Increased formation of distinct F2 isoprostanes in hypercholesterolemia

Childhood Cardiovascular Health, Obesity, and Some Related Disorders: Insights into Chronic Inflammation and Oxidative Stress

Childhood obesity and associated metabolic abnormalities have become pressing public health concerns worldwide, significantly impacting cardiovascular health. Metabolic syndrome, characterized by a cluster of metabolic abnormalities including central obesity, altered glucose metabolism, dyslipidemia, and arterial hypertension, has emerged as a critical precursor to cardiovascular disease. Chronic systemic inflammation and oxidative stress seem to play pivotal roles in the pathogenesis of childhood obesity-related disorders such as early atherosclerosis. A significant distinction between the objective components of cardiovascular health metrics, including body mass index, blood pressure, cholesterol, and fasting glucose levels, and the definition of metabolic syndrome is evident in the identification of obesity. Whereas cardiovascular health metrics predominantly rely on body mass index percentiles to assess obesity, metabolic syndrome criteria prioritize waist circumference, specifically targeting individuals with a measurement ≥90th percentile. This discrepancy emphasizes the need for a nuanced approach in assessing the risks associated with obesity and underscores the importance of considering multiple factors when evaluating cardiovascular risk in children. By recognizing the complex interplay between various health metrics, obesity and metabolic syndrome criteria, clinicians can more accurately identify individuals at risk and tailor interventions accordingly to mitigate cardiovascular disease in children with obesity.

Lipid metabolites and nitric oxide production in the cerebrospinal fluid and plasma of dogs with meningoencephalitis of unknown origin and idiopathic epilepsy: a pilot study

Introduction

Idiopathic epilepsy (IE) and meningoencephalomyelitis of unknown origin (MUO) are common causes of brain diseases leading to seizures in dogs. In this study, the concentrations of 196 lipid metabolites and nitrogen oxide (NO) production in the cerebrospinal fluid (CSF) and plasma of dogs with MUO or IE were measured using a LC-MS/MS and a NOx analyzer, respectively.

Methods

Nine clinically healthy dogs and 11 and 12 dogs with IE and MUO, respectively, were included in the study.

Results

Lipid analysis revealed variations in the levels of four and six lipid metabolites in CSF and plasma, respectively, between the groups. The levels of 6-keto-prostaglandin (PG) F1α (PGF1α), 20-carboxy arachidonic acid (20-carboxy-AA), 9-hydroxyoctadecadienoic acid, and lyso-platelet-activating factor were high in the CSF of dogs with MUO. In addition, the plasma levels of 11,12-dihydroxyeicosatrienoic acid, 20-carboxy-AA, and oleoylethanolamide were high in dogs with IE, and those of PGF1α were high in dogs with MUO. NO production levels were high in CSF but not in plasma in dogs with MUO or IE.

Discussion

It remains unknown whether these changes represent the cause or effect of diseases of the central nervous system; however, lipid metabolites and NO production in CSF and plasma may be used as diagnostic biomarkers and could be exploited for treating idiopathic or inflammatory epilepsy in dogs.

Association between F2-isoprostanes and self-reported stressors in pregnant americans of African and European ancestry

Background

Poor birth outcomes such as preterm birth/delivery disproportionately affect African Americans compared to White individuals. Reasons for this disparity are likely multifactorial, and include prenatal psychosocial stressors, and attendant increased lipid peroxidation; however, empirical data linking psychosocial stressors during pregnancy to oxidative status are limited.

Methods

We used established scales to measure five psychosocial stressors. Maternal adverse childhood experiences, financial stress, social support, anxiety, and depression were measured among 50 African American and White pregnant women enrolled in the Stress and Health in Pregnancy cohort. Liquid chromatography-tandem mass spectrometry was used to measure biomarkers of oxidative stress (four urinary F2-isoprostane isomers), to estimate oxidative status. Linear regression models were used to evaluate associations between psychosocial stressors, prenatal oxidative status and preterm birth.

Results

After adjusting for maternal obesity, gestational diabetes, and cigarette smoking, African American women with higher oxidative status were more likely to report higher maternal adverse childhood experience scores (β = 0.16, se = 1.07, p-value = 0.024) and depression scores (β = 0.05, se = 0.02, p = 0.014). Higher oxidative status was also associated with lower gestational age at birth (β = -0.13, se = 0.06, p = 0.04) in this population. These associations were not apparent in Whites. However, none of the cross-product terms for race/ethnicity and social stressors reached statistical significance (p > 0.05).

Conclusion

While the small sample size limits inference, our novel data suggest that psychosocial stressors may contribute significantly to oxidative stress during pregnancy, and preterm birth or delivery African Americans. If replicated in larger studies, these findings would support oxidative stress reduction using established dietary or pharmacological approaches present a potential avenue to mitigate adverse effects of psychosocial stressors on birth outcomes.

Evaluation of the relationship between insulin resistance and 8-iso prostaglandin levels in obesity children

INTRODUCTION

The rising rate of childhood obesity and the serious health problems it causes are gaining increasing attention in medical research and health policy.

Protective Effects of Diets Rich in Polyphenols in Cigarette Smoke (CS)-Induced Oxidative Damages and Associated Health Implications

Cigarette smoking has been responsible for causing many life-threatening diseases such as pulmonary and cardiovascular diseases as well as lung cancer. One of the prominent health implications of cigarette smoking is the oxidative damage of cellular constituents, including proteins, lipids, and DNA. The oxidative damage is caused by reactive oxygen species (ROS, oxidants) present in the aqueous extract of cigarette smoke (CS). In recent years, there has been considerable interest in the potential health benefits of dietary polyphenols as natural antioxidant molecules. Epidemiological studies strongly suggest that long-term consumption of diets (fruits, vegetables, tea, and coffee) rich in polyphenols offer protective effects against the development of cancer, cardiovascular diseases, diabetes, osteoporosis, and neurodegenerative diseases. For instance, green tea has chemopreventive effects against CI-induced lung cancer. Tea might prevent CS-induced oxidative damages in diseases because tea polyphenols, such as catechin, EGCG, etc., have strong antioxidant properties. Moreover, apple polyphenols, including catechin and quercetin, provide protection against CS-induced acute lung injury such as chronic obstructive pulmonary disease (COPD). In CS-induced health problems, the antioxidant action is often accompanied by the anti-inflammatory effect of polyphenols. In this narrative review, the CS-induced oxidative damages and the associated health implications/pathological conditions (or diseases) and the role of diets rich in polyphenols and/or dietary polyphenolic compounds against various serious/chronic conditions of human health have been delineated.

Intervention of 4% salmon phospholipid on metabolic syndrome in mice based on colonic lipidomics analysis

BACKGROUND

The incidence of metabolic syndrome (MetS) is increasing, and n-3 polyunsaturated fatty acids (PUFAs) in salmon (Oncorhynchus) phospholipids can effectively reduce the risk of MetS.

RESULTS

Under the intervention of 4% salmon phospholipid, the levels of fasting blood glucose (FBG), insulin, monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were significantly reduced in the plasma of MetS mice, whereas adiponectin was significantly increased. By screening, we found that the 18 differential metabolites, consisting of seven triglycerides (TGs), six diglycerides (DGs), one phosphatidylethanolamine (PE), three sphingomyelins (SMs) and one eicosanoid, could be the key differential metabolites, and two metabolic pathways were significantly affected: glycerolipid metabolism and glycerophospholipid metabolism.

