Possible role of oxidative stress in the pathogenesis of hypertension

High serum levels of reactive nitrogen species and low total antioxidant capacity in patients with resistant hypertension compared to those in age- gender matched healthy controls, controlled hypertension and follow up with propranolol treatment in the extended APPROPRIATE trial

OBJECTIVES

To perform a comparative analysis of the extended APPROPRIATE trial of measures of reactive nitrogen species and antioxidant capacity in patients having resistant hypertension with controlled hypertension and healthy controls.

RESULTS

Mean serum NO2- and NOx levels were significantly lower and mean AOC was significantly higher in patients with controlled hypertension (n = 38) and healthy controls (n = 38) compared to resistant hypertension (RHTN) patients (n = 40) at the pre-intervention stage (p < 0.001). The serum NO2-, NOx and AOC levels of both controlled hypertension and healthy controls were comparable to those of the RHTN patients following treatment with propranolol (n = 18). Considering all samples (n = 114) we noted that there were significant weak and moderate positive correlations between NO2- levels with systolic blood pressure (SBP) and diastolic blood pressure (DBP) (r = 0.396, p < 0.001 and r = 0.292, p = 0.004) as well as total NOx levels with SBP and DBP (r = 0.636 and r = 0.480 respectively, p < 0.001). Conversely, there was a significant negative correlation between AOC levels with SBP and DBP (r= -0.846 and r = -0.626 respectively, p < 0.001).

The association between dietary selenium intake and telomere length in hypertension

Telomere length is closely linked to biological aging, oxidative stress, and the development of cardiovascular diseases. This study aimed to assess the association between dietary selenium intake and telomere length in individuals with hypertension. Data on dietary selenium intake were captured through the National Health and Nutrition Examination Survey (NHANES) computer-assisted dietary interview system (CADI). Telomere length determination entailed selecting blood samples from all participants in the NHANES database. The analysis was performed using Analysis System software, with Empower stats utilized for data analysis. Results showed that there was a significant association between dietary selenium intake and telomere length in hypertension, particularly within the female group. In female hypertension cases, a 1 mcg increase in dietary selenium intake corresponded to a telomere length increase of 1.19 bp, even after adjusting for age, race, BMI, marital status, physical activity, energy intake, and stroke history. The relationship between dietary selenium intake and telomere length exhibited a linear pattern in female hypertension patients. This study identified a positive association between dietary selenium intake and telomere length in hypertension, particularly within the female group.

Calotropis procera and the Pharmacological Properties of Its Aqueous Leaf Extract: A Review

Calotropis procera (C. procera) is a versatile plant often used for fuel, fodder, wood, fiber, phytoremediation, medicine, and synthesis of nanoparticles. Its ability to tolerate abiotic stresses and its morphophysiological adaptation have made it popular worldwide. Currently, it is identified as an environmental weed across the world. C. procera owes its therapeutic qualities to the secondary metabolites like tannins, alkaloids, and phenols present in it. New synthetic drugs are being formulated by using these secondary metabolites as a prototype. This review aimed to provide a summary of the chemometric profile, toxicity, and pharmacological activities of the aqueous leaf extract of C. procera based on the current literature.

Protective potential of naringenin and its nanoformulations in redox mechanisms of injury and disease

Increasing evidence suggests that elevated intracellular levels of reactive oxygen species (ROS) play a significant role in the pathogenesis of many diseases. Increased intracellular levels of ROS can lead to the oxidation of lipids, DNA, and proteins, contributing to cellular damage. Hence, the maintenance of redox hemostasis is essential. Naringenin (NAR) is a flavonoid included in the flavanones subcategory. Various pharmacological actions have been ascribable to this phytochemical composition, including antioxidant, anti-inflammatory, antibacterial, antiviral, antitumor, antiadipogenic, neuro-, and cardio-protective activities. This review focused on the underlying mechanism responsible for the antioxidative stress properties of NAR and its' nanoformulations. Several lines of in vitro and in vivo investigations suggest the effects of NAR and its nanoformulation on their target cells via modulating signaling pathways. These nanoformulations include nanoemulsion, nanocarriers, solid lipid nanoparticles (SLN), and nanomicelle. This review also highlights several beneficial health effects of NAR nanoformulations on human diseases including brain disorders, cancer, rheumatoid arthritis, and small intestine injuries. Employing nanoformulation can improve the pharmacokinetic properties of NAR and consequently efficiency by reducing its limitations, such as low bioavailability. The protective effects of NAR and its' nanoformulations against oxidative stress may be linked to the modulation of Nrf2-heme oxygenase-1, NO/cGMP/potassium channel, COX-2, NF-κB, AMPK/SIRT3, PI3K/Akt/mTOR, BDNF, NOX, and LOX-1 pathways. Understanding the mechanism behind the protective effects of NAR can facilitate drug development for the treatment of oxidative stress-related disorders.

From reactive species to disease development: Effect of oxidants and antioxidants on the cellular biomarkers

The influence of modern lifestyle, diet, exposure to chemicals such as phytosanitary substances, together with sedentary lifestyles and lack of exercise play an important role in inducing reactive stress (RS) and disease. The imbalance in the production and scavenging of free radicals and the induction of RS (oxidative, nitrosative, and halogenative) plays an essential role in the etiology of various chronic pathologies, such as cardiovascular diseases, diabetes, neurodegenerative diseases, and cancer. The implication of free radicals and reactive species injury in metabolic disturbances and the onset of many diseases have been accumulating for several decades, and are now accepted as a major cause of many chronic diseases. Exposure to elevated levels of free radicals can cause molecular structural impact on proteins, lipids, and DNA, as well as functional alteration of enzyme homeostasis, leading to aberrations in gene expression. Endogenous depletion of antioxidant enzymes can be mitigated using exogenous antioxidants. The current interest in the use of exogenous antioxidants as adjunctive agents for the treatment of human diseases allows a better understanding of these diseases, facilitating the development of new therapeutic agents with antioxidant activity to improve the treatment of various diseases. Here we examine the role that RS play in the initiation of disease and in the reactivity of free radicals and RS in organic and inorganic cellular components.

Co-supplementation of Vitamin K2 and Selenium Synergistically Improves Metabolic Status and Reduces Cardiovascular Risk Markers in Dyslipidemic Rabbits

This work investigated the impact of vitamin K2 and selenium co-supplementation on metabolic profile and indicators of cardiovascular health in dyslipidemic rabbits. Fifty adult male rabbits were equally allocated into 5 groups: Control group, Dyslipidemic group: received 0.5% cholesterol in diet for 12 weeks, groups 3, 4 and 5 dyslipidemic rabbits daily treated with vitamin K2 (10 mg/kg bw) or/and selenium (1 mg/kg bw) for 8 weeks. Co-supplementation of vitamin K2 and selenium significantly decreased body weight gain and blood pressure elevation in dyslipidemic rabbits compared to un-treated ones. Consuming vitamin K2 plus selenium also markedly lowered serum lipids encompassing cholesterol, triglycerides and LDL and elevated HDL relative to placebo. Additionally, such co-supplementation reduced fasting glucose and insulin, enhancing insulin sensitivity with respect to placebo. Regarding cardiovascular risk markers, dyslipidemic rabbits received vitamin K2 concurrently with selenium displayed lower levels of atherogenic index (LDL/HDL), serum C-reactive protein, heart fatty acid-binding protein and asymmetric dimethylarginine as well as aortic ox-LDL, lipid peroxidation and calcium but higher levels of serum nitric oxide and aortic total antioxidants than un-treated ones. Concomitant administration of vitamin K2 and selenium improved metabolic profile, markers of cardiovascular health and atherosclerosis in dyslipidemic rabbits.

