Oxidative stress and central cardiovascular regulation. - Pathogenesis of hypertension and therapeutic aspects -

Clarification of hypertension mechanisms provided by the research of central circulatory regulation

Sympathoexcitation, under the regulatory control of the brain, plays a pivotal role in the etiology of hypertension. Within the brainstem, significant structures involved in the modulation of sympathetic nerve activity include the rostral ventrolateral medulla (RVLM), caudal ventrolateral medulla (CVLM), nucleus tractus solitarius (NTS), and paraventricular nucleus (paraventricular). The RVLM, in particular, is recognized as the vasomotor center. Over the past five decades, fundamental investigations on central circulatory regulation have underscored the involvement of nitric oxide (NO), oxidative stress, the renin-angiotensin system, and brain inflammation in regulating the sympathetic nervous system. Notably, numerous significant findings have come to light through chronic experiments conducted in conscious subjects employing radio-telemetry systems, gene transfer techniques, and knockout methodologies. Our research has centered on elucidating the role of NO and angiotensin II type 1 (AT1) receptor-induced oxidative stress within the RVLM and NTS in regulating the sympathetic nervous system. Additionally, we have observed that various orally administered AT1 receptor blockers effectively induce sympathoinhibition by reducing oxidative stress via blockade of the AT1 receptor in the RVLM of hypertensive rats. Recent advances have witnessed the development of several clinical interventions targeting brain mechanisms. Nonetheless, Future and further basic and clinical research are needed.

Toxicity effects of chlorantraniliprole in zebrafish (Danio rerio) involving in liver function and metabolic phenotype

Chlorantraniliprole (CAP), a representative bisamide insecticide, is widely used in rice fields around the world, posing potential toxicity risks to aquatic organisms. In this study, we examined the effects of exposure to CAP on growth and metabolic phenotype of zebrafish (Danio rerio) and oxidative stress and apoptosis in the liver of zebrafish (Danio rerio). First, we identified that CAP had a low bioaccumulation in zebrafish. Subsequently, growth phenotype analysis revealed that CAP could significantly increase liver weight and liver index in zebrafish. In addition, we found that CAP exposure could cause significant changes in indicators of oxidative stress, resulting in a significant increase in the content of malondialdehyde (MDA), causing oxidative stress in the liver of zebrafish. Meanwhile, the expression levels of apoptosis-related genes were also significantly changed and apoptosis was promoted in the liver of zebrafish with CAP exposure. Importantly, the results of metabolomics analysis shown that CAP exposure could significantly disrupt the metabolic phenotype of zebrafish, interfering with multiple metabolic pathways, mainly including valine, leucine and isoleucine biosynthesis and degradation, alanine, aspartate and glutamate metabolism and d-glutamine and D-glutamate metabolism. Last but not least, correlation analysis identified strong links between changes in liver function involving oxidative stress and apoptosis and changes in metabolic phenotype of zebrafish following CAP exposure. In brief, these results indicate that potential environmental risks of CAP to aquatic organisms should receive more attention.

Bioaccumulation and toxicity effects of flubendiamide in zebrafish (Danio rerio)

Flubendiamide is a widely used diamide insecticide with many adverse effects on environmental organisms. This study assessed its bioaccumulation and toxicity effects in zebrafish (Danio rerio) using LC-MS/MS. The concentrations of flubendiamide in the whole zebrafish increased in the early stages and achieved steady levels at 14 days. The bioconcentration factors (BCFs) of flubendiamide was 1.125-2.011. Although flubendiamide did not significantly affect the growth phenotypes of zebrafish, it significantly changed the hepatic somatic index (HSI) of zebrafish. Histopathological analysis showed that flubendiamide could cause structural damage to the liver tissue of zebrafish. Further physiological and biochemical analysis showed that flubendiamide significantly changed the activity of catalase (CAT) and the contents of malondialdehyde (MDA) and glutathione (GSH) in liver of zebrafish. Moreover, flubendiamide significantly changed the mRNA expression levels of cell apoptosis-related genes, including p53, puma, caspase-3, caspase-9, apaf-1, and bax in liver of zebrafish. In summary, these results indicate that flubendiamide can cause liver damage by inducing oxidative stress and apoptosis in the liver of zebrafish. This study provides a background for further safety evaluation of flubendiamide to aquatic organisms.

Antioxidant therapy reverses sympathetic dysfunction, oxidative stress, and hypertension in male hyperadipose rats

AIMS

The rostral ventrolateral medulla (RVLM) is the main sympathetic output of the central nervous system to control blood pressure. Reportedly, reactive oxygen species (ROS) can increase arterial pressure, leading to hypertension. As ROS increase the sympathetic tone in RVLM and obese animals present grater oxidative stress, it would be important to note this relationship.

MAIN METHODS

Therefore, we evaluated the systemic and central effects (in the RVLM) of vitamin C (vit C, an antioxidant) on the redox balance and cardiovascular and autonomic profiles in hyperadipose male rats. We also evaluated the neurotransmission by L-glutamate (L-glu) and vit C in the RVLM of awake hyperadipose rats.

KEY FINDINGS

Our study confirmed that hyperadipose rats were hypertensive and tachycardic, presented increased sympathetic and decreased parasympathetic modulation of the heart, and had increased plasma lipoperoxidation compared with the control rats (CTR). Oral vitamin C treatment reverted cardiovascular, autonomic, and plasma redox dysfunction. Hyperadipose rats presented a higher blood pressure increase after L-glu microinjection and a lower response to vit C in the RVLM compared with the CTR group. Biochemical analysis of redox balance in RVLM punches showed that hyperadipose rats have increased NBT and T-BARS, and after treatment with vit C, the oxidative profile decreased. The antioxidative activity of vit C reduced the amount of ROS in the RVLM area that might have resulted in lowered blood pressure and sympathetic modulation.

SIGNIFICANCE

Our data suggest central and peripheral benefits of vit C treatment on cardiovascular, autonomic, and oxidative dysfunctions in hyperadipose animals.

Coenzyme Q10 effects in neurological diseases

Coenzyme Q10 (CoQ10), a lipophilic substituted benzoquinone, is present in animal and plant cells. It is endogenously synthetized in every cell and involved in a variety of cellular processes. CoQ10 is an obligatory component of the respiratory chain in inner mitochondrial membrane. In addition, the presence of CoQ10 in all cellular membranes and in blood. It is the only endogenous lipid antioxidant. Moreover, it is an essential factor for uncoupling protein and controls the permeability transition pore in mitochondria. It also participates in extramitochondrial electron transport and controls membrane physicochemical properties. CoQ10 effects on gene expression might affect the overall metabolism. Primary changes in the energetic and antioxidant functions can explain its remedial effects. CoQ10 supplementation is safe and well-tolerated, even at high doses. CoQ10 does not cause any serious adverse effects in humans or experimental animals. New preparations of CoQ10 that are less hydrophobic and structural derivatives, like idebenone and MitoQ, are being developed to increase absorption and tissue distribution. The review aims to summarize clinical and experimental effects of CoQ10 supplementations in some neurological diseases such as migraine, Parkinson´s disease, Huntington´s disease, Alzheimer´s disease, amyotrophic lateral sclerosis, Friedreich´s ataxia or multiple sclerosis. Cardiovascular hypertension was included because of its central mechanisms controlling blood pressure in the brainstem rostral ventrolateral medulla and hypothalamic paraventricular nucleus. In conclusion, it seems reasonable to recommend CoQ10 as adjunct to conventional therapy in some cases. However, sometimes CoQ10 supplementations are more efficient in animal models of diseases than in human patients (e.g. Parkinson´s disease) or rather vague (e.g. Friedreich´s ataxia or amyotrophic lateral sclerosis).

