rise in CSF. In Mg+HT compared to HT, there was overall reduced cell death (p = 0.01) and increased oligodendrocytes (p = 0.002). No improvement was seen on aEEG recovery (p = 0.084) or MRS (Lac/NAA; PCr/Pi; NTP/epp) (p > 0.05) at 48 h.

CONCLUSION

Doubling serum magnesium with HT was safe; however, the small incremental benefit of Mg+HT compared to HT is unlikely to translate into substantive long-term improvement. Such an incremental effect might justify further study of MgSO₄ in combination with multiple therapies.

Magnesium Regulates Endothelial Barrier Functions through TRPM7, MagT1, and S1P1

Mg2+-deficiency is linked to hypertension, Alzheimer's disease, stroke, migraine headaches, cardiovascular diseases, and diabetes, etc., but its exact role in these pathophysiological conditions remains elusive. Mg2+ can regulate vascular functions, yet the mechanistic insight remains ill-defined. Data show that extracellular Mg2+ enters endothelium mainly through the TRPM7 channel and MagT1 transporter. Mg2+ can act as an antagonist to reduce Ca2+ signaling in endothelium. Mg2+ also reduces the intracellular reactive oxygen species (ROS) level and inflammation. In addition, Mg2+-signaling increases endothelial survival and growth, adhesion, and migration. Endothelial barrier integrity is significantly enhanced with Mg2+-treatment through S1P1-Rac1 pathways and barrier-stabilizing mediators including cAMP, FGF1/2, and eNOS. Mg2+ also promotes cytoskeletal reorganization and junction proteins to tighten up the barrier. Moreover, Mg2+-deficiency enhances endothelial barrier permeability in mice, and Mg2+-treatment rescues histamine-induced transient vessel hyper-permeability in vivo. In summary, Mg2+-deficiency can cause deleterious effects in endothelium integrity, and Mg2+-treatment may be effective in the prevention or treatment of vascular dysfunction.

The role of magnesium in different inflammatory diseases

Magnesium deficiency (MgD) can cause inflammation in human body. The known mechanisms of inflammation caused by MgD include activation of phagocytic cells, opening of calcium channels, activation of the N-methyl-D-aspartate (NMDA) receptor, and activation of nuclear factor (NF)-κB. In addition, MgD causes systemic stress response through neuroendocrinological pathways. The inflammation caused by MgD can result in pro-atherogenic changes in the metabolism of lipoproteins, endothelial dysfunction, and high blood pressure. Studies suggest that magnesium may play an important role in the pathophysiology of some inflammatory diseases. Several clinical trials and laboratory studies have been done on the functional role of magnesium. In this study, we review some inflammatory diseases, in which the magnesium has a role in their pathophysiology. Among these diseases, diabetes, asthma, preeclampsia, atherosclerosis, heart damage, and rheumatoid arthritis have been highlighted.

Magnesium induces preconditioning of the neonatal brain via profound mitochondrial protection

Magnesium sulphate (MgSO4) given to women in preterm labor reduces cerebral palsy in their offspring but the mechanism behind this protection is unclear, limiting its effective, safe clinical implementation. Previous studies suggest that MgSO4 is not neuroprotective if administered during or after the insult, so we hypothesised that MgSO4 induces preconditioning in the immature brain. Therefore, we administered MgSO4 at various time-points before/after unilateral hypoxia-ischemia (HI) in seven-day-old rats. We found that MgSO4 treatment administered as a bolus between 6 days and 12 h prior to HI markedly reduced the brain injury, with maximal protection achieved by 1.1 mg/g MgSO4 administered 24 h before HI. As serum magnesium levels returned to baseline before the induction of HI, we ascribed this reduction in brain injury to preconditioning. Cerebral blood flow was unaffected, but mRNAs/miRNAs involved in mitochondrial function and metabolism were modulated by MgSO4. Metabolomic analysis (H+-NMR) disclosed that MgSO4 attenuated HI-induced increases in succinate and prevented depletion of high-energy phosphates. MgSO4 pretreatment preserved mitochondrial respiration, reducing ROS production and inflammation after HI. Therefore, we propose that MgSO4 evokes preconditioning via induction of mitochondrial resistance and attenuation of inflammation.

