Antioxidant enzyme activity and coronary heart disease: meta-analyses of observational studies

Comprehensive proteomics of monocytes indicates oxidative imbalance functionally related to inflammatory response in chronic kidney disease-related atherosclerosis

Atherosclerosis-induced cardiovascular events are the leading cause of mortality in chronic kidney disease (CKD) patients. Monocytes are involved in the formation of atherosclerotic plaques and mediate in the overproduction of ROS, promoting inflammation and oxidative stress. However, the relationship between monocytes, inflammation, and oxidative status in CKD-associated atherosclerosis has not been thoroughly investigated. Monocytes and plasma derived from two groups of CKD patients with varying degrees of atherosclerosis and two groups of patients with cardiovascular disease (CVD) and non-CKD atherosclerosis were analyzed. This study was designed to perform a comprehensive proteomic analysis of monocytes in combination with functional bioinformatics. In addition, a targeted investigation of oxidative stress- and inflammatory-related factors to explore CKD-associated atherosclerosis was applied. Dysregulation of proteins involved in lipid oxidation, cell survival, ROS synthesis and metabolism, and inflammatory responses has been revealed. The characteristic disturbances in the monocyte proteome changed with the progression of CKD. A closer examination of oxidative stress's triggers, mediators, and effects on protein and lipid levels showed alterations in the oxidative imbalance between CKD and CVD. CKD monocytes demonstrated a significant increase of oxidized glutathione without changing the level of its reduced form. Evaluation of enzymatic antioxidants, sources of ROS, and modifications caused by ROS also revealed significant alterations between the study groups. In CKD, inflammation and oxidative imbalance correlated and drove each other. However, in CVD, oxidative stress-related factors were associated with each other but not to inflammatory proteins. Moreover, lipid abnormalities were more specific to classical CVD and unrelated to CKD. Such a comprehensive characterization of monocytes and oxidative stress in CKD and CVD patients has never been presented so far. Obtained results support the involvement of distinct mechanisms underlying the acceleration of atherosclerotic and non-atherosclerotic CKD.

Advances in the molecular mechanisms of statins in regulating endothelial nitric oxide bioavailability: Interlocking biology between eNOS activity and L-arginine metabolism

Statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A, are widely used to treat hypercholesterolemia. In addition, statins have been suggested to reduce the risk of cardiovascular events owing to their pleiotropic effects on the vascular system, including vasodilation, anti-inflammation, anti-coagulation, anti-oxidation, and inhibition of vascular smooth muscle cell proliferation. The major beneficial effect of statins in maintaining vascular homeostasis is the induction of nitric oxide (NO) bioavailability by activating endothelial NO synthase (eNOS) in endothelial cells. The mechanisms underlying the increased NO bioavailability and eNOS activation by statins have been well-established in various fields, including transcriptional and post-transcriptional regulation, kinase-dependent phosphorylation and protein-protein interactions. However, the mechanism by which statins affect the metabolism of L-arginine, a precursor of NO biosynthesis, has rarely been discussed. Autophagy, which is crucial for energy homeostasis, regulates endothelial functions, including NO production and angiogenesis, and is a potential therapeutic target for cardiovascular diseases. In this review, in addition to summarizing the molecular mechanisms underlying increased NO bioavailability and eNOS activation by statins, we also discuss the effects of statins on the metabolism of L-arginine.

Randomized Clinical Trial of Antioxidant Therapy Patients with Septic Shock and Organ Dysfunction in the ICU: SOFA Score Reduction by Improvement of the Enzymatic and Non-Enzymatic Antioxidant System

BACKGROUND AND AIM

Here, we assess the effect of adjuvant antioxidant therapies in septic shock patients with organ dysfunction and their effect on the enzymatic and non-enzymatic antioxidant systems.

METHODS

Randomized clinical trial run between 2018 and 2022. One hundred and thirty-one patients with septic shock were included in five groups with 25, 27, 24, 26 and 29 patients each. Group 1 received vitamin C (Vit C), Group 2 vitamin E (Vit E), Group 3 n-acetylcysteine (NAC), Group 4 melatonin (MT) and group 5 no treatment. All antioxidants were administered orally or through a nasogastric tube for 5 days as an adjuvant to standard therapy.

RESULTS

All patients had multiple organ failure (MOF) and low Vit C levels. Vit C therapy decreased CRP, PCT and NO₃^-/NO₂^- but increased Vit C levels. The SOFA score decreased with MT in 75%, Vit C 63% and NAC 50% vs. controls 33% (p = 0.0001, p = 0.03 and p = 0.001 respectively). MT diminished lipid peroxidation (LPO) (p = 0.01) and improved total antioxidant capacity (TAC) (p = 0.04). Vit E increased thiol levels (p = 0.02) and tended to decrease LPO (p = 0.06). Selenium levels were decreased in the control group (p = 0.04).

CONCLUSIONS

Antioxidants used as an adjuvant therapy in the standard treatment of septic shock decrease MOF and oxidative stress markers. They increase the TAC and thiols, and maintain selenium levels.

NRF2 Genetic Polymorphism Modifies the Association of Plasma Selenium Levels With Incident Coronary Heart Disease Among Individuals With Type 2 Diabetes

Plasma selenium and NRF2 promoter variants (e.g., rs6721961) are associated with cardiovascular disease risk in the general population. However, epidemiological evidence on the interaction between plasma selenium and NRF2 genetic susceptibility in relation to incident coronary heart disease (CHD) risk remains scarce, especially among individuals with type 2 diabetes (T2D). Thus, we examined whether rs6721961 in the NRF2 gene might modify the association between plasma selenium levels and incident CHD risk among people with T2D. During a mean (SD) follow-up period of 6.90 (2.96) years, 798 incident CHD cases were identified among 2,251 T2D cases. Risk-allele carriers of rs6721961 had a higher risk of incident CHD among people with T2D (adjusted hazard ratio [HR] 1.17; 95% CI 1.02-1.35) versus nonrisk-allele carriers. Each 22.8-μg/L increase in plasma selenium levels was associated with a reduced risk of incident CHD among risk-allele carriers with T2D (HR 0.80; 95% CI 0.71-0.89), whereas no association was found in those without risk alleles (P for interaction = 0.004), indicating that the NRF2 promoter polymorphism might modify the association between plasma selenium levels and incident CHD risk among people with T2D. Our study findings suggest redox-related genetic variants should be considered to identify populations that might benefit most from selenium supplementation. More mechanistic studies are warranted.

Examining the expression levels of ferroptosis-related genes in angiographically determined coronary artery disease patients

BACKGROUND

Cardiovascular diseases are the leading cause of death worldwide, with several conditions being affected by oxidative stress. Ferroptosis, recently identified programmed cell death mechanism, is relies on oxidative stress. This study aimed to determine the expressions of the genes involved in the molecular pathways of oxidative stress and ferroptosis and the association of these genes with CAD risk factors in CAD and non-CAD individuals.

METHODS AND RESULTS

The blood samples of individuals who underwent coronary angiography were collected and divided according to CAD status. Total RNA isolation was performed using the PAXgene RNA isolation kit from the whole blood samples. The mRNA expression levels of RTN3, GPX4, CAT, HMOX1, ELOVL5, SLC25A1, SLC7A11, and ACSL4 genes were determined using Real-Time PCR. Biochemical analyses were done before coronary angiography, and the results were evaluated statistically. The expression levels of the CAT gene are significantly lower in the CAD group when compared to non-CAD. HMOX1 expression levels are positively correlated with stenosis percentage, Gensini, and SYNTAX scores in the CAD group. RTN3, SLC25A1, and GPX4 mRNA expressions are correlated with HDL-C levels. Moreover, HbA1c levels and BMI, correlate negatively with ACSL4 expression in non-CAD controls. Also, ELOVL5 expression is negatively correlated with total bilirubin and direct bilirubin levels in the CAD group.

CONCLUSIONS

In this study, the genes related to oxidative stress and ferroptosis were found associated with biochemical parameters associated with CAD risk. These preliminary results may provide a new perspective to further studies investigating the reasons behind the identified associations.