Breakfast skipping and cardiometabolic risk factors in adolescents: Systematic review

OBJECTIVE

To systematically review the results of the association between breakfast skipping and cardiometabolic risk factors in adolescents.

METHODS

The articles were searched in May 2020 from PubMed, Virtual Health Library, Scopus, Web of Science and Scientific Electronic Library Online (SciELO). The review included observational studies conducted with adolescents (10-19 years old), which estimated the association of breakfast skipping with at least one outcome (markers of body adiposity, blood pressure, serum lipid and glucose levels). Regarding the risk of bias, the articles were evaluated using the Research Triangle Institute (RTI) Item Bank on bias risk and accuracy of observational studies. The quality of the evidence was assessed by the Grade rating.

RESULTS

A total of 43 articles involving 192,262 participants met the inclusion criteria and were considered in this review. The prevalence of breakfast skipping ranged from 0.7% to 94% and 60.5% of studies were classified with low risk of bias. The significant association between breakfast skipping and cardiometabolic risk factors was found in twenty-nine cross-sectional articles (n = 106,031) and four longitudinal articles (n = 5,162) for excess adiposity, in three articles (n = 8,511) for high total cholesterol levels, low-density lipoprotein and triglycerides, and in three studies (n = 6,303) for high blood pressure levels. However, there was no significant association between breakfast skipping and glycemic profile. According to the Grade rating, all the associations had low quality of evidence.

CONCLUSION

The results of this review suggest that breakfast skipping is associated with cardiometabolic risk factors in adolescents aged 10 to 19 years. However, considering the low quality of the evidence, the present results should be interpreted carefully. In addition, our findings highlight the importance of standardizing the definition of breakfast skipping and that more prospective studies are needed to determine how skipping breakfast can affect cardiometabolic risk factors in the long time.

Bioaccumulation, Metabolism and the Toxic Effects of Chlorfenapyr in Zebrafish (Danio rerio)

Chlorfenapyr is widely used as an insecticide/miticide. Tralopyril, the active metabolite of chlorfenapyr, is used as an antifouling biocide in antifouling systems, and negatively affects aquatic environments. However, it is unclear whether tralopyril is a metabolite of chlorfenapyr in aquatic vertebrates, and there is little data on the bioaccumulation and toxicity of chlorfenapyr to aquatic vertebrates. In this study, the bioaccumulation and elimination of chlorfenapyr in zebrafish were assessed, and tralopyril, the active metabolite of chlorfenapyr, was determined. The effects of chronic exposure to chlorfenapyr on zebrafish liver and brain oxidative damage, apoptosis, immune response, and metabolome were investigated. These results showed that chlorfenapyr has a high bioaccumulation in zebrafish, with bioaccumulation factors of 864.6 and 1321.9 after exposure to 1.0 and 10 μg/L chlorfenapyr for 21 days, respectively. Chlorfenapyr at these concentrations also rapidly accumulated in zebrafish, reaching 615.5 and 10336 μg/kg on the second and third days of exposure, respectively. Chlorfenapyr was degraded to tralopyril in zebrafish; therefore, both chlorfenapyr and tralopyril should be considered when evaluating the risk of chlorfenapyr to aquatic organisms. In addition, chronic exposure caused oxidative damage, apoptosis, and immune disorders in zebrafish liver. Chronic exposure also altered the levels of endogenous metabolites in liver and brain. After 9 days of depuration, some indicators of oxidative damage, apoptosis, and immunity returned to normal levels, but the concentration of endogenous metabolites in zebrafish liver was still altered. Overall, these results provide useful information for evaluating the toxicity and environmental fate of chlorfenapyr in aquatic vertebrates.

Renal Dopamine Receptors and Oxidative Stress: Role in Hypertension

Significance: The kidney plays an important role in the long-term control of blood pressure. Oxidative stress is one of the fundamental mechanisms responsible for the development of hypertension. Dopamine, via five subtypes of receptors, plays an important role in the control of blood pressure by various mechanisms, including the inhibition of oxidative stress. Recent Advances: Dopamine receptors exert their regulatory function to decrease the oxidative stress in the kidney and ultimately maintain normal sodium balance and blood pressure homeostasis. An aberration of this regulation may be involved in the pathogenesis of hypertension. Critical Issues: Our present article reviews the important role of oxidative stress and intrarenal dopaminergic system in the regulation of blood pressure, summarizes the current knowledge on renal dopamine receptor-mediated antioxidation, including decreasing reactive oxygen species production, inhibiting pro-oxidant enzyme nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase, and stimulating antioxidative enzymes, and also discusses its underlying mechanisms, including the increased activity of G protein-coupled receptor kinase 4 (GRK4) and abnormal trafficking of renal dopamine receptors in hypertensive status. Future Directions: Identifying the mechanisms of renal dopamine receptors in the regulation of oxidative stress and their contribution to the pathogenesis of hypertension remains an important research focus. Increased understanding of the role of reciprocal regulation between renal dopamine receptors and oxidative stress in the regulation of blood pressure may give us novel insights into the pathogenesis of hypertension and provide a new treatment strategy for hypertension.

Effects of exposure to prothioconazole and its metabolite prothioconazole-desthio on oxidative stress and metabolic profiles of liver and kidney tissues in male mice

Prothioconazole (PTC), a popular agricultural fungicide, and its main metabolite prothioconazole-desthio (PTCd) are receiving great attention due to their toxicological effects in the non-target organisms. This study investigated their dosage-dependent (1 and 5 mg/kg BW/day) toxicological effects on oxidative stress and metabolic profiles of liver and kidney tissues using male mice. PTC and PTCd significantly inhibited the growth phenotype including body weights gain, liver and kidney indices. Furthermore, these effects were deeply investigated using the biomarkers of oxidative stress, and metabolomics. Notably, these effects were dose and tissue-dependent. Specifically, the more serious impacts involving oxidative stress and metabolic disorders were observed in the high concentration treatment groups. Also, the liver tissue was more severely affected than the kidney tissue. Lastly, the change in oxidative stress biomarkers and metabolomics profile revealed that PTCd induced more severe toxic effects than the parent compound PTC. In brief, these results indicate that exposure to PTC and PTCd could cause potential health risks in mammals.

