Hypercholesterolemia increases endothelial superoxide anion production

Human In Vitro Oxidized Low-Density Lipoprotein (oxLDL) Increases Urinary Albumin Excretion in Rats

Hypercholesterolemia-associated oxidative stress increases the formation of oxidized low-density lipoprotein (oxLDL), which can affect endothelial cell function and potentially contribute to renal dysfunction, as reflected by changes in urinary protein excretion. This study aimed to investigate the impact of exogenous oxLDL on urinary excretion of albumin and nephrin. LDL was isolated from a patient with familial hypercholesterolemia (FH) undergoing lipoprotein apheresis (LA) and was oxidized in vitro with Cu (II) ions. Biochemical markers of LDL oxidation, such as TBARS, conjugated dienes, and free ε-amino groups, were measured. Wistar rats were treated with a single intraperitoneal injection of PBS, LDL, or oxLDL (4 mg of protein/kg b.w.). Urine was collected one day before and two days after the injection. We measured blood lipid profiles, urinary protein excretion (specifically albumin and nephrin), and markers of systemic oxidative stress (8-OHdG and 8-iso-PGF2α). The results showed that injection of oxLDL increased urinary albumin excretion by approximately 28% (310 ± 27 μg/24 h vs. 396 ± 26 μg/24 h, p = 0.0003) but had no effect on nephrin excretion. Neither PBS nor LDL had any effect on urinary albumin or nephrin excretion. Additionally, oxLDL did not affect systemic oxidative stress. In conclusion, hypercholesterolemia may adversely affect renal function through oxidatively modified LDL, which interferes with the renal handling of albumin and leads to the development of albuminuria.

Direct real-time measurements of superoxide release from skeletal muscles in rat limbs and human blood platelets using an implantable Cytochrome C microbiosensor

Oxidative stress and excessive accumulation of the superoxide (O2.-) anion are at the genesis of many pathological conditions and the onset of several diseases. The real time monitoring of (O2.-) release is important to assess the extent of oxidative stress in these conditions. Herein, we present the design, fabrication and characterization of a robust (O2.-) biosensor using a simple and straightforward procedure involving deposition of a uniform layer of L-Cysteine on a gold wire electrode to which Cytochrome C (Cyt c) was conjugated. The immobilized layers, studied using conductive Atomic Force Microscopy (c-AFM) revealed a stable and uniformly distributed redox protein on the gold surface, visualized as conductivity and surface topographical plots. The biosensor enabled detection of (O2.-) at an applied potential of 0.15 V with a sensitivity of 42.4 nA/μM and a detection limit of 2.4 nM. Utility of the biosensor was demonstrated in measurements of real time (O2.-) release in activated human blood platelets and skeletal rat limb muscles following ischemia reperfusion injury (IRI), confirming the biosensor's stability and robustness for measurements in complex biological systems. The results demonstrate the ability of these biosensors to monitor real time release of (O2.-) and estimate the extent of oxidative injury in models that could easily be translated to human pathologies.

Association of plasma xanthine oxidoreductase activity with vascular endothelial function independent of serum uric acid level: MedCity21 health examination registry

Background

Xanthine oxidoreductase (XOR) inhibitor administration, known to reduce uric acid and reactive oxygen species (ROS) production, also improves vascular endothelial function (VEF). This cross-sectional study examined our hypothesis that XOR contributes to impaired VEF through ROS but not uric acid production.

Methods

In 395 subjects (196 males, 199 females) without urate-lowering agent administration who underwent a health examination, plasma XOR activity was determined using our highly sensitive assay based on [13C2,15N2] xanthine and liquid chromatography/triple quadrupole mass spectrometry. For VEF evaluation, flow-mediated dilatation (FMD) in the brachial artery was determined by ultrasound, with physical and laboratory measurements also obtained.

Results

The median values for plasma XOR activity, serum uric acid, and FMD were 26.6 pmol/h/mL, 5.4 mg/dL, and 6.2%, respectively. Simple regression analysis showed weak correlations of both log plasma XOR activity and serum uric acid level with FMD (r = -0.213, p < 0.001 and r = -0.139, p = 0.006, respectively). However, multivariable linear regression analyses revealed that log plasma XOR activity but not serum uric acid level remained associated with FMD (β = -0.116, p = 0.037 and β = 0.041, p = 0.549, respectively) after adjustments for various clinical parameters, with no remarkable inconsistencies for the association observed in subgroups divided based on sex or uric acid level. Finally, a series of mediation analyses showed that serum uric acid level did not meet the criteria for mediator of the association of plasma XOR activity with FMD (p = 0.538).

Conclusions

These findings suggest the possibility that XOR contributes to the pathophysiology of impaired VEF through ROS but not uric acid production.

Consumption of cashew nut induced anxiolytic-like behavior in dyslipidemic rats consuming a high fat diet

This study aimed to evaluate the effect of cashew nut consumption on anxiety-like behavior in dyslipidemic rats. The groups formed were: Control (CONT), Dyslipidemic (DL) and Dyslipidemic cashew nuts (DLCN). Tests to assess anxiety parameters were performed after the treatment period. Brain fatty acid profiles were analyzed. The animals in the DLCN group showed more rearing than DL, without differing from the CONT and less grooming than either the DL and CONT in the Open Field. In the Elevated Plus Maze, DLCN spent more time on the open arms and in the central area compared to the other groups. As for brain fatty acids, there was a reduction in polyunsaturated fatty acids for the DLCN compared to the other groups. The cashew nut, rich in fatty acids, phenolic and flavonoid compounds, reduced the anxiogenic-like behavior caused by dyslipidemia in rats without altering brain fatty acids.

Resistin Contribution to Cardiovascular Risk in Chronic Kidney Disease Male Patients

BACKGROUND

Resistin is a molecule that belongs to the Resistin-Like Molecules family (RELMs), the group of proteins taking part in inflammatory processes. Increased resistin concentrations are observed in cardiovascular complications. Resistin contributes to the onset of atherosclerosis and intensifies the atherosclerotic processes. The aim of this study was to investigate the relationship between resistin and cardiovascular (CV) risk in men with chronic kidney disease (CKD) not treated with dialysis.