Fetal neuroprotective mechanism of maternal magnesium sulfate for late gestation inflammation: in a rodent model

Background: Maternal administration of magnesium sulfate (Mg) is used in humans to protect the fetal brain during preterm delivery. We sought to determine the neuroprotective mechanism of Mg in a rat model of late gestation maternal inflammation.Methods: Pregnant rats at 20 d of gestation (20 total, four groups, N = 5 in each group) received i.p. LPS or saline. Dams were randomized for s.c. saline or Mg supplementation 2 h prior and following the LPS/saline injections. Dams were sacrificed 4 h following the last treatment. Fetal brains were collected from the four treatment groups. Fetal brain caspase 3 active form, NF-kB p65, neuronal nitric oxide synthase (phospho-nNos), and proinflammatory cytokines levels were determined by western blot.Results: Maternal LPS at e20 significantly (p < .01) increased fetal brain caspase 3 active form (af) (0.27 ± 0.02 versus 0.15 ± 0.06u), NFkB (0.23 ± 0.01 versus 0.13 ± 0.01u), and phospho-nNOS (0.22 ± 0.01 versus 0.12 ± 0.01u) and fetal brain proinflammatory cytokines (IL-6 0.21 ± 0.01 versus 0.11 ± 0.01 u; TNFα 0.29 ± 0.01 versus 0.15 ± 0.01u), compared with control fetuses. Mg treatment significantly (p < .05) reduced fetal brain caspase 3 af (0.16 ± 0.01u), NFkB p65 (0.11 ± 0.01u), phospho-nNOS (0.1 ± 0.01u), as well as brain proinflammatory cytokines (IL-6 0.07 ± 0.01u; TNFα 0.15 ± 0.01u) to levels similar to controls.Conclusion: Maternal inflammation-induced fetal brain injury at late gestation may be mediated by the activation of inflammatory response, oxidative stress, and apoptosis. Maternal Mg may attenuate the injury by inhibition of these putative pathways.

Magnesium sulfate differentially modulates fetal membrane inflammation in a time-dependent manner

PROBLEM

Chorioamnionitis and infection-associated inflammation are major causes of preterm birth. Magnesium sulfate (MgSO₄ ) is widely used in obstetrics as a tocolytic; however, its mechanism of action is unclear. This study sought to investigate how MgSO₄ modulates infection-associated inflammation in fetal membranes (FMs), and whether the response was time dependent.

METHOD OF STUDY

Human FM explants were treated with or without bacterial lipopolysaccharide (LPS); with or without MgSO₄ added either: 1 hour before LPS; at the same time as LPS; 1 hour post-LPS; or 2 hours post-LPS. Explants were also treated with or without viral dsRNA and LPS, alone or in combination; and MgSO₄ added 1 hour post-LPS After 24 hours, supernatants were measured for cytokines/chemokines; and tissue lysates measured for caspase-1 activity.

RESULTS

Lipopolysaccharide-induced FM inflammation by upregulating the secretion of a number of inflammatory cytokines/chemokines. Magnesium sulfate administered 1-hour post-LPS inhibited FM secretion of IL-1β, IL-6, G-CSF, RANTES, and TNFα. Magnesium sulfate administered 2 hours post-LPS augmented FM secretion of these factors as well as IL-8, IFNγ, VEGF, GROα and IP-10. Magnesium sulfate delivered 1- hour post-LPS inhibited LPS-induced caspase-1 activity, and inhibited the augmented IL-1β response triggered by combination viral dsRNA and LPS.

CONCLUSION

Magnesium sulfate differentially modulates LPS-induced FM inflammation in a time-dependent manner, in part through its modulation of caspase-1 activity. Thus, the timing of MgSO₄ administration may be critical in optimizing its anti-inflammatory effects in the clinical setting. MgSO₄ might also be useful at preventing FM inflammation triggered by a polymicrobial viral-bacterial infection.

Antenatal glucocorticoids, magnesium sulfate, and mode of birth in preterm fetal small for gestational age