Joint effects of microplastic and dufulin on bioaccumulation, oxidative stress and metabolic profile of the earthworm (Eisenia fetida)

Microplastics and pesticides are identified as two environmental pollutants that have an adverse impact on the environment. The knowledge about the combined exposure of pesticides and microplastics may facilitate further assessment of their ecotoxicity. In this study, we investigated joint effects of microplastic and dufulin on bioaccumulation, oxidative stress and metabolic profile of the earthworm. Bioaccumulation analysis showed that the bio-soil accumulation factor of dufulin in earthworms reached its maximum value on the 14th day, and microplastics could significantly increase the bioaccumulation of dufulin in earthworms. Biochemical analysis showed that the oxidative damage of earthworms could be observed on the 14th day of the exposure to dufulin, while the oxidative damage of earthworms could be observed on the 7th day of the combined exposure to microplastics and dufulin, and it could still be observed on the 14th day. ¹H-NMR-based metabolomics revealed that the exposure of dufulin significantly altered the relative abundances of 14 metabolites and two metabolic pathways, but the combined exposure of dufulin and microplastics significantly changed the relative abundances of 21 metabolites and three metabolic pathways. It could be seen that microplastics could aggravate the oxidative damage and the interference with the metabolic profile caused by dufulin to earthworms. The results of this study could provide effective information for the risk assessment of dufulin and microplastic in environmental safety.

Glycopenia - induced sympathoadrenal activation in diabetes mellitus and uncontrolled arterial hypertension: an observational study

BACKGROUND

Aim of this study is to investigate a possible association of hypoglycemic episodes and arterial hypertension. We hypothesize that hospitalized insulin-treated diabetes patients with hypertensive crisis have more hypoglycemic episodes than their counterparts without hypertensive crisis on admission.

METHODS

In a prospective, observational cohort study, 65 insulin-treated diabetes patients (type 1, type 2, type 3c) were included in Group 1, when a hypertensive crisis was present, as control patients in Group 2 without hypertensive crisis or hypoglycemia, in Group 3, when a symptomatic hypoglycemia was present on admission. All patients were subjected to open-label continuous glucose monitoring, 24-h blood-pressure- and Holter electrocardiogram recordings, and to laboratory tests including plasma catecholamines.

RESULTS

53 patients, thereof 19 Group-1, 19 Group-2, 15 Group-3 patients, completed this study. Group-1 patients had the highest maximum systolic blood pressure, a higher daily cumulative insulin dose at admission, a higher body-mass index, and a higher plasma norepinephrine than control patients of Group 2. Group-3 patients had more documented hypoglycemic episodes (0.8 ± 0.5 per 24 h) than Group-2 patients (0.2 ± 0.3 per 24 h), however, they were not different to the ones in Group-1 patients (0.4 ± 0.4 per 24 h). Plasma norepinephrine and mean arterial blood pressure were higher Group-1 and Group-3 patients than in control patients of Group 2. At discharge, the daily cumulative insulin dose was reduced in Group-1 (- 18.4 ± 24.9 units) and in Group-3 patients (- 18.6 ± 22.7 units), but remained unchanged in Group-2 control patients (- 2.9 ± 15.6 units).

CONCLUSIONS

An association between hypoglycemic events and uncontrolled hypertension was found in this study.

Inhalation of odors containing DMHF generated by the Maillard reaction affects physiological parameters in rats

The effects of odors generated by the Maillard reaction from amino acids and reducing sugars on physiological parameters (blood pressure, heart rate, and oxidative stress levels) in Wistar rats were investigated in the present study. The Maillard reaction samples were obtained from glycine, arginine, or lysine of 1.0 mol/L and glucose of 1.0 mol/L with heat treatment. The odor-active compounds in the Maillard reaction samples were identified using the aroma extract dilution analysis. Among the odor-active compounds identified, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF, FURANEOL and strawberry furanone) had the highest odor activity and its concentration was affected by amino acid types. The Maillard reaction odors generated from glycine or arginine significantly decreased systolic blood pressure and heart rate in rats when inhaled. These physiological effects were associated with DMHF. Furthermore, oxidative stress marker levels in rat plasma were decreased by the inhalation of DMHF. The inhalation of DMHF appears to at least partly affect physiological parameters by decreasing oxidative stress.

Prenatal Exposure to PM2.5 and Cardiac Vagal Tone during Infancy: Findings from a Multiethnic Birth Cohort

BACKGROUND

The autonomic nervous system plays a key role in maintaining homeostasis and responding to external stimuli. In adults, exposure to fine particulate matter (PM2.5) has been associated with reduced heart rate variability (HRV), an indicator of cardiac autonomic control.

OBJECTIVES

Our goal was to investigate the associations of exposure to fine particulate matter (PM2.5) with HRV as an indicator of cardiac autonomic control during early development.

METHODS

We studied 237 maternal-infant pairs in a Boston-based birth cohort. We estimated daily residential PM2.5 using satellite data in combination with land-use regression predictors. In infants at 6 months of age, we measured parasympathetic nervous system (PNS) activity using continuous electrocardiogram monitoring during the Repeated Still-Face Paradigm, an experimental protocol designed to elicit autonomic reactivity in response to maternal interaction and disengagement. We used multivariable linear regression to examine average PM2.5 exposure across pregnancy in relation to PNS withdrawal and activation, indexed by changes in respiration-corrected respiratory sinus arrhythmia (RSAc)-an established metric of HRV that reflects cardiac vagal tone. We examined interactions with infant sex using cross-product terms.

RESULTS

In adjusted models we found that a 1-unit increase in PM2.5 (in micrograms per cubic meter) was associated with a 3.53% decrease in baseline RSAc (95% CI: -6.96, 0.02). In models examining RSAc change between episodes, higher PM2.5 was generally associated with reduced PNS withdrawal during stress and reduced PNS activation during recovery; however, these associations were not statistically significant. We did not observe a significant interaction between PM2.5 and sex.

DISCUSSION

Prenatal exposure to PM2.5 may disrupt cardiac vagal tone during infancy. Future research is needed to replicate these preliminary findings. https://doi.org/10.1289/EHP4434.

Differential impacts of brain stem oxidative stress and nitrosative stress on sympathetic vasomotor tone

Based on work-done in the rostral ventrolateral medulla (RVLM), this review presents four lessons learnt from studying the differential impacts of oxidative stress and nitrosative stress on sympathetic vasomotor tone and their clinical and therapeutic implications. The first lesson is that an increase in sympathetic vasomotor tone because of augmented oxidative stress in the RVLM is responsible for the generation of neurogenic hypertension. On the other hand, a shift from oxidative stress to nitrosative stress in the RVLM underpins the succession of increase to decrease in sympathetic vasomotor tone during the progression towards brain stem death. The second lesson is that, by having different cellular sources, regulatory mechanisms on synthesis and degradation, kinetics of chemical reactions, and downstream signaling pathways, reactive oxygen species and reactive nitrogen species should not be regarded as a singular moiety. The third lesson is that well-defined differential roles of oxidative stress and nitrosative stress with distinct regulatory mechanisms in the RVLM during neurogenic hypertension and brain stem death clearly denote that they are not interchangeable phenomena with unified cellular actions. Special attention must be paid to their beneficial or detrimental roles under a specific disease or a particular time-window of that disease. The fourth lesson is that, to be successful, future antioxidant therapies against neurogenic hypertension must take into consideration the much more complicated picture than that presented in this review on the generation, maintenance, regulation or modulation of the sympathetic vasomotor tone. The identification that the progression towards brain stem death entails a shift from oxidative stress to nitrosative stress in the RVLM may open a new vista for therapeutic intervention to slow down this transition.

