Antioxidants and Cardiovascular Risk Factors

Doxorubicin-Induced Cardiac Senescence Is Alleviated Following Treatment with Combined Polyphenols and Micronutrients through Enhancement in Mitophagy

Oxidative stress and impaired mitophagy are the hallmarks of cardiomyocyte senescence. Specifically, a decrease in mitophagic flux leads to the accumulation of damaged mitochondria and the development of senescence through increased ROS and other mediators. In this study, we describe the preventive role of A5+, a mix of polyphenols and other micronutrients, in doxorubicin (DOXO)-induced senescence of H9C2 cells. Specifically, H9C2 cells exposed to DOXO showed an increase in the protein expression proteins of senescence-associated genes, p21 and p16, and a decrease in the telomere binding factors TRF1 and TRF2, indicative of senescence induction. Nevertheless, A5+ pre-treatment attenuated the senescent-like cell phenotype, as evidenced by inhibition of all senescent markers and a decrease in SA-β-gal staining in DOXO-treated H9C2 cells. Importantly, A5+ restored the LC3 II/LC3 I ratio, Parkin and BNIP3 expression, therefore rescuing mitophagy, and decreased ROS production. Further, A5+ pre-treatment determined a ripolarization of the mitochondrial membrane and improved basal respiration. A5+-mediated protective effects might be related to its ability to activate mitochondrial SIRT3 in synergy with other micronutrients, but in contrast with SIRT4 activation. Accordingly, SIRT4 knockdown in H9C2 cells further increased MnSOD activity, enhanced mitophagy, and reduced ROS generation following A5+ pre-treatment and DOXO exposure compared to WT cells. Indeed, we demonstrated that A5+ protects H9C2 cells from DOXO-induced senescence, establishing a new specific role for A5+ in controlling mitochondrial quality control by restoring SIRT3 activity and mitophagy, which provided a molecular basis for the development of therapeutic strategies against cardiomyocyte senescence.

Phytochemistry, Medicinal Properties, Bioactive Compounds, and Therapeutic Potential of the Genus Eremophila (Scrophulariaceae)

The genus Eremophila (family Scrophulariaceae) consists of approximately 200 species that are widely distributed in the semi-arid and arid regions of Australia. Multiple Eremophila spp. are used as traditional medicines by the First Australians in the areas in which they grow. They are used for their antibacterial, antifungal, antiviral, antioxidant, anti-diabetic, anti-inflammatory, and cardiac properties. Many species of this genus are beneficial against several diseases and ailments. The antibacterial properties of the genus have been relatively well studied, with several important compounds identified and their mechanisms studied. In particular, Eremophila spp. are rich in terpenoids, and the antimicrobial bioactivities of many of these compounds have already been confirmed. The therapeutic properties of Eremophila spp. preparations and purified compounds have received substantially less attention, and much study is required to validate the traditional uses and to highlight species that warrant further investigation as drug leads. The aim of this study is to review and summarise the research into the medicinal properties, therapeutic mechanisms, and phytochemistry of Eremophila spp., with the aim of focussing future studies into the therapeutic potential of this important genus.

Urinary Nitric Oxide Levels Are Associated with Blood Pressure, Fruit and Vegetable Intake and Total Polyphenol Excretion in Adolescents from the SI! Program

Nitric oxide (NO) is important to cardiovascular health (CVH), and its bioavailability could be regulated by the antioxidant effect of polyphenols, improving endothelial function and consequently blood pressure (BP). However, scant research has been carried out on NO and CVH correlates in adolescent populations. Therefore, our aim was to investigate the association between NO and the CVH status and other health factors in adolescents. NO, total polyphenol excretion (TPE), anthropometric measurements, BP, blood lipid profile, blood glucose, diet, physical activity, and smoking status were recorded, while CVH score was classified as ideal, intermediate, and poor. Negative associations were observed between NO and body mass index, body fat percentage, BP, and triglycerides; and positive associations between NO and skeletal muscle percentage, HDL-cholesterol, fruit and vegetable intake, and TPE was observed. To capture more complex interactions among different factors, multiple linear regression was performed, obtaining a significant association between NO and fruit and vegetable intake (β = 0.175), TPE (β = 0.225), and systolic BP (β = -0.235). We conclude that urinary NO levels are positively associated with the consumption of fruits and vegetables rich in antioxidants such as polyphenols and negatively associated with systolic BP.