A diagnosis of fetal growth restriction and subsequent preterm birth is associated with increased risks of adverse perinatal and neurodevelopmental outcomes and potentially long-lasting effects to adulthood. Most such cases are associated with placental insufficiency and the fetal response to chronic intrauterine hypoxemia and nutrient deprivation leads to substantial physiological and metabolic adaptations. The management of such pregnancies, especially with respect to perinatal interventions and birth mode, remains an unresolved dilemma. The benefits from standard interventions for threatened preterm birth may not be necessarily translated to pregnancies with small-for-gestational-age fetuses. Clinical trials or retrospective studies on outcomes following administration of antenatal glucocorticoids and magnesium sulfate for neuroprotection when preterm birth is imminent either have yielded conflicting results for small-for-gestational-age fetuses, or did not include this subgroup of patients. Experimental models highlight potential harmful effects of administration of antenatal glucocorticoids and magnesium sulfate in the pregnancies with fetal small for gestational age although clinical data do not substantiate these concerns. In addition, heterogeneity in definitions of fetal small for gestational age, variations in the inclusion criteria, and the glucocorticoid regime contribute to inconsistent results. In this review, we discuss the physiologic adaptions of the small-for-gestational-age fetus to its abnormal in utero environment in relation to antenatal glucocorticoids; the impact of antenatal glucocorticoids and intrapartum magnesium sulfate in pregnancies with fetal small for gestational age; the current literature on birth mode for pregnancies with fetal small for gestational age; and the knowledge gaps in the existing literature.

Chorioamnionitis, IL-17A, and fetal origins of neurologic disease

The Centers for Disease Control and Prevention estimate that 1 in 323 infants have cerebral palsy. Highly correlated to intrauterine infection and inflammation, the incidence of cerebral palsy has remained constant over the last few decades despite significant advances in neonatal intensive care including improved ventilator techniques, surfactant therapy, maternal steroid administration, and use of intrapartum empiric antimicrobials. Recent advances in our understanding of immune responses to infection and inflammation have identified the cytokine IL-17A as a crucial component of early proinflammatory mediators that cause brain injury associated with neurologic impairment. Remarkably, maternal inflammatory responses to in utero inflammation and infection can also lead to potentially debilitating neurologic conditions in the offspring, which often become clinically apparent during childhood and/or early adulthood. This review details the role of IL-17A in fetal and maternal proinflammatory responses that lead to fetal brain injury and neurologic sequelae, including cerebral palsy. Recent findings regarding the role of maternal inflammatory responses in the development of childhood and adult neurologic conditions, such as autism, schizophrenia, and multiple sclerosis, will also be highlighted.

Magnesium sulfate (MG) prevents maternal inflammation induced offspring cerebral injury evident on MRI but not via IL-1β

OBJECTIVE

As maternal treatment with magnesium sulfate (MG) may protect the fetal brain, we sought to assess the inflammation associated neuroprotective potential of MG and its association to interleukin 1β (IL-1β).

METHODS

Pregnant Sprague-Dawley rats at 18-day gestation received i.p. lipopolysaccharide (LPS) or saline. Dams were randomized to treatment with s.c. saline (control), or MG prior to or following the i.p. injection, resulting in three groups. At the end of the treatment, fetal brain IL-1β was quantified for 18 pregnant rats (six of each group). Another 18 pregnant rats delivered spontaneously and pups were allowed to mature. At postnatal day 25, female offspring were examined by magnetic resonance imaging (MRI) and analyzed using voxel based analysis. Apparent diffusion coefficient (ADC) and T2 relaxation protocols were performed to assess white and gray matter injury.

RESULTS

Offspring of LPS-treated dams exhibited (1) significantly increased T2 levels, and (2) increased ADC levels in white and gray matter, consistent with diffuse cerebral injury. Offspring of MG-treated LPS dams demonstrated similar T2 and ADC levels as control dams. Fetal brain IL-1β was significantly increased following maternal LPS compared to control (0.125±0.01 vs 0.100±0.01u, p<0.05). No significant decrease in IL-1β level was observed in response to maternal MG.

CONCLUSIONS

Maternal LPS-induced neonatal brain injury can be prevented by maternal MG. Maternal MG therapy may be effective in human deliveries associated with maternal/fetal inflammation. The absence of a decrease in fetus brain levels of IL-1β following MG treatment implies that the mechanism of MG is not through inhibition of IL-1β production.

SIGNIFICANCE STATEMENT

Intrauterine fetal exposure to maternal inflammation and pro-inflammatory cytokines is associated with adverse offspring neurological outcomes. Although its precise mechanism is not elucidated, magnesium sulfate (MG) is commonly used as neuroprotection for white matter brain injuries in preterm fetuses. A proposed mechanism involves the ability of MG to reduce pro-inflammatory cytokine levels. In the current study, we used a rat model of LPS-induced maternal inflammation to investigate the short-term effect of MG on fetal brain IL-1β levels, and its long-term neuroprotective effect on the offspring brain by using MRI. We demonstrated that maternal administration of MG can prevent long-term neonatal brain injury but, since no decrease was observed in fetal brain IL-1β levels, the neuro-protective mechanism of MG is not mediated by inhibition of IL-1β production.