The Interplay of Hypoxia Signaling on Mitochondrial Dysfunction and Inflammation in Cardiovascular Diseases and Cancer: From Molecular Mechanisms to Therapeutic Approaches

Simple Summary

The regulation of hypoxia has recently emerged as having a central impact in mitochondrial function and dysfunction in various diseases, including the major disorders threatening worldwide: cardiovascular diseases and cancer. Despite the studies in this matter, its effective role in protection and disease progression even though its direct molecular mechanism in both disorders is still to be elucidated. This review aims to cover the current knowledge about the effect of hypoxia on mitochondrial function and dysfunction, and inflammation, in cardiovascular diseases and cancer, and reports further therapeutic strategies based on the modulation of hypoxic pathways.

Abstract

Cardiovascular diseases (CVDs) and cancer continue to be the primary cause of mortality worldwide and their pathomechanisms are a complex and multifactorial process. Insufficient oxygen availability (hypoxia) plays critical roles in the pathogenesis of both CVDs and cancer diseases, and hypoxia-inducible factor 1 (HIF-1), the main sensor of hypoxia, acts as a central regulator of multiple target genes in the human body. Accumulating evidence demonstrates that mitochondria are the major target of hypoxic injury, the most common source of reactive oxygen species during hypoxia and key elements for inflammation regulation during the development of both CVDs and cancer. Taken together, observations propose that hypoxia, mitochondrial abnormality, oxidative stress, inflammation in CVDs, and cancer are closely linked. Based upon these facts, this review aims to deeply discuss these intimate relationships and to summarize current significant findings corroborating the molecular mechanisms and potential therapies involved in hypoxia and mitochondrial dysfunction in CVDs and cancer.

Associations of Antioxidant Enzymes with the Concentration of Fatty Acids in the Blood of Men with Coronary Artery Atherosclerosis

Objective: To identify associations of fatty acids (FAs) with the antioxidant enzymes in the blood of men with coronary atherosclerosis and ischemic heart disease (IHD). Methods: The study included 80 patients: control group—20 men without IHD, the core group—60 men with IHD. The core group was divided into subgroups: subgroup A—with the presence of vulnerable atherosclerotic plaques, subgroup B—with the absence of vulnerable atherosclerotic plaques. We analyzed the levels of FAs, free radicals, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the blood. Results. Patients with IHD, compared with the control group: (1) had higher levels of SOD, CAT, myristic, palmitic, palmitoleic, and octadecenoic FAs; (2) had lower levels of GPx, α-linolenic, docosapentaenoic, docosahexaenoic, and arachidonic FAs. In subgroup A there were found: (1) negative associations of SOD—with linoleic, eicosatrienoic, arachidonic, eicosapentaenoic, docosapentaenoic and docosahexaenoic FAs, positive associations—with palmitic acid; (2) positive correlations of CAT level with palmitoleic and stearic acids; (3) negative associations between of GPx and palmitic, palmitoleic, stearic and octadecenoic FAs. Conclusions: Changes in the levels of antioxidant enzymes, and a disbalance of the FAs profile, probably indicate active oxidative processes in the body and may indicate the presence of atherosclerotic changes in the vessels.

A Systematic Review and Meta-Analysis of the Effect of Statins on Glutathione Peroxidase, Superoxide Dismutase, and Catalase

Statins may exert protective effects against oxidative stress by upregulating specific antioxidant mechanisms. We conducted a systematic review and meta-analysis of the effect of statins on three key antioxidant enzymes: glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase. The electronic databases PubMed, Web of Science, and Scopus were searched from inception to July 2021. The risk of bias was assessed with the Joanna Briggs Institute Critical Appraisal Checklist and certainty of evidence was assessed using the GRADE framework. In 15 studies, reporting 17 treatment arms in 773 patients (mean age 53 years, 54% males), statins significantly increased the concentrations of both GPx (standardized mean difference, SMD = 0.80, 95% confidence interval, CI 0.13 to 1.46, p = 0.018; high certainty of evidence) and SOD (SMD = 1.54, 95% CI 0.71 to 2.36, p < 0.001; high certainty of evidence), but not catalase (SMD = −0.16, 95% CI −0.51 to 0.20, p = 0.394; very low certainty of evidence). The pooled SMD values were not altered in sensitivity analysis. There was no publication bias. In conclusion, statin treatment significantly increases the circulating concentrations of GPx and SOD, suggesting an antioxidant effect of these agents (PROSPERO registration number: CRD42021271589).

Glutathione Peroxidase Activity Is Altered in Vascular Cognitive Impairment-No Dementia and Is a Potential Marker for Verbal Memory Performance

Background:

Coronary artery disease (CAD) increases risk for vascular cognitive impairment-no dementia (VCIND), a precursor to dementia, potentially through persistent oxidative stress.

Objective:

This study assessed peripheral glutathione peroxidase activity (GPX), which is protective against oxidative stress, in VCIND versus cognitively normal CAD controls (CN). GPX activity was also evaluated as a biomarker of cognition, particularly verbal memory.

Methods:

120 CAD patients with VCIND (1SD below norms on executive function or verbal memory (VM)) or without (CN) participated in exercise rehabilitation for 24 weeks. Neurocognitive and cardiopulmonary fitness (VO_2peak) assessments and plasma were collected at baseline and 24-weeks.

Results:

GPX was higher in VCIND compared to CN (F_1,119 = 3.996, p = 0.048). Higher GPX was associated with poorer baseline VM (β= –0.182, p = 0.048), and longitudinally with VM decline controlling for sex, body mass index, VO_2peak, and education (b[SE] = –0.02[0.01], p = 0.004). Only CN participants showed improved VM performance with increased fitness (b[SE] = 1.30[0.15], p < 0.005).

Conclusion:

GPX was elevated in VCIND consistent with a compensatory response to persistent oxidative stress. Increased GPX predicted poorer cognitive outcomes (verbal memory) in VCIND patients despite improved fitness.

Antioxidant and the ameliorating effect of Allium cepa (Onion) fortified feed against potassium bromate induced oxidative damage in Wistar rats

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Allium cepa fortified feed protected against oxidative damage by potassium bromate.

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Malondialdehyde (MDA) levels in the hepato-renal declined significantly in rat fed fortified feed.

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Histo-architectural of hepato-renal cells were restored to near normal following the administration of fortified feed.

Allium cepa Linn (Onion) Organosulfuric compounds and phytonutrients have medicinal benefits. The study estimated the antioxidant effect of Allium cepa in fortified feed against oxidative damage caused by potassium bromate. Commercial feed was fortified by substituting 10 %, 20 %, and 30 % of rat's daily ration with the respective portion of pulverized Allium cepa. Potassium bromate was administered orally to the rats in all the groups except rats in the normal control. The rats in the test groups were allowed access to the fortified feed ad libitum. The animals were sacrificed; consequently, the serum, liver, and kidney were obtained for biochemical assay and histological assessment. The percentage composition of some amino acids and some proximate were higher in the fortified feed. Furthermore, Malondialdehyde (MDA) level in the liver, kidney, and serum decreased significantly (P ≤ 0.05) in rats fed with fortified feed compared to administered only Potassium bromate. Similarly, the concentration of total protein increased significantly (P ≤ 0.05) in the liver, kidney, and serum of the animals fed with fortified feed. The hematology result was normal in rats fed with fortified feed. The liver and kidney cell architecture was normal in animals fed with fortified feed. Allium cepa may have conferred protection and amelioration to oxidative damage by potassium bromate in rats.

Common and Novel Markers for Measuring Inflammation and Oxidative Stress Ex Vivo in Research and Clinical Practice-Which to Use Regarding Disease Outcomes?