CONCLUSION

4% salmon phospholipids could affect MetS by inhibiting insulin resistance, reducing inflammatory factors and promoting the synthesis of PE, yet the mechanism required further study. Our results could help in the treatment of MetS. © 2021 Society of Chemical Industry.

Systemic Inflammation, Oxidative Stress and Cardiovascular Health in Children and Adolescents: A Systematic Review

Recent studies indicate that cerebrovascular diseases and processes of atherosclerosis originate in the childhood era and are largely influenced by chronic inflammation. Some features of vascular dysfunction in adulthood may even be programmed prenatally via genetic influences and an unfavorable intrauterine milieu. Oxidative stress, defined by an imbalance between the production and generation of reactive oxygen species (ROS) in cells and tissues and the capability of an organism to scavenge these molecules via antioxidant mechanisms, has been linked to adverse cardiovascular health in adults, yet has not been systematically reviewed in the pediatric population. We performed a systematic search as per the PRISMA guidelines in PubMed/Medline and Cochrane Reviews and detected, in total, 1228 potentially eligible pediatric articles on systemic inflammation, oxidative stress, antioxidant use, cardiovascular disease and endothelial dysfunction. The abstracts and full-text manuscripts of these were screened for inclusion and exclusion criteria, and a total of 160 articles were included. The results indicate that systemic inflammation and oxidative stress influence cardiovascular health in many chronic pediatric conditions, including hypertension, obesity, diabetes mellitus types 1 and 2, chronic kidney disease, hyperlipidemia and obstructive sleep apnea. Exercise and diet may diminish ROS formation and enhance the total serum antioxidant capacity. Antioxidant supplementation may, in selected conditions, contribute to the diminution of the oxidative state and improve endothelial function; yet, in many areas, studies provide unsatisfactory results.

Hibernating brown bears are protected against atherogenic dyslipidemia

To investigate mechanisms by which hibernators avoid atherogenic hyperlipidemia during hibernation, we assessed lipoprotein and cholesterol metabolisms of free-ranging Scandinavian brown bears (Ursus arctos). In winter- and summer-captured bears, we measured lipoprotein sizes and sub-classes, triglyceride-related plasma-enzyme activities, and muscle lipid composition along with plasma-levels of antioxidant capacities and inflammatory markers. Although hibernating bears increased nearly all lipid levels, a 36%-higher cholesteryl-ester transfer-protein activity allowed to stabilize lipid composition of high-density lipoproteins (HDL). Levels of inflammatory metabolites, i.e., 7-ketocholesterol and 11ß-prostaglandin F2α, declined in winter and correlated inversely with cardioprotective HDL2b-proportions and HDL-sizes that increased during hibernation. Lower muscle-cholesterol concentrations and lecithin-cholesterol acyltransferase activity in winter suggest that hibernating bears tightly controlled peripheral-cholesterol synthesis and/or release. Finally, greater plasma-antioxidant capacities prevented excessive lipid-specific oxidative damages in plasma and muscles of hibernating bears. Hence, the brown bear manages large lipid fluxes during hibernation, without developing adverse atherogenic effects that occur in humans and non-hibernators.

Treatment with PCSK9 Inhibitors in Patients with Familial Hypercholesterolemia Lowers Plasma Levels of Platelet-Activating Factor and Its Precursors: A Combined Metabolomic and Lipidomic Approach

INTRODUCTION

Familial hypercholesterolemia (FH) is characterized by extremely high levels of circulating low-density lipoprotein cholesterol (LDL-C) and is caused by mutations of genes involved in LDL-C metabolism, including LDL receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin/Kexin type 9 (PCSK9). Accordingly, PCSK9 inhibitors (PCSK9i) are effective in LDL-C reduction. However, no data are available on the pleiotropic effect of PCSK9i. To this end, we performed an untargeted metabolomics approach to gather a global view on changes in metabolic pathways in patients receiving treatment with PCSK9i.

METHODS

Twenty-five FH patients starting treatment with PCSK-9i were evaluated by an untargeted metabolomics approach at baseline (before PCSK9i treatment) and after 12 weeks of treatment.

RESULTS

All the 25 FH subjects enrolled were on maximal tolerated lipid-lowering therapy prior to study entry. After a 12 week treatment with PCSK9i, we observed an expected significant reduction in LDL-cholesterol levels (from 201.0 ± 69.5 mg/dL to 103.0 ± 58.0 mg/dL, p < 0.001). The LDL-C target was achieved in 36% of patients. After peak validation and correction, after 12 weeks of PCSK9i treatment as compared to baseline, we observed increments in creatine (p-value = 0.041), indole (p-value = 0.045), and indoleacrylic acid (p-value= 0.045) concentrations. Conversely, significant decreases in choline (p-value = 0.045) and phosphatidylcholine (p-value < 0.01) together with a reduction in platelet activating factor (p-value = 0.041) were observed.

CONCLUSIONS

Taking advantage of untargeted metabolomics, we first provided evidence of concomitant reductions in inflammation and platelet activation metabolites in FH patients receiving a 12 week treatment with PCSK9i.

Celecoxib exhibits therapeutic potential in experimental model of hyperlipidaemia

Hyperlipidaemia is a major risk factor for cardiovascular diseases, the leading cause of death globally. Celecoxib attenuated hypercholesterolaemia associated with CCl4-induced hepatic injury in rats without improving liver function in our previous study. This present study investigated the lipid lowering potential of celecoxib in normal rats fed with coconut oil subjected to five deep-frying episodes. Male Sprague Dawley rats were randomly assigned to groups (n = 6 rats/group) which received physiological saline (10 mL/kg), unheated coconut oil (UO, 10 mL/kg) or heated coconut oil (HO, 10 ml/kg) for 60 days. Groups that received HO were subsequently treated with either physiological saline, atorvastatin (25 mg/kg), celecoxib (5 mg/kg) or celecoxib (10 mg/kg) in the last fifteen days of the experiment. Rats were sacrificed 24 hours after last treatment and blood and tissue samples collected for analysis. HO consumption produced significant hyperlipidaemia and elevation in marker enzymes of hepatic function. Celecoxib ameliorated the hyperlipidaemia as shown by the significantly (P<0.05) lower total cholesterol, triglycerides, low and very low density lipoprotein in the celecoxib-treated rats when compared with HO-fed rats that received saline. Celecoxib also reduced (P<0.05) alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and liver weight of hyperlipidaemic rats. Similarly, hepatocellular damage with the hyperlipidaemia was significantly reversed by celecoxib. However, serum TNF-α and IL-6 did not change significantly between the various groups. Taken together, data from this study suggest that celecoxib may exert therapeutic benefit in hyperlipidaemia and its attendant consequences.