MATERIALS AND METHODS

One hundred and forty-two men were included in the study: 99 men with eGFR lower than 60 mL/min/1.73 m² and 43 men with eGFR ≥ 60 mL/min/1.73 m². CV risk was assessed. Serum resistin, tumor necrosis factor-alpha (TNF-alpha) and plasminogen activator inhibitor-1 (PAI-1) were measured among other biochemical parameters.

RESULTS

We observed that resistin concentrations were significantly higher in patients with CKD compared to individuals with eGFR ≥ 60 mL/min/1.73 m² (p = 0.003). In CKD, after estimating the general linear model (GLM), we found that resistin is associated with CV risk (p = 0.026) and PAI-1 serum concentrations (0.012). The relationship of PAI-1 with resistin depends on the level of CV risk in CKD (p = 0.048).

CONCLUSIONS

Resistin concentrations rise with the increase of CV risk in CKD patients and thus resistin may contribute to the progression of cardiovascular risk in this group of patients. The relationship between resistin and CV risk is modified by PAI-1 concentrations.

Endothelial dysfunction due to eNOS uncoupling: molecular mechanisms as potential therapeutic targets

Nitric oxide (NO) is one of the most important molecules released by endothelial cells, and its antiatherogenic properties support cardiovascular homeostasis. Diminished NO bioavailability is a common hallmark of endothelial dysfunction underlying the pathogenesis of the cardiovascular disease. Vascular NO is synthesized by endothelial nitric oxide synthase (eNOS) from the substrate L-arginine (L-Arg), with tetrahydrobiopterin (BH₄) as an essential cofactor. Cardiovascular risk factors such as diabetes, dyslipidemia, hypertension, aging, or smoking increase vascular oxidative stress that strongly affects eNOS activity and leads to eNOS uncoupling. Uncoupled eNOS produces superoxide anion (O₂^-) instead of NO, thus becoming a source of harmful free radicals exacerbating the oxidative stress further. eNOS uncoupling is thought to be one of the major underlying causes of endothelial dysfunction observed in the pathogenesis of vascular diseases. Here, we discuss the main mechanisms of eNOS uncoupling, including oxidative depletion of the critical eNOS cofactor BH₄, deficiency of eNOS substrate L-Arg, or accumulation of its analog asymmetrical dimethylarginine (ADMA), and eNOS S-glutathionylation. Moreover, potential therapeutic approaches that prevent eNOS uncoupling by improving cofactor availability, restoration of L-Arg/ADMA ratio, or modulation of eNOS S-glutathionylation are briefly outlined.

Vascular redox signaling, eNOS uncoupling and endothelial dysfunction in the setting of transportation noise exposure or chronic treatment with organic nitrates

SIGNIFICANCE

Cardiovascular disease and drug-induced health side effects are frequently associated with - or even caused by - an imbalance between the concentrations of reactive oxygen and nitrogen species (RONS) and antioxidants respectively determining the metabolism of these harmful oxidants.

RECENT ADVANCES

According to the "kindling radical" hypothesis, initial formation of RONS may further trigger the additional activation of RONS formation under certain pathological conditions. The present review will specifically focus on a dysfunctional, uncoupled endothelial nitric oxide synthase (eNOS) caused by RONS in the setting of transportation noise exposure or chronic treatment with organic nitrates, especially nitroglycerin. We will further describe the various "redox switches" that are proposed to be involved in the uncoupling process of eNOS.

CRITICAL ISSUES

In particular, the oxidative depletion of tetrahydrobiopterin (BH4), and S-glutathionylation of the eNOS reductase domain will be highlighted as major pathways for eNOS uncoupling upon noise exposure or nitroglycerin treatment. In addition, oxidative disruption of the eNOS dimer, inhibitory phosphorylation of eNOS at threonine or tyrosine residues, redox-triggered accumulation of asymmetric dimethylarginine (ADMA) and L-arginine deficiency will be discussed as alternative mechanisms of eNOS uncoupling.

FUTURE DIRECTIONS

The clinical consequences of eNOS dysfunction due to uncoupling on cardiovascular disease will be summarized also providing a template for future clinical studies on endothelial dysfunction caused by pharmacological or environmental risk factors.

A comparison of principal component analysis, partial least-squares, and reduced-rank regressions in the identification of dietary patterns associated with hypertension: YaHS-TAMYZ and Shahedieh cohort studies

Limited data exist on the advantage of data reduction hybrid methodologies for evaluating the relationship between dietary patterns (DPs) and chronic diseases and they have led to inconsistent results. This study aimed to investigate the association between DPs extracted using principal component analysis (PCA), partial least-squares (PLS), and reduced-rank regressions (RRRs) in identifying DPs associated with hypertension (HTN) risk. The current study was conducted in the context of two cohort studies accomplished in Iran. DPs were generated using PCA, PLS, and RRR methods. Log-binomial logistic regression test was used to assess the association between DPs and the risk of HTN. From a total of 12,403 included participants aged 20-70 years, 507 incident cases of confirmed HTN were identified. The PCA-DP2 was associated with HTN in the fully adjusted model (T3 vs. T1: RR: 0.737, 95% CI: 0.57-0.93, P _trend = 0.013). The PLS-DP2 and HTN risk were inversely associated in the multivariate model (T3 vs. T1: RR: 0.704, 95% CI: 0.54-0.91, P _trend = 0.013). The RRR-DP2 was associated with an increased risk of HTN (T3 vs. T1: RR: 1.412, 95% CI: 1.11-1.80, P _trend = 0.007). Our findings suggest that the RRR method reveals stronger results in association with HTN risk. However, further investigations are required to confirm the association between DPs derived by PLS and RRR methods by incorporating biomarkers related to HTN as the response variables.

Association between atherogenic risk-modulating proteins and endothelium-dependent flow-mediated dilation in coronary artery disease patients

PURPOSE

Endothelial dysfunction is an early and integral event in the development of atherosclerosis and coronary artery disease (CAD). Reduced NO bioavailability, oxidative stress, vasoconstriction, inflammation and senescence are all implicated in endothelial dysfunction. However, there are limited data examining associations between these pathways and direct in vivo bioassay measures of endothelial function in CAD patients. This study aimed to examine the relationships between in vivo measures of vascular function and the expression of atherogenic risk-modulating proteins in endothelial cells (ECs) isolated from the radial artery of CAD patients.