Many chronic conditions such as cancer, chronic obstructive pulmonary disease, type-2 diabetes, obesity, peripheral/coronary artery disease and auto-immune diseases are associated with low-grade inflammation. Closely related to inflammation is oxidative stress (OS), which can be either causal or secondary to inflammation. While a low level of OS is physiological, chronically increased OS is deleterious. Therefore, valid biomarkers of these signalling pathways may enable detection and following progression of OS/inflammation as well as to evaluate treatment efficacy. Such biomarkers should be stable and obtainable through non-invasive methods and their determination should be affordable and easy. The most frequently used inflammatory markers include acute-phase proteins, essentially CRP, serum amyloid A, fibrinogen and procalcitonin, and cytokines, predominantly TNFα, interleukins 1β, 6, 8, 10 and 12 and their receptors and IFNγ. Some cytokines appear to be disease-specific. Conversely, OS-being ubiquitous-and its biomarkers appear less disease or tissue-specific. These include lipid peroxidation products, e.g., F2-isoprostanes and malondialdehyde, DNA breakdown products (e.g., 8-OH-dG), protein adducts (e.g., carbonylated proteins), or antioxidant status. More novel markers include also -omics related ones, as well as non-invasive, questionnaire-based measures, such as the dietary inflammatory-index (DII), but their link to biological responses may be variable. Nevertheless, many of these markers have been clearly related to a number of diseases. However, their use in clinical practice is often limited, due to lacking analytical or clinical validation, or technical challenges. In this review, we strive to highlight frequently employed and useful markers of inflammation-related OS, including novel promising markers.

Dietary Strategies by Foods with Antioxidant Effect on Nutritional Management of Dyslipidemias: A Systematic Review

Nutrition plays a fundamental role in the prevention and treatment of dyslipidemias and its oxidative-related complications. Currently, there is evidence about the beneficial effects of isolated antioxidants or foods enriched or added with antioxidant compounds. However, the application of the natural foods is more integrated than the analysis of a single nutrient. Our aim is compiling scientific literature regarding the nutritional strategies by foods with antioxidant effect in blood lipids, enzymatic and non-enzymatic antioxidants, and oxidative and inflammatory markers of subjects with dyslipidemia. We searched in MEDLINE/PubMed, Scopus, and Web of Science. From a total of 263 studies screened, 16 were included. Dietary strategies included walnuts, olive oil, raw almonds, G. paraguayase, white sesame, mate tea, Brazil nut flour, red wine, granulated Brazil nuts, grapes, wolfberry fruit, fermented beverage, coffee, orange, and blackberry juices showed significant differences in blood lipids, antioxidant activity, antioxidant enzymes, and oxidative and inflammatory markers. This systematic review compiling scientific studies about dietary strategies using foods with antioxidant effect to improve the antioxidant status in dyslipidemias.

Berry-Derived Polyphenols in Cardiovascular Pathologies: Mechanisms of Disease and the Role of Diet and Sex

Cardiovascular disease (CVD) prevalence, pathogenesis, and manifestation is differentially influenced by biological sex. Berry polyphenols target several signaling pathways pertinent to CVD development, including inflammation, oxidative stress, and cardiac and vascular remodeling, and there are innate differences in these pathways that also vary by sex. There is limited research systematically investigating sex differences in berry polyphenol effects on these pathways, but there are fundamental findings at this time that suggest a sex-specific effect. This review will detail mechanisms within these pathological pathways, how they differ by sex, and how they may be individually targeted by berry polyphenols in a sex-specific manner. Because of the substantial polyphenolic profile of berries, berry consumption represents a promising interventional tool in the treatment and prevention of CVD in both sexes, but the mechanisms in which they function within each sex may vary.

Serum Total Antioxidant Capacity and Enzymatic Defence of Dogs with Chronic Heart Failure and Atrial Fibrillation: A Preliminary Study

Introduction

Atrial fibrillation may potentially contribute to oxidative stress to a greater extent than chronic heart failure. The aim of the study was to compare the serum total antioxidant capacity and enzymatic antioxidant defence of dogs with chronic heart failure and atrial fibrillation with those of subjects with chronic heart failure and sinus rhythm and healthy controls.

Material and Methods

A total of 33 dogs were divided into three groups: dogs with chronic heart failure and atrial fibrillation (CHF + AF; n = 12), chronic heart failure and sinus rhythm (CHF + SR; n = 9), and healthy controls (n = 12). Serum total antioxidant capacity (TAC), serum CuZn-superoxide dismutase (SOD) and catalase, and plasma glutathione peroxidase (GPx) activity were determined.

Results

SOD activity and serum TAC were significantly lower in the study groups than in control animals. Catalase activity was significantly higher and plasma GPx activity significantly lower in dogs with CHF + AF compared with the CHF + SR and control dogs.

Conclusion

The results suggest that chronic heart failure in dogs significantly impacts the serum TAC and the antioxidant enzymatic defence, while plasma GPx activity is markedly lower in dogs with chronic heart failure and atrial fibrillation. The role of that imbalance needs further investigation.

Sex Differences in Glutathione Peroxidase Activity and Central Obesity in Patients with Type 2 Diabetes at High Risk of Cardio-Renal Disease

Women with type 2 diabetes (T2DM) have an increased susceptibility of developing cardio-renal disease compared to men, the reasons and the mechanisms of this vulnerability are unclear. Since oxidative stress plays a key role in the development of cardio-renal disease, we investigated the relationship between sex, plasma antioxidants status (glutathione peroxidase (GPx-3 activity), vitamin E and selenium), and adiposity in patients with T2DM at high risk of cardio-renal disease. Women compared to men had higher GPx-3 activity (p = 0.02), bio-impedance (p ≤ 0.0001), and an increase in waist circumference in relation to recommended cut off-points (p = 0.0001). Waist circumference and BMI were negatively correlated with GPx-3 activity (p ≤ 0.05 and p ≤ 0.01, respectively) and selenium concentration (p ≤ 0.01 and p ≤ 0.02, respectively). In multiple regression analysis, waist circumference and sex were independent predictors of GPx-3 activity (p ≤ 0.05 and p ≤ 0.05, respectively). The data suggest that increased central fat deposits are associated with reduced plasma antioxidants which could contribute to the future risk of cardio-renal disease. The increased GPx-3 activity in women could represent a preserved response to the disproportionate increase in visceral fat. Future studies should be aimed at evaluating if the modulation of GPx-3 activity reduces cardio-renal risk in men and women with T2DM.

Optogenetic Medicine: Synthetic Therapeutic Solutions Precision-Guided by Light

Gene- and cell-based therapies are well recognized as central pillars of next-generation medicine, but controllability remains a critical issue for clinical applications. In this context, optogenetics is opening up exciting new opportunities for precision-guided medicine by using illumination with light of appropriate intensity and wavelength as a trigger signal to achieve pinpoint spatiotemporal control of cellular activities, such as transgene expression. In this review, we highlight recent advances in optogenetics, focusing on devices for biomedical applications. We introduce the construction and applications of optogenetic-based biomedical tools to treat neurological diseases, diabetes, heart diseases, and cancer, as well as bioelectronic implants that combine light-interfaced electronic devices and optogenetic systems into portable personalized precision bioelectronic medical tools. Optogenetics-based technology promises the capability to achieve traceless, remotely controlled precision dosing of an enormous range of therapeutic outputs. Finally, we discuss the prospects for optogenetic medicine, as well as some emerging challenges.

Trolox prevents high glucose-induced apoptosis in rat myocardial H9c2 cells by regulating GLUT-4 and antioxidant defense mechanism

Redox imbalance due to hyperglycemia is a causative factor for an increased generation of reactive oxygen species (ROS) that leads to mitochondrial dysfunction and the release of cytochrome-c. The aim of the present study is to elucidate the functional role of oxidative stress (OS) in the induction of apoptosis in H9c2 cells in the hyperglycemic state through glucose transporter-4 (GLUT-4) regulation and antioxidant status. H9c2 cells were incubated with 15, 24, and 33 mM glucose for 24, 48, and 72 hr to induce hyperglycemic stress. Hyperglycemic episodes have significantly influenced GLUT-4 mRNA regulation, depleted glutathione (GSH) and its associated enzymes, reduced cellular antioxidant enzymes (AOEs), caused nuclear condensation, and induced apoptosis by activating caspase-9 and 3 and annexin V binding in a concentration and duration-dependent manner. Trolox pretreatment significantly enhanced the GLUT-4 mRNA and antioxidant defense mechanism, suppressed nuclear condensation, and prevented cytochrome-c release, thereby reducing mitochondrial-dependent apoptosis. The present study shows that the toxic effect of high glucose is significantly regulated and that OS induction can be prevented through a water-soluble vitamin E analog "Trolox" treatment.