Effects of the Mediterranean diet on the components of metabolic syndrome

Metabolic syndrome, also as known as Syndrome X or Insulin Resistance Syndrome, is a complex health problem featuring visceral obesity (the main diagnostic criterion), insulin resistance, dyslipidemia and high blood pressure. Currently, this health condition has gained a momentum globally while raising concerns among health-related communities. The World Health Organization, American Heart Association and International Diabetes Federation have formulated diagnostic criteria for metabolic syndrome. Diet and nutrition can influence this syndrome: for example, the Western diet is associated with increased risk of metabolic syndrome, whereas the Nordic and Mediterranean diets and the Dietary Approach to Stop Hypertension are potentially beneficial. The Mediterranean diet can affect the components of metabolic syndrome due to its high dietary fiber, omega 3 and 9 fatty acids, complex carbohydrates, antioxidants, minerals, vitamins and bioactive substances, such as polyphenols. These nutrients and bioactive substances can combat obesity, dyslipidemia, hypertension and diabetes mellitus. The mechanisms by which they do so are generally related to oxidative stress, inflammation (the most common risk factors for metabolic syndrome) and gastrointestinal function. The literature also shows examples of positive effects of the Mediterranean diet on the metabolic syndrome. In this review of the literature, we shed light on the effects, mechanisms and dynamic relationship between the Mediterranean diet and metabolic syndrome.

The Impact of Exercise on Redox Equilibrium in Cardiovascular Diseases

Cardiovascular diseases constitute the most important public health problem in the world. They are characterized by inflammation and oxidative stress in the heart and blood. Physical activity is recognized as one of the best ways to prevent these diseases, and it has already been applied in treatment. Physical exercise, both aerobic and anaerobic and single and multiple, is linked to the oxidant–antioxidant imbalance; however, this leads to positive adaptive changes in, among others, the increase in antioxidant capacity. The goal of the paper was to discuss the issue of redox equilibrium in the human organism in the course of cardiovascular diseases to systemize updated knowledge in the context of exercise impacts on the organism. Antioxidant supplementation is also an important issue since antioxidant supplements still have great potential regarding their use as drugs in these diseases.

Ciprofloxacin-Loaded Silver Nanoparticles as Potent Nano-Antibiotics against Resistant Pathogenic Bacteria

Silver nanoparticles (AgNPs) have demonstrated numerous physicochemical, biological, and functional properties suitable for biomedical applications, including antibacterial and drug carrier properties. In the present study, the antibiotic, ciprofloxacin (CIP), was loaded onto AgNPs, which were synthesized via the chemical reduction method, thereby enhancing CIP's antibacterial activity against Gram-negative (Acinetobacter baumannii and Serratia marcescens) and Gram-positive (Staphylococcus aureus) bacterial strains. Polyethylene glycol-400 (PEG) was used to prepare an AgNPs-PEG conjugate with enhanced stability and to act as the linker between CIP and AgNPs, to produce the novel nanocomposite, AgNPs-PEG-CIP. The prepared AgNPs and their conjugates were characterized by ultraviolet-visible spectrophotometry, Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy, transmission electron microscopy, zeta potential analysis, and dynamic light scattering techniques. The inhibitory activity of AgNPs and their conjugates on the growths of pathogenic bacteria was assessed using the well-diffusion method. The results showed the enhanced antibacterial effects of AgNPs-CIP compared to CIP alone. The AgNPs-PEG-CIP nanocomposite showed excellent inhibitory effects against bacterial isolates, with its inhibition zones diameters reaching 39, 36, and 40 mm in S. aureus, A. baumannii, and S. marcescens, respectively. The minimum inhibitory concentration and minimum bactericidal concentration of fogNPs and their conjugates and their antibiofilm effects were also determined. The antioxidant potentials of AgNPs and their conjugates, tested via their 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging ability, showed that the activity increased with increasing AgNPs concentration and the addition of the PEG and/or CIP. Overall, according to the results obtained in the present study, the new nanocomposite, AgNPs-PEG-CIP, showed the highest antibacterial, antibiofilm, and antioxidant activity against the pathogenic bacteria tested, compared to CIP alone. The preparation has high clinical potential for prospective use as an antibacterial agent.