METHODS

Fifty-six patients with established CAD underwent trans-radial catheterization. Prior to catheterization, radial artery vascular function was assessed using a) flow-mediated dilation (FMD), and b) exercise-induced dilation in response to handgrip (HE%). Freshly isolated ECs were obtained from the radial artery during catheterization and protein content of eNOS, NAD(P)H oxidase subunit NOX2, NFκB, ET-1 and the senescence markers p53, p21 and p16 were evaluated alongside nitrotyrosine abundance and eNOS Ser¹¹⁷⁷ phosphorylation.

RESULTS

FMD was positively associated with eNOS Ser¹¹⁷⁷ phosphorylation (r = 0.290, P = 0.037), and protein content of p21 (r = 0.307, P = 0.027) and p16 (r = 0.426, P = 0.002). No associations were found between FMD and markers of oxidative stress, vasoconstriction or inflammation. In contrast to FMD, HE% was not associated with any of the EC proteins.

CONCLUSION

These data revealed a difference in the regulation of endothelium-dependent vasodilation measured in vivo between patients with CAD compared to previously reported data in subjects without a clinical diagnosis, suggesting that eNOS Ser¹¹⁷⁷ phosphorylation may be the key to maintain vasodilation in CAD patients.

Erectile Dysfunction: Pharmacological Pathways with Understudied Potentials

Erectile dysfunction (ED) is a public health concern worldwide. In the past, it was perceived as a phenomenon attributed to age advancement. However, more individuals are affected every year that do not fall under that age criterion. Epidemiological research revealed that this abnormality has an association with endothelial dysfunction connected to several cardiovascular (CV) risk factors. Currently, ED is interpreted as a clinical marker for future adverse events and not only as a present health issue that negatively affects the quality of life. The management of ED involves lifestyle modifications, therapeutic optimization for comorbid conditions, and pharmacological and psychosexual therapy. Phosphodiesterase type 5 (PDE5) inhibitors are the first-line pharmacological agents to be prescribed for such a condition. Nonetheless, other pharmacological pathways and agents remain underinvestigated or were investigated at some stage. This review aimed to present to future researchers interested in this field with some pharmacological agents that showed favorable effects on a limited number of studies on human subjects or experimental models.

mTOR contributes to endothelium-dependent vasorelaxation by promoting eNOS expression and preventing eNOS uncoupling

Clinically used inhibitors of mammalian target of rapamycin (mTOR) negatively impacts endothelial-dependent vasodilatation (EDD) through unidentified mechanisms. Here we show that either the endothelium-specific deletion of Mtor to inhibit both mTOR complexes, or depletion of Raptor or Rictor to disrupt mTORC1 or mTORC2, causes impaired EDD, accompanied by reduced NO in the serum of mice. Consistently, inhibition of mTOR decreases NO production by human and mouse EC. Specifically, inhibition of mTORC1 suppresses eNOS gene expression, due to impairment in p70S6K-mediated posttranscriptional regulation of the transcription factor KLF2 expression. In contrast to mTORC1 inhibition, a positive-feedback between MAPK (p38 and JNK) activation and Nox2 upregulation contributes to the excessive generation of reactive oxygen species (ROS), which causes eNOS uncoupling and decreased NO bioavailability in mTORC2-inhibited EC. Adeno-associated virus-mediated EC-specific overexpression of KLF2 or suppression of Nox2 restores EDD function in endothelial mTORC1- or mTORC2-inhibited mice.

The endothelium-specific inhibition of either of mammalian target of rapamycin (mTOR) complexes impairs endothelial-dependent vasodilatation (EDD), accompanied by decreased nitric oxide bioavailability in both human and mice endothelial cells.

Effects of superoxide anion attack on the lipoprotein HDL

High-density lipoprotein (HDL) is an anti-atherosclerotic lipoprotein. Thanks to the activity of apolipoprotein ApoA1, the principal protein component of HDL, this last is responsible for converting cholesterol into ester form and transporting excessive cholesterol to the liver ("reverse cholesterol transport" RCT). When HDL undergoes oxidation, it becomes dysfunctional and proatherogenic. ApoA1 is a target of oxidation, and its alteration affects RCT and contributes to atherosclerosis development. Until now, the mechanism of HDL oxidation is not fully understood and only hydroxyl radicals seem to induce direct oxidation of protein and lipidic components of lipoproteins. Here we demonstrate that superoxide radical, widely produced in early atherosclerosis, directly oxidizes HDL, and as a consequence, ApoA1 undergoes structural alterations impairing its anti-atherosclerotic functions. Our results highlight in an in vitro system the potential mechanism by which O₂^·- triggers atherosclerotic pathogenesis in vivo. Our study gets the basis for therapeutic approaches focused on the management of superoxide generation in early atherosclerosis onset.

Role of CD40(L)-TRAF signaling in inflammation and resolution—a double-edged sword

Cardiovascular diseases (CVD) and cardiovascular risk factors are the leading cause of death in the world today. According to the Global Burden of Disease Study, hypertension together with ischemic heart and cerebrovascular diseases is responsible for approximately 40% of all deaths worldwide. The major pathomechanism underlying almost all CVD is atherosclerosis, an inflammatory disorder of the vascular system. Recent large-scale clinical trials demonstrated that inflammation itself is an independent cardiovascular risk factor. Specific anti-inflammatory therapy could decrease cardiovascular mortality in patients with atherosclerosis (increased markers of inflammation). Inflammation, however, can also be beneficial by conferring so-called resolution, a process that contributes to clearing damaged tissue from cell debris upon cell death and thereby represents an essential step for recovery from, e.g., ischemia/reperfusion damage. Based on these considerations, the present review highlights features of the detrimental inflammatory reactions as well as of the beneficial process of immune cell-triggered resolution. In this context, we discuss the polarization of macrophages to either M1 or M2 phenotype and critically assess the role of the CD40L-CD40-TRAF signaling cascade in atherosclerosis and its potential link to resolution. As CD40L can bind to different cellular receptors, it can initiate a broad range of inflammatory processes that may be detrimental or beneficial. Likewise, the signaling of CD40L downstream of CD40 is mainly determined by activation of TRAF1-6 pathways that again can be detrimental or beneficial. Accordingly, CD40(L)-based therapies may be Janus-faced and require sophisticated fine-tuning in order to promote cardioprotection.