Selenium and selenoproteins: from endothelial cytoprotection to clinical outcomes

The role of the vascular endothelium in inflammation was demonstrated experimentally through biomarkers of endothelial dysfunction and cytoprotection. Selenium is a trace element essential for cell protection against oxidative lesions triggered by reactive oxygen species or inflammatory responses. Preclinical studies have demonstrated a relationship between adhesion molecules as biomarkers of endothelial dysfunction and selenoproteins as biomarkers of selenium status under conditions that mimic different diseases. Most studies in humans indicate an association between selenium deficiency and increased risk of morbidity and mortality, yet the pathophysiology of selenium in endothelial activation remains unknown. Here, we summarize selenium-dependent endothelial function evaluation techniques and focus on the role of selenium in endothelial cytoprotection according to current scientific knowledge. Most studies on the role of selenium in endothelial processes show selenium-dependent endothelial functions and explain how cells and tissues adapt to inflammatory insults. Taken together, these studies show an increase in adhesion molecules and a decrease in the expression of selenoproteins following a decreased exposure to selenium. Few clinical trials have enough methodological quality to be included in meta-analysis on the benefits of selenium supplementation. Furthermore, the methodology adopted in many studies does not consider the relevant findings on the pathophysiology of endothelial dysfunction. Preclinical studies should be more frequently integrated into clinical studies to provide clearer views on the role of selenium status in endothelial cytoprotection.

Influence of mTOR signaling pathway on ketamine-induced injuries in the hippocampal neurons of rats

OBJECTIVE

To explore the influences of mammalian target of rapamycin (mTOR) signaling pathway on ketamine-induced apoptosis, oxidative stress and Ca²⁺ concentration in the hippocampal neurons of rats.

METHODS

The primary hippocampal neurons isolated from fetal Sprague Dawley rats were treated with ketamine (0, 50, 100 and 500 μM) for 4 days to observe its effect on mTOR signaling pathway and apoptosis of rat hippocampal neurons. Then, the hippocampal neurons were divided into C (Control), R (Rapamycin, an inhibitor of mTOR signaling pathway), K (Ketamine) and R + K (Rapamycin + Ketamine) groups to detect the apoptosis, reactive oxygen species (ROS) production, and Ca²⁺ concentration via the terminal transferase uridyl nick end labelling (TUNEL) assay, dichloro-dihydro-fluorescein diacetate (DCFH-DA) method and Fluo-3 acetoxymethyl ester (Fluo-3AM) staining, respectively. The expressions of mTOR signaling pathway and apoptosis-related proteins in hippocampal neurons were examined by qRT-PCR and Western blot.

RESULTS

Ketamine could dose-dependently promote the apoptosis of rat hippocampal neurons with upregulation of p-mTOR and its downstream regulators (p-4E-BP-1 and p-p70S6K). However, ketamine-induced apoptosis in hippocampal neurons was reversed significantly by the administration of rapamycin, as evident by the decrease in expressions of pro-apoptotic proteins (Bax and cleaved Caspase-3) and the increase in anti-apoptotic protein (Bcl-2). Meanwhile, the ROS generation and Ca²⁺ concentration was inhibited accompanied with reduced malonildialdehyde levels but elevated superoxide and glutathione peroxidase activities.

CONCLUSION

Inhibition of mTOR signaling pathway protected rat hippocampal neurons from ketamine-induced injuries via reducing apoptosis, oxidative stress, as well as Ca²⁺ concentration.

ABBREVIATIONS

mTOR: mammalian target of rapamycin; SD: Sprague-Dawley; SPF: Specific-pathogen free; ROS: reactive oxygen species; TUNEL: terminal transferase uridyl nick end labelling; DCFH-DA: Dichloro-dihydro-fluorescein diacetate; Fluo-3A: Fluo-3 acetoxymethyl ester; NMDAR: non-competitive N-methyl-D-aspartame glutamate receptor; 4E-BP1: 4E binding protein 1; p70S6K: p70 S6 Kinase; PCR: Polymerase chain reaction; MDA: malonildialdehyde; GSH-PX: glutathione peroxidase; ANOVA: One-way Analysis of Variance.

Association between Polymorphisms of Antioxidant Gene (MnSOD, CAT, and GPx1) and Risk of Coronary Artery Disease

Objective

Reactive oxygen species (ROS) been cited as one of the major causes of atherosclerosis and coronary artery disease which are possible agents inducing DNA damage. Manganese superoxide dismutase (MnSOD), catalase (CAT), and glutathione peroxidase-1 (GPx1) have evolved to address primary defense against free radical mediated damage in mitochondria. The aim of this study was to delineate the association of MnSOD, CAT, and GPx1 polymorphisms and risk of CAD in Taiwan.

Methods

We conducted a case-control study with 657 participants recruited at a medical center. All subjects were evaluated by noninvasive stress test and then quantitative coronary angiography to confirm the diagnosis of CAD. 447 CAD cases were defined as >50% stenosis of coronary artery and 210 controls were stenosed below 50%. Polymorphisms of MnSOD (Val16Ala), CAT (C-262T), and GPx1 (Pro198Leu) genes were determined by polymerase chain reaction methods. Multivariate logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs).

Results

The MnSOD Val/Ala+Ala/Ala genotype was significantly associated with an increased risk of CAD compared to the Val/Val genotype (OR = 1.86, 95% CI = 1.15-3.01). This polymorphism was also associated with the severity of CAD of single and two vessel diseases. The corresponding ORs were 2.31 (95% CI = 1.32-4.03) and 1.92 (95% CI = 1.02-3.61), respectively. Among cigarette smokers, the harmful genetic effect of MnSOD Ala allele on CAD risk was much higher (OR = 2.23, 95% CI = 1.02-4.88). However, the interaction between MnSOD genotype and cigarette smoking on CAD risk was not significant. No significant association between CAT and GPx1 polymorphisms and CAD risk was observed.

Conclusion

Our results suggest that MnSOD polymorphism is an independent risk factor for susceptibility to CAD in the Chinese population.

The protective effects of selenium supplementation on ambient PM2.5-induced cardiovascular injury in rats

Substantial epidemiological and experimental studies have shown that ambient fine particulate matter (PM_2.5) exposure can lead to myocardial damage in human and animal through the mechanism of inflammation and oxidative stress. The purpose of the current study was to investigate whether selenium yeast (SeY) supplementation could prevent cardiovascular injury caused by PM_2.5 in rats. Fifty-six Sprague-Dawley rats were randomly divided into seven groups: saline control group; solvent control group, low-, middle-, and high-dose Se pretreatment groups, PM_2.5 exposure group, and high-dose Se control group. The rats were pretreated with different concentration of dietary SeY for 28 days, then were exposed to PM₂.₅ by intratracheal instillation every other day, a total of three times. The levels of inflammatory markers (tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), soluble intercellular adhesion molecule-1 (sICAM-1), and oxidative responses-related indicators total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) were measured in blood and myocardium of the left ventricle. The results showed that although PM_2.5 caused a decrease of T-AOC, T-AOD, and GSH-Px and increase of MDA and sICM-1, pretreatment with SeY induced a dose-dependent increase in these anti-oxidative indicators and a decrease in oxidative indicators. In addition, the levels of TNF-α and IL-1β in Se pretreatment groups were significantly lower than that in PM_2.5 exposure group. The results indicated that Se supplementation could effectively prevent cardiovascular inflammation and oxidative stress induced by PM_2.5. The results also indicated that the nutritional supplementation might be an effective way to protecting people's health from air pollution.