Oxidative Stress Parameters as Biomarkers of Cardiovascular Disease towards the Development and Progression

Cardiovascular disease (CVD) remains the leading cause of death globally, with unhealthy lifestyles today greatly increasing the risk. Over the decades, scientific investigation has been carried out on reactive oxygen species (ROS) and their resultant oxidative stress based on their changes made on biological targets such as lipids, proteins, and DNA. Since the existing clinical studies with antioxidants failed to provide relevant findings on CVD prediction, the focus has shifted towards recognition of oxidised targets as biomarkers to predict prognosis and response to accurate treatment. The identification of redox markers could help clinicians in providing risk stratification for CVD events beyond the traditional prognostic and diagnostic targets. This review will focus on how oxidant-related parameters can be applied as biomarkers for CVD based on recent clinical evidence.

Kolaviron attenuates cardiovascular injury in fructose-streptozotocin induced type-2 diabetic male rats by reducing oxidative stress, inflammation, and improving cardiovascular risk markers

The prevalence of cardiovascular disease among type-2 diabetic patients has become a source of major concern world over. This study explored the protective effect of kolaviron, a bioflavonoid, against oxidative cardiovascular injury in fructose- streptozotocin-induced type 2 diabetic male Sprague Dawley rats. After acclimatization, induction, and confirmation of type-2 diabetes, kolaviron was administered for 28days, after which the animals were anesthetized with Isofor and euthanized. Blood from each rat were collected, and blood samples were then centrifuged for serum and plasma. Cardiac troponin I (cTnI), creatine kinase myocardial band (CK-MB), Creatine phosphokinase (CK), and insulin levels were immediately determined in serum, while remaining samples (serum, plasma, and organs) were stored in the bio-freezer at - 80 °C and 10% formalin for enzyme-link immunosorbent assay (ELISA), biochemical, molecular, and histopathological studies. The results show that type-2 diabetes induction with fructose and streptozotocin led to increased blood glucose levels, decreased insulin levels and cardiac antioxidant enzyme activities, increased malondialdehyde levels, cardiac biomarkers and pro-inflammatory cytokines levels, resulted in abnormal lipid profile, increased blood pressure and angiotensin-converting enzyme (ACE) activity, and decreased plasma endothelial nitric oxide synthase (eNOS) concentration. The histopathological examination of the cardiac tissue revealed severe lesion, hypertrophy, and myofibrils degeneration. However, administration of kolaviron for 28days remarkably improved these conditions. Hence the result from the study validates the potency of kolaviron, and suggests it could serve as an alternative to existing remedy in ameliorating or protecting against cardiovascular injury in type-2 diabetes.

Mycosynthesis of Silver Nanoparticles by Candida albicans Yeast and its Biological Applications

This study conducted a mycosynthesis of silver nanoparticles (AgNPs) by Candida albicans supernatant. The mycosynthesized AgNPs were identified by color visualization, ultraviolet-visible (UV) spectroscopy device, X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDX), field emission scanning electron microscope (FESEM), and zeta potential analysis. The UV-Vis spectroscopy examination has shown the highest absorbance (λmax) at the wavelength of 429 nanometers, which was the indicator of the creation of AgNPs. Furthermore, XRD showed the crystalline structure of AgNPs, and EDX revealed the weight percentage of silver atoms in the sample (82.4%). According to the FESEM, the morphology of AgNPs was spherical, and its size was 40.19 nanometers. Zeta potential analysis indicated that AgNPs were middling stable in the solution, and the zeta potential of AgNPs mycosynthesized by C. albicans was-23.02 mV. The cytotoxic effect of AgNPs against a human colon cancer cell line using MTT assay has shown the presence of toxic action against the cells, and no cytotoxic effect appears on the normal cells. The antioxidant activity of AgNPs using DPPH assay demonstrated 17.0%, 29.3%, 48.3%, 67.6%, and 83.6% at concentrations of 6.25, 12.5, 25, 50, and 100 µg/ml, respectively. The impact of AgNPs on the chromosomal pattern has also been studied. The importance of this study lies in the possibility of the synthesis of AgNPs using this yeast since most nanoparticle preparation methods utilize molds.