Sex-dependent compensatory mechanisms preserve blood pressure homeostasis in prostacyclin receptor-deficient mice

Inhibitors of microsomal prostaglandin E synthase 1 (mPGES-1) are in the early phase of clinical development. Deletion of mPges-1 in mice confers analgesia, restrains atherogenesis, and fails to accelerate thrombogenesis, while suppressing prostaglandin E2 (PGE2), but increasing the biosynthesis of prostacyclin (PGI2). In low-density lipoprotein receptor-deficient (Ldlr-/-) mice, this last effect represents the dominant mechanism by which mPges-1 deletion restrains thrombogenesis, while suppression of PGE2 accounts for its antiatherogenic effect. However, the effect of mPges-1 depletion on blood pressure (BP) in this setting remains unknown. Here, we show that mPges-1 depletion significantly increased the BP response to salt loading in male Ldlr-/- mice, whereas, despite the direct vasodilator properties of PGI2, deletion of the I prostanoid receptor (Ipr) suppressed this response. Furthermore, combined deletion of the Ipr abrogated the exaggerated BP response in male mPges-1-/- mice. Interestingly, these unexpected BP phenotypes were not observed in female mice fed a high-salt diet (HSD). This is attributable to the protective effect of estrogen in Ldlr-/- mice and in Ipr-/- Ldlr-/- mice. Thus, estrogen compensates for a deficiency in PGI2 to maintain BP homeostasis in response to high salt in hyperlipidemic female mice. In male mice, by contrast, the augmented formation of atrial natriuretic peptide (ANP) plays a similar compensatory role, restraining hypertension and oxidant stress in the setting of Ipr depletion. Hence, men with hyperlipidemia on a HSD might be at risk of a hypertensive response to mPGES-1 inhibitors.

Intake of Camelina Sativa Oil and Fatty Fish Alter the Plasma Lipid Mediator Profile in Subjects with Impaired Glucose Metabolism - A Randomized Controlled Trial

n-3 and n-6 polyunsaturated fatty acids (PUFAs) and their lipid mediator metabolites are associated with inflammation. We investigated the effect of dietary intake of plant- and animal-derived n-3 PUFAs and fish protein on the circulatory concentrations of lipid mediators. Seventy-nine subjects with impaired fasting glucose who completed the controlled dietary intervention after randomization to the fatty fish (FF, n=20), lean fish (LF, n=21), Camelina sativa oil (CSO, n=18) or control group (n=20) for 12 weeks were studied. Lipid mediator profiling from fasting plasma samples before and after the intervention was performed by liquid chromatography-mass spectrometry (LC-MS/MS). The FF diet increased concentrations of 18-hydroxyeicosapentaenoic acid (18-HEPE) and 4- and 17-hydroxydocosahexaenoic acid (4-, 17-HDoHE) derived from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively. Concentrations of lipid mediators derived from α-linolenic acid (ALA) increased and arachidonic acid (AA) derived 5-iso prostaglandin F_2α-VI decreased in the CSO group. There were no significant changes in lipid mediators in the LF group. The dietary intake of both plant and animal-based n-3 PUFAs increased circulatory concentrations of lipid mediators with potential anti-inflammatory properties.

Impact of chronic kidney dysfunction on serum Sulfatides and its metabolic pathway in mice

Serum sulfatides are critical glycosphingolipids that are present in lipoproteins and exert anticoagulant effects. A previous study reported decreased levels of serum sulfatides in hemodialysis patients and suggested an association with cardiovascular disease. However, the mechanism of changes in serum sulfatides in chronic kidney dysfunction has not been well investigated. The current study examined whether a chronic kidney disease (CKD) state could decrease serum sulfatide levels using 5/6 nephrectomy (5/6NCKD) mice, an established CKD murine model, and studied the mechanisms contributing to diminished sulfatides. 5/6NCKD mice and sham operation control mice were sacrificed at the 4th or 12th postoperative week (POW) for measurement of serum sulfatide levels. Hepatic sulfatide content, which is the origin of serum sulfatides, and the expression of sulfatide metabolic enzymes in liver tissue were assessed as well. The 5/6NCKD mice developed CKD and showed increased serum creatinine and indoxyl sulfate. The serum levels and hepatic amounts of sulfatides were significantly decreased in 5/6NCKD mice at both 4 and 12 POW, while the degradative enzymes of sulfatides arylsulfatase A and galactosylceramidase were significantly increased. In a Hepa1-6 murine liver cell line, indoxyl sulfate addition caused intracellular levels of sulfatides to decrease and degradative enzymes of sulfatides to increase in a manner comparable to the changes in 5/6NCKD mice liver tissue. In conclusion, chronic kidney dysfunction causes degradation of sulfatides in the liver to decrease serum sulfatide levels. One explanation of these results is that indoxyl sulfate, a uremic toxin, accelerates the degradation of sulfatides in liver tissue.

Oxidative burden in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a genetic disorder characterized by high serum levels of low-density lipoprotein cholesterol (LDL-c). FH is characterized by accelerated development of atherosclerosis and represents the most frequent hereditary cause of premature coronary heart disease. Mutations of the LDL receptor gene are the genetic signature of FH, resulting in abnormal levels of circulating LDLs. Moreover, FH promotes the generation of reactive oxygen species (ROS) which is another key mechanism involved in atherosclerosis development and progression. The aim of this narrative review is to update the current knowledge on the pathophysiological mechanisms linking FH to ROS generation and their detrimental impact on atherosclerotic pathophysiology. With this purpose, we reviewed experimental and clinical data on the association between FH and OS and the functional role of OS as a promoter of inflammation and atherosclerosis. In this regard, oxidant species such as oxidized LDL, malondialdehyde, ROS, and isoprostanes emerged as leading mediators of the oxidative injury in FH. In conclusion, targeting oxidative stress may be a promising therapeutic strategy to reduce atherogenesis in patients with FH.

Dietary fats and F2-isoprostanes: A review of the clinical evidence

Evidence supports that a high dietary fat intake increases oxidative stress and the risk of diet-induced metabolic disorders such as obesity, diabetes and cardiovascular diseases. F₂-isoprostanes (F₂-isoP) are formed by the non-enzymatic oxidation of arachidonic acid and are widely used as reliable biomarkers of oxidative stress in clinical studies. Dietary fats may influence F₂-isoP levels, as they (1) are metabolic substrates for their formation, (2) modify the lipid composition of tissues, and (3) affect the plasma lipoprotein concentrations which are involved in F₂-isoP transport. This review examined the latest clinical evidence on how dietary fats can affect blood circulation and excretion of F₂-isoP in individuals with healthy or deteriorated metabolic profiles. Clinical studies reported that saturated or monounsaturated fat-rich diets did not affect F₂-isoP levels in adults with healthy or deteriorated metabolic profiles. Though, ω-3 polyunsaturated fatty acids decreased F₂-isoP levels in numerous studies, whereas trans-fatty acids raised F₂-isoP excretion. Yet, the reported heterogeneous results reveal important considerations, such as the health status of the participants, the biological fluids used to determine F₂-isoP, the analytical methods employed and the specific F₂-isoP isomers detected. Therefore, future clinical studies should be designed in order to consider these issues in the studies of the effects of fat intake on oxidative stress.

Unraveling mechanisms of toxicant-induced oxidative stress in cardiovascular disease

To date, numerous clinical studies examining correlations between oxidative stress biomarkers and cardiovascular diseases (CVD) have repeatedly suggested a role for oxidant injury in the pathogenesis of diseases such as atherosclerosis. Despite this, antioxidant supplementation trials have not demonstrated a reduction in disease progression. Nevertheless, small animal and epidemiological studies have linked exposures to certain toxicants with increased CVD risk involving putative oxidative stress mechanisms. A few prototypical vascular toxicants will be discussed as examples of toxicants that likely act via oxidative stress mechanisms. For discussion, we will classify these toxicants as those that induce direct (e.g., arsenic, nucleoside reverse transcriptase inhibitors) versus indirect (particulate matter, ozone) oxidative stress mechanisms, and those that likely induce CVD through both direct and indirect mechanisms (cigarette smoke). Finally, new findings in oxidative stress research, including the emerging importance of reactive sulfur species, hydrogen peroxide as a presumed endothelium-derived hyperpolarizing factors, etc., will be discussed, as well as the need to determine the role of toxicants in modulating these newly identified pathways. Moreover, given the lack of success in conclusively demonstrating the roles of oxidative stress in CVD risk stratification, research probing the roles of toxicant exposures in propagating CVD pathogenesis may be a novel approach for more conclusively delineating the causal role of oxidative stress in CVD initiation and progression.