Role of Oxidative Stress in the Pathogenesis of Atherothrombotic Diseases

Oxidative stress is generated by the imbalance between reactive oxygen species (ROS) formation and antioxidant scavenger system’s activity. Increased ROS, such as superoxide anion, hydrogen peroxide, hydroxyl radical and peroxynitrite, likely contribute to the development and complications of atherosclerotic cardiovascular diseases (ASCVD). In genetically modified mouse models of atherosclerosis, the overexpression of ROS-generating enzymes and uncontrolled ROS formation appear to be associated with accelerated atherosclerosis. Conversely, the overexpression of ROS scavenger systems reduces or stabilizes atherosclerotic lesions, depending on the genetic background of the mouse model. In humans, higher levels of circulating biomarkers derived from the oxidation of lipids (8-epi-prostaglandin F_2α, and malondialdehyde), as well as proteins (oxidized low-density lipoprotein, nitrotyrosine, protein carbonyls, advanced glycation end-products), are increased in conditions of high cardiovascular risk or overt ASCVD, and some oxidation biomarkers have been reported as independent predictors of ASCVD in large observational cohorts. In animal models, antioxidant supplementation with melatonin, resveratrol, Vitamin E, stevioside, acacetin and n-polyunsaturated fatty acids reduced ROS and attenuated atherosclerotic lesions. However, in humans, evidence from large, placebo-controlled, randomized trials or prospective studies failed to show any athero-protective effect of antioxidant supplementation with different compounds in different CV settings. However, the chronic consumption of diets known to be rich in antioxidant compounds (e.g., Mediterranean and high-fish diet), has shown to reduce ASCVD over decades. Future studies are needed to fill the gap between the data and targets derived from studies in animals and their pathogenetic and therapeutic significance in human ASCVD.

Allopurinol Lowers Serum Urate but Does Not Reduce Oxidative Stress in CKD

Xanthine oxidase (XO) contributes to oxidative stress and vascular disease. Hyperuricemia and gout are common in patients with chronic kidney disease (CKD), a population at increased risk of vascular disease. We evaluated effects of allopurinol on serum XO activity and metabolome of CKD patients who had participated in a randomized double-blind clinical trial of allopurinol vs. placebo. XO activity was measured in participants' serum. XO expression in venous endothelial cells was evaluated via immunofluorescence. Gas chromatography mass spectrometry (GC/MS) was utilized for metabolomics analysis. We found that in patients with stage 3 CKD and hyperuricemia, allopurinol lowered serum urate while increasing serum xanthine levels. Allopurinol, however, did not significantly suppress measured serum XO activity. Of note, baseline serum XO activity was low. Additionally, neither baseline serum XO activity nor XO protein expression were associated with measures of vascular dysfunction or with systemic or endothelial biomarkers of oxidative stress. Allopurinol affected several pathways, including pentose phosphate, pyrimidine, and tyrosine metabolism. Our findings suggest that circulating XO does not contribute to vascular disease in CKD patients. In addition to inhibition of XO activity, allopurinol was observed to impact other pathways; the implications of which require further study.

Preventive effect of Artichoke (Cynara scolymus L.) in kidney dysfunction against high fat-diet induced obesity in rats

A high-fat diet (HFD) promotes oxidative stress, which contributes to the development of kidney dysfunction. We examined the protective effects of an ethanol extract of artichoke leaves (EEA) compared to Atorvastatin (ATOR) in the kidney of Wistar rats fed a high-fat diet. The experimental animals were divided into five groups: control (Cont), HFD, HFD treated with EEA (200 mg/kg), HFD treated with EEA (400 mg/kg), and HFD treated with ATOR. Organ weights, lipid profile, renal markers, and antioxidants enzymes were measured. Oral administration of EEA (200 and 400 mg/kg) for 60 days showed a significant decrease in organ weights and kidney markers levels accompanied by decreasing in oxidative stress biomarkers as compared to HFD groups. The histological findings showed a renoprotective effect of artichoke extract. These findings suggest that EEA exerts anti-oxidant kidney effects in HFD- induced obese rats.

Small molecule compound M12 reduces vascular permeability in obese mice via blocking endothelial TRPV4-Nox2 interaction

Transient receptor potential channel TRPV4 and nicotinamide adenine dinucleotide phosphate oxidase (Nox2) are involved in oxidative stress that increases endothelial permeability. It has been shown that obesity enhances the physical association of TRPV4 and Nox2, but the role of TRPV4-Nox2 association in obesity has not been clarified. In this study we investigated the function of TRPV4-Nox2 complex in reducing oxidative stress and regulating abnormal vascular permeability in obesity. Obesity was induced in mice by feeding a high-fat diet (HFD) for 14 weeks. The physical interaction between TRPV4 and Nox2 was measured using FRET, co-immunoprecipitation and GST pull-down assays. The functional interaction was measured by rhodamine phalloidin, CM-H₂DCFDA in vitro, the fluorescent dye dihydroethidium (DHE) staining assay, and the Evans blue permeability assay in vivo. We demonstrated that TRPV4 physically and functionally associated with Nox2, and this physical association was enhanced in aorta of obese mice. Furthermore, we showed that interrupting TRPV4-Nox2 coupling by TRPV4 knockout, or by treatment with a specific Nox2 inhibitor Nox2 dstat or a specific TRPV4 inhibitor HC067046 significantly attenuated obesity-induced ROS overproduction in aortic endothelial cells, and reversed the abnormal endothelial cytoskeletal structure. In order to discover small molecules disrupting the over-coupling of TPRV4 and Nox2 in obesity, we performed molecular docking analysis and found that compound M12 modulated TRPV4-Nox2 association, reduced ROS production, and finally reversed disruption of the vascular barrier in obesity. Together, this study, for the first time, provides evidence for the TRPV4 physically interacting with Nox2. TRPV4-Nox2 complex is a potential drug target in improving oxidative stress and disruption of the vascular barrier in obesity. Compound M12 targeting TRPV4-Nox2 complex can improve vascular barrier function in obesity.