Effects of perinatal exposure to BPA, BPF and BPAF on liver function in male mouse offspring involving in oxidative damage and metabolic disorder

Bisphenols (BPs) are common environmental pollutants that are ubiquitous in the natural environment and can affect human health. In this study, we explored the effects of perinatal exposure to BPA, BPF and BPAF on liver function involving in oxidative damage and metabolic disorders in male mouse offspring. We found that BPA exposure impairs the antioxidant defense system, increases lipid peroxidation, and causes oxidative damage in the liver. Furthermore, the levels of 13 metabolites were significantly altered following BPA exposure. We found that BPF exposure significantly increased the expression and activity of CAT, suggesting disturbances in the antioxidant defense system. Moreover, BPF exposure led to metabolic disorders in the liver due to changes in the levels of 8 key metabolites. Exposure to BPAF caused no negative effects on oxidative damage, but altered the levels of β-glucose and glycogen. In summary, perinatal exposure to BPA, BPF and BPAF differentially influence oxidative damage and metabolic disorders in the livers of male mouse offspring. The impact of early life exposure to BPs now warrants future investigations.

Effects of the Prdx2 depletion on blood pressure and life span in spontaneously hypertensive rats

Oxidative stress is involved in the pathogenesis of hypertension and hypertensive organ damage. Our previous study suggested that stroke-prone spontaneously hypertensive rats (SHRSP) exhibited greater oxidative stress than SHR and that the stroke incidence was significantly greater in SHRSP than SHR. Therefore, we hypothesized that oxidative stress was responsible for the stroke susceptibility in SHRSP. The present study constructed Prdx2 (a gene coding an antioxidative enzyme)-knockout (KO) SHR to examine whether Prdx2 knockout would make SHR more vulnerable to hypertensive organ damage, including stroke. Prdx2-KO SHR were created using CRISPR/CAS9 for genome editing. Eight-week-old male SHR and Prdx2-KO SHR were fed 1% NaCl for 2 months to induce blood pressure (BP) changes and stroke occurrence. The baseline BP was significantly greater in KO SHR, and this difference disappeared after salt loading. The life span of KO SHR was significantly reduced compared to that of SHR despite no differences in BP under salt-loading. However, no stroke was observed in KO SHR. The severity of hypertensive renal and cardiac injuries did not differ significantly between the two strains, but oxidative stress, evaluated using urinary isoprostane excretion and DHE staining, was greater in KO SHR. These results indicated that the Prdx2-depletion caused a shorter life span and modest BP increase in SHR via increased oxidative stress. The pathophysiological roles of oxidative stress in this model should be clarified in future studies.

Contribution of Oxidative Stress and Inflammation to the Neurogenic Hypertension Induced by Intermittent Hypoxia

Chronic intermittent hypoxia (CIH), the hallmark of obstructive sleep apnea, is the main risk factor to develop systemic hypertension. Oxidative stress, inflammation, and sympathetic overflow have been proposed as possible mechanisms underlying the CIH-induced hypertension. CIH potentiates the carotid body (CB) chemosensory discharge leading to sympathetic overflow, autonomic dysfunction, and hypertension. Oxidative stress and pro-inflammatory molecules are involved in neurogenic models of hypertension, acting on brainstem and hypothalamic nuclei related to the cardiorespiratory control, such as the nucleus of the solitary tract, which is the primary site for the afferent inputs from the CB. Oxidative stress and pro-inflammatory molecules contribute to the activation of the CB chemoreflex pathway in CIH-induced hypertension. In this brief review, we will discuss new evidence for a critical role of oxidative stress and neuro-inflammation in development of the CIH-induced hypertension through activation of the CB chemoreflex pathway.

Maternal protein malnutrition induced-hypertension: New evidence about the autonomic and respiratory dysfunctions and epigenetic mechanisms

Maternal protein malnutrition during the critical stages of development (pregnancy, lactation and first infancy) can lead to adult hypertension. Studies have shown that renal and cardiovascular dysfunctions can be associated to the development of hypertension in humans and rats exposed to maternal protein malnutrition. The etiology of hypertension, however, includes a complex network involved in central and peripheral blood pressure control. Recently, the hyperactivity of the sympathetic nervous system in protein-restricted rats has been reported. Studies have shown that protein malnutrition during pregnancy and/or lactation alters blood pressure control through mechanisms that include central sympathetic-respiratory dysfunctions and epigenetic modifications, which may contribute to adult hypertension. Thus, this review will discuss the historical context, new evidences of neurogenic disruption in respiratory-sympathetic activities and possible epigenetic mechanisms involved in maternal protein malnutrition induced- hypertension.

Tonic aortic depressor nerve stimulation does not impede baroreflex dynamic characteristics concomitantly mediated by the stimulated nerve

Although electrical activation of the carotid sinus baroreflex (baroreflex activation therapy) is being explored as a device therapy for resistant hypertension, possible effects on baroreflex dynamic characteristics of interaction between electrical stimulation and pressure inputs are not fully elucidated. To examine whether the electrical stimulation of the baroreceptor afferent nerve impedes normal short-term arterial pressure (AP) regulation mediated by the stimulated nerve, we electrically stimulated the right aortic depressor nerve (ADN) while estimating the baroreflex dynamic characteristics by imposing pressure inputs to the isolated baroreceptor region of the right ADN in nine anesthetized rats. A Gaussian white noise signal with a mean of 120 mmHg and standard deviation of 20 mmHg was used for the pressure perturbation. A tonic ADN stimulation (2 or 5 Hz, 10 V, 0.1-ms pulse width) decreased mean sympathetic nerve activity (367.0 ± 70.9 vs. 247.3 ± 47.2 arbitrary units, P < 0.01) and mean AP (98.4 ± 7.8 vs. 89.2 ± 4.5 mmHg, P < 0.01) during dynamic pressure perturbation. The ADN stimulation did not affect the slope of dynamic gain in the neural arc transfer function from pressure perturbation to sympathetic nerve activity (16.9 ± 1.0 vs. 14.7 ± 1.6 dB/decade, not significant). These results indicate that electrical stimulation of the baroreceptor afferent nerve does not significantly impede the dynamic characteristics of the arterial baroreflex concomitantly mediated by the stimulated nerve. Short-term AP regulation by the arterial baroreflex may be preserved during the baroreflex activation therapy.