Prediction of coronary disease incidence by biomarkers of inflammation, oxidation, and metabolism

The effect of circulating biomarkers in predicting coronary artery disease (CAD) is not fully elucidated. This study aimed to determine the relationship with CAD and the predictive capacity of nine biomarkers of inflammation (TNF-α, IL-10, IL-6, MCP-1, CRP), oxidation (GHS-Px), and metabolism (adiponectin, leptin, and insulin). This was a case-cohort study, within the REGICOR population-cohorts (North-Eastern Spain), of 105 CAD cases and 638 individuals randomly selected from a cohort of 5,404 participants aged 35–74 years (mean follow-up = 6.1 years). Biomarkers’ hazard ratio (HR)/standard deviation was estimated with Cox models adjusted for age, sex, and classical risk factors. Discrimination improvement and reclassification were analyzed with the c-index and the Net reclassification index (NRI). GHS-Px (adjusted HRs = 0.77; 95%CI:0.60–0.99), insulin (1.46; 1.08–1.98), leptin (1.40; 1.03–1.90), IL-6 (1.34; 1.03–1.74), and TNF-α (1.80; 1.26–2.57) were significantly associated with CAD incidence. In the model adjusted for all biomarkers, TNF-α (1.87;1.31–2.66) and insulin (1.59;1.16–2.19) were independently associated with CAD. This final model, compared to a model without biomarkers, showed a c-index difference of 1.3% (−0.7, 3.2) and a continuous NRI of 33.7% (2.6, 61.9). TNF-α and insulin are independently associated with CAD incidence and they improve reclassification when added to a model including classical risk factors.

Selenium in the prevention of atherosclerosis and its underlying mechanisms

Atherosclerosis and related cardiovascular diseases (CVDs) represent the greatest threats to human health worldwide. Selenium, an essential trace element, is incorporated into selenoproteins that play a crucial role in human health and disease. Although findings from a limited number of randomized trials have been inconsistent and cannot support a protective role of Se supplementation in CVDs, prospective observational studies have generally shown a significant inverse association between selenium or selenoprotein status and CVD risk. Furthermore, a benefit of selenium supplementation in the prevention of CVDs has been seen in population with low baseline selenium status. Evidence from animal studies shows consistent results that selenium and selenoproteins might prevent experimental atherosclerosis, which can be explained by the molecular and cellular effects of selenium observed both in animal models and cell cultures. Selenoproteins of particular relevance to atherosclerosis are glutathione peroxidases, thioredoxin reductase 1, selenoprotein P, selenoprotein S. The present review is focusing on the existing evidence that supports the concept that optimal selenium intake can prevent atherosclerosis. Its underlying mechanisms include inhibiting oxidative stress, modulating inflammation, suppressing endothelial dysfunction, and protecting vascular cells against apoptosis and calcification. However, the benefit of selenium supplementation in the prevention of atherosclerosis remains insufficiently documented so far. Future studies with regard to the effects of selenium supplementation on atherosclerosis should consider many factors, especially the baseline selenium status, the dose and forms of selenium supplementation, and the selenoprotein genotype. Additionally, much more studies are needed to confirm the roles of selenoproteins in atherosclerosis prevention and clarify the underlying mechanisms.

Plasma coenzyme Q10 concentration, antioxidant status, and serum N-terminal pro-brain natriuretic peptide concentration in dogs with various cardiovascular diseases and the effect of cardiac treatment on measured variables

OBJECTIVE To determine the plasma total antioxidant capacity, erythrocyte superoxide dismutase activity, whole blood glutathione peroxidase activity, and plasma coenzyme Q₁₀ (CoQ₁₀) concentration in dogs with various stages of cardiovascular diseases and in healthy dogs; assess the influence of cardiac treatment on the levels of antioxidant variables, plasma CoQ₁₀ concentration, and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration, and determine any correlation between the disease severity (NT-proBNP concentration) and antioxidant variables or CoQ₁₀ concentration. ANIMALS 43 dogs with various types and stages of cardiovascular diseases (congenital and acquired) and 29 healthy dogs. PROCEDURES Blood samples were collected from all dogs for spectrophotometric assessment of antioxidant variables. Plasma CoQ₁₀ concentration was determined with a high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry method. Serum NT-proBNP concentration was measured with an ELISA. RESULTS Values for antioxidant variables did not differ among groups of dogs with cardiovascular diseases, regardless of disease stage or treatment. Plasma CoQ₁₀ concentration was significantly increased in treated dogs with congestive heart failure (CHF), compared with untreated patients. However, plasma CoQ₁₀ concentration did not differ among heart failure classes. A significant, negative correlation between serum NT-proBNP and plasma CoQ₁₀ concentrations was identified in treated CHF-affected dogs, suggesting that low plasma CoQ₁₀ concentration may be associated with increased severity of CHF. CONCLUSIONS AND CLINICAL RELEVANCE The antioxidant variables evaluated were not altered in dogs with CHF, regardless of cardiac disease stage or treatment. Further investigation into the possible effects of CoQ₁₀ supplementation in dogs with advanced stages of CHF is warranted.

Case control feasibility study assessing the association between severity of coronary artery disease with Glutathione Peroxidase-1 (GPX-1) and GPX-1 polymorphism (Pro198Leu)

Background

Glutathione peroxidase-1 (GPX-1) activity was reported to be useful marker for monitoring cardiovascular disease. However, accurate assessment of coronary artery disease (CAD) using GPX-1 polymorphism is limited for South Asian population. Present study aim to assess GPX-1activity and GPX-1 polymorphismin patients with coronary artery disease (CAD) who were confirmed with coronary angiography findings and in apparently healthy subjects.

Methods

Case control study was carried out with 85 patients (58 males and 27 females) 40–60 years of age confirmed as having CAD on coronary angiography findings and 85 age and sex matched healthy volunteers as controls. Blood samples were analyzed for erythrocyte GPX-1 activity and GPX-1 polymorphism in both groups and the severity of CAD was assessed using coronary angiography scoring system based on vessel, stenosis and extent score.

Results

Coronary angiography scores indicated that erythrocyteGPX-1 cutoff value of 23.9 U/gHb showed a high sensitivity and negative predictive value in ruling out major vessel disease. The GPX-1 Pro198Leu (CT) polymorphism was higher in patients with CAD (25.3 %) when compared to controls (10.7 %). Pro198Leu (CT) genotype showed a 2.84 fold risk for CAD [odds ratio 2.84 (95 % CI 1.15–6.98), p = 0.019].

Conclusion

Coronary angiography findings indicated that individuals possessing Pro198Leu (CT) polymorphism were found to be associated with low erythrocyte GPX-1 activity and increased susceptibility for CAD.

MnSOD and GPx1 polymorphism relationship with coronary heart disease risk and severity

BACKGROUND

Disturbance of the equilibrium between reactive oxygen species (ROS) and anti-oxidants (AOX) has been implicated in various diseases, including atherosclerosis, the most common pathologic process underlying coronary heart disease (CHD). Thus, the defense systems against ROS are critical protecting blood vessel walls against oxidative damage. In this study, we investigate whether Ala16Val MnSOD and Pro198Leu GPx polymorphisms are associated with CHD susceptibility and/or severity.

METHODS

Both polymorphisms were genotyped in a sample of 203 controls and 164 patients. CHD risk and severity, antioxidant status (enzymatic and/or non enzymatic) and biochemical parameters were assessed and analysed by genotype.

RESULTS

A significant association of MnSOD variant to CHD risk was revealed in males. Males harboring the Val/Val genotype were approximately at twofold increased risk of CHD compared to controls (Ala carriers vs Val/Val, adjusted OR 1.89; 95 % CI 1.18‒3.42, p = 0.03). Significant decreases in SOD activity and total antioxidant status (TAS) were observed in Val carriers and by CHD status. Whereas, no association of GPx variant genotype (Leu/Leu) and activity to cardiopathy events was discerned. CHD severity, as demonstrated by the number of vessel stenosis, was associated with significantly higher frequency of Val allele and LDL levels in CHD subjects.

CONCLUSIONS

Our results showed a lack of association of Pro198Leu GPx polymorphism to CHD risk and severity. However, they suggest that Ala16Val MnSOD polymorphism and decreased antioxidant defences are likely contributed to CHD risk in Tunisian men. Furthermore, the Val encoding MnSOD allele and decreased SOD activity were significantly correlated with CHD stenosis progression.