Relevance of the electron transfer pathway in photodynamic activity of Ru(II) polypyridyl complexes containing 4,7-diphenyl-1,10-phenanthroline ligands under normoxic and hypoxic conditions

The purpose of this study was to investigate the correlation between the spectroscopic and photophysical properties of Ru(II) polypyridyl complexes and their photodynamic activity in vitro. A series of Ru(II) polypyridyl complexes with 4,7-diphenyl-1,10-phenanthroline (dip) and 2,3-bis(2-pyridyl)quinoxaline (dpq) and its derivatives were synthesized and characterized regarding their photophysical, biological, and photodynamic properties. The complexes were evaluated not only in the context of ¹O₂ generation but also regarding other types of reactive oxygen species (ROS) to assess the possibility of Ru(II) complexes to induce phototoxicity via various ROS using fluorescence and EPR spectroscopy. The compounds were found to be moderately cytotoxic with IC₅₀ values ranging from 1 to 35 μM and retained their cytotoxic activity under hypoxic conditions. The unraveled phototoxic activity is based mainly on the generation of H₂O₂ and ¹O₂, highlighting the importance of electron-transfer processes in the observed photodynamic activity of Ru polypyridyl complexes. A combination of photodynamic activity with cytotoxicity under decreased dioxygen concentrations may help overcome the current photodynamic therapy (PDT) limitation. The findings highlight the need for broadening the scope of tested Ru-based photosensitizers.

Therapeutic potential of Mucuna pruriens (Linn.) on high-fat diet-induced testicular and sperm damage in rats

Objective

Mucuna pruriens Linn., a leguminous plant, is identified as a herbal medicine for improving fertility-related disorders in the alternative and complementary systems of medicine. The study was focused on evaluating the therapeutic potential of M. pruriens on testis and sperm parameters in a high-fat-induced hypercholesterolemia model.

Materials and Methods

Male rats were divided as normal-control rats (NCR); normal-control rats + M.pruriens (200 mg/kg b.w. of ethanolic extract of M. pruriens seed) treated (NCRD); hypercholesterolemic rats (HCR) and hypercholesterolemic rats + M. pruriens (HCRD). Groups were further divided into three post-exposure periods (subgroups) of 9, 18, and 36 days, and the progressive changes in testis histology and sperm were analyzed.

Results

The study showed a significant impairment in testicular histoarchitecture, depletion of antioxidant enzyme levels, increased oxidative stress and lipid peroxidation in the HCR group. The study indicated severe structural and functional damage in sperm parameters and diminished chromatin integrity in the HCR group. In the HCR rats, the follicular stimulating hormone (FSH) and luteinizing hormone (LH) and testosterone were significantly reduced. There was a significant improvement in sperm parameters and testis histology in the HCRD group.

Conclusion

The study reveals the potential efficacy of M. pruriens to improve spermatogenesis, sperm parameters and hormone levels in hypercholesterolemic rats.

Endothelial Nitric Oxide Synthase (eNOS) and the Cardiovascular System: in Physiology and in Disease States

Endothelial nitric oxide synthase (eNOS) plays a critical role in regulating and maintaining a healthy cardiovascular system. The importance of eNOS can be emphasized from the genetic polymorphisms of the eNOS gene, uncoupling of eNOS dimerization, and its numerous signaling regulations. The activity of eNOS on the cardiac myocytes, vasculature, and the central nervous system are discussed. The effects of eNOS on the sympathetic autonomic nervous system (SANS) and the parasympathetic autonomic nervous system (PANS), both of which profoundly influence the cardiovascular system, will be elaborated. The relationship between the eNOS protein with cardiovascular autonomic reflexes such as the baroreflex and the Exercise Pressor Reflex will be discussed. For example, the effects of endogenous nitric oxide (NO) are shown to be mediated by the eNOS protein and that eNOS-derived endothelial NO is most effective in regulating blood pressure oscillations via modulating the baroreflex mechanisms. The protective action of eNOS on the CVS is emphasized here because dysfunction of the eNOS enzyme is intricately correlated with the pathogenesis of several cardiovascular diseases such as hypertension, arteriosclerosis, myocardial infarction, and stroke. Overall, our current understanding of the eNOS protein with a focus on its role in the modulation, regulation, and control of the cardiovascular system in a normal physiological state and in cardiovascular diseases are discussed.

Alterations in Glycemic Variability, Vascular Health, and Oxidative Stress following a 12-Week Aerobic Exercise Intervention-A Pilot Study

The state of being overweight or obese leads to an increased risk of development of cardiometabolic disease. Increases in glycemic variability have been associated with greater induction of oxidative stress and declined vascular health, which may be exacerbated by higher weight status and improved through exercise. The purpose of this study was to examine the impact of a twelve-week aerobic exercise intervention on continuous glucose monitor (CGM) assessed glucose concentrations and glycemic variability, and biomarkers of vascular health and oxidative stress in overweight or obese adults. Eight adults (Age = 48.9 ± 5.2 years; BMI = 29.4 ± 8.3 kg/m2) completed a twelve-week aerobic exercise intervention. Participants walked three times per week at moderate intensity for ~150 minutes each week. All participants wore a CGM for seven consecutive days at baseline and post-intervention. On the final day of monitoring, a fasting blood sample was collected, and an oral glucose tolerance test (OGTT) was performed. Intra- and inter-day glycemic variability was assessed as the mean amplitude of glycemic excursions, continuous overlapping net glycemic action of one-, two-, and four-hour, and the mean observation of daily differences. Plasma concentrations of nitric oxide (NO) and myeloperoxidase (MPO) were measured, and their ratio was calculated (NO:MPO). No CGM-assessed glucose concentrations or measures of glycemic variability changed from baseline to post-intervention. MPO concentration decreased (24.8 ± 8.2 ng/mL to 16.4 ± 4.6 ng/mL, p < 0.01), the NO:MPO ratio improved (3.5:1 to 6.4:1, p < 0.01) following the twelve-week intervention. Individual level changes in body weight and V̇O₂peak were found. In conclusion, twelve weeks of aerobic exercise reduced oxidative stress and improved the propensity to vasodilate but did not alter CGM-assessed glucose concentrations or glycemic variability in this group of overweight or obese non-diabetic adults. These findings may be due to individual changes in body weight or V̇O2peak, which necessitates further research to explore their influence on these outcomes of interest.