Variation in the Main Health-Promoting Compounds and Antioxidant Capacity of Three Leafy Vegetables in Southwest China

Malabar spinach (Basella alba), amaranth (Amaranthus tricolor), and sweet potato (Ipomoea batatas) are leafy vegetables found in Southwest China. The variation of chlorophyll, carotenoids, ascorbic acid, total flavonoids, phenolic compounds, and antioxidant capacity was studied in the leaves and stems of the three vegetables. The content of main health-promoting compounds and the antioxidant capacity in the leaves were higher than that in the stems, indicating that the leaves of the three vegetables possess greater nutritional value. The trend of total flavonoids in all three vegetables was similar to the trend of antioxidant capacity, suggesting that the total flavonoids may be the major antioxidants wihin these vegetables. Eight individual phenolic compounds were detected in three different vegetables. The most abundant levels of individual phenolic compounds in the leaves and stems of malabar spinach, amaranth, and sweet potato were 6'-O-feruloyl-d-sucrose (9.04 and 2.03 mg g^-1 DW), hydroxyferulic acid (10.14 and 0.73 mg g^-1 DW), and isorhamnetin-7-O-glucoside (34.93 and 6.76 mg g^-1 DW), respectively. Sweet potato exhibited a higher total and individual phenolic compound content compared to malabar spinach and amaranth. Overall, the results demonstrate that the three leafy vegetables possess high nutritional value, and could be used not only for consumption but also in various other fields, including medicine and chemistry.

The relationship between perfluoroalkyl substances and hypertension: A systematic review and meta-analysis

Hypertension is an important risk factor for cardiovascular diseases (CVDs) and a leading cause of premature death. Epidemiological studies have found that perfluoroalkyl substances (PFASs) are associated with hypertension. However, the correlation between PFASs and hypertension has not been systematically reported. Based on evidence from population epidemiological surveys, we conducted a meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to assess the correlation between PFASs exposure and hypertension. In this study, three databases of PubMed, Web of science, Embase were searched and 13 literatures with 81,096 participants were included. Literature heterogeneity was evaluated by I² statistic, and the random effect model (I² > 50%) and fixed effect model (I² < 50%) were used to combine the studies in meta-analysis. The results showed that PFNA (OR = 1.11, 95% CI: 1.04-1.19), PFOA (OR = 1.12, 95% CI: 1.02-1.23), PFOS (OR = 1.19, 95% CI: 1.06-1.34) and PFHxS (OR = 1.03, 95% CI: 1.00-1.06) were significantly associated with hypertension, while other types of PFASs (∑PFAS, PFDA, PFUnDA) had no statistical significance. In addition, PFNA (OR = 1.12, 95% CI: 1.03-1.22), PFOA (OR = 1.12, 95% CI: 1.01-1.25) and PFOS (OR = 1.12, 95% CI: 1.00-1.25) exposure were positively correlated with the risk of hypertension in men, but not in women. Our study reveals that PFASs are risk factors for hypertension, with notable gender differences observed in PFASs-exposed populations. Specifically, males exposed to PFNA, PFOA, and PFOS exhibit a higher risk of hypertension compared to females. However, further investigations are needed to delve into the precise mechanism through which PFASs contribute to the development of hypertension.

Nrf2 and Oxidative Stress: A General Overview of Mechanisms and Implications in Human Disease

Organisms are continually exposed to exogenous and endogenous sources of reactive oxygen species (ROS) and other oxidants that have both beneficial and deleterious effects on the cell. ROS have important roles in a wide range of physiological processes; however, high ROS levels are associated with oxidative stress and disease progression. Oxidative stress has been implicated in nearly all major human diseases, from neurogenerative diseases and neuropsychiatric disorders to cardiovascular disease, diabetes, and cancer. Antioxidant defence systems have evolved as a means of protection against oxidative stress, with the transcription factor Nrf2 as the key regulator. Nrf2 is responsible for regulating an extensive panel of antioxidant enzymes involved in the detoxification and elimination of oxidative stress and has been extensively studied in the disease contexts. This review aims to provide the reader with a general overview of oxidative stress and Nrf2, including basic mechanisms of Nrf2 activation and regulation, and implications in various major human diseases.

Associations of serum PFOA and PFOS levels with incident hypertension risk and change of blood pressure levels

Evidence on the associations of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) with hypertension or blood pressure (BP) levels was limited and inconsistent. The present prospective study aims to evaluate the longitudinal associations of serum levels of PFOA and PFOS with incident hypertension risk and change of blood pressure levels. At baseline 1080 participants (mean age 62 years, 58.9% females) free of hypertension, cardiovascular disease, diabetes, and cancer were followed up for nearly 5 years. Baseline serum levels of PFOA and PFOS were measured with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS). Hypertension was defined as any of (1) self-reported physician-diagnosed hypertension (2) use of hypotension drugs (3) measured systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg. Change of BP was evaluated as a difference between twice measurements (BP at follow-up visit－BP at baseline). After adjustment for multiple covariates, serum PFOS levels were negatively correlated with risk of hypertension [RR per lg-unit = 0.94 (95% CI: 0.88, 0.99)] and change of systolic BP [β = -1.48 (95% CI: -2.56, -0.41)]. The highest vs lowest quartiles of PFOS concentration was negatively associated with hypertension risk. Compared with Q1, the RRs (95% CIs) for Q2, Q3, and Q4 were 0.83 (0.67-0.98), 0.81 (0.67-0.97), and 0.81(0.67-0.97), respectively (p for trend = 0.016). The negative associations remained in females but not in males (p for interaction = 0.44). No significant association of PFOA with hypertension risk was observed. Further studies are needed to validate our findings.

Per- and Polyfluoroalkyl Substances and Incident Hypertension in Multi-Racial/Ethnic Women: The Study of Women's Health Across the Nation

BACKGROUND

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are ubiquitous synthetic chemicals that may disrupt blood pressure controls; however, human evidence to support this hypothesis is scant. We examined the association between serum concentrations of PFAS and risks of developing hypertension.

METHODS

This study included 1058 midlife women initially free of hypertension from the multiracial and multiethnic SWAN (Study of Women's Health Across the Nation) with annual follow-up visits between 1999 and 2017. Hypertension was defined as blood pressure ≥140 mm Hg systolic or ≥90 mm Hg diastolic or receiving antihypertensive treatment. Cox proportional hazards models were utilized to calculate hazard ratios and 95% CIs. Quantile g-computation was implemented to evaluate the joint effect of PFAS mixtures.

RESULTS

During 11 722 person-years of follow-up, 470 participants developed incident hypertension (40.1 cases per 1000 person-years). Compared with the lowest tertile, women in the highest tertile of baseline serum concentrations had adjusted hazard ratios of 1.42 (95% CI, 1.19-1.68) for perfluorooctane sulfonate (P trend=0.01), 1.47 (95% CI, 1.24-1.75) for linear perfluorooctanoate (P trend=0.01), and 1.42 (95% CI, 1.19-1.70) for 2-(N-ethyl-perfluorooctane sulfonamido) acetate (P trend=0.01). No significant associations were observed for perfluorononanoate and perfluorohexane sulfonate. In the mixture analysis, women in the highest tertile of overall PFAS concentrations had a hazard ratio of 1.71 (95% CI, 1.15-2.54; P trend=0.008), compared with those in the lowest tertile.

CONCLUSIONS

Several PFAS showed positive associations with incident hypertension. These findings suggest that PFAS might be an underappreciated contributing factor to women's cardiovascular disease risk.