Maternal protein restriction induced-hypertension is associated to oxidative disruption at transcriptional and functional levels in the medulla oblongata

Maternal protein restriction during pregnancy and lactation predisposes the adult offspring to sympathetic overactivity and arterial hypertension. Although the underlying mechanisms are poorly understood, dysregulation of the oxidative balance has been proposed as a putative trigger of neural-induced hypertension. The aim of the study was to evaluate the association between the oxidative status at transcriptional and functional levels in the medulla oblongata and maternal protein restriction induced-hypertension. Wistar rat dams were fed a control (normal protein; 17% protein) or a low protein ((Lp); 8% protein) diet during pregnancy and lactation, and male offspring was studied at 90 days of age. Direct measurements of baseline arterial blood pressure (ABP) and heart rate (HR) were recorded in awakened offspring. In addition, quantitative RT-PCR was used to assess the mRNA expression of superoxide dismutase 1 (SOD1) and 2 (SOD2), catalase (CAT), glutathione peroxidase (GPx), Glutamatergic receptors (Grin1, Gria1 and Grm1) and GABA(A)-receptor-associated protein like 1 (Gabarapl1). Malondialdehyde (MDA) levels, CAT and SOD activities were examined in ventral and dorsal medulla. Lp rats exhibited higher ABP. The mRNA expression levels of SOD2, GPx and Gabarapl1 were down regulated in medullary tissue of Lp rats (P<.05, t test). In addition, we observed that higher MDA levels were associated to decreased SOD (approximately 45%) and CAT (approximately 50%) activities in ventral medulla. Taken together, our data suggest that maternal protein restriction induced-hypertension is associated with medullary oxidative dysfunction at transcriptional level and with impaired antioxidant capacity in the ventral medulla.

Effects of high fructose intake on the development of hypertension in the spontaneously hypertensive rats: the role of AT1R/gp91PHOX signaling in the rostral ventrolateral medulla

Both genetic and dietary factors determine the development of hypertension. Whether dietary factor impacts the development of hereditary hypertension is unknown. Here, we evaluated the effect of daily high-fructose diet (HFD) on the development of hypertension in adolescent spontaneously hypertensive rats (SHR). Six-week-old SHR were randomly divided into two groups to receive HFD or normal diet (ND) for 3 weeks. The temporal profile of systolic blood pressure, alongside the sympathetic vasomotor activity, in the SHR-HFD showed significantly greater increases at 9-12 weeks of age compared with the age-matched SHR-ND group. Immunofluorescence was used to identify the distribution of reactive oxygen species (ROS), oxidants and antioxidants in rostral ventrolateral medulla (RVLM) where sympathetic premotor neurons reside. In RVLM of SHR-HFD, the levels of ROS accumulation and lipid peroxidation were elevated. The changes in protein expression were measured by Western blot. NADPH oxidase subunit gp91^phox and angiotensin II type I receptor were up-regulated in RVLM neuron. On the other hand, the expression of extracellular superoxide dismutase was suppressed. Both molecular and hemodynamic changes in the SHR-HFD were rescued by oral pioglitazone treatment from weeks 7 to 9. Furthermore, central infusion with tempol, a ROS scavenger, effectively ameliorated ROS accumulation in RVLM and diminished the heightened pressor response and enhanced sympathetic activity in the SHR-HFD. Together, these results suggest that HFD intake at adolescent SHR may impact the development of hypertension via increasing oxidative stress in RVLM which could be effectively attenuated by pioglitazone treatment.

Effect of p22phox depletion on sympathetic regulation of blood pressure in SHRSP: evaluation in a new congenic strain

Oxidative stress in the rostral ventrolateral medulla (RVLM), a sympathetic center in the brainstem, was implicated in the regulation of sympathetic activity in various hypertensive models including stroke-prone spontaneously hypertensive rats (SHRSP). In this study, we evaluated the role of the NADPH oxidases (NOX) in the blood pressure (BP) regulation in RVLM in SHRSP. The P22PHOX-depleted congenic SHRSP (called SP.MES) was constructed by introducing the mutated p22phox gene of Matsumoto Eosinophilic Shinshu rat. BP response to glutamate (Glu) microinjection into RVLM was compared among SHRSP, SP.MES, SHR and Wistar Kyoto (WKY); the response to Glu microinjection was significantly greater in SHRSP than in SP.MES, SHR and WKY. In addition, tempol, losartan and apocynin microinjection reduced the response to Glu significantly only in SHRSP. The level of oxidative stress, measured in the brainstem using lucigenin and dihydroethidium, was reduced in SP.MES than in SHRSP. BP response to cold stress measured by telemetry system was also blunted in SP.MES when compared with SHRSP. The results suggested that oxidative stress due to the NOX activation in RVLM potentiated BP response to Glu in SHRSP, which might contribute to the exaggerated response to stress in this strain.

Breakfast frequency, adiposity, and cardiovascular risk factors as markers in adolescents

OBJECTIVE

To analyse the relationship between skipping breakfast and haemodynamic, metabolic, inflammatory, and cardiovascular risk factors in adolescents.

METHODS

A cross-sectional study was carried out with information from an ongoing cohort study in Presidente Prudente, São Paulo, Brazil. The sample comprised of 120 adolescents (11.7±0.8 years old) who met the following inclusion criteria: age between 11 and 14 years; enrolled in the school unit of elementary education; absence of any known disease; and no drug consumption. The parents or legal guardians of the patients signed a formal informed consent. Skipping breakfast was self-reported through face-to-face interviews. Blood pressure, intima-media thickness, trunk fatness, total and fractional cholesterol levels - high-density lipoprotein cholesterol and low-density lipoprotein cholesterol - triacylglycerol levels, and high-sensitivity C-reactive protein levels were measured.

RESULTS

In this study, 47.5% (95% CI: 38.5-56.4%) of the adolescents reported skipping breakfast at least 1 day/week. Adolescents who skipped breakfast had higher values of trunk fatness and systolic blood pressure. Breakfast frequency was negatively related to systolic blood pressure (β -1.99 [-3.67; -0.31]) and z score dyslipidaemia (β -0.46 [-0.90; -0.01]), but this relationship was mediated by trunk fatness.

CONCLUSION

Skipping breakfast is related to cardiovascular risk factors in adolescents, and this relationship was mainly mediated by trunk fatness.

SOHPRED: a new bioinformatics tool for the characterization and prediction of human S-sulfenylation sites

SOHPRED is a new and competitive bioinformatics tool for characterizing and predicting human S-sulfenylation sites.