Maternal magnesium sulfate fetal neuroprotective effects to the fetus: inhibition of neuronal nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells activation in a rodent model

BACKGROUND

Maternal magnesium administration has been shown to protect the preterm fetus from white- and gray-matter injury, although the mechanism is unknown.

OBJECTIVE

The purpose of the study is to test the following hypotheses: (1) maternal infections/inflammation activate fetal neuronal N-methyl-D-aspartate receptors that up-regulate neuronal nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells pathways; and (2) maternal magnesium sulfate attenuates fetal brain neuronal nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells activation through N-methyl-D-aspartate receptors.

STUDY DESIGN

Pregnant rats at embryonic day 16 and embryonic day 18 (n = 6, 48 total) received injections of intraperitoneal lipopolysaccharide 500 μg/kg or saline at time 0. Dams were randomized for treatment with subcutaneous magnesium sulfate (270 mg/kg) or saline for 2 hours prior to and following lipopolysaccharide/saline injections. At 4 hours after lipopolysaccharide administration, fetal brains were collected from the 4 treatment groups (lipopolysaccharide/saline, lipopolysaccharide/magnesium sulfate, saline/magnesium sulfate, saline/saline), and phosphoneuronal nitric oxide synthase, nuclear factor kappa-light-chain-enhancer of activated B cells p65, and chemokine (C-C motif) ligand 2 protein levels were determined by Western blot. An additional group of pregnant rats (n = 5) received N-methyl-D-aspartate-receptor antagonist following the lipopolysaccharide injection to study magnesium sulfate protective mechanism.

RESULTS

Lipopolysaccharide (lipopolysaccharide/saline) significantly increased fetal brain phosphoneuronal nitric oxide synthase, nuclear factor kappa-light-chain-enhancer of activated B cells p65, and chemokine (C-C motif) ligand 2 protein levels compared to the saline/saline group at both embryonic day 16 (phosphoneuronal nitric oxide synthase 0.23 ± 0.01 vs 0.11 ± 0.01 U; nuclear factor kappa-light-chain-enhancer of activated B cells 0.24 ± 0.01 vs 0.14 ± 0.01 U; chemokine (C-C motif) ligand 2 0.28 ± 0.01 vs .01 ± 0.01 U) and embryonic day 18 (phosphoneuronal nitric oxide synthase 0.28 ± 0.01 vs 0.12 ± 0.01 U; nuclear factor kappa-light-chain-enhancer of activated B cells 0.12 ± 0.01 vs 0.1 ± 0.01 U; chemokine (C-C motif) ligand 2 0.27 ± 0.01 vs 0.11 ± 0.01 U). Magnesium sulfate treatment to lipopolysaccharide dams (lipopolysaccharide/magnesium sulfate) significantly decreased fetal brain phosphoneuronal nitric oxide synthase, nuclear factor kappa-light-chain-enhancer of activated B cells, and chemokine (C-C motif) ligand 2 protein levels compared to lipopolysaccharide/saline dams at both embryonic day 16 (neuronal nitric oxide synthase 0.17 ± 0.02 U; nuclear factor kappa-light-chain-enhancer of activated B cells 0.17 ± 0.03 U; chemokine (C-C motif) ligand 2 0.18 ± 0.01 U) and embryonic day 18 (phosphoneuronal nitric oxide synthase 0.1 ± 0.01 U; nuclear factor kappa-light-chain-enhancer of activated B cells 0.09 ± 0.01 U; chemokine (C-C motif) ligand 2 0.21 ± 0.01 U). Notably, maternal lipopolysaccharide at embryonic day 16 activated nuclear factor kappa-light-chain-enhancer of activated B cells twice as often compared to dams induced at embryonic day 18. N-methyl-D-aspartate-receptor antagonist decreased fetal brain phosphoneuronal nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells levels comparable to magnesium sulfate.

CONCLUSION

Lipopolysaccharide-simulated inflammation during pregnancy may cause brain injury through activation of neuronal nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells pathways and, potentially, production of excitotoxic nitric oxide and inflammatory mediators. The increased susceptibility to brain injury in preterm fetuses may be due to enhanced nuclear factor kappa-light-chain-enhancer of activated B cells activation. Magnesium sulfate protective effects may be secondary, in part, to inhibition of neuronal nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells activation and decrease proinflammatory cytokine production through blocking nuclear factor kappa-light-chain-enhancer of activated B cells receptors.