Interleukin-1 receptor antagonism leads to improved anaemia in a murine model of sickle cell disease and is associated with reduced ex vivo platelet-mediated erythrocyte sickling

Sickle cell disease (SCD) is associated with haemolytic anaemia and secondary activation of leucocytes and platelets, which in turn may further exacerbate haemolysis. As cytokine signalling pathways may participate in this cycle, the present study investigated whether pharmacological blockade of the interleukin-1 receptor (IL-1R) would mitigate anaemia in a murine model of SCD. Within 2 weeks of treatment, reduced markers of haemolysis were observed in anakinra-treated mice compared to vehicle-treated mice. After 4 weeks of anakinra treatment, mice showed increased numbers of erythrocytes, haemoglobin, and haematocrit, along with reduced reticulocytes. Blood from anakinra-treated mice was less susceptible to ex vivo erythrocyte sickling and was resistant to exogenous IL-1β-mediated sickling. Supernatant generated from IL-1β-treated platelets was sufficient to promote erythrocyte sickling, an effect not observed with platelet supernatant generated from IL-1R^-/- mice. The sickling effect of IL-1β-treated platelet supernatant was inhibited by a transforming growth factor-β (TGF-β) neutralising antibody, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibition, and superoxide scavengers, but replicated by recombinant TGF-β. In conclusion, pharmacological IL-1R antagonism leads to improved anaemia in a murine SCD model. IL-1β stimulation of platelets promotes erythrocyte sickling. This effect may be mediated by platelet-derived TGF-β-induced reactive oxygen species generation though erythrocyte NADPH oxidase.

Arterial stiffness is associated with oxidative stress and endothelial activation among persons with treated HIV in Zambia

BACKGROUND

Cardiovascular disease (CVD) prevalence is rising among persons with HIV (PLWH) in sub-Saharan Africa. Oxidative stress and endothelial activation, resulting in reduced vascular compliance, are contributors to CVD risk. However, there is a paucity of vascular health data in this population.

OBJECTIVES

To assess the relationships of oxidative stress and endothelial activation with vascular stiffness among PLWH.

METHOD

Fifty-four PLWH on antiretroviral therapy > 5 years and 57 HIV-negative controls, all aged 18-45 years, were enrolled from the University Teaching Hospital, Lusaka, Zambia. Oxidative stress was measured by nitrotyrosine, a peroxynitrite biomarker, and endothelial activation by soluble intercellular adhesion molecule-1 (sICAM-1) plasma levels. Vascular compliance was measured using carotid-radial pulse wave velocity (crPWV) and arterial stiffness index (crASI).

RESULTS

PLWH had higher sICAM-1 levels (median 345 ng/mL) compared to controls (275 ng/mL, p < 0.01), as well as higher nitrotyrosine levels (297 versus 182 nM; p = 0.02). Median crPWV was similar between the groups, but PLWH had higher crASI (2.4 versus 2.2 cm/ms; p < 0.05). After adjusting for age, fat mass, and blood pressure, the estimated effect of a one unit increase in nitrotyrosine on crPWV were twofold higher in the PLWH, but neither reached significance. In a model pooling all participants, there were significant differences in the relationship of nitrotyrosine with crPWV and crASI by HIV status.

CONCLUSION

PLWH in sub-Saharan Africa had significantly greater oxidative stress and endothelial activation compared to HIV-negative individuals. These factors may contribute to increased arterial stiffness and higher CVD prevalence in this population.

The Effects of Spironolactone in Preventing Bile Duct Ligation-induced Hepatitis in A Rat Model

Cholestasis is associated with the accumulation of bile acids and bilirubin in the hepatocytes and leads to liver injury. Pregnane X Receptor (PXR) coordinates protective hepatic responses to toxic stimuli, and this receptor was reported to stimulate bile secretion by increasing MRP2 expression. Since PXR activators were reported to be anti-inflammatory in the liver, PXR was proposed as a drug target for the treatment of chronic inflammatory liver diseases. We investigated the potential protective effect of spironolactone (SPL), an enzyme inducer, in hepatotoxicity induced by bile duct ligation in rats. Wistar Albino (250-300 g) rats were divided into the control group and the bile duct ligated (BDL) group. BDL group was divided into three subgroups; following BDL, for 3 days, the first group received propylene glycol (vehicle of SPL) (blinded), the second subgroup received spironolactone (SPL) (200 mg/kg oral), and the third subgroup received SPL for 3 days, starting 3 days after the bile duct ligation, in order to investigate if it has a healing effect after hepatitis had developed. The control group was sham-operated and received saline. At the end of the experiment, blood and tissue samples were collected. Serum TNF-α, NF-ĸB, bilirubin, IL-6 levels, ALT, AST, ALP activities and tissue MPO activity and oxidant damage increased after the bile duct ligation was significantly decreased following SPL administration. PXR and MRP2 activity showed an increase in the hepatocytes as a result of the treatment. In conclusion, it was observed that SPL administration significantly decreases liver inflammation and damage related to BDL.

Oxidative Stress-Induced Ferroptosis in Cardiovascular Diseases and Epigenetic Mechanisms

The recently discovered ferroptosis is a new kind of iron-regulated cell death that differs from apoptosis and necrosis. Ferroptosis can be induced by an oxidative stress response, a crucial pathological process implicated in cardiovascular diseases (CVDs). Accordingly, mounting evidence shows that oxidative stress-induced ferroptosis plays a pivotal role in angio-cardiopathy. To date, the inhibitors and activators of ferroptosis, as well as the many involved signaling pathways, have been widely explored. Among which, epigenetic regulators, molecules that modify the package of DNA without altering the genome, emerge as a highly targeted, effective option to modify the signaling pathway of ferroptosis and oxidative stress, representing a novel and promising therapeutic potential target for CVDs. In this review, we will briefly summarize the mechanisms of ferroptosis, as well as the role that ferroptosis plays in various CVDs. We will also expound the epigenetic regulators of oxidative stress-induced ferroptosis, and the promise that these molecules hold for treating the intractable CVDs.

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.