Biological Antioxidant Potential Negatively Correlates With Carotid Artery Intima-Media Thickness

Oxidative stress is a crucial factor in the pathogenesis and development of cardiovascular disease. Recently, simplified methods for the detection of reactive oxygen species (ROS) using the derivatives of reactive oxygen metabolites (d-ROMs) test as an index of ROS products and the biological antioxidant potential (BAP) test as an index of antioxidant potential have been utilized. These methods are easy to perform, quick, inexpensive since they use small equipment, and provide reliable results compared with established oxidative stress and antioxidant markers. Because oxidative stress has been shown to represent the balance of production of ROS and antioxidant capacity, it is more appropriate to evaluate ROS and antioxidant capacity simultaneously. However, no study has examined the associations among d-ROMs, BAP values, and carotid artery intima-media thickness (IMT) concurrently. Therefore, we studied the associations among d-ROMs, BAP values, and the carotid artery IMT. Carotid artery IMT, blood pressure (BP), fasting circulating d-ROMs, BAP, glucose metabolism, lipid, and C-reactive protein levels were measured in 95 subjects (age: 49.5 ± 13.8 years; men: 41; women: 54), including 42 healthy subjects and 53 patients with hypertension, dyslipidemia, and diabetes mellitus who were not on medication. The results of multiple regression analysis revealed that dependent carotid artery IMT determinants remained significantly associated with age, systolic BP, total cholesterol, and BAP, whereas dependent BAP determinants remained significantly associated with body mass index and carotid artery IMT. BAP was strongly correlated with carotid artery IMT in our cohort. Our results suggest that BAP may be a useful risk marker for carotid atherosclerosis.

Aspalathin, a dihydrochalcone C-glucoside, protects H9c2 cardiomyocytes against high glucose induced shifts in substrate preference and apoptosis

SCOPE

Energy deprivation in the myocardium is associated with impaired heart function. This study aims to investigate if aspalathin (ASP) can ameliorate hyperglycemic-induced shift in substrate preference and protect the myocardium against cell apoptosis.

METHODS AND RESULTS

H9c2 cells were exposed to, either normal (5.5 mM) or high (33 mM) glucose concentrations for 48 h. Thereafter, cells exposed to 33 mM glucose were treated with metformin (1 μM) or ASP (1 μM), as well as a combination of metformin and ASP for 6 h. In vitro studies revealed that ASP improved glucose metabolism by decreasing fatty acid uptake and subsequent β-oxidation through the decreased expression of adenosine monophosphate-activated protein kinase threonine 172 (pAMPK (Thr172)) and carnitine palmitoyltransferase 1 (CPT1), while increasing acetyl-CoA carboxylase (ACC) and glucose transporter 4 (GLUT4) expression. ASP inhibited high glucose induced loss of membrane potential in H9c2 cells as observed by an increase in 5' ,6,6'-tetrachloro-1,1',3,3' -tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) ratio (orange\red fluorescence) and decreased apoptosis by reducing intracellular reactive oxygen species and DNA nick formation, while increasing glutathione, superoxide dismutase, uncoupling protein 2 (UCP2), and Bcl-2\Bax ratio.

CONCLUSION

Our study provides evidence that ASP increases glucose oxidation and modulates fatty acid utilization producing a favorable substrate shift in H9c2 cardiomyocytes exposed to high glucose. Such a favorable shift will be of importance in the protection of cardiomyocytes in the diabetic heart.

Uric Acid and Coronary Artery Disease, Two Sides of a Single Coin: A Determinant of Antioxidant System or a Factor in Metabolic Syndrome

INTRODUCTION

Uric acid has antioxidant activity and it is expected to protect against coronary artery disease (CAD). Contradictory, it is a component of metabolic syndrome and so a risk factor for CAD. The associations of plasma total antioxidant capacity (TAOC) and uric acid (UA) as well as other risk factors were investigated relative to the occurrence and severity of CAD.

MATERIALS AND METHODS

The study population consisted of 148 males and 152 females aged 35-76 years who were classified as CAD cases and controls according to the results of coronary angiography. The severity of CAD was scored on the basis of the number and the extent of lesions at coronary arteries. The concentrations of UA and TAOC were measured by using of FRAP and enzymatic uricase methods.

RESULTS

The prevalence of hypertension, cigarette smoking and diabetes mellitus was more frequent in CAD cases than controls. Patients with CAD when compared with the controls had increased levels of glucose, triglycerides, creatinine, UA, TAOC and decreased levels of HDL- cholesterol. Serum UA was high positive correlate of serum total and LDL-cholesterol, triglyceride, creatinine, BUN, bilirubin, TAOC and negative correlate of glucose and HDL-C. TAOC and its major determinant UA but not bilirubin and albumin are significantly associated with the prevalence and severity of CAD. In multivariate analysis and in the absence of hypertension, UA but not TAOC would remain and be associated with CAD by the OR of 1.57 (1.07-2.29), p=0.02. If the results adjusted for all major risk factors including hypertension, neither TAOC nor UA would remain in the regression equation.

CONCLUSION

The results suggest that TAOC and UA but not bilirubin and albumin are associated with CAD significantly. But, the correlation is not independent and is attributed to the metabolic syndrome. The measurement of UA and TAOC will not improve the prognostic power beyond the classical risk factors.

Chronic selective serotonin reuptake inhibition modulates endothelial dysfunction and oxidative state in rat chronic mild stress model of depression

Major depression is known to be associated with cardiovascular abnormalities, and oxidative stress has been suggested to play a role. We tested the hypothesis that antidepressant treatment reduces oxidative stress and endothelial dysfunctions in the chronic mild stress (CMS) model of depression in rats. Rats with >30% reduction in sucrose intake after 4 wk of CMS were defined in the study as CMS-susceptible and compared with unstressed controls. Sixteen CMS-susceptible and eight unstressed rats were treated during weeks 5 to 8 of the CMS protocol with escitalopram. Escitalopram-treated rats with >20% recovery in the sucrose consumption during the last 2 wk of treatment were defined as escitalopram responders. Rats that did not reach these criteria were defined as escitalopram nonresponders. In the open field test, escitalopram responders demonstrated anxiolytic effect of treatment. In mesenteric small arteries, escitalopram affected neither NO nor cyclooxygenase-1 (COX-1)-mediated vasodilation. Escitalopram potentiated endothelium-dependent hyperpolarization-like response, which was suppressed in the vehicle-treated CMS-susceptible rats and reduced COX-2-dependent relaxation, which was elevated in the vehicle-treated CMS-susceptible rats. Escitalopram did not affect blood pressure and heart rate, which were elevated in the vehicle-treated CMS-susceptible rats. Oxidative stress markers were changed in association with CMS in liver, heart, and brain. Escitalopram normalized oxidative stress markers in the majority of tissues. This study demonstrates that the antidepressant effect of escitalopram is associated with partial improvement of endothelial function in small arteries affecting COX-2 and endothelium-dependent hyperpolarization-like pathways.

Amelioration of altered antioxidant enzyme activity by Satureja khuzistanica essential oil in alloxan-induced diabetic rats

AIM

To examine the possible protective effect of Satureja khuzistanica essential oil (SKE) on antioxidant enzyme activity in alloxan-induced Type 1 diabetic rats.

METHOD

Thirty Sprague-Dawley male rats were divided into three groups randomly; group one as control, group two diabetic, with no treatment, and group three treatment with SKE at 500 ppm in drinking water, respectively. Diabetes was induced in the second and third groups by alloxan injection subcutaneously. After eight weeks, animals were anaesthetized. Blood samples were also collected before killing to measure antioxidant enzymes activity.

RESULTS

SKE significantly increased the serum level of glutathione and the serum activity of glutathione peroxidase, superoxide dismutase, and catalase in the treated group compared with the diabetic untreated group.

CONCLUSION

The findings showed that SKE exerts beneficial effects on the antioxidant enzymes activity in alloxan-induced Type 1 diabetic rats.

Antioxidant activity and nutritional status in anorexia nervosa: effects of weight recovery

Few studies are focused on the antioxidant status and its changes in anorexia nervosa (AN). Based on the hypothesis that renutrition improves that status, the aim was to determine the plasma antioxidant status and the antioxidant enzymes activity at the beginning of a personalized nutritional program (T₀) and after recovering normal body mass index (BMI) (T₁). The relationship between changes in BMI and biochemical parameters was determined. Nutritional intake, body composition, anthropometric, hematological and biochemical parameters were studied in 25 women with AN (19.20 ± 6.07 years). Plasma antioxidant capacity and antioxidant enzymes activity were measured. Mean time to recover normal weight was 4.1 ± 2.44 months. Energy, macronutrients and micronutrients intake improved. Catalase activity was significantly modified after dietary intake improvement and weight recovery (T₀ = 25.04 ± 1.97 vs. T₁ = 35.54 ± 2.60μmol/min/mL; p < 0.01). Total antioxidant capacity increased significantly after gaining weight (T₀ = 1033.03 ± 34.38 vs. T₁ = 1504.61 ± 99.73 μmol/L; p < 0.01). Superoxide dismutase activity decreased (p < 0.05) and glutathione peroxidase did not change. Our results support an association between nutrition improvement and weight gain in patients with AN, followed by an enhancement of antioxidant capacity and catalase antioxidant system.