Oxidative stress - Complex pathological issues concerning the hallmark of cardiovascular and metabolic disorders

Oxidative stress is a complex biological process characterized by the excessive production of reactive oxygen species (ROS) that act as destroyers of the REDOX balance in the body and, implicitly, inducing oxidative damage. All the metabolisms are impaired in oxidative stress and even nucleic acid balance is influenced. ROS will promote structural changes of the tissues and organs due to interaction with proteins and phospholipids. The constellation of the cardiovascular risk factors (CVRFs) will usually develop in subjects with predisposition to cardiac disorders. Oxidative stress is usually related with hypertension (HTN), diabetes mellitus (DM), obesity and cardiovascular diseases (CVDs) like coronary artery disease (CAD), cardiomyopathy or heart failure (HF), that can develop in subjects with the above-mentioned diseases. Elements describing the complex relationship between CVD and oxidative stress should be properly explored and described because prevention may be the optimal approach. Our paper aims to expose in detail the complex physiopathology of oxidative stress in CVD occurrence and novelties regarding the phenomenon. Biomarkers assessing oxidative stress or therapy targeting specific pathways represent a major progress that actually change the outcome of subjects with CVD. New antioxidants therapy specific for each CVD represents a captivating and interesting future perspective with tremendous benefits on subject's outcome.

Carotenoids in Human SkinIn Vivo: Antioxidant and Photo-Protectant Role against External and Internal Stressors

The antioxidant system of the human body plays a crucial role in maintaining redox homeostasis and has an important protective function. Carotenoids have pronounced antioxidant properties in the neutralization of free radicals. In human skin, carotenoids have a high concentration in the stratum corneum (SC)-the horny outermost layer of the epidermis, where they accumulate within lipid lamellae. Resonance Raman spectroscopy and diffuse reflectance spectroscopy are optical methods that are used to non-invasively determine the carotenoid concentration in the human SC in vivo. It was shown by electron paramagnetic resonance spectroscopy that carotenoids support the entire antioxidant status of the human SC in vivo by neutralizing free radicals and thus, counteracting the development of oxidative stress. This review is devoted to assembling the kinetics of the carotenoids in the human SC in vivo using non-invasive optical and spectroscopic methods. Factors contributing to the changes of the carotenoid concentration in the human SC and their influence on the antioxidant status of the SC in vivo are summarized. The effect of chemotherapy on the carotenoid concentration of the SC in cancer patients is presented. A potential antioxidant-based pathomechanism of chemotherapy-induced hand-foot syndrome and a method to reduce its frequency and severity are discussed.

The Association between Blood Concentrations of PCDD/DFs, DL-PCBs and the Risk of Type 2 Diabetes Mellitus and Thyroid Cancer in South Korea

Background and Objectives: Epidemiological studies have inconsistently shown an association between dioxin and risk of type 2 diabetes mellitus (T2DM) and cancer. This study aims to examine the effects of blood concentration of dioxin-like polychlorinated biphenyls (DL-PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) on T2DM and thyroid cancer. Methods: We conducted a nested case–control study within the Korean cancer prevention study-II (KCPS-II) consisting of 15 thyroid cancer cases, 30 T2DM cases, and 55 controls. A total of 500 samples were used in 100 pooling samples. An average value of a pooled sample was calculated weighted by the blood volume of each sample. Results: The study population included 100 participants from the KCPS-II (median (IQR) baseline age, 54.06 [21.04] years; 48 women). The toxic equivalents of PCDD/DFs showed a significant positive association with T2DM and thyroid cancer, after adjustments for potential confounders (T2DM ORs  =  1.23; 95% CI  =  1.05–1.43; thyroid cancer ORs  =  1.34; 95% CI  =  1.12–1.61). Conclusion: In this study, both T2DM and thyroid cancer were associated with the blood concentrations of PCDD/DFs. The association between PCDD/DFs and T2D was found among women but not among men. Our findings suggest that further biochemical in vivo research and epidemiologic studies are needed to clarify the association between dioxins concentrations and diseases.

Aryl Hydrocarbon Receptor in Oxidative Stress as a Double Agent and Its Biological and Therapeutic Significance

The aryl hydrocarbon receptor (AhR) has long been implicated in the induction of a battery of genes involved in the metabolism of xenobiotics and endogenous compounds. AhR is a ligand-activated transcription factor necessary for the launch of transcriptional responses important in health and disease. In past decades, evidence has accumulated that AhR is associated with the cellular response to oxidative stress, and this property of AhR must be taken into account during investigations into a mechanism of action of xenobiotics that is able to activate AhR or that is susceptible to metabolic activation by enzymes encoded by the genes that are under the control of AhR. In this review, we examine various mechanisms by which AhR takes part in the oxidative-stress response, including antioxidant and prooxidant enzymes and cytochrome P450. We also show that AhR, as a participant in the redox balance and as a modulator of redox signals, is being increasingly studied as a target for a new class of therapeutic compounds and as an explanation for the pathogenesis of some disorders.

Neuroprotective Effects and Therapeutic Potential of the Citrus Flavonoid Hesperetin in Neurodegenerative Diseases

Neurodegenerative disorders affect more than fifty million Americans each year and represent serious health threats as the population ages. Neuroinflammation and oxidative stress are critical in the onset, progression, and pathogenesis of neurodegenerative diseases such as Alzheimer’s (AD), Parkinson’s (PD), and amyotrophic lateral sclerosis (ALS). A wide range of natural compounds has been investigated because of their antioxidant, anti-inflammatory, and neuroprotective properties. The citrus flavonoid hesperetin (HPT), an aglycone of hesperidin found in oranges, mandarins, and lemons, has been extensively reported to exert neuroprotective effects in experimental models of neurogenerative diseases. This review has compiled multiple studies on HPT in both in vivo and in vitro models to study neurodegeneration. We focused on the modulatory effects of hesperetin on the release of cellular anti-inflammatory and antioxidative stress mediators. Additionally, this review discusses the hesperetin effect in maintaining the levels of microRNA (miRNA) and modulating autophagy as it relates to hesperetin’s protective mechanisms against neurodegeneration. Moreover, this review is focused on providing experimental data for hesperetin’s potential as a neuroprotective compound and discusses reported evidence that HPT crosses the blood–brain barrier. In summary, this review shows the evidence available in the literature to indicate the efficacy of hesperetin in delaying the onset of neurodegenerative diseases.

Dietary Polyphenols and Their Role in Oxidative Stress-Induced Human Diseases: Insights Into Protective Effects, Antioxidant Potentials and Mechanism(s) of Action

Dietary polyphenols including phenolic acids, flavonoids, catechins, tannins, lignans, stilbenes, and anthocyanidins are widely found in grains, cereals, pulses, vegetables, spices, fruits, chocolates, and beverages like fruit juices, tea, coffee and wine. In recent years, dietary polyphenols have gained significant interest among researchers due to their potential chemopreventive/protective functions in the maintenance of human health and diseases. It is believed that dietary polyphenols/flavonoids exert powerful antioxidant action for protection against reactive oxygen species (ROS)/cellular oxidative stress (OS) towards the prevention of OS-related pathological conditions or diseases. Pre-clinical and clinical evidence strongly suggest that long term consumption of diets rich in polyphenols offer protection against the development of various chronic diseases such as neurodegenerative diseases, cardiovascular diseases (CVDs), cancer, diabetes, inflammatory disorders and infectious illness. Increased intake of foods containing polyphenols (for example, quercetin, epigallocatechin-3-gallate, resveratrol, cyanidin etc.) has been claimed to reduce the extent of a majority of chronic oxidative cellular damage, DNA damage, tissue inflammations, viral/bacterial infections, and neurodegenerative diseases. It has been suggested that the antioxidant activity of dietary polyphenols plays a pivotal role in the prevention of OS-induced human diseases. In this narrative review, the biological/pharmacological significance of dietary polyphenols in the prevention of and/or protection against OS-induced major human diseases such as cancers, neurodegenerative diseases, CVDs, diabetes mellitus, cancer, inflammatory disorders and infectious diseases have been delineated. This review specifically focuses a current understanding on the dietary sources of polyphenols and their protective effects including mechanisms of action against various major human diseases.