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

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

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

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

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

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

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

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Cancer and cardiovascular diseases have surprisingly low F₂-isoprostanes.

Body mass index associates with white matter microstructure in bipolar depression

OBJECTIVES

Obesity has been reported in over 60% of bipolar disorder (BD) patients. It worsens the severity of illness, and influences cognition and functional outcomes. White matter (WM) abnormalities are one of the most consistently reported findings in neuroimaging studies of BD. We hypothesized that body mass index (BMI) could correlate with WM integrity in bipolar patients.

METHODS

We evaluated BMI in a sample of 164 depressed patients affected by BD. We performed whole-brain tract-based spatial statistics with threshold-free cluster enhancement for the diffusion tensor imaging (DTI) measures of WM integrity: fractional anisotropy; axial, radial, and mean diffusivity.

RESULTS

We observed that BMI was associated with DTI measures of WM integrity in several fiber tracts: anterior corona radiata, anterior thalamic radiation, inferior fronto-occipital fasciculus and corpus callosum.

CONCLUSIONS

The association of BMI in key WM tracts that are crucial to mood regulation and neurocognitive functioning suggests that BMI might contribute to the pathophysiology of BD through a detrimental action on structural connectivity in critical cortico-limbic networks.

The enigma ofin vivooxidative stress assessment: isoprostanes as an emerging target

Oxidative stress is believed to be one of the major factors behind several acute and chronic diseases, and may also be associated with ageing. Excess formation of free radicals in miscellaneous body environment may originate from endogenous response to cell injury, but also from exposure to a number of exogenous toxins. When the antioxidant defence system is overwhelmed, this leads to cell damage. However, the measurement of free radicals or their endproducts is tricky, since these compounds are reactive and short lived, and have diverse characteristics. Specific evidence for the involvement of free radicals in pathological situations has been difficult to obtain, partly owing to shortcomings in earlier described methods for the measurement of oxidative stress. Isoprostanes, which are prostaglandin-like bioactive compounds synthesized in vivo from oxidation of arachidonic acid, independently of cyclooxygenases, are involved in many human diseases, and their measurement therefore offers a way to assess oxidative stress. Elevated levels of F₂-isoprostanes have also been seen in the normal human pregnancy, but their physiological role has not yet been defined. Large amounts of bioactive F₂-isoprostanes are excreted in the urine in normal basal situations, with a wide interindividual variation. Their exact role in the regulation of normal physiological functions, however, needs to be explored further. Current understanding suggests that measurement of F₂-isoprostanes in body fluids provides a reliable analytical tool to study oxidative stress-related diseases and experimental inflammatory conditions, and also in the evaluation of various dietary antioxidants, as well as drugs with radical-scavenging properties. However, assessment of isoprostanes in plasma or urine does not necessarily reflect any specific tissue damage, nor does it provide information on the oxidation of lipids other than arachidonic acid.

Pravastatin and Clopidogrel Combined Inhibit Intimal Hyperplasia in a Rat Carotid Endarterectomy Model

Intimal hyperplasia, resulting from a complex cascade of events involving platelets, leukocytes, and smooth muscle cells, may be inhibited by the HMG-CoA reductase inhibitor pravastatin, which demonstrates inhibition of platelet activity and leukocyte adhesion and may be associated with inhibition of vascular smooth muscle cell proliferation and migration. Clopidogrel, an adenosine diphosphate (ADP) receptor inhibitor, was shown to decrease platelet activity and aggregation but not intimal hyperplasia (IH). We postulated that the combination of both pravastatin and clopidogrel would significantly decrease IH in a rat carotid endarterectomy model. Male Sprague-Dawley rats (n = 18) divided by treatment regimen underwent treatment for 2 weeks both before and after an open carotid endarterectomy. Serum collected at the time of harvest was measured for C-reactive protein (CRP), platelet activity, and total serum cholesterol; carotid arteries were removed and processed for IH determination. Control rats (n = 7) received oral vehicle daily before and following endarterectomy. Pravastatin-alone rats (n = 6) received oral pravastatin (10 mg/kg/day) before and after endarterectomy. Pravastatin plus clopidogrel rats (n = 5) received oral pravastatin (10 mg/kg/day) plus a preendarterectomy bolus of oral clopidogrel (4.3 mg/kg) before endarterectomy and resumed pravastatin (10 mg/kg/day) plus oral clopidogrel (1 mg/kg/day) postendarterectomy. Pravastatin alone and pravastatin plus clopidogrel significantly decreased CRP compared to controls (120.2 ±11.2 and 134.1 ±9.9 vs 191.1 ±9.2 µg/mL, respectively p = 0.003 and p = 0.0024). CRP levels were not different between pravastatin alone and pravastatin plus clopidogrel (p = 0.35). Platelet activity was significantly decreased by pravastatin alone and pravastatin plus clopidogrel in comparison to controls (7.3 ±2.2 and 6.6 ±2.8 vs 19.2 ±6.1 platelet reactive units (PRU), respectively p = 0.048 and p = 0.045). No significant difference was noted in platelet activity between pravastatin alone and pravastatin plus clopidogrel (p = 0.89). Pravastatin plus clopidogrel significantly reduced serum cholesterol compared to control and pravastatin alone (84.0 ±6.6 vs 110.4 ±7.4 and 117.0 ±8.8 mg/dL, respectively p = 0.03 and p = 0.01). Pravastatin alone did not decrease serum cholesterol compared to controls (p = 0.54). IH was not reduced by pravastatin alone compared to controls (p = 0.61) but was significantly decreased by pravastatin plus clopidogrel in comparison to control and pravastatin alone (3.0 ±1.1 vs 46.3 ±13.7 and 37.4 ±14.6% luminal stenosis, respectively p = 0.01 and p = 0.05). Pravastatin plus clopidogrel significantly decreased CRP, platelet activity, total serum cholesterol, and IH while pravastatin alone decreased only CRP and platelet activity. Intimal hyperplasia reduction may therefore be dependent on other contributors, possibly growth factors, cytokines, and oxidative stress. The combination of pravastatin plus clopidogrel may have synergistic or even additional inhibitory effects on IH. Pravastatin plus clopidogrel was effective in decreasing IH in a rat carotid endarterectomy model and may prove a useful therapy for IH reduction in the clinical setting.