Cardiovascular Properties of the Androgen-Induced PCOS Model in Rats: The Role of Oxidative Stress

Polycystic ovary syndrome (PCOS) is a multifaced reproductive endocrinopathy affecting 6-20% of women of childbearing age. It was previously shown that women with PCOS have an increased risk of cardiovascular (CV) diseases. The aim of this study was to evaluate the cardiodynamic parameters of isolated rats' hearts, blood pressure levels, and histomorphological changes in the heart tissue following the androgen-induced PCOS model in rats and the role of oxidative stress in the development of these CV properties of PCOS. 21-day-old female rats (n = 12) were divided into control and PCOS groups. PCOS was induced by administration of testosterone enanthate (1 mg/kg BW, daily) during 35 days. During the autoregulation protocol (40-120 mmHg) on the Langendorff apparatus, ex vivo cardiodynamic parameters of retrogradely perfused hearts showed enhanced contractile function and increased lusitropic effects in the left ventricle (LV) in PCOS rats. Systolic and diastolic pressures in LV were elevated at all perfusion pressure values. Systemic arterial systolic blood pressure showed borderline elevation, while mean arterial blood pressure was significantly higher in PCOS rats. Histological evaluation of heart tissue depicted hypertrophic (8.3%) alterations in LV cardiomyocytes and increase (7.3%) in LV wall thickness. Oxidative stress parameters were altered in systemic circulation, coronary venous effluent (CVE), and heart tissue. Levels of superoxide dismutase and reduced glutathione were decreased in blood and heart tissue, while catalase activity was not altered. Degree of lipid peroxidation was increased in circulation as well as heart tissue. Increased levels of O₂⁻ in CVE indicated the cardiotoxic effects in the rat PCOS model. The mentioned alterations of oxidative stress parameters in the blood, CVE, and heart could be recommended as potential contributors underlying the development of CV risk in PCOS women.

Dietary and supplemental antioxidant intake and risk of major adverse cardiovascular events in older men: The concord health and ageing in men project

BACKGROUND AND AIMS

The role of antioxidant intake in cardiovascular disease remains inconclusive. This study evaluates the association between antioxidant intake and the risk of major adverse cardiovascular events (MACE) among older Australian men.

METHODS AND RESULTS

794 men aged ≥75 years participated in the 3rd wave of the Concord Health and Ageing in Men Project. Dietary adequacy of antioxidant intake was assessed by comparing participants' intake of vitamins A, E, C and zinc to the Nutrient Reference Values (NRV) for Australia. Attainment of NRVs of antioxidants was categorised into a dichotomised variable 'inadequate' (meeting≤2 of 4 antioxidants) or 'adequate' (meeting≥3 of 4 antioxidants). The usage of antioxidant supplements was assessed. The outcome measure was MACE. The composite MACE endpoint was defined as having one of the following: death, myocardial infarction, ischemic stroke, congestive cardiac failure (CCF), and revascularization during the period of observation. There was no significant association between dietary (HR: 1.03, 95% CI: 0.71, 1.48) or supplemental antioxidant intake (HR: 1.10, 95% CI: 0.75, 1.63) and overall MACE. However, a significant association was observed between inadequate antioxidant intake and CCF (HR: 1.32; 95% CI: 1.16, 1.50). The lowest quartile of zinc intake (<11.00 mg/d) was significantly associated with CCF (HR 2.36; 95% CI: 1.04, 5.34). None of the other antioxidants were significantly associated with CCF or other MACE components.