Phytoantioxidant Functionalized Nanoparticles: A Green Approach to Combat Nanoparticle-Induced Oxidative Stress

Nanotechnology is gaining significant attention, with numerous biomedical applications. Silver in wound dressings, copper oxide and silver in antibacterial preparations, and zinc oxide nanoparticles as a food and cosmetic ingredient are common examples. However, adverse effects of nanoparticles in humans and the environment from extended exposure at varied concentrations have yet to be established. One of the drawbacks of employing nanoparticles is their tendency to cause oxidative stress, a significant public health concern with life-threatening consequences. Cardiovascular, renal, and respiratory problems and diabetes are among the oxidative stress-related disorders. In this context, phytoantioxidant functionalized nanoparticles could be a novel and effective alternative. In addition to performing their intended function, they can protect against oxidative damage. This review was designed by searching through various websites, books, and articles found in PubMed, Science Direct, and Google Scholar. To begin with, oxidative stress, its related diseases, and the mechanistic basis of oxidative damage caused by nanoparticles are discussed. One of the main mechanisms of action of nanoparticles was unearthed to be oxidative stress, which limits their use in humans. Secondly, the role of phytoantioxidant functionalized nanoparticles in oxidative damage prevention is critically discussed. The parameters for the characterization of nanoparticles were also discussed. The majority of silver, gold, iron, zinc oxide, and copper nanoparticles produced utilizing various plant extracts were active free radical scavengers. This potential is linked to several surface fabricated phytoconstituents, such as flavonoids and phenols. These phytoantioxidant functionalized nanoparticles could be a better alternative to nanoparticles prepared by other existing approaches.

Impaired antioxidant KEAP1-NRF2 system in amyotrophic lateral sclerosis: NRF2 activation as a potential therapeutic strategy

BACKGROUND

Oxidative stress (OS) is an imbalance between oxidant and antioxidant species and, together with other numerous pathological mechanisms, leads to the degeneration and death of motor neurons (MNs) in amyotrophic lateral sclerosis (ALS).

MAIN BODY

Two of the main players in the molecular and cellular response to OS are NRF2, the transcription nuclear factor erythroid 2-related factor 2, and its principal negative regulator, KEAP1, Kelch-like ECH (erythroid cell-derived protein with CNC homology)-associated protein 1. Here we first provide an overview of the structural organization, regulation, and critical role of the KEAP1-NRF2 system in counteracting OS, with a focus on its alteration in ALS. We then examine several compounds capable of promoting NRF2 activity thereby inducing cytoprotective effects, and which are currently in different stages of clinical development for many pathologies, including neurodegenerative diseases.

CONCLUSIONS

Although challenges associated with some of these compounds remain, important advances have been made in the development of safer and more effective drugs that could actually represent a breakthrough for fatal degenerative diseases such as ALS.

Current Status of Primary, Secondary, and Tertiary Prevention of Coronary Artery Disease

Fifty percent of all death from cardiovascular diseases is due to coronary artery disease (CAD). This is avoidable if early identification is made. Preventive health care has a major role in the fight against CAD. Atherosclerosis and atherosclerotic plaque rupture are involved in the development of CAD. Modifiable risk factors for CAD are dyslipidemia, diabetes, hypertension, cigarette smoking, obesity, chronic renal disease, chronic infection, high C-reactive protein, and hyperhomocysteinemia. CAD can be prevented by modification of risk factors. This paper defines the primary, secondary, and tertiary prevention of CAD. It discusses the mechanism of risk factor-induced atherosclerosis. This paper describes the CAD risk score and its use in the selection of individuals for primary prevention of CAD. Guidelines for primary, secondary, and tertiary prevention of CAD have been described. Modification of risk factors and use of guidelines for prevention of CAD would prevent, regress, and slow down the progression of CAD, improve the quality of life of patient, and reduce the health care cost.

A U-Shaped Relationship Between Selenium Concentrations and All-Cause or Cardiovascular Mortality in Patients With Hypertension

Background: Given the antioxidant activity of selenium, it has been reported benefits for blood pressure control and hypertension prevention, but few studies have investigated the association between serum selenium with mortality in hypertensive population. Methods: All participants with hypertension aged ≥18 years at baseline were recruited from the National Health and Nutritional Examination Surveys (NHANES) 2003-2004, and followed for mortality through December 31, 2015. Subjects were categorized by quartiles of serum selenium (Q1: ≤124 μg/L, Q2: 125-135 μg/L, Q3: 136-147 μg/L, Q4: ≥148 μg/L). Multivariate Cox regression were implemented to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Restricted cubic spline analysis and two-piecewise linear regression were used to evaluate the relationship of serum selenium with mortality. Survival curves were used to depict cause-specific mortalities. Results: A total of 929 participants (52.53% were male) were eligible for the current study with the average age of 63.10 ± 12.59 years. There were 307 deaths occurred including 56 cardiovascular death events during the mean follow-up time of 121.05 ± 40.85 months. A U-shaped association was observed between serum selenium and all-cause or cardiovascular mortality. In fully adjusted model, comparisons among quartiles revealed that risks of all-cause [HR (95%CI), 0.57 (0.39-0.81)] and cardiovascular death [HR (95%CI), 0.33 (0.13-0.86)] were lower in Q3. The nadir mortality of all-cause and cardiovascular was occurred at the serum selenium level of 136 μg/L and 130 μg/L, respectively. Conclusion: Serum selenium concentration showed a U-shaped association with all-cause and cardiovascular mortality.

In Utero Exposure to Heavy Metals and Trace Elements and Childhood Blood Pressure in a U.S. Urban, Low-Income, Minority Birth Cohort

BACKGROUND

In utero exposure to heavy metals lead (Pb), mercury (Hg), and cadmium (Cd) may be associated with higher childhood blood pressure (BP), whereas trace elements selenium (Se) and manganese (Mn) may have protective antioxidant effects that modify metal-BP associations.

OBJECTIVES

We examined the individual and joint effects of in utero exposure to Pb, Hg, Cd, Se, and Mn on childhood BP.

METHODS

We used data from the Boston Birth Cohort (enrolled 2002-2013). We measured heavy metals and trace elements in maternal red blood cells collected 24-72 h after delivery. We calculated child BP percentile per the 2017 American Academy of Pediatrics Clinical Practice Guideline. We used linear regression models to estimate the association of each metal, and Bayesian kernel machine regression (BKMR) to examine metal coexposures, with child BP between 3 to 15 years of age.

RESULTS

Our analytic sample comprised 1,194 mother-infant pairs (61% non-Hispanic Black, 20% Hispanic). Hg and Pb were not associated with child systolic BP (SBP). Se and Mn were inversely associated with child SBP percentiles, which, on average, were 6.23 points lower with a doubling of Se (95% CI: -11.51, -0.96) and 2.62 points lower with a doubling of Mn (95% CI: -5.20, -0.04). BKMR models showed similar results. Although Cd was not associated with child SBP overall, the inverse association between Mn and child SBP was stronger at higher levels of Cd (p-interaction=0.04). Consistent with this finding, in utero exposure to cigarette smoke modified the Mn-child SBP association. Among children whose mothers smoked during pregnancy, a doubling of Mn was associated with a 10.09-point reduction in SBP percentile (95% CI: -18.03, -2.15), compared with a 1.49-point reduction (95% CI: -4.21, 1.24) in children whose mothers did not smoke during pregnancy (p-interaction=0.08).

CONCLUSION

Se and Mn concentrations in maternal red blood cells collected 24-72 h after delivery were associated with lower child SBP at 3 to 15 years of age. There was an interaction between Mn and Cd on child SBP, whereby the protective association of Mn on child SBP was stronger among mothers who had higher Cd. The association of Mn and child SBP was also modified by maternal cigarette smoking-a source of Cd-during pregnancy. Optimizing in utero Se levels, as well as Mn levels in women who had high Cd or smoked during pregnancy, may protect offspring from developing high BP during childhood. https://doi.org/10.1289/EHP8325.