Effects of BM-573 on Endothelial Dependent Relaxation and Increased Blood Pressure at Early Stages of Atherosclerosis

Endothelial dysfunction is considered to be an early event in atherosclerosis and plays a pivotal role in the development, progression and clinical complications of atherosclerosis. Previous studies have shown the beneficial effects of combined inhibition of thromboxane synthase and antagonism of thromboxane receptors by BM-573 on atherosclerosis; however our knowledge about the beneficial effects of BM-573 on endothelial function and increased blood pressure related to early stage of atherosclerosis is limited. In the present study, we investigated the effects of short-term (3 μM, 1 hour) and chronic (10 mg/L, 8 weeks) treatments with BM-573 on vasodilatory function, nitric oxide (NO) bioavailability, oxidative stress and systolic blood pressure in 15 weeks old apolipoprotein E-deficient (ApoE-KO) mice. ApoE-KO mice showed a reduced endothelium-derived relaxation. In addition, NO bioavailability was reduced and oxidative stress and blood pressure were increased in ApoE-KO mice versus wild-type mice. BM-573 treatments were able to improve the relaxation profile in ApoE-KO mice. Short-term effects of BM-573 were mainly mediated by an increased phosphorylation of both eNOS and Akt, whereas BM-573 in vivo treatment also reduced oxidative stress and restored NO bioavailability. In addition, chronic administration of BM-573 reduced systolic blood pressure in ApoE-KO mice. In conclusion, pharmacological modulation of TxA2 biosynthesis and biological activities by dual TP antagonism/TxAS inhibition with BM-573, already known to prevent plaque formation, has the potential to correct vasodilatory dysfunction at the early stages of atherosclerosis.

Urinary Phthalate Metabolites and Biomarkers of Oxidative Stress in a Mexican-American Cohort: Variability in Early and Late Pregnancy

People are exposed to phthalates through their wide use as plasticizers and in personal care products. Many phthalates are endocrine disruptors and have been associated with adverse health outcomes. However, knowledge gaps exist in understanding the molecular mechanisms associated with the effects of exposure in early and late pregnancy. In this study, we examined the relationship of eleven urinary phthalate metabolites with isoprostane, an established marker of oxidative stress, among pregnant Mexican-American women from an agricultural cohort. Isoprostane levels were on average 20% higher at 26 weeks than at 13 weeks of pregnancy. Urinary phthalate metabolite concentrations suggested relatively consistent phthalate exposures over pregnancy. The relationship between phthalate metabolite concentrations and isoprostane levels was significant for the sum of di-2-ethylhexyl phthalate and the sum of high molecular weight metabolites with the exception of monobenzyl phthalate, which was not associated with oxidative stress at either time point. In contrast, low molecular weight metabolite concentrations were not associated with isoprostane at 13 weeks, but this relationship became stronger later in pregnancy (p-value = 0.009 for the sum of low molecular weight metabolites). Our findings suggest that prenatal exposure to phthalates may influence oxidative stress, which is consistent with their relationship with obesity and other adverse health outcomes.

Overweight and urban pollution: preliminary results

The aim of this study is to determine whether in workers exposed to urban pollution the risk of developing overweight and obesity is higher in workers exposed to urban pollution compared to a control group. The study was conducted on 150 volunteers, 75 workers exposed to urban pollution (50 women and 25 men) and 75 indoor workers (50 women and 25 men). Once measured the weight and height and calculated body mass index (BMI) for each worker, the research was based on the comparison, between the two groups, of the mean values of the measurements and of the frequency of workers with BMI index higher than the cut-off of normality. The only statistically significant difference found was for the mean value of weight in women, which was higher among outdoor workers compared to indoor workers. The mean values of BMI and the frequency of workers with BMI higher than normal was higher among outdoor workers compared to indoor workers in both sexes, but not statistically significant. The data suggest that outdoor workers may be subject to an additional risk of developing obesity as a result of exposure to urban air pollution (which, like obesity, is a source of oxidative stress). So, our preliminary study encourages to continue this line of research by implementing the sample and considering all the confounding factors. Furthermore, the results highlight the necessity to take account of gender differences in the context of health surveillance of workers.

Oxidative stress, insulin resistance, dyslipidemia and type 2 diabetes mellitus

Oxidative stress is increased in metabolic syndrome and type 2 diabetes mellitus (T2DM) and this appears to underlie the development of cardiovascular disease, T2DM and diabetic complications. Increased oxidative stress appears to be a deleterious factor leading to insulin resistance, dyslipidemia, β-cell dysfunction, impaired glucose tolerance and ultimately leading to T2DM. Chronic oxidative stress, hyperglycemia and dyslipidemia are particularly dangerous for β-cells from lowest levels of antioxidant, have high oxidative energy requirements, decrease the gene expression of key β-cell genes and induce cell death. If β-cell functioning is impaired, it results in an under production of insulin, impairs glucose stimulated insulin secretion, fasting hyperglycemia and eventually the development of T2DM.

Urinary biomarkers of oxidative and nitrosative stress and the risk for incident stroke: a nested case-control study from a community-based cohort

BACKGROUND

Oxidative and nitrosative stress has suggested to be involved in the pathophysiology of cardiovascular diseases, but has unclear relationship with the risk for incident stroke.

METHODS

In this nested case-control study, cases consisted of 131 participants who were free of stroke at screening and experienced incident stroke during the follow-up period. Controls were 1:1 frequency-matched for age and sex. Baseline levels of urinary creatinine-indexed biomarkers were measured using liquid chromatography-tandem mass spectrometry, including 8-iso-prostaglandin F₂α (8-iso-PGF₂α), 4-hydroxynonenal conjugate with mercapturic acid, 8-hydroxydeoxyguanosine and 8-nitroguanine.

RESULTS

The levels of urinary 8-iso-PGF₂α in stroke cases were higher than in controls [median (interquartile range), 1.13 (2.23-4.36) μg/g creatinine versus 0.71 (1.34-3.02) μg/g creatinine, p=0.004]. After adjusting cardiovascular risk factors, the association remained that higher level of urinary 8-iso-PGF₂α entailed the greater risk for incident stroke [per 1 standard deviation increase in log-transformed value, adjusted odds ratio, 1.40; 95% confidence interval (CI), 1.06-1.85; p=0.005] with a significant increasing trend across its quartiles (p for trend=0.016). After adding urinary 8-iso-PGF₂α, the prediction model not only improved discrimination between participants with or without incident stroke (integrated discrimination improvement, 0.025; 95% CI, 0.006-0.045; p=0.005), but enhanced stroke risk stratification (net reclassification improvement, 19.8%; 95% CI, 4.6-35.1%; p=0.011). In contrast, the relationships were non-significant among the other three biomarkers.

CONCLUSIONS

Our findings demonstrated that urinary 8-iso-PGF₂α could be an independent biomarker of oxidative stress for prediction of the risk for incident stroke.

Pathophysiology of isoprostanes in the cardiovascular system: implications of isoprostane-mediated thromboxane A2 receptor activation

Isoprostanes are free radical-catalysed PG-like products of unsaturated fatty acids, such as arachidonic acid, which are widely recognized as reliable markers of systemic lipid peroxidation and oxidative stress in vivo. Moreover, activation of enzymes, such as COX-2, may contribute to isoprostane formation. Indeed, formation of isoprostanes is considerably increased in various diseases which have been linked to oxidative stress, such as cardiovascular disease (CVD), and may predict the atherosclerotic burden and the risk of cardiovascular complications in the latter patients. In addition, several isoprostanes may directly contribute to the functional consequences of oxidant stress via activation of the TxA2 prostanoid receptor (TP), for example, by affecting endothelial cell function and regeneration, vascular tone, haemostasis and ischaemia/reperfusion injury. In this context, experimental and clinical data suggest that selected isoprostanes may represent important alternative activators of the TP receptor when endogenous TxA2 levels are low, for example, in aspirin-treated individuals with CVD. In this review, we will summarize the current understanding of isoprostane formation, biochemistry and (patho) physiology in the cardiovascular context.