CONCLUSION

Inadequate dietary antioxidant intake, particularly zinc, is associated with increased risk of CCF in older Australian men but not associated with overall MACE.

Reactive Oxygen Species: Modulators of Phenotypic Switch of Vascular Smooth Muscle Cells

Reactive oxygen species (ROS) are natural byproducts of oxygen metabolism in the cell. At physiological levels, they play a vital role in cell signaling. However, high ROS levels cause oxidative stress, which is implicated in cardiovascular diseases (CVD) such as atherosclerosis, hypertension, and restenosis after angioplasty. Despite the great amount of research conducted to identify the role of ROS in CVD, the image is still far from being complete. A common event in CVD pathophysiology is the switch of vascular smooth muscle cells (VSMCs) from a contractile to a synthetic phenotype. Interestingly, oxidative stress is a major contributor to this phenotypic switch. In this review, we focus on the effect of ROS on the hallmarks of VSMC phenotypic switch, particularly proliferation and migration. In addition, we speculate on the underlying molecular mechanisms of these cellular events. Along these lines, the impact of ROS on the expression of contractile markers of VSMCs is discussed in depth. We conclude by commenting on the efficiency of antioxidants as CVD therapies.

Isolation and Characterization of a New Endophytic Actinobacterium Streptomyces californicus Strain ADR1 as a Promising Source of Anti-Bacterial, Anti-Biofilm and Antioxidant Metabolites

In view of the fast depleting armamentarium of drugs against significant pathogens, like methicillin-resistant Staphylococcus aureus (MRSA) and others due to rapidly emerging drug-resistance, the discovery and development of new drugs need urgent action. In this endeavor, a new strain of endophytic actinobacterium was isolated from the plant Datura metel, which produced secondary metabolites with potent anti-infective activities. The isolate was identified as Streptomyces californicus strain ADR1 based on 16S rRNA gene sequence analysis. Metabolites produced by the isolate had been investigated for their antibacterial attributes against important pathogens: S. aureus, MRSA, S. epidermis, Enterococcus faecium and E. faecalis. Minimum inhibitory concentration (MIC₉₀) values against these pathogens varied from 0.23 ± 0.01 to 5.68 ± 0.20 μg/mL. The metabolites inhibited biofilm formation by the strains of S. aureus and MRSA (Biofilm inhibitory concentration [BIC₉₀] values: 0.74 ± 0.08–4.92 ± 0.49 μg/mL). The BIC₉₀ values increased in the case of pre-formed biofilms. Additionally, the metabolites possessed good antioxidant properties, with an inhibitory concentration (IC₉₀) value of 217.24 ± 6.77 µg/mL for 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging. An insight into different classes of compounds produced by the strain ADR1 was obtained by chemical profiling and GC-MS analysis, wherein several therapeutic classes, for example, alkaloids, phenolics, terpenes, terpenoids and glycosides, were discovered.

Recent progress in the use of functional foods for older adults: A narrative review

The number and proportion of older adults are increasing globally, and it is predicted that in 2020, there will be 723 million people worldwide aged 66 and older. In recent decades, numerous studies showed that healthy eating is positively associated with better nutritional status and quality of life, and the decreased incidence of noncommunicable diseases. As older adults become health conscious, the demand for foods and beverages rich in nutrients and bioactive compounds has increased. The increased demand for healthy food stimulated a recent rapid increase in designing, producing, and marketing functional foods to prevent or correct nutrient deficiencies and to improve the nutritional status of older adults. These functional products contain and/or are enriched with dietary fiber; omega-3 polyunsaturated fatty acids; phytoestrogens; polyphenols; carotenoids such as alpha- and beta-carotene; lutein and zeaxanthin; pre-, pro-, and synbiotics; and plant sterols and stanols. A limited number of publications have thoroughly addressed the effect of functional foods on the nutritional status of older adults. The goal of this review was to review existing recent research on the role of functional foods in healthy and active aging.