Estrogen Replacement Reduces Oxidative Stress in the Rostral Ventrolateral Medulla of Ovariectomized Rats

Cardiovascular disease prevalence rises rapidly after menopause, which is believed to be derived from the loss of estrogen. It is reported that sympathetic tone is increased in postmenopause. The high level of oxidative stress in the rostral ventrolateral medulla (RVLM) contributes to increased sympathetic outflow. The focus of this study was to determine if estrogen replacement reduces oxidative stress in the RVLM and sympathetic outflow in the ovariectomized (OVX) rats. The data of this study showed that OVX rat increased oxidative stress in the RVLM and sympathetic tone; estrogen replacement improved cardiovascular functions but also reduced the level of oxidative stress in the RVLM. These findings suggest that estrogen replacement decreases blood pressure and sympathoexcitation in the OVX rats, which may be associated with suppression in oxidative stress in the RVLM through downregulation of protein expression of NADPHase (NOX4) and upregulation of protein expression of SOD1. The data from this study is beneficial for our understanding of the mechanism of estrogen exerting cardiovascular protective effects on postmenopause.

Mechanisms of sudden cardiac death: oxidants and metabolism

Ventricular arrhythmia is the leading cause of sudden cardiac death (SCD). Deranged cardiac metabolism and abnormal redox state during cardiac diseases foment arrhythmogenic substrates through direct or indirect modulation of cardiac ion channel/transporter function. This review presents current evidence on the mechanisms linking metabolic derangement and excessive oxidative stress to ion channel/transporter dysfunction that predisposes to ventricular arrhythmias and SCD. Because conventional antiarrhythmic agents aiming at ion channels have proven challenging to use, targeting arrhythmogenic metabolic changes and redox imbalance may provide novel therapeutics to treat or prevent life-threatening arrhythmias and SCD.

Salidroside protects retinal endothelial cells against hydrogen peroxide-induced injury via modulating oxidative status and apoptosis

Oxidative stress can cause injury in retinal endothelial cells. Salidroside is a strong antioxidative and cytoprotective supplement in Chinese traditional medicine. In this study, we investigated the effects of salidroside on H2O2-induced primary retinal endothelial cells injury. Salidroside decreased H2O2-induced cell death, and efficiently suppressed cellular ROS production, malondialdehyde generation, and cell apoptosis induced by H2O2 treatment. Salidroside induced the intracellular mRNA expression, protein expression, and enzymatic activities of catalase and Mn-SOD and increased the ratio of Bcl2/Bax. Our results demonstrated that salidroside protected retinal endothelial cells against oxidative injury through increasing the Bcl2/Bax signaling pathway and activation of endogenous antioxidant enzymes. This finding presents salidroside as an attractive agent with potential to attenuate retinopathic diseases.

miR-103 Regulates Oxidative Stress by Targeting the BCL2/Adenovirus E1B 19 kDa Interacting Protein 3 in HUVECs

Oxidative stress plays a critical role in cardiovascular diseases. Salidroside, a glycoside from Rhodiola rosea, has been used as an antioxidative therapy for oxidative injury in cardiac diseases. However, the mechanism underlying its antioxidant effect needs to be elucidated. Treatment of HUVECs with H₂O₂ significantly decreased the expression of miR-103 in a dose- and time-dependent manner, whereas pretreatment with salidroside significantly inhibited this decrease. Subsequent analysis showed that overexpression of miR-103 abrogated cell activity and ROS production induced by H₂O₂. Bcl2/adenovirus E1B 19 kDa interacting protein 3 (BNIP3) was determined to be a novel miR-103 target in HUVECs. Interestingly, H₂O₂ treatment upregulated BNIP3 expression; in turn, this effect was inhibited by pretreatment with salidroside. Further studies confirmed that the knockdown of BNIP3 enhanced cell activity and suppressed the ROS production induced by H₂O₂. These results demonstrated for the first time that salidroside protects HUVECs in part by upregulating the expression of miR-103, which mediates BNIP3 downregulation and plays an important role in the cytoprotective actions.

[Sports practice is related to parasympathetic activity in adolescents]

OBJECTIVE

To analyze the relationship among sports practice, physical education class, habitual physical activity and cardiovascular risk in adolescents.

METHODS

Cross-sectional study with 120 schoolchildren (mean: 11.7±0.7 years old), with no regular use of medicines. Sports practice and physical education classes were assessed through face-to-face interview, while habitual physical activity was assessed by pedometers. Body weight, height and height-cephalic trunk were used to estimate maturation. The following variables were measured: body fatness, blood pressure, resting heart rate, blood flow velocity, intima-media thickness (carotid and femoral) and heart rate variability (mean between consecutive heartbeats and statistical index in the time domain that show the autonomic parasympathetic nervous system activity root-mean by the square of differences between adjacent normal R-R intervals in a time interval. Statistical treatment used Spearman correlation adjusted by sex, ethnicity, age, body fatness and maturation.

RESULTS

Independently of potential confounders, sports practice was positively related to autonomic parasympathetic nervous system activity (β=0.039 [0.01; 0.76]). On the other hand, the relationship between sport practice and mean between consecutive heartbeats (β=0,031 [-0.01; 0.07]) was significantly mediated by biological maturation.

CONCLUSIONS

Sport practice was related to higher heart rate variability at rest.

The association between resting heart rate and blood pressure among children and adolescents with different waist circumferences

Resting heart rate (RHR) is an accessible index of sympathetic activity. The objective of this study was to assess the associations between blood pressure (BP) and RHR in children with different waist circumferences (WCs). The data of the Chinese National Survey on Students' Constitution and Health in 2010 were used. A total of 91,762 participates aged 9 to 18 years with complete records were included. RHR was categorised into quintile groups and WC was stratified into small (<-1.035), medium (≥-1.035 and <1.035) and large (≥1.035) groups respectively, after they were converted into age- and sex-specific z-score. Multivariate linear regression revealed that the association between RHR z-score and BP was similar before and after WC was adjusted for. With 1 standard deviation variation in RHR, BP changed from 2.22 (95 % confidence interval (CI): 1.51, 2.93) to 3.58 mmHg (95 % CI: 2.54, 4.62) in small WC group and 1.83 (95 % CI: 1.10, 2.56) to 4.23 mmHg (95 % CI: 3.38, 5.09) in large WC group respectively.

CONCLUSIONS

This study revealed that BP was positively associated with RHR among children with different WCs, which implied the positive association between sympathetic activity and BP in children regardless of the amount of abdominal fat.

Predominant role of neural arc in sympathetic baroreflex resetting of spontaneously hypertensive rats

BACKGROUND

There is ongoing controversy over whether neural or peripheral factors are the predominant cause of hypertension. The closed-loop negative feedback operation of the arterial baroreflex hampers understanding of how arterial pressure (AP) is determined through the interaction between neural and peripheral factors. METHODS AND RESULTS: A novel analysis of an isolated open-loop baroreceptor preparation to examine sympathetic nervous activity (SNA) and AP responses to changes in carotid sinus pressure (CSP) in adult spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) was conducted. In the neural arc (CSP-SNA relationship), the midpoint pressure (128.9±3.8 vs. 157.9±8.1 mmHg, P<0.001) and the response range of SNA to CSP (90.5±3.7 vs. 115.4±7.6%/mmHg, P=0.011) were higher in SHR. In the peripheral arc (SNA-AP relationship), slope and intercept did not differ. A baroreflex equilibrium diagram was obtained by depicting neural and peripheral arcs in a pressure-SNA plane with rescaled SNA (% in WKY). The operating-point AP (111.3±4.4 vs. 145.9±5.2 mmHg, P<0.001) and SNA (90.8±3.2 vs. 125.1±6.9% in WKY, P<0.001) were shifted towards a higher level in SHR.