The Cardiovascular Effects of Electronic Cigarettes

PURPOSE OF REVIEW

Electronic cigarettes (e-cigarettes) are gaining rapid popularity among all age groups, especially among youth. They have evolved into technologically advanced devices capable of delivering nicotine concentration and other substances. In addition to nicotine, e-cigarettes' constituents possess variety of toxic chemicals that have adverse effects on human body.

RECENT FINDINGS

In recent years, steady downward trend in tobacco usage has been observed; however, e-cigarette use is on upward trend. E-cigarettes are advertised as "safer" alternatives to conventional smoking and as an aid to smoking cessation. Emerging studies have, however, shown that e-cigarettes have harmful effects on the cardiovascular system and that most of the e-cigarette users are dual users, concurrently using e-cigarettes and smoking conventional cigarettes. Despite a gap in clinical studies and randomized trials analyzing adverse cardiovascular effects of e-cigarette use, the existing literature supports that different constituents of e-cigarettes such as nicotine, carbonyls, and particulate matters carry potential risk for cardiovascular diseases (CVD) on its users.

Gestational and childhood exposure to per- and polyfluoroalkyl substances and cardiometabolic risk at age 12 years

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) may adversely influence cardiometabolic risk. However, few studies have examined if the timing of early life PFAS exposure modifies their relation to cardiometabolic risk. We examined the influence of gestational and childhood PFAS exposure on adolescents' cardiometabolic risk.

METHODS

We quantified concentrations of four PFAS (perfluorooctanoate [PFOA], perfluorooctane sulfonate [PFOS], perfluorononanoate [PFNA], and perfluorohexane sulfonate [PFHxS]) in sera collected during pregnancy, at birth, and at ages 3, 8, and 12 years from 221 mother-child pairs in the HOME Study (enrolled 2003-06, Cincinnati, Ohio). We measured cardiometabolic risk factors using physical examinations, fasting serum biomarkers, and dual-energy X-ray absorptiometry scans at age 12 years. Cardiometabolic risk summary scores were calculated by summing age- and sex-standardized z-scores for individual cardiometabolic risk factors. We used multiple informant models to estimate covariate-adjusted associations of serum PFAS concentrations (log2-transformed) at each visit with cardiometabolic risk scores and their individual components, and tested for differences in associations across visits.

RESULTS

The associations of serum PFOA concentrations with cardiometabolic risk scores differed across visits (P for heterogeneity = 0.03). Gestational and cord serum PFOA concentrations were positively associated with cardiometabolic risk scores (βs and 95% confidence intervals [95% CIs]: gestational 0.8 [0.0, 1.6]; cord 0.9 [-0.1, 1.9] per interquartile range increase). These positive associations were primarily driven by homeostatic model assessment for insulin resistance index (β = 0.3 [0.1, 0.5]) and adiponectin to leptin ratio (β = -0.5 [-1.0, 0.0]). Other individual cardiometabolic risk factors associated with gestational PFOA included insulin and waist circumference. Gestational and cord PFHxS were also associated with higher cardiometabolic risk scores (βs: gestational 0.9 [0.2, 1.6]; cord 0.9 [0.1, 1.7]).

CONCLUSION

In this cohort of children with higher gestational PFOA exposure, fetal exposure to PFOA and PFHxS was associated with unfavorable cardiometabolic risk in adolescence.

Ballota nigra L. – an overview of pharmacological effects and traditional uses

Ballota nigra, also known as black horehound is a common medical herb used in folk medicine around the world. First reported mentions of its medical properties and use goes as far as the 13th century. The use of black horehound depends on regions and countries. It is used mostly to treat e.g. mild sleep disorders, nervousness, upset stomach, wound healing. It can be used as an anti-inflammatory, antibacterial, antiprotozoal, antifungal drug. Moreover, it has been reported as a potential cancer drug. This extensive usage is particularly interesting for us. The aim of this review is to present available data on B. nigra pharmacological effects and known traditional uses gathered from a wide range of scientific articles published in 1997–2020.

The effect of Malus doumeri leaf flavonoids on oxidative stress injury induced by hydrogen peroxide (H2O2) in human embryonic kidney 293 T cells

BACKGROUND

In this study, Malus doumeri leaf flavonoids (MDLF) were used as the research object to observe their in vitro antioxidant stress ability. Hydrogen peroxide (H2O2) was used to induce oxidative stress in 293 T cells.

METHODS

MTT, flow cytometry, and qPCR were used to verify the effect of MDLF.

RESULTS

In vitro cell experiments showed that at a concentration of 0-160 μg/mL, MDLF did not affect the normal proliferation of human embryonic kidney 293 T cells (HEK 293 T cells), and MDLF had no cytotoxic effect in this concentration range. It was found that MDLF could maintain the survival of HEK 293 T cells (82.6%) at a high concentration (160 μg/mL). Morphological observation also found that MDLF can inhibit the cell structure imperfection caused by H2O2. It was also observed that MDLF could significantly increase the levels of catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-Px) and reduce the level of malondialdehyde (MDA). The results of quantitative polymerase chain reaction (qPCR) showed that MDLF could significantly up-regulate the mRNA expression levels of CAT, SOD, GSH, GSH-Px, B-cell lymphoma-2 (Bcl-2) and downregulate the expression levels of B-cell lymphoma-2 associated x protein (Bax), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa-B (NF-κB) in oxidative stress-injured cells. The HPLC analysis showed that MDLF contained hyperin, isoquercetin, quercitrin, hesperidin, myricetin, baicalin and quercetin.

CONCLUSION

From the experimental results, it was observed that MDLF has a strong anti-oxidation ability in vitro, and it can interfere with the oxidative stress damage caused by H2O2 in 293 T cells. Therefore, MDLF is a type of natural substance with good anti-oxidant effect, and it has the potential to interfere with many diseases.

Activation of Liver X Receptors by GW3965 Attenuated Deoxycorticosterone Acetate-Salt Hypertension-Induced Cardiac Functional and Structural Changes

In this study, the effect of liver X receptor (LXR) activation on hypertension-induced cardiac structural and functional alterations was investigated. Hypertension was induced by deoxycorticosterone acetate (DOCA)-salt administration in uninephrectomized rats for 6 weeks. LXR agonist GW3965 (3-{3-[(2-chloro-3-trifluoromethyl-benzyl)-(2,2-diphenyl-ethyl)-amino]-propoxy}-phenyl)-acetic acid was given for the past week. Rhythmic activity and contractions of the isolated heart tissues were recorded. Biochemical parameters were assessed in ventricular tissue and plasma samples. Cardiac expressions of various proteins were examined, and histopathological evaluation was performed in the left ventricle and liver. GW3965 reduced systolic blood pressure and enhanced noradrenaline-stimulated papillary muscle contraction induced by DOCA-salt + uninephrectomy. Plasma and tissue total antioxidant capacity (TAC) increased and tissue 4-hydroxynonenal (4-HNE) levels decreased in the DOCA-salt group. GW3965 elevated plasma and tissue TAC levels in both of groups. Glucose-regulated protein-78 (GRP78), phospho-dsRNA-activated-protein kinase-like ER kinase (p-PERK), matrix metalloproteinase-2 (MMP-2), and nuclear factor-κB p65 (NF-κB p65) expression was augmented, and inhibitor-κB-α (IκB-α) expression was reduced in hypertensive hearts. The altered levels of all these markers were reversed by GW3965. Also, GW3965 ameliorated DOCA-salt + uninephrectomy-induced cardiac and hepatic inflammation and fibrosis. However, GW3965 unchanged the plasma lipid levels and hepatic balloon degeneration score. These results demonstrated that LXR activation may improve hypertension-induced cardiac changes without undesired effects.