Effect of common single nucleotide polymorphisms in COX-1 gene on related metabolic activity in diabetic patients treated with acetylsalicylic acid

INTRODUCTION

The objective of this study was to investigate the effect of common single nucleotide genomic polymorphisms in the cyclooxygenase-1 (COX-1) gene on the thromboxane A2 (TxA2) metabolite concentrations in serum and urine, as well as on prostaglandin F2α (PGF2α) urinary excretion in the diabetic population on acetylsalicylic acid (ASA) therapy.

MATERIAL AND METHODS

The study cohort consisted of 284 Caucasians with diabetes type 2 who had been taking ASA tablets at the dose of 75 mg/day for at least 3 months. Genotyping for the 4 selected SNPs within the COX-1 gene (two nonsynonymous-coding variants, rs3842787 [C50T, P17L] and rs5789 [C174A, L237M]; and two other synonymous SNPs, rs3842788 [G128A, Q41Q] and rs5788 [C644A]) was performed using the Sequenom iPLEX platform.

RESULTS

No statistically significant results were observed for the investigated SNPs and measured metabolites in the investigated cohort of patients. Statistically significant differences in S-TxB2 could however be observed for rs5788 in the subgroup of patients with very high S-TxB2 concentrations. In particular, more patients who were carriers of the minor allele for this polymorphism were observed in the group with S-TxB2 levels > 95(th) percentile, when compared with similar carriers in the group with S-TxB2 < 95(th) percentile (20% vs. 1.1%, respectively, p < 0.001, Mann-Whitney test).

CONCLUSIONS

The results of our study suggest that the four investigated common SNPs in the COX1 gene are not associated with obviously altered TxA2 metabolism and PGF2α synthesis in the investigated diabetic cohort treated with ASA.

F2-isoprostanes are correlated with trans fatty acids in the plasma of pregnant women

We hypothesized that the mild physiological oxidative stress present during pregnancy could increase both, plasma F2-isoprostanes (F2-isoPs) by lipid oxidation and trans fatty acids (TFA) through cis-trans isomerization respectively. Plasma samples collected at 12-18 weeks (MIROS cohort; n=65) and 38-41 weeks of pregnancy (CHUL cohort; n=21) were subjected to alkaline hydrolysis followed by liquid-liquid extraction in order to extract total F2-isoPs for quantification by HPLC-MS/MS. Several positive correlations were found between F2-isoPs and TFA, measured by GC-FID in plasma phospholipids, such as 6t-18:1, 9t-18:1 and 9t,12c-18:2 (r>0.306; p<0.045). Despite its low level, the 9t,12c-18:2 trans isomer, known to be associated to cardiovascular diseases, showed the most significant correlations with F2-isoPs. No correlation was observed between F2-isoPs and 9t-16:1 or 11t-18:1. In summary, this study suggests either a concomitant phenomenon or a competition between lipid peroxidation and cis-trans isomerisation of the cis precursor fatty acid in vivo during pregnancy.

Plasma 15-F2t-isoprostane in idiopathic pulmonary arterial hypertension

BACKGROUND

15-F2t-isoprostane (15-F2t-IsoP), a prostaglandin F2-like compound, is widely recognized as a biomarker of chronic heart failure. This study investigated the potential role and prognostic significance of plasma 15-F2t-IsoP in patients with idiopathic pulmonary arterial hypertension (IPAH).

METHODS

Plasma 15-F2t-IsoP concentrations were determined in 80 consecutive IPAH patients at the time of their first right heart catheterization, and monitored for 30±12 months. The expression of 15-F2t-IsoP protein in autopsy lung samples was determined by immunohistochemical staining.

RESULTS

Plasma 15-F2t-IsoP concentrations were significantly increased in patients with IPAH compared with healthy controls (91 pg/ml vs. 30 pg/ml, respectively; P<0.001). Patients with baseline 15-F2t-IsoP concentrations≥97 pg/ml had a significantly lower survival rate than those with lower baseline concentrations (P<0.001). During follow-up, 15-F2t-IsoP concentrations in survivors decreased, whereas concentrations in non-surviving patients increased further (P<0.05). Elevated concentrations of 15-F2t-IsoP were correlated with a severity of WHO functional class, lower 6-minute walking distance and mixed venous oxygen saturation, higher mean right atrial pressure and brain natriuretic peptide. Multivariate analysis revealed that the plasma 15-F2t-IsoP concentration was an independent factor associated with mortality. Histological studies showed that the expression of 15-F2t-IsoP was up-regulated in remodeled pulmonary vessels.

CONCLUSIONS

An elevated plasma 15-F2t-IsoP concentration and a further increase during follow-up may be a risk factor for higher mortality in patients with IPAH.

Targeted analysis of omega-6-derived eicosanoids in human serum by SPE-LC-MS/MS for evaluation of coronary artery disease

A targeted approach has been applied to quantitative analysis of eicosanoids derived from omega-6 fatty acids in serum from individuals diagnosed with coronary artery disease (CAD). The target metabolites were series-2 prostaglandins, thromboxane B2, hydroxyeicosatetraenoic acids, and hydroxyoctadecadienoic acids. The method was based on SPELC-MS/MS in selected reaction monitoring mode for highly selective and sensitive determination of the target eicosanoids. The combination of SPE and LC-MS/MS involved the benefits from both direct analysis of serum without a step for protein precipitation and fully automation of the analysis. The method allowed comparison of omega-6-derived eicosanoids in serum from patients diagnosed with CAD and from control individuals. The effect of treatment with aspirin on the profile of the target compounds was evaluated through its incidence on the different pathways. Finally, the serum levels of the target metabolites in patients diagnosed with CAD were also statistically examined according to the severity of the coronary lesion stratified as stable angina, non-ST-elevation acute coronary syndrome, and acute myocardial infarction.

Impact of vascular thromboxane prostanoid receptor activation on hemostasis, thrombosis, oxidative stress, and inflammation

The activation of thromboxane prostanoid (TP) receptor on platelets, monocytes/macrophages, endothelial cells, and vascular smooth muscle cells (SMC) plays important roles in regulating platelet activation and vascular tone and in the pathogenesis of thrombosis and vascular inflammation. Oxidative stress and vascular inflammation increase the formation of TP receptor agonists, which promote initiation and progression of atherogenesis and thrombosis. Furthermore, TP receptor activation promotes angiogenesis and vessel wall constriction. Besides thromboxane A₂ and its endoperoxide precursors, prostaglandin G₂ and H₂, isoprostanes, and 20-hydroxyeicosatetraenoic acid also activate TP receptor as autocrine or paracrine ligands. These additional TP activators play a role in pathological conditions such as diabetes, obesity, and hypertension, and their biosynthesis is not inhibited by aspirin, at variance with that of thromboxane A₂. The understanding of TP receptor function increased our current knowledge of the pathogenesis of atherosclerosis and thrombosis, highlighting the great impact that this receptor has in cardiovascular disorders.

Analysis of F2-isoprostanes in plasma of pregnant women by HPLC-MS/MS using a column packed with core-shell particles

Plasma F2-isoprostanes (F2-isoPs) are reliable biomarkers of oxidative stress. Several possible F2-isoPs are generated by the oxidation of arachidonic acid esterified in phospholipids. The separation of these isomers represents a technical challenge for rapid and selective determination. We have developed a HPLC-MS/MS method for the simultaneous determination of seven plasma F2-isoPs, namely 8-iso-15(R)-prostaglandin F2α (PGF2α), 8-iso-PGF2α, 15(R)-PGF2α, iPF2α-IV, iPF2α-VI, 5-iPF2α-VI, and (±)5-8,12-iso-iPF2α-VI. We have validated this method in plasma of pregnant women, a mild physiological oxidative stress known to increase F2-isoPs. Thus, plasma samples of women collected at the third trimester of pregnancy (n = 20) were subjected to alkaline hydrolysis followed by liquid-liquid extraction in order to extract total F2-isoPs. The F2-isoPs were separated within 16.5 min using a column packed with core-shell particles. The class VI isomers were the most abundant, accounting for 65% of the total level of all quantified F2-isoPs in plasma of pregnant women (P < 0.05). The 15(R)-PGF2α was the most abundant of the class III isomers quantified. This method allowed fast and selective separation of seven isomers from three different classes of F2-isoP regioisomers.