CONCLUSIONS

The shift of the neural arc towards a higher SNA range indicated a predominant contribution to baroreflex resetting in SHR. Notwithstanding the resetting, the carotid sinus baroreflex in SHR preserved an ability to reduce AP if activated with a high enough pressure.

The sympathetic nervous system and heart failure

Heart failure (HF) is a syndrome characterized by upregulation of the sympathetic nervous system and abnormal responsiveness of the parasympathetic nervous system. Studies in the 1980s and 1990s demonstrated that inhibition of the renin-angiotensin-aldosterone system with angiotensin-converting enzyme inhibitors improved symptoms and mortality in HF resulting from systolic dysfunction, thus providing a framework to consider the use of β-blockers for HF therapy, contrary to the prevailing wisdom of the time. Against this backdrop, this article reviews the contemporary understanding of the sympathetic nervous system and the failing heart.

Essential hypertension and oxidative stress: New insights

Essential hypertension is a highly prevalent pathological condition that is considered as one of the most relevant cardiovascular risk factors and is an important cause of morbidity and mortality around the world. Despite the fact that mechanisms underlying hypertension are not yet fully elucidated, a large amount of evidence shows that oxidative stress plays a central role in its pathophysiology. Oxidative stress can be defined as an imbalance between oxidant agents, such as superoxide anion, and antioxidant molecules, and leads to a decrease in nitric oxide bioavailability, which is the main factor responsible for maintaining the vascular tone. Several vasoconstrictor peptides, such as angiotensin II, endothelin-1 and urotensin II, act through their receptors to stimulate the production of reactive oxygen species, by activating enzymes like NADPH oxidase and xanthine oxidase. The knowledge of the mechanism described above has allowed generating new therapeutic strategies against hypertension based on the use of antioxidants agents, including vitamin C and E, N-Acetylcysteine, polyphenols and selenium, among others. These substances have different therapeutic targets, but all represent antioxidant reinforcement. Several clinical trials using antioxidants have been made. The aim of the present review is to provide new insights about the key role of oxidative stress in the pathophysiology of essential hypertension and new clinical attempts to demonstrate the usefulness of antioxidant therapy in the treatment of hypertension.

Combining irbesartan and trichlormethiazide enhances blood pressure reduction via inhibition of sympathetic activity without adverse effects on metabolism in hypertensive rats with metabolic syndrome

Sympathoexcitation and oxidative stress in the brain have pivotal roles in hypertension with metabolic syndrome (MetS). Here, we examined whether oral administration of irbesartan (IRB) and trichlormethiazide (TCM) decreases blood pressure (BP) via inhibiting sympathetic activity through anti-oxidant effects in the brain of spontaneously hypertensive rats (SHR-cp). IRB/TCM treatment decreased BP more profoundly than IRB monotherapy. Urinary norepinephrine excretion and oxidative stress in the brain were decreased in both IRB and IRB/TCM groups without any adverse effect on the metabolic profile. These findings suggest that IRB/TCM profoundly decreases BP in SHR-cp by inhibiting sympathetic activity via anti-oxidant effects in the brain.

Proteomic analysis of peptides tagged with dimedone and related probes

Owing to its labile nature, a new role for cysteine sulfenic acid (-SOH) modification has emerged. This oxidative modification modulates protein function by acting as a redox switch during cellular signaling. The identification of proteins that undergo this modification represents a methodological challenge, and its resolution remains a matter of current interest. The development of strategies to chemically modify cysteinyl-containing peptides for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis has increased significantly within the past decade. The method of choice to selectively label sulfenic acid is based on the use of dimedone or its derivatives. For these chemical probes to be effective on a proteome-wide level, their reactivity toward -SOH must be high to ensure reaction completion. In addition, the presence of an adduct should not interfere with electrospray ionization, the efficiency of induced dissociation in MS/MS experiments or with the identification of Cys-modified peptides by automated database searching algorithms. Herein, we employ a targeted proteomics approach to study the electrospray ionization and fragmentation effects of different -SOH specific probes and compared them to commonly used alkylating agents. We then extend our study to a whole proteome extract using shotgun proteomic approaches. These experiments enable us to demonstrate that dimedone adducts do not interfere with electrospray by suppressing the ionization nor impede product ion assignment by automated search engines, which detect a + 138 Da increase from unmodified peptides. Collectively, these results suggest that dimedone can be a powerful tool to identify sulfenic acid modifications by high-throughput shotgun proteomics of a whole proteome.

Telmisartan reduces mortality and left ventricular hypertrophy with sympathoinhibition in rats with hypertension and heart failure

BACKGROUND

Angiotensin II type 1 receptor (AT1R) blockers have various benefits on hypertension and/or heart failure. We demonstrated that telmisartan (TLM), an AT1R blocker, causes sympathoinhibition by reduction of reactive oxygen species (ROS) in the rostral ventrolateral medulla (RVLM) of stroke-prone spontaneously hypertensive rats (SHRSPs). The aim of this study was to determine whether TLM improves survival in rats with hypertension and heart failure.

METHODS

Angiotensin II-infused and salt-loaded SHRSPs were divided into TLM-treated, candesartan cilexetil (CAN)-treated, and control groups. We determined the dose of TLM or CAN with similar depressor effects. We examined survival, urinary norepinephrine excretion (uNE) as a parameter of sympathoexcitation, ROS in the RVLM, and left ventricular (LV) end-diastolic pressure (LVEDP). LV hypertrophy (LVH) was assessed by echocardiography and heart/body weight.

RESULTS

Compared with the control group, TLM improved survival to a greater extent than CAN. At 4 weeks after treatment, ROS in the RVLM and uNE were significantly lower in the TLM-treated group than in the CAN-treated group, despite the similar depressor effects. At 8 weeks after the treatments, LVH and LVEDP were attenuated in the TLM-treated group compared with the CAN-treated group.

CONCLUSIONS

Our results suggest that TLM has the potential to reduce mortality, LVH, and LVEDP and that enhanced sympathoinhibition by reduction of ROS in the RVLM might be one of the mechanisms contributing to the beneficial actions of TLM in a model of rats with severe hypertension and heart failure.

Brain stem NOS and ROS in neural mechanisms of hypertension

SIGNIFICANCE

There is now compelling evidence to substantiate the notion that by depressing baroreflex regulation of blood pressure and augmenting central sympathetic outflow through their actions on the nucleus tractus solitarii (NTS) and rostral ventrolateral medulla (RVLM), brain stem nitric oxide synthase (NOS) and reactive oxygen species (ROS) are important contributing factors to neural mechanisms of hypertension. This review summarizes our contemporary views on the impact of NOS and ROS in the NTS and RVLM on neurogenic hypertension, and presents potential antihypertensive strategies that target brain stem NOS/ROS signaling.