Per- and polyfluoroalkyl substances and blood pressure in pre-diabetic adults-cross-sectional and longitudinal analyses of the diabetes prevention program outcomes study

The relationship of plasma concentration of per- and polyfluoroalkyl substances (PFAS) with blood pressure (BP) is uncertain. This study examined cross-sectional and prospective associations of PFAS with BP and hypertension. We quantified plasma PFAS concentrations from 957 participants enrolled in the lifestyle and placebo arms of the Diabetes Prevention Program (DPP), a randomized controlled trial with approximately 15 years of follow-up. We used multivariable linear and logistic regressions to test cross-sectional associations of six PFAS, including perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), N-ethyl-perfluorooctane sulfonamido acetic acid (EtFOSAA), N-methyl-perfluorooctane sulfonamido acetic acid (MeFOSAA), and perfluorononanoic acid (PFNA), with BP and hypertension prevalence, respectively, at baseline. We used generalized linear mixed models to estimate longitudinal associations between baseline PFAS and the rate of BP changes, and Cox-Proportional hazard models to estimate risk of developing hypertension relative to baseline PFAS. Models were adjusted for baseline age, sex, race/ethnicity, treatment arm, educational attainment, income, marital status, smoking habit, alcohol drinking, and diet. We tested for effect modification by the treatment arm and sex, and accounted for multiple comparisons using the False-Discovery Rate (FDR). PFAS concentrations and hypertension prevalence within the study population (65.3% female, 57.7% White, 65.3% aged 40-59 years) were comparable to the general U.S. population. Cross-sectionally, we found small but statistically significant associations of baseline plasma concentrations of PFOA with systolic BP (β per doubling: 1.49 mmHg, 95% CI: 0.29, 2.70); and MeFOSAA with hypertension (RR = 1.09 per doubling, 95% CI: 1.01, 1.19). Estimates were not statistically significant after FDR adjustment. Longitudinally, we observed null associations in the placebo arm, but some inverse associations of baseline PFOS and MeFOSAA with systolic BP in the lifestyle arm, perhaps due to regression toward the mean. Baseline PFAS concentrations also were not prospectively associated with hypertension risk. Overall, there were modest and mostly null associations of plasma PFAS concentrations with BP and hypertension.

Vitis vinifera L. Grape Skin Extract Prevents Development of Hypertension and Altered Lipid Profile in Spontaneously Hypertensive Rats: Role of Oxidative Stress

This study investigated the protective effect of a Vitis vinifera L. grape skin extract (ACH09) on blood pressure, lipid profile, and oxidative status in spontaneously hypertensive rats (SHR). Systolic blood pressure (SBP), total cholesterol, triglyceride, and glucose levels, as well as oxidative damage and antioxidant activity in the plasma and kidney, were evaluated in four experimental groups: control Wistar rats (W-C) and SHR-C that received water, and Wistar rats and SHR treated with ACH09 (200 mg/kg/d) in drinking water for 12 weeks (W-ACH09 and SHR-ACH09, respectively). SBP increased in the SHR group compared with the W groups and the treatment with ACH09 prevented the development of hypertension. Plasma triglyceride and total cholesterol levels increased in SHR compared with W-C rats; these changes prevented by treatment with ACH09. Glucose levels did not differ between the groups. The SHR group had increased oxidative damage in plasma, as expressed by 2-thiobarbituric acid reactive substances (TBARS) levels, and this prevented by ACH09. Levels of TBARS in the kidneys were lower in the SHR-ACH09 group than in the SHR-C group. Further, ACH09 increased the superoxide dismutase activity in both the plasma and kidneys of both SHR and Wistar rats. These results suggest that ACH09 is protective against disruption of blood pressures, oxidant status, and lipid profile in SHR, and provide important evidence on the benefits of ACH09 on hypertension and associated cardiovascular complications.

Battle between plants as antioxidants with free radicals in human body

Free radicals are constructed by natural physiological activities in the human cells as well as in the environment. They may be produced as a result of diet, smoking, exercise, inflammation, exposure to sunlight, air pollutants, stress, alcohol and drugs. Imbalanced redox status may lead to cellular oxidative stress, which can damage the cells of the body, resulting in an incidence of various diseases. If the endogenous antioxidants do not stop the production of reactive metabolites, they will be needed to bring about a balance in redox status. Natural antioxidants, for example plants, play an important part in this context. This paper seeks to report the available evidence about oxidative stress and the application of plants as antioxidant agents to fight free radicals in the human body. For this purpose, to better understand oxidative stress, the principles of free radical production, the role of free radicals in diseases, antioxidant defense mechanisms, and the role of herbs and diet in oxidative stress are discussed.

Two-step approach for assessing the health effects of environmental chemical mixtures: application to simulated datasets and real data from the Navajo Birth Cohort Study

BACKGROUND

There is increasing interest in examining the consequences of simultaneous exposures to chemical mixtures. However, a consensus or recommendations on how to appropriately select the statistical approach analyzing the health effects of mixture exposures which best aligns with study goals has not been well established. We recognize the limitations that existing methods have in effectively reducing data dimension and detecting interaction effects when analyzing chemical mixture exposures collected in high dimensional datasets with varying degrees of variable intercorrelations. In this research, we aim to examine the performance of a two-step statistical approach in addressing the analytical challenges of chemical mixture exposures using two simulated data sets, and an existing data set from the Navajo Birth Cohort Study as a representative case study.

METHODS

We propose to use a two-step approach: a robust variable selection step using the random forest approach followed by adaptive lasso methods that incorporate both dimensionality reduction and quantification of the degree of association between the chemical exposures and the outcome of interest, including interaction terms. We compared the proposed method with other approaches including (1) single step adaptive lasso; and (2) two-step Classification and regression trees (CART) followed by adaptive lasso method.

RESULTS

Utilizing simulated data sets and applying the method to a real-life dataset from the Navajo Birth Cohort Study, we have demonstrated good performance of the proposed two-step approach. Results from the simulation datasets indicated the effectiveness of variable dimension reduction and reliable identification of a parsimonious model compared to other methods: single-step adaptive lasso or two-step CART followed by adaptive lasso method.

CONCLUSIONS

Our proposed two-step approach provides a robust way of analyzing the effects of high-throughput chemical mixture exposures on health outcomes by combining the strengths of variable selection and adaptive shrinkage strategies.

Effects of abdominal visceral fat compared with those of subcutaneous fat on the association between PM10 and hypertension in Korean men: A cross-sectional study

We assessed whether visceral adipose tissue (VAT) compared with subcutaneous adipose tissue (SAT) has modifying effects on the cross-sectional association between ambient air pollution and hypertension in Korean men. This study included 1,417 adult men who visited a health checkup center. Abdominal fat depots were measured by computed tomography, and we used the annual average concentrations of ambient air pollutants such as particulate matter with an aerodynamic diameter of ≤10 μm (PM₁₀), nitrogen dioxide, sulfur dioxide, and carbon monoxide (CO). The annual mean concentrations of PM₁₀ (odds ratio [OR] = 1.30; 95% confidence interval [CI] = 1.12-1.52) and CO (OR = 1.20; 95% CI = 1.03-1.39) showed a positive association with hypertension. In particular, modifying effects on hypertension were found between PM₁₀ and VAT-related traits such as VAT and visceral-to-subcutaneous fat ratio (VSR). The association between PM₁₀ and hypertension was much stronger in the high-VAT (OR = 1.74; 95% CI = 1.12-2.71) and high-VSR groups (OR = 1.53; 95% CI = 1.23-1.91). However, the strength of association across levels of SAT was not observed (P_int = 0.4615). In conclusion, we found that association between PM₁₀ exposure and hypertension is different by abdominal fat distribution.