Peroxidative degradation of proteins and lipids in undifferentiated connective tissue dysplasia in children, Ukraine

The aim of the study was to assess the state of lipid and protein peroxidation in children with undifferentiated connective tissue dysplasia (UCTD). In this study, 63 children (33 children with UCTD and 30 children without UCTD were recruited and the indicators of lipid and protein peroxidation were measured. The enzymatic, colorimetric method was used to measure the level of total cholesterol (TC). The phospholipids were analyzed by liquid chromatography/mass spectrometry using electrospray ionization. Lipid peroxidation was studied by assessing the change of index and the end product of lipid peroxidation, malondialdehyde (MDA), using spectrophotometric method. Protein peroxidation - by the content of carbonylated protein based on 2,4 dinitrophenyl-hydrazones derivatization. The activity of the antioxidant defense system enzymes was assessed by measuring catalase (CAT) and superoxide dismutase (SOD). Our study revealed a significant increase of PPO products in the venous blood plasma and LPO products in erythrocytes in children with UCTD. Furthermore, an imbalance of the antioxidant defense system was observed in both blood plasma and erythrocytes membrane.

Urine organic acids may be useful biomarkers for metabolic syndrome and its components in Korean adults

OBJECTIVES

Although metabolic syndrome (MetS) and its components are defined clinically, those with MetS may have various derangements in metabolic pathways. Thus, this study aimed to evaluate the traits of urine organic acid metabolites indicating the metabolic intermediates of the pathways in the subjects with MetS.

METHODS

This cross-sectional study included 246 men and 283 women in a hospital health check-up setting. Urine organic acid metabolites were assayed via high-performance liquid chromatography-mass spectrometry analyses. A high level of each metabolite was defined as the fifth quintile of the distribution.

RESULTS

The subjects with MetS had high levels of pyruvate, α-ketoglutarate, α-ketoisovalerate, α-ketoisocaproate, formiminoglutamate, and quinolinate (odds ratios from 1.915 to 2.809 in logistic models adjusted for age and sex). Among the metabolites, pyruvate, formiminoglutamate, and quinolinate were not independent of homeostatic model assessment of insulin resistance (HOMA2-IR). Several metabolites were associated with one or more components of MetS and HOMA2-IR.

CONCLUSIONS

Urine organic acid metabolites in MetS are characterized in altered carbohydrate and amino acid metabolism. MetS shared some traits in insulin resistance. These findings may promote the understanding of the pathophysiology of MetS.

Anti-Inflammatory Drugs in Patients with Ischemic Heart Disease

Inflammation has long been known to play a role in atherogenesis and plaque complication, as well as in some drugs used in therapy for atherosclerotic disease, such as statins, acetylsalicylic acid, and modulators of the renin-angiotensin system, which also have anti-inflammatory effects. Furthermore, inflammatory biomarkers have been demonstrated to predict the incidence of cardiovascular events. In spite of this, and with the exception of acetylsalicylic acid, non-steroidal anti-inflammatory drugs are unable to decrease the incidence of cardiovascular events and may even be harmful to the cardiovascular system. In recent years, other anti-inflammatory drugs, such as canakinumab and colchicine, have shown an ability to reduce the incidence of cardiovascular events in secondary prevention. Colchicine could be a potential candidate for use in clinical practice given its safety and low price, although the results of temporary studies require confirmation in large randomized clinical trials. In this paper, we discuss the evidence linking inflammation with atherosclerosis and review the results from various clinical trials performed with anti-inflammatory drugs. We also discuss the potential use of these drugs in routine clinical settings.

Redox regulation of hemodynamics response to diadenosine tetraphosphate an agonist of P2 receptors and renal function in diet-induced hypercholesterolemic rats

Hypercholesterolemia and oxidative stress may lead to disturbances in the renal microvasculature in response to vasoactive agents, including P2 receptors (P2R) agonists. We investigated the renal microvascular response to diadenosine tetraphosphate (Ap₄A), an agonist of P2R, in diet‐induced hypercholesteremic rats over 28 days, supplemented in the last 10 days with tempol (2 mM) or DL‐buthionine‐(S,R)‐sulfoximine (BSO, 20 mM) in the drinking water. Using laser Doppler flowmetry, renal blood perfusion in the cortex and medulla (CBP, MBP) was measured during the infusion of Ap₄A. This induced a biphasic response in the CBP: a phase of rapid decrease was followed by one of rapid increase extended for 30 min in both the normocholesterolemic and hypercholesterolemic rats. The phase of decreased CBP was not affected by tempol or BSO in either group. Early and extended increases in CBP were prevented by tempol in the hypercholesterolemia rats, while, in the normocholesterolemic rats, only the extended increase in CBP was affected by tempol; BSO prevented extended increase in CBP in normocholesterolemic rats. MBP response is not affected by hypercholesterolemia. The hypercholesterolemic rats were characterized by increased urinary albumin and 8‐isoPGF_2α excretion. Moreover, BSO increased the urinary excretion of nephrin in the hypercholesterolemic rats but, similar to tempol, did not affect the excretion of albumin in their urine. The results suggest the important role of redox balance in the extracellular nucleotide regulation of the renal vasculature and glomerular injury in hypercholesterolemia.

Excesive consumption of unsaturated fatty acids leads to oxidative and inflammatory instability in Wistar rats

Lifestyle modifications such as increase in high-fat food consumption importantly increases the risks for cardiovascular disease. The principal objective of this study is to analyze effects of different high fat diet (HFD) sources on haemodynamic parameters, lipid and oxidative profile, myeloperoxidase activity, and markers of inflammation (IL-6/pentraxin-3). HFD containing 20% of fat, provided by lard (saturated) or soybean oil (unsaturated), as well as control diet were administering to three groups (L, SO and C). Food efficiency ratio and plasma lipids were significantly elevated in both HFD groups. However, only SO group showed an increase in systolic arterial pressure, oxidative stress index, myeloperoxidase activity, liver lipids as well as markers of inflammation: IL-6 and pentraxin-3 (PTX3). In summary, these results indicate inflammogenic potential of excessive soybean oil consumption in triggering liver damage.