Different treatment regimens of magnesium sulphate for tocolysis in women in preterm labour

BACKGROUND

Magnesium sulphate has been used to inhibit preterm labour to prevent preterm birth. There is no consensus as to the safety profile of different treatment regimens with respect to dose, duration, route and timing of administration.

OBJECTIVES

To assess the efficacy and safety of alternative magnesium sulphate regimens when used as single agent tocolytic therapy during pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2015) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised trials comparing different magnesium sulphate treatment regimens when used as single agent tocolytic therapy during pregnancy in women in preterm labour. Quasi-randomised trials were eligible for inclusion but none were identified. Cross-over and cluster trials were not eligible for inclusion. Health outcomes were considered at the level of the mother, the infant/child and the health service.

INTERVENTION

intravenous or oral magnesium sulphate given alone for tocolysis.Comparison: alternative dosing regimens of magnesium sulphate given alone for tocolysis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and quality and extracted data.

MAIN RESULTS

Three trials including 360 women and their infants were identified as eligible for inclusion in this review. Two trials were rated as low risk of bias for random sequence generation and concealment of allocation. A third trial was assessed as unclear risk of bias for these domains but did not report data for any of the outcomes examined in this review. No trials were rated to be of high quality overall.Intravenous magnesium sulphate was administered according to low-dose regimens (4 g loading dose followed by 2 g/hour continuous infusion and/or increased by 1 g/hour hourly until successful tocolysis or failure of treatment), or high-dose regimens (4 g loading dose followed by 5 g/hour continuous infusion and increased by 1 g/hour hourly until successful tocolysis or failure of treatment, or 6 g loading dose followed by 2 g/hour continuous infusion and increased by 1 g/hour hourly until successful tocolysis or failure of treatment).There were no differences seen between high-dose magnesium sulphate regimens compared with low-dose magnesium sulphate regimens for the primary outcome of fetal, neonatal and infant death (risk ratio (RR) 0.43, 95% confidence interval (CI) 0.12 to 1.56; one trial, 100 infants). Using the GRADE approach, the evidence for fetal, neonatal and infant death was considered to be VERY LOW quality. No data were reported for any of the other primary maternal and infant health outcomes (birth less than 48 hours after trial entry; composite serious infant outcome; composite serious maternal outcome).There were no clear differences seen between high-dose magnesium sulphate regimens compared with low-dose magnesium sulphate regimens for the secondary infant health outcomes of fetal death; neonatal death; and rate of hypocalcaemia, osteopenia or fracture; and secondary maternal health outcomes of rate of caesarean birth; pulmonary oedema; and maternal self-reported adverse effects. Pulmonary oedema was reported in two women given high-dose magnesium sulphate, but not in any of the women given low-dose magnesium sulphate.In a single trial of high and low doses of magnesium sulphate for tocolysis including 100 infants, the risk of respiratory distress syndrome was lower with use of a high-dose regimen compared with a low-dose regimen (RR 0.31, 95% CI 0.11 to 0.88; one trial, 100 infants). Using the GRADE approach, the evidence for respiratory distress syndrome was judged to be LOW quality. No difference was seen in the rate of admission to the neonatal intensive care unit. However, for those babies admitted, a high-dose regimen was associated with a reduction in the length of stay in the neonatal intensive care unit compared with a low-dose regimen (mean difference -3.10 days, 95% confidence interval -5.48 to -0.72).We found no data for the majority of our secondary outcomes.

AUTHORS' CONCLUSIONS

There are limited data available (three studies, with data from only two studies) comparing different dosing regimens of magnesium sulphate given as single agent tocolytic therapy for the prevention of preterm birth. There is no evidence examining duration of therapy, timing of therapy and the role for repeat dosing.Downgrading decisions for our primary outcome of fetal, neonatal and infant death were based on wide confidence intervals (crossing the line of no effect), lack of blinding and a limited number of studies. No data were available for any of our other important outcomes: birth less than 48 hours after trial entry; composite serious infant outcome; composite serious maternal outcome. The data are limited by volume and the outcomes reported. Only eight of our 45 pre-specified primary and secondary maternal and infant health outcomes were reported on in the included studies. No long-term outcomes were reported. Downgrading decisions for the evidence on the risk of respiratory distress were based on wide confidence intervals (crossing the line of no effect) and lack of blinding.There is some evidence from a single study suggesting a reduction in the length of stay in the neonatal intensive care unit and a reduced risk of respiratory distress syndrome where a high-dose regimen of magnesium sulphate has been used compared with a low-dose regimen. However, given that evidence has been drawn from a single study (with a small sample size), these data should be interpreted with caution.Magnesium sulphate has been shown to be of benefit in a wide range of obstetric settings, although it has not been recommended for tocolysis. In clinical settings where health benefits are established, further trials are needed to address the lack of evidence regarding the optimal dose (loading dose and maintenance dose), duration of therapy, timing of therapy and role for repeat dosing in terms of efficacy and safety for mothers and their children. Ongoing examination of different regimens with respect to important health outcomes is required.