The in Vivo Antioxidant Effects of (-)-Epigallocatechin-3-Gallate Consumption in Healthy Postmenopausal Women Measured by Urinary Excretion of Secondary Lipid Peroxidation Products

The present study was carried out to determine whether the consumption of epigallocatechin (EGCG), the major bioactive green tea catechin, exerts a positive effect on lowering in vivo lipid peroxidation, a measure of oxidative stress, in healthy postmenopausal women. Urinary excretion of secondary lipid peroxidation products, a measure of in vivo lipid peroxidation, was determined in 40 participants randomly assigned to consume a green tea catechin extract (843.0 ± 44.0 mg EGCG/d) or placebo capsules for 12 months. Urine samples were analyzed for individual polar and nonpolar lipophilic aldehydes and related carbonyl compounds by high-performance liquid chromatography (HPLC) at the beginning and at the end of the 12-month intervention period. Results show that two nonpolar aldehydes, nonanal and decatrienal, were both 48% lower (p < 0.005) following consumption of EGCG. These results indicate that a modest degree of in vivo antioxidant activity exists with long-term EGCG consumption, which could slightly limit oxidative damage associated with lipid peroxidation and the onset and progression of chronic diseases.

Combined Aerobic and Resistance Exercise Training Improve Hypertension Associated With Menopause

The prevalence of hypertension sharply increases in menopausal women. Recent studies have demonstrated that aerobic or resistance training may help control hypertension. In this study, we report that combining aerobic and resistance training may provide an effective therapeutic approach for hypertension control, attenuating inflammation and oxidative stress in ovariectomized rats. Female Wistar and spontaneous hypertensive rats (SHR) were distributed into four groups: sedentary control (C), sedentary hypertensive (HR), sedentary hypertensive ovariectomized (HR-O), and combined trained hypertensive ovariectomized (T-HR-O). Combined exercise training was performed on a motor treadmill (aerobic training) and on a ladder adapted to rats (resistance training), in alternate days for 8 weeks. Direct arterial pressure was recorded and oxidative stress and inflammation were evaluated in cardiac and renal tissue. Ovariectomy increases increased mean arterial blood pressure, sympathetic modulation, and oxidative stress in SHR. Combining aerobic and resistance training reduced mean arterial blood pressure (12% vs. HR-O), heart rate (8% vs. HR-O), vascular sympathetic modulation (40% vs. HR-O), and improved baroreflex sensitivity. Combined training reduced cardiac inflammation (TNF and IL-6) and cardiac and renal lipoperoxidation (59% and 57%, respectively vs. HR-O). It also enhanced cardiac (71%) and renal (76%) total antioxidant capacity when compared to HR-O group. In conclusion, combining aerobic and resistance training improves mean arterial blood pressure, cardiovascular autonomic control, preventing cardiac and renal oxidative stress and inflammation in an experimental hypertension model with surgical menopause induced with ovariectomy.

Cross-sectional Study: Relationship Between Serum Selenium and Hypertension in the Shandong Province of China

Although selenium, which is a necessary trace element for the human body, has been considered to be beneficial to the cardiovascular system and helpful to lower blood pressure, more and more evidence shows that high amounts of selenium are a risk factor for hypertension. A random multistage sampling which included the cluster method was performed; a total of 9076 urban and rural residents between 18 and 80 years old in the Shandong province of China were investigated by questionnaire, physical examination, and laboratory tests. The prevalence of hypertension was 42.1% in males and 35.3% in females. The mean (standard deviation) selenium concentration was 124.68 (36.32) μg/l in males and 119.54 (31.88) μg/l in females. After adjusting for potential confounders, logistic regression analysis showed that the highest selenium levels were associated with a risk of hypertension (OR = 1.192; 95% CI 1.009-1.407) in females, while there was no significant difference in males (OR = 1.043; 95% CI 0.864-1.259). Our findings suggest that high selenium levels in females are more likely to increase the risk of hypertension compared to similar levels in males. More attention should be paid to the metabolic mechanisms and physiological effects of selenium in females.

Antioxidant properties, ACE/renin inhibitory activities of pigeon pea hydrolysates and effects on systolic blood pressure of spontaneously hypertensive rats

Legumes are rich sources of protein in human diet and their consumption has been associated with the prevention of chronic diseases attributable to their bioactive components. Pigeon pea (Cajanus cajan) is an underutilized legume with relatively high protein content (~24%). Protein hydrolysates were prepared from pea isolate by enzymatic hydrolysis using pepsin and pancreatin. Hydrolysates were evaluated for their amino acid composition, antioxidant properties, in vitro and in vivo antihypertensive properties. The hydrolysates had high hydrophobic amino acids, especially isoleucine, phenylalanine, and leucine. Pepsin-pancreatin-hydrolyzed pea protein (PPHPp) showed significantly higher ability to scavenge DPPH˙ while pancreatin-hydrolyzed pea protein (PPHPa) had higher ˙OH, ABTS˙+ scavenging, Fe3+ reducing and linoleic acid peroxidation inhibition. PPHPp exhibited superior angiotensin-converting enzyme inhibition (61.82%) while PPHPa showed higher renin inhibition (14.28%). PPHPp exhibited strong antihypertensive effect, showing an instantaneous systolic blood pressure lowering effect (-26.12 mmHg) within 2-h post-oral administration. Pigeon pea protein hydrolysate (especially from pancreatin digest) could therefore, be a promising source of bioactive peptides and potential ingredient for formulation of functional foods against oxidative stress and hypertension.

Senescent Microvesicles: A Novel Advance in Molecular Mechanisms of Atherosclerotic Calcification

Atherosclerosis, a chronic inflammatory disease that causes the most heart attacks and strokes in humans, is the leading cause of death in the developing world; its principal clinical manifestation is coronary artery disease. The development of atherosclerosis is attributed to the aging process itself (biological aging) and is also associated with the development of chronic diseases (premature aging). Both aging processes produce an increase in risk factors such as oxidative stress, endothelial dysfunction and proinflammatory cytokines (oxi-inflamm-aging) that might generate endothelial senescence associated with damage in the vascular system. Cellular senescence increases microvesicle release as carriers of molecular information, which contributes to the development and calcification of atherosclerotic plaque, as a final step in advanced atherosclerotic plaque formation. Consequently, this review aims to summarize the information gleaned to date from studies investigating how the senescent extracellular vesicles, by delivering biological signalling, contribute to atherosclerotic calcification.

Hydrogen gas improves left ventricular hypertrophy in Dahl rat of salt-sensitive hypertension

PURPOSE

Hypertension is an important risk factor for death resulting from stroke, myocardial infarction, and end-stage renal failure. Hydrogen (H₂) gas protects against many diseases, including ischemia-reperfusion injury and stroke. The effects of H₂ on hypertension and its related left ventricular (LV) function have not been fully elucidated. The purpose of this study was to investigate the effects of H₂ gas on hypertension and LV hypertrophy using echocardiography.

METHODS

Dahl salt-sensitive (DS) rats were randomly divided into three groups: those fed an 8% NaCl diet until 12 weeks of age (8% NaCl group), those additionally treated with 2% H₂ gas (8% NaCl + 2% H₂ group), and control rats maintained on a diet containing 0.3% NaCl until 12 weeks of age (0.3% NaCl group). H₂ gas was supplied through a gas flowmeter and delivered by room air (2% hydrogenated room air, flow rate of 10 L/min) into a cage surrounded by an acrylic chamber. We evaluated interventricular septal wall thickness (IVST), LV posterior wall thickness (LVPWT), and LV mass using echocardiography.

RESULTS

IVST, LVPWT, and LV mass were significantly higher in the 8% NaCl group than the 0.3% NaCl group at 12 weeks of age, whereas they were significantly lower in the 8% NaCl + 2% H₂ group than the 8% NaCl group. There was no significant difference in systolic blood pressure between the two groups.

CONCLUSION

Our findings suggest that chronic H₂ gas inhalation may help prevent LV hypertrophy in hypertensive DS rats.