Effects of estrogen on glutathione and catalase levels in human erythrocyte during menstrual cycle

The present study evaluated the effects of physiological serum estrogen during the menstrual cycle on glutathione (GSH) and catalase activities. The sample included 43 healthy females between the ages of 22 and 51 years. The subjects were divided into two groups according to the stage of the menstrual cycle. Group A consisted of 16 samples extracted between days 10 and 20 from the first day of menstruation when estrogen levels were considered to be at their highest. Group B consisted of 27 samples extracted during other times of the estimated 30 days of menstruation. Data showed that the estrogen level in group A (184±106 pg/ml) was higher than that in group B (105±56 pg/ml) (P<0.01). The GSH and catalase levels in group A (4.4±2.3 µg/mg and 210±72 IU/mg, respectively) were also significantly higher compared to the levels in group B (3.2±1.8 µg/mg and 168±62 IU/mg, respectively) (P <0.05). Spearman's rank correlation showed that the expression of catalase in red blood cells significantly correlated with serum estrogen level but not with GSH. However, the changes in estrogen plasma levels, erythrocyte GSH level and catalase activity suggested that the consumption of GSH and catalase in erythrocyte during the menstrual cycle may be associated with the level of estrogen present in the bloodstream.

Erythrocyte superoxide dismutase, glutathione peroxidase, and catalase activities and risk of coronary heart disease in generally healthy women: a prospective study

Erythrocyte antioxidant enzymes are major circulating antioxidant enzymes in the oxidative stress defense system. Few prospective studies have assessed the association between these enzymes and the risk of coronary heart disease (CHD) in generally healthy adults. We conducted a prospective nested case-control study of CHD among 32,826 women at baseline with 15 years of follow-up from 1989 to 2004 in the Nurses' Health Study. We investigated the association of baseline erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities with the risk of CHD. A total of 365 cases and 728 controls were included in the analysis. Overall, the relative risks of CHD associated with 1-standard deviation higher SOD, GPx, and CAT activities were 1.07 (95% confidence interval (CI): 0.94, 1.22), 1.04 (95% CI: 0.91, 1.18), and 1.04 (95% CI: 0.92, 1.17), respectively. Multivariable adjustments did not change the associations appreciably. Fasting status did not modify the associations, with the exception that SOD activity was positively associated with the risk of CHD among participants who provided blood samples within 12 hours of fasting. Overall, activities of SOD, GPx, and CAT were not associated with CHD among women who were generally healthy at the time of blood collection.

Effects of oxidative stress on fatty acid- and one-carbon-metabolism in psychiatric and cardiovascular disease comorbidity

OBJECTIVE

Cardiovascular disease (CVD) is the leading cause of death in severe psychiatric disorders (depression, schizophrenia). Here, we provide evidence of how the effects of oxidative stress on fatty acid (FA) and one-carbon (1-C) cycle metabolism, which may initially represent adaptive responses, might underlie comorbidity between CVD and psychiatric disorders.

METHOD

We conducted a literature search and integrated data in a narrative review.

RESULTS

Oxidative stress, mainly generated in mitochondria, is implicated in both psychiatric and cardiovascular pathophysiology. Oxidative stress affects the intrinsically linked FA and 1-C cycle metabolism: FAs decrease in chain length and unsaturation (particularly omega-3 polyunsaturated FAs), and lipid peroxidation products increase; the 1-C cycle shifts from the methylation to transsulfuration pathway (lower folate and higher homocysteine and antioxidant glutathione). Interestingly, corresponding alterations were reported in psychiatric disorders and CVD. Potential mechanisms through which FA and 1-C cycle metabolism may be involved in brain (neurocognition, mood regulation) and cardiovascular system functioning (inflammation, thrombosis) include membrane peroxidizability and fluidity, eicosanoid synthesis, neuroprotection and epigenetics.

CONCLUSION

While oxidative-stress-induced alterations in FA and 1-C metabolism may initially enhance oxidative stress resistance, persisting chronically, they may cause damage possibly underlying (co-occurrence of) psychiatric disorders and CVD. This might have implications for research into diagnosis and (preventive) treatment of (CVD in) psychiatric patients.

Vitamin E and diabetic nephropathy in mice model and humans

Diabetes mellitus (DM) is associated with increased oxidative stress due to elevated glucose levels in the plasma. Glucose promotes glycosylation of both plasma and cellular proteins with increased risk for vascular events. Diabetic patients suffer from a higher incidence of cardiovascular complications such as diabetic nephropathy. Haptoglobin (Hp) is an antioxidant plasma protein which binds free hemoglobin, thus preventing heme-iron mediated oxidation. Two alleles exist at the Hp gene locus (1 and 2) encoding three possible Hp genotypes that differ in their antioxidant ability, and may respond differently to vitamin E treatment. Several clinical studies to have shown that Hp 1-1 genotype is a superior antioxidant to the Hp 2-2 genotype and Hp 2-2 genotype is associated with a higher incidence of cardiovascular disease. Vitamin E was found to have beneficial effect in patient and mice with Hp 2-2 genotype. In this review we have summarized the results of our studies in patients with diabetic nephropathy treated with vitamin E and in diabetic mice with different haptoglobin genotypes.

Increased oxidative stress and decreased membrane fluidity in erythrocytes of CAD patients

One of many risk factors for cardiovascular disease appears to be oxidative stress. To estimate possible changes in redox balance, membrane fluidity, and cholesterol level in erythrocytes was collected erythrocytes from patients diagnosed with coronary artery disease (CAD). The study included 20 patients with previous myocardial infarction occurring more than 6 months prior to the time of screening with low-density lipoprotein cholesterol (LDL-C) >70 mg/dL and 21 healthy controls. The following parameters were studied: catalase, glutathione peroxidase (GPx), superoxide dismutase (SOD), thiobarbituric acid reactive substrates (TBARS), sulfhydryl (SH) groups in membrane protein, total cholesterol level, and erythrocyte membrane fluidity. Our study showed an increase in the level of lipid peroxidation (13%) and total cholesterol (19%), and a decrease in membrane fluidity (14%) in the subsurface layers and in the deeper layers of erythrocyte membrane (7%) isolated from patients with CAD in comparison to healthy controls. A significant decrease in catalase (10%) and SOD (17%) activities were also observed. No changes in GPx activity or the level of SH groups were observed. Our study indicates that there are disorders in the antioxidant system as well as changes in the membrane structure of erythrocytes obtained from CAD patients.

Redox signaling in cardiovascular health and disease

Spatiotemporal regulation of the activity of a vast array of intracellular proteins and signaling pathways by reactive oxygen species (ROS) governs normal cardiovascular function. However, data from experimental and animal studies strongly support that dysregulated redox signaling, resulting from hyperactivation of various cellular oxidases or mitochondrial dysfunction, is integral to the pathogenesis and progression of cardiovascular disease (CVD). In this review, we address how redox signaling modulates the protein function, the various sources of increased oxidative stress in CVD, and the labyrinth of redox-sensitive molecular mechanisms involved in the development of atherosclerosis, hypertension, cardiac hypertrophy and heart failure, and ischemia-reperfusion injury. Advances in redox biology and pharmacology for inhibiting ROS production in specific cell types and subcellular organelles combined with the development of nanotechnology-based new in vivo imaging systems and targeted drug delivery mechanisms may enable fine-tuning of redox signaling for the treatment and prevention of CVD.