RECENT ADVANCES

NO signaling in the brain stem may be pro- or antihypertensive depending on the NOS isoform that generates this gaseous moiety and the site of action. Elevation of the ROS level when its production overbalances its degradation in the NTS and RVLM underlies neurogenic hypertension. Interventional strategies with emphases on alleviating the adverse actions of these molecules on blood pressure regulation have been investigated.

CRITICAL ISSUES

The pathological roles of NOS in the RVLM and NTS in neural mechanisms of hypertension are highly complex. Likewise, multiple signaling pathways underlie the deleterious roles of brain-stem ROS in neurogenic hypertension. There are recent indications that interactions between brain stem ROS and NOS may play a contributory role.

FUTURE DIRECTIONS

Given the complicity of action mechanisms of brain-stem NOS and ROS in neural mechanisms of hypertension, additional studies are needed to identify the most crucial therapeutic target that is applicable not only in animal models but also in patients suffering from neurogenic hypertension.

A randomized placebo-controlled trial of an omega-3 fatty acid and vitamins E+C in schizophrenia

Membrane lipid metabolism and redox regulation may be disturbed in schizophrenia. We examined the clinical effect of adding an omega-3 fatty acid and/or vitamins E+C to antipsychotics. It was hypothesized that lower baseline levels of polyunsaturated fatty acids (PUFAs) would predict more benefit from the add-on treatment. The trial had a multicenter, randomized, double-blind, placebo-controlled 2 × 2 factorial design. Patients aged 18-39 years with schizophrenia or related psychoses were consecutively included at admission to psychiatric departments in Norway. They received active or placebo ethyl-eicosapentaenoate (EPA) 2 g day⁻¹ and active or placebo vitamin E 364 mg day⁻¹+vitamin C 1000 mg day⁻¹ (vitamins) for 16 weeks. The main outcome measures were Positive and Negative Syndrome Scale (PANSS) total and subscales scores, analyzed by linear mixed models. Ninety-nine patients were included. At baseline, erythrocyte PUFA were measured in 97 subjects. Given separately, EPA and vitamins increased drop-out rates, whereas when combined they did not differ from placebo. In low PUFA patients, EPA alone impaired the course of total PANSS (Cohen's d=0.29; P=0.03) and psychotic symptoms (d=0.40; P=0.003), especially persecutory delusions (d=0.48; P=0.0004). Vitamins alone impaired the course of psychotic symptoms (d= 0.37; P=0.005), especially persecutory delusions (d=0.47; P=0.0005). Adding vitamins to EPA neutralized the detrimental effect on psychosis (interaction d=0.31; P=0.02). In high PUFA patients, there were no significant effects of trial drugs on PANSS scales. In conclusion, given separately during an acute episode, EPA and vitamins E+C induce psychotic symptoms in patients with low levels of PUFA. Combined, these agents seem safe.

The antioxidant activity of daidzein metabolites, O‑desmethylangolensin and equol, in HepG2 cells

Daidzein and its glycoside form daidzin, are known to have potential health benefits and are metabolized to O‑desmethylangolensin (O‑DMA) and equol following consumption. In the current study, the antioxidant activity and cytotoxicity of O‑DMA, equol, daidzein and daidzin was investigated and their effects on HepG2 human hepatocelluar carcinoma cells were compared. For cytotoxicity assays, lactose dehydrogenase (LDH) release and 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide‑based cell viability, cells were exposed to various concentrations of each compound (5‑200 µM) for 24, 48 or 72 h. O‑DMA and equol did not affect LDH release, but higher concentrations (<75 µM) showed inhibition of cell growth. By contrast, daidzein and daidzin (200 µM) increased LDH release and cell growth. All compounds stimulated catalase and total superoxide dismutase (SOD) (CuZn‑ and Mn‑SOD) activity, and mRNA and protein expression. This phenomenon was most pronounced for O‑DMA and equol, as their effects were similar. These data suggested that O‑DMA and equol possess greater antioxidant properties compared with daidzein and may, thus, be beneficial for human health.

Salidroside protects against hydrogen peroxide-induced injury in HUVECs via the regulation of REDD1 and mTOR activation

Antioxidative therapy is considered an effective strategy for treating oxidative stress-induced apoptosis in cardiovascular diseases. Salidroside has been used as an antioxidative therapy for oxidative injury in cardiac diseases. However, the mechanism underlying its antioxidant effect is poorly understood. The present study aimed to investigate the pharmacological effects of salidroside on cultured human umbilical vein endothelial cells (HUVECs) under conditions of oxidative injury induced by hydrogen peroxide (H2O2) and the underlying mechanisms in vitro. HUVECs pretreated with or without salidroside for 24 h were exposed to H2O2-induced oxidative stress conditions for 6 h and then cell viability, apoptosis, HIF-1α, regulated in development and DNA damage responses-1 (REDD1) and the PI3K/Akt/mTOR pathway were investigated. The results demonstrated that salidroside effectively attenuated H2O2-impaired cell viability and the production of reactive oxygen species (ROS) in a concentration-dependent manner. Reduced H2O2-induced apoptosis and activation of the cellular PI3K/Akt/mTOR pathway were demonstrated in HUVECs pretreated with salidroside. Furthermore, the level of REDD1, a direct regulator of mitochondrial metabolism, significantly increased in parallel with the level of HIF-1α following pretreatment with salidroside. The antioxidative effect of salidroside was abrogated in REDD1 knockdown cells. However, LY294002, a PI3K inhibitor, attenuated the anti-apoptotic effect of salidroside and blocked the increase of Akt and mTOR; however, did not affect the antioxidative effect of salidroside. These findings suggested that salidroside was capable of protecting HUVECs against H2O2-induced apoptosis by activating the PI3K/Akt/mTOR-dependent pathway and inhibiting ROS production by activating REDD1.

Differential regulation of brain-derived neurotrophic factor in term and preterm preeclampsia

Our earlier studies in preeclampsia (PE) suggest a causal relationship between altered angiogenic factors and birth outcomes. Recent studies suggest that brain-derived neurotrophic factor (BDNF) can stimulate angiogenesis. The present study examines the levels of maternal and cord BDNF in women with PE (n = 106; full term [n = 60] and preterm [n = 46]) and normotensive women (n = 95; control) delivering at term. Maternal BDNF levels were lower (P < .05) in women with PE when compared to normotensive women. Cord BDNF levels were higher (P < .01) in women with PE delivering at term, while it was lower (P < .01) in women delivering preterm. Maternal BDNF levels were negatively associated with systolic and diastolic blood pressure (P < .01 for both). Our data for the first time suggest a possible role for BDNF in the pathophysiology of PE. Differential regulation of cord BDNF levels in preterm PE suggests a need to follow-up children to assess the neurodevelopmental effects in later life.