Magnesium ion influx reduces neuroinflammation in Aβ precursor protein/Presenilin 1 transgenic mice by suppressing the expression of interleukin-1β

Alzheimer's disease (AD) has been associated with magnesium ion (Mg²⁺) deficits and interleukin-1β (IL-1β) elevations in the serum or brains of AD patients. However, the mechanisms regulating IL-1β expression during Mg²⁺ dyshomeostasis in AD remain unknown. We herein studied the mechanism of IL-1β reduction using a recently developed compound, magnesium-L-threonate (MgT). Using human glioblastoma A172 and mouse brain D1A glial cells as an in vitro model system, we delineated the signaling pathways by which MgT suppressed the expression of IL-1β in glial cells. In detail, we found that MgT incubation stimulated the activity of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) and peroxisome proliferator-activated receptor gamma (PPARγ) signaling pathways by phosphorylation, which resulted in IL-1β suppression. Simultaneous inhibition of the phosphorylation of ERK1/2 and PPARγ induced IL-1β upregulation in MgT-stimulated glial cells. In accordance with our in vitro data, the intracerebroventricular (i.c.v) injection of MgT into the ventricles of APP/PS1 transgenic mice and treatment of Aβ precursor protein (APP)/PS1 brain slices suppressed the mRNA and protein expression of IL-1β. These in vivo observations were further supported by the oral administration of MgT for 5 months. Importantly, Mg²⁺ influx into the ventricles of the mice blocked the effects of IL-1β or amyloid β-protein oligomers in the cerebrospinal fluid. This reduced the stimulation of IL-1β expression in the cerebral cortex of APP/PS1 transgenic mice, which potentially contributed to the inhibition of neuroinflammation.

Magnesium protects against cisplatin-induced acute kidney injury by regulating platinum accumulation

Despite its success as a potent antineoplastic agent, ∼25% of patients receiving cisplatin experience acute kidney injury (AKI) and must discontinue therapy. Impaired magnesium homeostasis has been linked to cisplatin-mediated AKI, and because magnesium deficiency is widespread, we examined the effect of magnesium deficiency and replacement on cisplatin-induced AKI in physiologically relevant older female mice. Magnesium deficiency significantly increased cisplatin-associated weight loss and markers of renal damage (plasma blood urea nitrogen and creatinine), histological changes, inflammation, and renal cell apoptosis and modulated signaling pathways (e.g., ERK1/2, p53, and STAT3). Conversely, these damaging effects were reversed by magnesium. Magnesium deficiency alone significantly induced basal and cisplatin-mediated oxidative stress, whereas magnesium replacement attenuated these effects. Similar results were observed using cisplatin-treated LLC-PK1 renal epithelial cells exposed to various magnesium concentrations. Magnesium deficiency significantly amplified renal platinum accumulation, whereas magnesium replacement blocked the augmented platinum accumulation after magnesium deficiency. Increased renal platinum accumulation during magnesium deficiency was accompanied by reduced renal efflux transporter expression, which was reversed by magnesium replacement. These findings demonstrate the role of magnesium in regulating cisplatin-induced AKI by enhancing oxidative stress and thus promoting cisplatin-mediated damage. Additional in vitro experiments using ovarian, breast, and lung cancer cell lines showed that magnesium supplementation did not compromise cisplatin's chemotherapeutic efficacy. Finally, because no consistently successful therapy to prevent or treat cisplatin-mediated AKI is available for humans, these results support developing more conservative magnesium replacement guidelines for reducing cisplatin-induced AKI in cancer patients at risk for magnesium deficiency.

Divalent cation signaling in immune cells

Divalent cations of two alkaline earth metals Ca(2+) and Mg(2+) and the transition metal Zn(2+) play vital roles in the immune system, and several immune disorders are associated with disturbances of their function. Until recently only Ca(2+) was considered to serve as a second messenger. However, signaling roles for Mg(2+) and Zn(2+) have been recently described, leading to a reevaluation of their role as potential second messengers. We review here the roles of these cations as second messengers in light of recent advances in Ca(2+), Mg(2+), and Zn(2+) signaling in the immune system. Developing a better understanding of these signaling cations may lead to new therapeutic strategies for immune disorders.