Extra virgin olive oil (EVOO) consumption and antioxidant status in healthy institutionalized elderly humans

Recent studies show that the elderly have increased oxidative stress and impaired antioxidant defense systems. Our study aims to evaluate the effects of daily consumption of EVOO in the healthy institutionalized elderly. We studied anthropometric, biochemical and antioxidant parameters in 62 subjects aged 65-96 years after a 6-week daily intake of polyphenol-rich EVOO with high oleuropein derivative contents. Subjects were divided into a control group (CG) who maintained their dietary habits (n=39) and an olive group (OG) who consumed EVOO as the only added fat, plus a daily dose of 50ml (n=23). We found a significant reduction of total cholesterol (TC), HDL, LDL and TGs in OG subjects and a significant increase of HDL levels. There was no significant variation in the CG parameters. In OG the total antioxidant capacity (TAC) in plasma increased with significant differences over CG. Plasma hydroxytyrosol (OH-Tyr) concentration showed a significant increase after EVOO intervention. Daily consumption of EVOO was found to have positive effects on lipid profiles, OH-Tyr levels and TAC. The results also show a significant increase of catalase (CAT) in erythrocytes and a decrease (p<0.05) in superoxide dismutase (SOD) and glutathione peroxidase (GH-PX) activity after EVOO intake. To our knowledge, no other study has examined the effects of EVOO consumption on biochemical parameters, antioxidant capacity and antioxidant enzyme activity in healthy elderly subjects. In conclusion, our results show that nutritional intervention with EVOO improves antioxidant status in healthy elderly people.

Amelioration of altered antioxidant enzymes activity and glomerulosclerosis by coenzyme Q10 in alloxan-induced diabetic rats

Coenzyme Q10 is a natural antioxidant and scavenging free radicals. In the present study, we examined antioxidative activities of coenzyme Q10 and possible protective effect of coenzyme Q10 on in vivo and in vitro lipid peroxidation, antioxidant enzymes activity and glomerulosclerosis in alloxan-induced type 1 diabetic rats. Thirty Sprague-Dawley male rats were divided into three groups randomly: group 1 as control, group 2 as diabetic untreatment, and group 3 as treatments with coenzyme Q10 by 15 mg/kg i.p. daily, respectively. Diabetes was induced in the second and third groups by alloxan injection subcutaneously. After 8 weeks, animals were anaesthetized, liver and kidney were then removed immediately and used fresh or kept frozen until their lipid peroxidation analysis. Blood samples were also collected before killing to measure the lipid peroxidation and antioxidant enzymes activity. Kidney paraffin sections were prepared and stained by periodic acid-Schiff method. Glomerular volume and leukocyte infiltration were estimated by stereological rules and glomerular sclerosis was studied semi-quantitatively. Coenzyme Q10 significantly inhibited leukocyte infiltration, glomerulosclerosis and the levels of malondialdehyde (MDA) serum and kidney content in treated group compared with the diabetic untreated group. Coenzyme Q10 significantly inhibited LDL oxidation in vitro. Coenzyme Q10 significantly increased the serum levels of glutathione (GSH) and serum activity of catalase (CAT) and superoxide dismutase (SOD) in treated group compared with the diabetic untreated group. Coenzyme Q10 alleviates leukocyte infiltration and glomerulosclerosis and exerts beneficial effects on the lipid peroxidation and antioxidant enzymes activity in alloxan-induced type 1 diabetic rats.

Nutrition and the healthy heart with an exercise boost

In this era of potent medications and major cardiovascular (CV) procedures, the value of nutrition can be forgotten. A healthy diet is essential, regardless of CV risk. Caloric balance is inherent to a good diet. Despite patients who say they eat little, ideal weight can be maintained if calories are burned. Composition is another component of a healthy diet. The Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets provide proof of CV benefit from their specific content. Metabolic syndrome (MS) is associated with poor diet and obesity. A healthy diet with good nutrition benefits the MS patient and associated conditions such as obesity and diabetes. Exercise, in conjunction with a healthy diet and good nutrition, helps maintain optimal weight and provides CV benefit such as decreased inflammation and increased vasodilatation. Whether vitamins or other nutritional supplements are important in a healthy diet is unproven. Nevertheless, the most promising data of added benefit to a healthy diet is with vitamin D. Some dietary supplements also have promise. Alcohol, in moderation, especially red wine, has nutritional and heart protective benefits. Antioxidants, endogenous or exogenous, have received increased interest and appear to play a favorable nutritional role. CV health starts with good nutrition.

Effects of ozone therapy on haemostatic and oxidative stress index in coronary artery disease

Coronary artery disease (CAD) is the most common cause of sudden death, and death of people over 20 years of age. Because ozone therapy can activate the antioxidant system and improve blood circulation and oxygen delivery to tissue, the aim of this study was to investigate the therapeutic efficacy of ozone in patients with CAD, treated with antithrombotic therapy, Aspirin and policosanol. A randomized controlled clinical trial was performed with 53 patients divided into two groups: one (n=27) treated with antithrombotic therapy and other (n=26) treated with antithrombotic therapy plus rectal insufflation of O(3). A parallel group (n=50) age and gender matched was used as reference for the experimental variables. The efficacy of the treatments was evaluated by comparing hemostatic indexes and biochemical markers of oxidative stress in both groups after 20 day of treatment. Ozone treatment significantly (P<0.001) improved prothrombin time when compared to the antithrombotic therapy only group, without modifying bleeding time. Combination antithrombotic therapy+O(3) improved the antioxidant status of patients reducing biomarkers of protein and lipid oxidation, enhancing total antioxidant status and modulating the level of superoxide dismutase and catalase with a 57% and 32% reduction in superoxide dismutase and catalase activities respectively, moving the redox environment to a status of low production of O(2)(•-) with an increase in H(2)O(2) detoxification. No side effects were observed. These results show that medical ozone treatment could be a complementary therapy in the treatment of CAD and its complications.

Cardiac aging: from molecular mechanisms to significance in human health and disease

Cardiovascular diseases (CVDs) are the major causes of death in the western world. The incidence of cardiovascular disease as well as the rate of cardiovascular mortality and morbidity increase exponentially in the elderly population, suggesting that age per se is a major risk factor of CVDs. The physiologic changes of human cardiac aging mainly include left ventricular hypertrophy, diastolic dysfunction, valvular degeneration, increased cardiac fibrosis, increased prevalence of atrial fibrillation, and decreased maximal exercise capacity. Many of these changes are closely recapitulated in animal models commonly used in an aging study, including rodents, flies, and monkeys. The application of genetically modified aged mice has provided direct evidence of several critical molecular mechanisms involved in cardiac aging, such as mitochondrial oxidative stress, insulin/insulin-like growth factor/PI3K pathway, adrenergic and renin angiotensin II signaling, and nutrient signaling pathways. This article also reviews the central role of mitochondrial oxidative stress in CVDs and the plausible mechanisms underlying the progression toward heart failure in the susceptible aging hearts. Finally, the understanding of the molecular mechanisms of cardiac aging may support the potential clinical application of several "anti-aging" strategies that treat CVDs and improve healthy cardiac aging.

Changes in expression of the antioxidant enzyme SOD3 occur upon differentiation of human bone marrow-derived mesenchymal stem cells in vitro

The discovery that mesenchymal stem cells (MSCs) secrete SOD3 may help explain studies in which MSCs have direct antioxidant activities both in vivo and in vitro. SOD3 is an antioxidant enzyme that dismutes toxic free radicals produced during inflammatory processes. Therefore, MSC production and secretion of active and therapeutically significant levels of SOD3 would further support the use of MSCs as a cellular based antioxidant therapy. The aim of this study was therefore to investigate in vitro if MSC differentiation down the adipogenic, chondrogenic, and osteogenic lineages influences the expression of the antioxidant molecule SOD3. Human bone marrow MSCs and their differentiated progeny were cultured under standard conditions and both the SOD3 gene and protein expression examined. Following adipogenesis, cultures demonstrated that both SOD3 protein and gene expression are significantly increased, and conversely, following chondrogenesis SOD3 protein and gene expression is significantly decreased. Following osteogenesis there were no significant changes in SOD3 protein or gene expression. This in vitro study describes the initial characterization of SOD3 expression and secretion by differentiated MSCs. This should help guide further in vivo work establishing the therapeutic and antioxidative potential of MSC and their differentiated progeny.