Exercise-Induced Regulation of Redox Status in Cardiovascular Diseases: The Role of Exercise Training and Detraining

Although low levels of reactive oxygen species (ROS) are beneficial for the organism ensuring normal cell and vascular function, the overproduction of ROS and increased oxidative stress levels play a significant role in the onset and progression of cardiovascular diseases (CVDs). This paper aims at providing a thorough review of the available literature investigating the effects of acute and chronic exercise training and detraining on redox regulation, in the context of CVDs. An acute bout of either cardiovascular or resistance exercise training induces a transient oxidative stress and inflammatory response accompanied by reduced antioxidant capacity and enhanced oxidative damage. There is evidence showing that these responses to exercise are proportional to exercise intensity and inversely related to an individual’s physical conditioning status. However, when chronically performed, both types of exercise amplify the antioxidant defense mechanism, reduce oxidative stress and preserve redox status. On the other hand, detraining results in maladaptations within a time-frame that depends on the exercise training intensity and mode, as high-intensity training is superior to low-intensity and resistance training is superior to cardiovascular training in preserving exercise-induced adaptations during detraining periods. Collectively, these findings suggest that exercise training, either cardiovascular or resistance or even a combination of them, is a promising, safe and efficient tool in the prevention and treatment of CVDs.

Oxidative Imbalance and Kidney Damage: New Study Perspectives from Animal Models to Hospitalized Patients

Chronic kidney disease (CKD) is a major public health problem worldwide and affects both elderly and young subjects. Its main consequences include the loss of renal function, leading to end-stage renal disease, an increased risk of cardiovascular disease, a significant increase in morbidity and mortality, and a decrease in health-related quality of life. This review arose in significant part from work in the authors' laboratory, complemented by literature data, and was based on a translational approach: we studied the role of many CKD risk factors, such as hypertension, obesity, and oxidative stress/inflammation. The aim was to identify new molecular mechanisms of kidney damage to prevent it through successful behavior modifications. For this purpose, in our studies, both human and animal models were used. In the animal models, we analyzed the mechanisms of renal damage induced by hypertension (spontaneously hypertensive rats) and obesity (cafeteria diet-fed rats), showing that redox disequilibrium in plasma and tissue is extremely important in renal alteration in terms of both oxidative damage (lipid peroxidation, altered expression antioxidant enzymes) and apoptotic pathway (intrinsic/extrinsic) activation. In hemodialysis patients, we explored the correlation between the global oxidative balance and both inflammatory markers and cardiovascular risk, showing a strong correlation between the oxidative index and the blood levels of C-reactive protein and previous cardiovascular events. This multilevel approach allowed us to individually and synergistically analyze some aspects of the complex pathogenic mechanisms of CKD in order to clarify the role of the new amplified risk factors for CKD and to prepare an effective personalized prevention plan by acting on both modifiable and nonmodifiable risk factors.

Impaired Oxidative Status Is Strongly Associated with Cardiovascular Risk Factors

The main target of primary prevention is the identification of cardiovascular risk factors aimed at reducing of the adverse impact of modifiable factors, such as lifestyle and pharmacological treatments. In humans, an alteration of the oxidative status has been associated with several pathologies, including diabetes and cardiovascular diseases. However, the prognostic relevance of circulating oxidative stress biomarkers remains poorly understood. Our study explored, in a healthy population (n = 322), the relationship between oxidative status and cardiovascular risk factors. Here, we were successful in demonstrating that plasmatic oxidative status is significantly associated with traditional cardiovascular risk factors. We revealed a significant depletion in the efficacy of total plasma antioxidant barrier in high cardiovascular risk categories, and we confirmed an age-related alteration of oxidative status. The efficacy of total plasma antioxidant barrier is significantly depleted in relation to metabolic disorders. Interestingly, the cholesterol imbalance is the main factor in depleting the efficacy of total plasma antioxidant barrier. The oxidative status is also influenced by hypertension, and a slight increase in systolic blood pressure determines a highly significant effect. We showed that the first detectable event of a redox disturbance is the repairing intervention of the antioxidant barrier that is thus decreased as overutilized.