Decreased seizure threshold in an eclampsia-like model induced in pregnant rats with lipopolysaccharide and pentylenetetrazol treatments

Objective

Eclampsia is a poorly understood but potentially fatal complication of pregnancy. Research to date on this disorder has been hampered by the lack of a suitable animal model. To correct this deficiency, this report describes the generation of a rat eclampsia-like model using pentylenetetrazol (PTZ) in a previously established rat preeclampsia model.

Method

Rats were administered lipopolysaccharide (1.0 µg/kg) by tail vein injection on gestational day 14 to establish preeclampsia (PE). PE and control rats (non-pregnant, NP; normal-pregnant, P) were injected intraperitoneally (i.p.) with PTZ (40 mg/kg) to induce seizures. In separate experiments, MgSO₄ (270 mg/kg IP) was injected in advance of PTZ into PE rats to observe its effect on PTZ-induced seizures.

Results

PE conditions were verified in rats after LPS administration by significantly higher blood pressure (P<0.01) and urinary albumin excretion (P<0.05), elevated sFlt-1 (P<0.05) and decreased PlGF serum levels (P<0.05), and evidence of hepatic dysfunction compared to control groups. PTZ successfully induced seizure activity in all groups studied. Latency to seizure was significantly (P<0.01) less in the PE-PTZ group (73.2±6.6 sec.) than in PTZ-treated controls (107.0±7.4 sec.). Pretreatment with MgSO₄ prolonged (P<0.05) latency to seizure, shortened seizure duration and decreased seizure rates. Significant increased (P<0.05) in the serum levels of the inflammatory cytokines TNF-α and IL-1β in PE and PE-PTZ groups, and decreased (P<0.05) in their levels following MgSO₄ administration.

Conclusion

This PTZ-induced eclampsia-like rat model is comparable to the human condition of eclampsia and may serve as a useful research tool for future studies of this disease. The increased inflammatory cytokines in preeclampsia are coincident with a decreased threshold for PTZ-induced seizures, suggesting that an inflammatory mechanism may contribute to the susceptibility to seizure activity and inflammation might have an important role in eclampsia.

Maternal magnesium supplementation reduces intrauterine growth restriction and suppresses inflammation in a rat model

OBJECTIVE

Intrauterine growth restriction (IUGR) is associated with increased inflammatory responses. We sought to investigate whether magnesium (Mg) attenuates inflammation and IUGR in a rat model.

STUDY DESIGN

Pregnant Wistar rats (12 weeks, gestational day 18) were randomly assigned to 1 of 4 groups: normal diet with bilateral uterine artery ligation (BL) (n = 6) or sham surgery (SH) (n = 5); and Mg chloride (MgCl2) 1% (wt/vol) in the drinking water throughout gestation + BL (MgBL) (n = 6) or SH (MgSH) (n = 5). Dams were euthanized 24 hours postsurgery (gestational day 19). Maternal plasma, fetal plasma (pooled), individual amniotic fluid (AF) samples, and placentas (PL) were collected and assessed from live fetal pups only (BL, n = 36; SH, n = 20; MgBL, n = 20; MgSH, n = 20). All samples were analyzed for cytokines/chemokines (interleukin [IL]-6, IL-1β, chemokine [C-X-C motif] ligand 1 [CXCL1], chemokine [C-C motif] ligand 2 [CCL2], and tumor necrosis factor [TNF-α] sensitivity <3 pg/mL) using a multiplex platform. Data were analyzed using Mann Whitney, analysis of variance, and Fisher exact tests.

RESULTS

The incidence of IUGR (pup weight <10th percentile of SH) in the MgBL group was significantly lower (31%) than the BL group (86.3%) (relative risk, 0.36; 95% confidence interval, 0.2-0.6; P < .0001). BL significantly increased AF levels of IL-6, IL-1β, TNF-α (P < .05), and CCL2 (P < .001) vs SH and PL levels of IL-6, IL-1β, CCL2 and CXCL1 (P < .001), and TNF-α (P < .05) vs SH. Maternal MgCl2 supplementation significantly decreased IL-1β, TNF-α, and CCL2 levels in AF and IL-1β in PL tissues of MgBL vs BL rats (P < .0001).