Oxidative stress and cardiovascular risk in overweight children in an exercise intervention program

BACKGROUND

This study aimed to determine whether oxidative stress was related to cardiovascular risk indices in children, and whether an exercise intervention would reduce oxidative stress.

METHODS

A randomized trial of two different doses of exercise and a no-exercise control group included 112 overweight and obese children, 7-11 years old. Plasma isoprostane levels were obtained at baseline and after the intervention. Cross-sectional analysis of oxidative stress and metabolic markers at baseline was performed. The effect of the exercise training on oxidative stress was tested.

RESULTS

Lower isoprostane levels were observed in blacks. At baseline, isoprostane was positively related to measures of fatness (BMI, waist circumference, percent body fat), insulin resistance and β-cell function (fasting insulin, insulin area under the curve, Matsuda index, disposition index, oral disposition index), and several lipid markers (low-density lipoprotein, triglycerides, total cholesterol), and inversely with fitness [peak oxygen consumption (VO(2))], independent of race, sex, and cohort. No relation was found with visceral fat, blood pressure, or glycemia. Independent of percent body fat, isoprostane predicted triglycerides, β=0.23, total cholesterol-to-high-density lipoprotein (TC/HDL) ratio, β=0.23, and insulin resistance (insulin area under the curve, β=0.24, Matsuda index, β=-0.21, oral disposition index, β=0.33). Exercise did not reduce oxidative stress levels, despite reduced fatness and improved fitness in these children.

CONCLUSIONS

Isoprostane levels were related to several markers of cardiovascular risk at baseline; however, despite reduced fatness and improved fitness, no effect of exercise was observed on isoprostane levels. To our knowledge, this is the first report in children to demonstrate a correlation of oxidative stress with disposition index, fitness, and TC/HDL ratio, the first to test the effect on oxidative stress of an exercise intervention that reduced body fat, and the first such exercise intervention study to include a substantial proportion of black children.

Mulberry leaf reduces oxidation and C-reactive protein level in patients with mild dyslipidemia

C-reactive protein (CRP) is the inflammatory marker that could represent the inflammation in blood vessels resulted from dyslipidemia. The objective of this study was to evaluate the antioxidative activity of mulberry leaf powder using DPPH assay and the effect of mulberry leaf powder on lipid profile, CRP level, and antioxidative parameters in mild dyslipidemia patients. A within-subjects design was conducted and patients received three tablets of 280 mg mulberry leaf powder three times a day before meals for 12 weeks. Total of 25 patients were enrolled but one subject was excluded. After three months of mulberry leaf consumption, serum triglyceride and low-density lipoprotein (LDL) level were significantly reduced and more than half of all patients' CRP levels decreased every month as well as the mean CRP level but no statistically significant difference was found. The average erythrocyte glutathione peroxidase activity of patients was increased but not at significant level; however, the mean serum 8-isoprostane level was significantly lower after mulberry treatment for 12 weeks. It can be concluded that mulberry leaf powder exhibited antioxidant activity and mulberry leaf powder has potential to decrease serum triglyceride, LDL, and CRP levels in mild dyslipidemia patients without causing severe adverse reactions.

Investigating endothelial activation and oxidative stress in relation to glycaemic control in a multiethnic population

AIM

An exploration of ethnic differences in measures of oxidative stress and endothelial activation in relation to known cardiovascular risk factors within South Asians (SA) and White Europeans (WE) residing in the UK.

METHODS

202 participants within a UK multiethnic population provided biomedical and anthropometric data. Human urinary 2,3-dinor-8-iso-prostaglandin-F1α and plasma ICAM-1 were quantified as measures of oxidative stress and endothelial activation, respectively.

RESULTS

2,3-Dinor-8-iso-prostaglandin-F1α levels were significantly higher in the SA group compared to WE group (10.36 (95% CI: 9.09, 11.79) versus 8.46 (7.71, 9.29), P = 0.021) after adjustment for age, gender, smoking status, body weight, HbA1c, and medication. Oxidative stress was positively associated with HbA1c (β = 1.08, 95% CI:1.02, 1.14, P = 0.009), fasting (β = 1.06, 95% CI: 1.02, 1.10, P = 0.002), and 2 hr glucose (β = 1.02, 95% CI: 1.00, 1.04, P = 0.052). In each adjusted model, SA continued to have elevated levels of oxidative stress compared to WE. ICAM-1 levels were significantly higher in the composite IGR group compared to the normoglycaemic group (P < 0.001). No ethnic differences in ICAM-1 were observed.

CONCLUSION

These results suggest that SA are more susceptible to the detrimental effects of hyperglycaemia-induced oxidative stress at lower blood glucose thresholds than WE. Further research into the potential mechanisms involved is warranted.

An eicosanoid-centric view of atherothrombotic risk factors

Cardiovascular disease is the foremost cause of morbidity and mortality in the Western world. Atherosclerosis followed by thrombosis (atherothrombosis) is the pathological process underlying most myocardial, cerebral, and peripheral vascular events. Atherothrombosis is a complex and heterogeneous inflammatory process that involves interactions between many cell types (including vascular smooth muscle cells, endothelial cells, macrophages, and platelets) and processes (including migration, proliferation, and activation). Despite a wealth of knowledge from many recent studies using knockout mouse and human genetic studies (GWAS and candidate approach) identifying genes and proteins directly involved in these processes, traditional cardiovascular risk factors (hyperlipidemia, hypertension, smoking, diabetes mellitus, sex, and age) remain the most useful predictor of disease. Eicosanoids (20 carbon polyunsaturated fatty acid derivatives of arachidonic acid and other essential fatty acids) are emerging as important regulators of cardiovascular disease processes. Drugs indirectly modulating these signals, including COX-1/COX-2 inhibitors, have proven to play major roles in the atherothrombotic process. However, the complexity of their roles and regulation by opposing eicosanoid signaling, have contributed to the lack of therapies directed at the eicosanoid receptors themselves. This is likely to change, as our understanding of the structure, signaling, and function of the eicosanoid receptors improves. Indeed, a major advance is emerging from the characterization of dysfunctional naturally occurring mutations of the eicosanoid receptors. In light of the proven and continuing importance of risk factors, we have elected to focus on the relationship between eicosanoids and cardiovascular risk factors.

Daily administration of the TP receptor antagonist terutroban improved endothelial function in high-cardiovascular-risk patients with atherosclerosis

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Terutroban is a selective TP receptor antagonist, i.e. a specific antagonist of the thromboxane A(2) and prostaglandin endoperoxide receptors, shown to improve endothelial function after a single administration in patients with coronary artery disease.

WHAT THIS STUDY ADDS

• This randomized, double-blind, placebo-controlled trial demonstrates that repeated-dose terutroban for 15 days improves endothelial function and inhibits thromboxane A(2) -induced platelet aggregation in high-cardiovascular-risk patients taking 300 mg of aspirin per day. Terutroban may prove useful for preventing cardiovascular events in such patients.