Long-Term Excessive Selenium Supplementation Induces Hypertension in Rats

Selenium (Se) is an essential trace element involved in several biological pathways, naturally found in rocks, soils, and food. Even though the daily requirement of Se is achieved through a balanced diet, the use of Se supplements has been frequent. Due to the risk of toxic effects of having Se in excess, supplementation is still under debate. The aim was to evaluate the effects of long-term Se supplementation upon systolic blood pressure (SBP) and redox status of rats exposed to sodium selenite. Male Wistar rats were exposed to 2 and 6 mg/L of sodium selenite in drinking water for 85 days. SBP and body weight were evaluated weekly; oxidative stress biomarkers were measured in blood or plasma; and Se levels were assessed in blood, plasma, kidney, and liver. Se supplementation (2 and 6 mg/L) induced significant increase in the SBP in rats from the 42nd day until the end of the study. This increase on SBP was not associated with significant changes in oxidative stress biomarkers. A significant increase in Se levels was found in whole blood, kidney, and liver from both groups of rats receiving Se supplementation when compared to control. Although the exact mechanisms underlying this augment in SBP are not clear, they are potentially related to other Se biological routes besides the synthesis of selenoproteins, such as GSH-Px. Due to the negative effects upon blood pressure, precautionary measures are advised, since the selling of supplements does not require a medical prescription.

Mechanistic Pathways Underlying the Antihypertensive Effect of Fermented Milk with Lactococcus lactis NRRL B-50571 in Spontaneously Hypertensive Rats

It has been reported that fermented milk (FM) with Lactococcus lactis NRRL B-50571 had an antihypertensive effect in spontaneously hypertensive rats (SHR) and prehypertensive subjects. Therefore, the objective of the present study was to evaluate the possible mechanisms involved (angiotensin converting enzyme inhibition (ACEI), enhancement of nitric oxide production, antioxidant activity and opioid effect), in the antihypertensive effect of FM with SHR. First, twenty one SHR were randomized into three groups to either receive in a single-oral dose of purified water (negative control), FM, or naloxone (opioid receptor antagonist) + FM. In a parallel study, twenty seven SHR were randomized into three groups to either receive ad libitum purified water (negative control), Captopril or FM. After six weeks of treatment ACEI activity, enhancement of nitric oxide production, and antioxidant activity were evaluated in plasma. Results indicated that opioid receptors were not involved in the hypotensive effect of FM. However, ACEI activity (94 U/L), the oxidative stress index (malondialdehyde/catalase + glutathione peroxidase) 0.9, and nitric oxide in plasma (4.4 ± 1.3 U/L), were significantly different from the negative control, and not significantly different from the Captopril group. Thus, these results suggested that these mechanisms are involved in the hypotensive effect of FM.

Oxidative stress impairs cGMP-dependent protein kinase activation and vasodilator-stimulated phosphoprotein serine-phosphorylation

Reactive oxygen species induce vascular dysfunction and hypertension by directly interacting with nitric oxide (NO) which leads to NO inactivation. In addition to a decrease in NO bioavailability, there is evidence that oxidative stress can also modulate NO signaling during hypertension. Here, we investigated the effect of oxidative stress on NO signaling molecules cGMP-dependent protein kinase (PKG) and vasodilator-stimulated phosphoprotein (VASP) which are known to mediate vasodilatory actions of NO. Male Sprague Dawley (SD) rats were provided with tap water (control), 30 mM L-buthionine sulfoximine (BSO, a pro-oxidant), 1 mM tempol (T, an antioxidant) and BSO + T for 3 wks. BSO-treated rats exhibited high blood pressure and oxidative stress. Incubation of mesenteric arterial rings with NO donors caused concentration-dependent relaxation in control rats. However, the response to NO donors was significantly lower in BSO-treated rats with a marked decrease in pD2. In control rats, NO donors activated mesenteric PKG, increased VASP phosphorylation and its interaction with transient receptor potential channels 4 (TRPC4) and inhibited store-operated Ca²⁺ influx. NO failed to activate these signaling molecules in mesenteric arteries from BSO-treated rats. Supplementation of BSO-treated rats with tempol reduced oxidative stress and blood pressure and normalized the NO signaling. These data suggest that oxidative stress can reduce NO-mediated PKG activation and VASP-TRPC4 interaction which leads to failure of NO to reduce Ca²⁺ influx in smooth muscle cells. The increase in intracellular Ca²⁺ contributes to sustained vasoconstriction and subsequent hypertension. Antioxidant supplementation decreases oxidative stress, normalizes NO signaling and reduces blood pressure.

Effects of Yoga Training on Body Composition and Oxidant-Antioxidant Status among Healthy Male

Background

The stressful condition may cause oxidative stress, which is responsible for various diseases.

Aims

The present study was designed to find out whether yoga has impact on the reduction of oxidative stress.

Methods

For the present study, 95 (n = 95) healthy male volunteers within the age group of 18-24 years were included, 35 (n = 35) volunteers were excluded. The remaining 60 (n = 60) volunteers were randomly divided into two groups: (a) Yoga Group (n = 30) and (b) Control Group (n = 30). Yoga training was given for 60 min per day, 6 days per week for 12 weeks in the yoga group, with no yoga training in control group. Assessment of body composition and oxidant-antioxidant status were performed in both the groups at baseline, before yoga training (0 week) and after (12 weeks) of the training.

Results

Significant reduction (P < 0.001) in the percentage of body fat and malondialdehyde; significant elevation (P < 0.001) in superoxide dismutase, catalase, reduced glutathione and ascorbic acid levels were noted in the yoga group after 12 weeks when compared to baseline data (0 week). However, there was no significant difference in height, weight, body mass index, body surface area and lean body mass among the yoga group after 12 weeks when compared to baseline data. These changes might be due to yoga training.

Conclusions

Regular yoga practice reduces body fat and oxidative stress. Yoga training may be helpful to reduce the chance of occurrence of various diseases and helps to maintain normal healthy lifestyle.

Gender-specific associations between serum isomers of perfluoroalkyl substances and blood pressure among Chinese: Isomers of C8 Health Project in China

Previous studies have demonstrated associations of perfluoroalkyl substances (PFASs), a group of highly persistent chemicals ubiquitous in wildlife and humans, with hypertension, but the relationships are mixed. Furthermore, academic literature on the relationship between isomers of PFASs and blood pressure (BP) and hypertension in populations from a higher pollution area is scant. We studied 1612 Chinese adults, ages 22-96years old, from Shenyang, China, utilizing high performance liquid chromatography-mass spectrometry to analyze isomers of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other PFASs in blood serum. We used a mercury sphygmomanometer to measure BP. Hypertension was defined as a mean systolic BP (SBP) of at least 140mmHg, and/or diastolic BP (DBP) of at least 90mmHg, and/or use of antihypertensive medications. The results showed that increased serum concentrations of all (both branched and linear) isomers of PFASs were associated with higher prevalence of hypertension. Adjusted odds ratios for hypertension per ln-unit (ng/mL) increase in PFASs ranged from 1.10 (95%CI: 1.04, 1.17) for perfluorobutanoic acid (PFBA) to 1.26 (95%CI: 1.12, 1.42) for 3+4+5m PFOS, and the estimated increases in mean SBP and DBP ranged from 0.80mmHg (95%CI: 0.25, 1.34) for PFBA to 4.51mmHg (95%CI: 3.52, 5.51) for 3+4+5m PFOS, and from 0.51mmHg (95%CI: 0.01, 1.01) for perfluorodecanesulfonate (PFDS) to 2.48 (1.80, 3.16) for perfluorononanoic acid (PFNA), respectively. Compared with linear PFASs isomers, we identified more and stronger associations among branched PFASs isomers and blood pressure. Furthermore, females exhibited consistently stronger effects than males. In conclusion, this study is the first of its kind to show that not only PFASs positively associated with elevated blood pressure, but also that branched PFAS isomers are more frequently associated with blood pressure than linear PFAS isomers.