CONCLUSION

Maternal oral MgCl2 supplementation reduced BL-induced IUGR by 64% and suppressed cytokine/chemokine levels in the AF and PL.

[Use of magnesium sulfate in obstetrics]

Magnesium sulfate (MgSO(4)) is the best treatment of eclampsia, reduces the risk of recurrence better than other anticonvulsants and is recommended as first line in cases of eclampsia. In cases of severe pre-eclampsia and especially when prodromes are present, MgSO(4) reduces better than conventional anticonvulsants the risk of eclampsia. More recently, MgSO(4) was used in cases of preterm delivery to reduce the risk of cerebral palsy in premature infants. Three large randomized trials have obtained convergent results which all tended to show a neuroprotective effect of MgSO(4). These trials were included in three meta-analyzes that showed a 30% reduction in the incidence of cerebral palsy before 32 weeks gestation suggesting that this drug should be used in cases of preterm birth. A protocol using low doses associated with a well-conducted maternal surveillance reduces of maternal hypermagnesemia and the risk of maternal toxicity.

Magnesium decreases inflammatory cytokine production: a novel innate immunomodulatory mechanism

MgSO(4) exposure before preterm birth is neuroprotective, reducing the risk of cerebral palsy and major motor dysfunction. Neonatal inflammatory cytokine levels correlate with neurologic outcome, leading us to assess the effect of MgSO(4) on cytokine production in humans. We found reduced maternal TNF-α and IL-6 production following in vivo MgSO(4) treatment. Short-term exposure to a clinically effective MgSO(4) concentration in vitro substantially reduced the frequency of neonatal monocytes producing TNF-α and IL-6 under constitutive and TLR-stimulated conditions, decreasing cytokine gene and protein expression, without influencing cell viability or phagocytic function. In summary, MgSO(4) reduced cytokine production in intrapartum women, term and preterm neonates, demonstrating effectiveness in those at risk for inflammation-associated adverse perinatal outcomes. By probing the mechanism of decreased cytokine production, we found that the immunomodulatory effect was mediated by magnesium and not the sulfate moiety, and it was reversible. Cellular magnesium content increased rapidly upon MgSO(4) exposure, and reduced cytokine production occurred following stimulation with different TLR ligands as well as when magnesium was added after TLR stimulation, strongly suggesting that magnesium acts intracellularly. Magnesium increased basal IĸBα levels, and upon TLR stimulation was associated with reduced NF-κB activation and nuclear localization. These findings establish a new paradigm for innate immunoregulation, whereby magnesium plays a critical regulatory role in NF-κB activation, cytokine production, and disease pathogenesis.

IL-6-induced pathophysiology during pre-eclampsia: potential therapeutic role for magnesium sulfate?

Pre-eclampsia is defined as new onset hypertension with proteinuria during pregnancy. Pre-eclampsia is also characterized by endothelial cell activation and dysfunction and intrauterine growth restriction. Preeclamptic women display a chronic inflammatory response characterized by elevated inflammatory cytokines, circulating monocytes, neutrophils, and T and B lymphocytes secreting autoantibodies that activate the angiotensin II type I receptor (AT1-AA). Although the pathophysiology of pre-eclampsia is becoming more defined, the genesis of the disease is still largely unknown. Furthermore, the only treatment for extreme forms of the disease is bed rest and administration of magnesium sulfate to sustain the pregnancy a few days prior to early delivery of the fetus, which can lead to devastating neurological and physical effects for the newborn. Administration of magnesium sulfate is routinely given without adverse effects. The focus of this review is to discuss the cascade of events leading to cytokines, specifically interleukin-6 (IL-6), in stimulating vasoactive substances such as AT1-AA (Figure 1) and to examine the mechanism whereby administration of magnesium sulfate can be beneficial during pre-eclampsia. One area is to decrease vascular resistance index parameters determined by Doppler velocimetry. Another potential area of benefit with magnesium sulfate administration may be to decrease inflammatory responses or decrease cardiovascular mechanisms stimulated by overexpression of inflammatory cytokines in response to placental ischemia or animal models of elevated IL-6 during pregnancy. Further studies identifying IL-6-driven mechanisms playing a role in the development of hypertension during pregnancy and how administration of magnesium sulfate can suppress them are critical to improve decisions affecting patient care in women with pre-eclampsia. The results of these types of studies will be advantageous to further our knowledge of the pathophysiological ramifications associated with pre-eclampsia and to further therapeutic development for this disease.