AIMS

The specific TP receptor antagonist terutroban improves endothelial function after a single dose in patients with coronary artery disease. Our aim was to evaluate the effects and dose dependency of repeated-dose terutroban on endothelial function and platelet aggregation in high-cardiovascular-risk patients with carotid atherosclerosis.

METHODS

We randomly allocated 48 patients taking 300 mg aspirin per day to placebo or to one of three terutroban dosages (2.5, 5 or 10 mg) for 15 days in a double-blind study. Flow-mediated vasodilatation was evaluated before and 2 h after the first oral dose on day 0 and 2 h after the last oral dose on day 14.

RESULTS

On day 0 and day 14, all three terutroban dosages improved flow-mediated vasodilatation and abolished platelet aggregation induced by the TP receptor agonist U46619, without changing the aggregation response to ADP or collagen.

CONCLUSION

Terutroban, by chronically improving endothelium-dependent vasodilatation and inhibiting platelet aggregation, may prove useful for preventing cardiovascular events in high-risk patients.

A high intake of trans fatty acids has little effect on markers of inflammation and oxidative stress in humans

Consumption of industrial trans fatty acids (iTFA) increases LDL cholesterol, decreases HDL cholesterol, and is strongly associated with a higher risk of cardiovascular disease (CVD). However, changes in circulating cholesterol cannot explain the entire effect. Therefore, we studied whether iTFA and conjugated linoleic acid (CLA) affect markers of inflammation and oxidative stress. Sixty-one healthy adults consumed each of 3 diets for 3 wk, in random order. Diets were identical except for 7% of energy provided by oleic acid (control diet), iTFA, or CLA. At the end of the 3 wk, we measured plasma inflammatory markers IL-6, C-reactive protein, tumor necrosis factor receptors I and II (TNF-RI and -RII), monocyte chemotactic protein-1 and E-selectin, and urinary 8-iso-PGF(2α), a marker of lipid peroxidation. Consumption of iTFA caused 4% lower TNF-RI concentrations and 6% higher E-selectin concentrations compared with oleic acid (control) and had no significant effect on other inflammatory markers. CLA did not significantly affect inflammatory markers. The urine concentration of 8-iso-PGF(2α) [geometric mean (95% CI)] was greater after the iTFA [0.54 (0.48, 0.60) nmol/mmol creatinine] and the CLA [1.2 (1.1, 1.3) nmol/mmol creatinine] diet periods than after the control period [0.45 (0.41, 0.50) nmol/mmol creatinine; P < 0.05]. In conclusion, high intakes of iTFA and CLA did not substantially affect plasma concentrations of inflammatory markers, but they increased the urine 8-iso-PGF(2α) concentration. However, it is unlikely this plays a major role in the mechanism by which iTFA increase the risk of CVD. However, more research is needed to fully understand the implications of these findings.

Ischemic stroke in patients receiving aspirin

BACKGROUND

The widespread use of aspirin-driven vascular prevention strategies does not impede the occurrence of first and recurrent ischemic strokes in numerous subjects. It is not clear what factors are associated with aspirin failure beyond the functional diagnosis of aspirin resistance in selected subjects. Current management guidelines provide little or no recommendations on the proper strategy for subjects who had a stroke while receiving aspirin. We assessed clinical features of subjects who had a first or recurrent stroke while taking aspirin.

METHODS

We studied demographic characteristics, vascular risk factors, stroke subtypes, and concomitant medication use in subjects with first or recurrent ischemic strokes. Patients receiving antiplatelet medications other than aspirin and/or oral anticoagulants were excluded from this analysis.

RESULTS

Seven hundred and nine patients with first (n = 552) or recurrent (n = 157) ischemic stroke were evaluated. Aspirin was being taken by 29% of first and 48% of recurrent stroke subjects. There was a higher prevalence of hypertension, hypercholesterolemia, and smoking in aspirin users with first and recurrent stroke (P < .05). Diabetes and coronary artery disease were more frequent in aspirin users with first ischemic strokes (P < .003), but not in those who had recurrent ischemic strokes. Aspirin users were more likely to be also receiving statins and antihypertensive drugs (P < .001).

CONCLUSIONS

Aspirin failure in ischemic stroke prevention may exceed functional resistance to aspirin and could be associated with a higher prevalence of lacunar stroke, comorbidities, and/or adverse interactions with other drugs. These patients may require a different approach regarding prevention strategies.

Effects of Nori- and Wakame-enriched meats with or without supplementary cholesterol on arylesterase activity, lipaemia and lipoproteinaemia in growing Wistar rats

Some seaweeds exert antioxidant and hypocholesterolaemic properties. The effects of diets including restructured meats (RM) containing Wakame (W) or Nori (N) algae on arylesterase (AE) activity and lipoprotein concentration and composition were tested. In the present study, six groups of ten male growing Wistar rats each were fed a mix of 85 % AIN-93M diet and 15 % freeze-dried RM for 35 d. The control group (C) consumed control RM, the W and N groups consumed RM with 5 % W and 5 % N, respectively. The cholesterol-enriched C (CC), W (CW) and N (CN) groups consumed their corresponding basal diets with supplementary cholesterol (2·43 %) and cholic acid (0·49 %). Cholesterol in the diet induced lower (P < 0·001) growth ratios. Both W and N diets significantly increased AE activity. VLDL-cholesterol values were lower in N rats than in W rats. AE activity increased (P < 0·001) in CC and CW rats but not in CN rats compared with their corresponding counterparts. AE was lower (P < 0·05) in the CN group than in the CC and CW groups. The CN diet partially blocked (P < 0·001) the hypercholesterolaemic induction observed in CC and CW diets and reduced TAG levels (at least P < 0·05) with respect to those of CC rats. Although dietary cholesterol supplementation increased total cholesterol, VLDL-cholesterol and (intermediate-density lipoprotein+LDL)-cholesterol (all P < 0·001) in all rats, the CN diet moderately improved the lipoprotein profile of hypercholesterolaemic rats. Changes in AE activity and plasma cholesterol in CN rats but not in CW rats suggest a possible relationship between the two parameters. It is concluded that inclusion of RM enriched with N may be used in hypercholesterolaemic diets to improve lipoprotein metabolism.

F2-isoprostanes as an indicator and risk factor for coronary heart disease

Coronary heart disease (CHD) is the leading single cause of death in the United States and most Western countries, killing more than 400,000 Americans per year. Although CHD often manifests suddenly as a fatal myocardial infarction, the atherosclerosis that gives rise to the infarction develops gradually and can be markedly slowed or even reversed through pharmacological and lifestyle interventions. These same atherosclerotic processes also drive related vascular diseases such as stroke and peripheral artery disease, and individuals surviving occlusive events often develop additional complications including ischemic cardiomyopathy and heart failure. Therefore, better detection of subclinical atherosclerosis, along with more effective treatments, could significantly reduce the rate of death from CHD and related vascular diseases in the United States. In recent years, oxidation of polyunsaturated fatty acids (PUFAs) in plasma lipoproteins has been postulated to be a critical step in the development of atherosclerosis. If so, then monitoring lipid peroxidation should be a useful indicator of disease risk and progression. This review focuses on the evidence that specific PUFA peroxidation products, the F(2)-isoprostanes, are useful biomarkers that could potentially be utilized as indicators of CHD.