The protective role of Coenzyme Q10 in metallothionein-3 expression in liver and kidney upon rats' exposure to lead acetate

Metallothionein-3 (MT3) is an antioxidant protein that alters after exposure to heavy metals. In this study, we investigated the hepatic and renal expression of MT3 gene following exposure to lead acetate (PbAc) alone and PbAc plus CoQ10 as an adjuvant antioxidant. Twenty-four rats were allocated into three groups, including control, PbAc (free access to drinking water contaminated with PbAc at 1 g/100 ml), and PbAc plus CoQ10 (10 mg/kg/day Oral). After 28 consecutive days of treatment, the mRNA expression of MT3 and Cyt-c genes and MT3 protein levels were assessed using real-time PCR and immunosorbent assay. The serum lipid profile was also monitored in the three groups. PbAc exposure significantly reduced the hepatic and renal MT3 mRNA and protein expression compared to the control group. This reduction was significantly increased with addition of CoQ10 to levels near those of the control group. The hepatic and renal expression of Cyt-c mRNA increased after treatment with PbAc, while such effect was reversed after addition of CoQ10. Alteration in lipid profile including increased cholesterol and low-density lipoprotein levels were observed after PbAc exposure which were counteracted by CoQ10. Our results confirm the cytotoxic effects of acute lead exposure manifested as changes in the serum lipid profile and cellular levels of Cyt-c mRNA. These cytotoxic effects may have been caused by decreased MT3 gene expression and be reduced by the protective role of CoQ10.

Oxidative Stress in Ischemic Heart Disease

One of the novel interesting topics in the study of cardiovascular disease is the role of the oxidation system, since inflammation and oxidative stress are known to lead to cardiovascular diseases, their progression and complications. During decades of research, many complex interactions between agents of oxidative stress, oxidation, and antioxidant systems have been elucidated, and numerous important pathophysiological links to na number of disorders and diseases have been established. This review article will present the most relevant knowledge linking oxidative stress to vascular dysfunction and disease. The review will focus on the role of oxidative stress in endotheleial dysfunction, atherosclerosis, and other pathogenetic processes and mechanisms that contribute to the development of ischemic heart disease.

ABCG1 Attenuates Oxidative Stress Induced by H2O2 through the Inhibition of NADPH Oxidase and the Upregulation of Nrf2-Mediated Antioxidant Defense in Endothelial Cells

Summary. Oxidative stress is an important factor that is related to endothelial dysfunction. ATP-binding cassette transporter G1 (ABCG1), a regulator of intracellular cholesterol efflux, has been found to prevent endothelial activation in vessel walls. To explore the role of ABCG1 in oxidative stress production in endothelial cells, HUAECs were exposed to H₂O₂ and transfected with the specific ABCG1 siRNA or ABCG1 overexpression plasmid. The results showed that overexpression of ABCG1 by ABCG1 plasmid or liver X receptor (LXR) agonist T0901317 treatment inhibited ROS production and MDA content induced by H₂O₂ in HUAECs. Furthermore, ABCG1 upregulation blunted the activity of prooxidant NADPH oxidase and the expression of Nox4, one of the NADPH oxidase subunits. Moreover, the increased migration of Nrf2 from the cytoplasm to the nucleus and antioxidant HO-1 expression were detected in HUAECs with upregulation of ABCG1. Conversely, ABCG1 downregulation by ABCG1 siRNA increased NADPH oxidase activity and Nox4 expression and abrogated the increase at Nrf2 nuclear protein levels. In addition, intracellular cholesterol load interfered with the balance between NADPH oxidase activity and HO-1 expression. It was suggested that ABCG1 attenuated oxidative stress induced by H₂O₂ in endothelial cells, which might be involved in the balance between decreased NADPH oxidase activity and increased Nrf2/OH-1 antioxidant defense signaling via its regulation for intracellular cholesterol accumulation.

Oxidative Stress and Antioxidant Treatments in Cardiovascular Diseases

Oxidative stress plays a key role in many physiological and pathological conditions. The intracellular oxidative homeostasis is tightly regulated by the reactive oxygen species production and the intracellular defense mechanisms. Increased oxidative stress could alter lipid, DNA, and protein, resulting in cellular inflammation and programmed cell death. Evidences show that oxidative stress plays an important role in the progression of various cardiovascular diseases, such as atherosclerosis, heart failure, cardiac arrhythmia, and ischemia-reperfusion injury. There are a number of therapeutic options to treat oxidative stress-associated cardiovascular diseases. Well known antioxidants, such as nutritional supplements, as well as more novel antioxidants have been studied. In addition, novel therapeutic strategies using miRNA and nanomedicine are also being developed to treat various cardiovascular diseases. In this article, we provide a detailed description of oxidative stress. Then, we will introduce the relationship between oxidative stress and several cardiovascular diseases. Finally, we will focus on the clinical implications of oxidative stress in cardiovascular diseases.

Protective effect of bromelain on corrosive burn in rats

INTRODUCTION

In some cases, the tongue and oesophagus tissues are damaged by the corrosive burn. Surgical interventions may cause scar formation, and severe burns treatment methods are limited. This study aims to investigate bromelain, a phytotherapeutic product, on the corrosive burn as a non-surgical option and as an adjunctive therapy, insofar as the treatment of corrosive wounds is not limited only to the treatment of oxidative stress and inflammatory reactions.

METHODS

On the tongues of Wistar albino rats, chemically produced oral ulcers were created by topical application of NaOH (40%) solution, and in the distal oesophagus same mixture was applied to produce a corrosive oesophageal burn. For a week, they were treated orally by bromelain (100 mg/kg/day) or saline solution. At the end of seven days, animals were decapitated to remove the tongue and oesophagus, and blood samples were collected to obtain serum. Myeloperoxidase (MPO) activity, malondialdehyde (MDA), glutathione (GSH), interleukin-1 beta (IL-1β) and tumour necrosis factor-alpha (TNF-α) concentrations were measured in serum, and luminol and lucigenin chemiluminescence (CL) were measured in tissue samples.

RESULTS

MDA and CL values were significantly increased, and GSH levels in tissue significantly decreased due to the corrosive burns. Saline treated corrosive burn group measured higher in the serum cytokines in according to the control group.

CONCLUSIONS

Bromelain administration decreased oxidant and inflammatory parameters and increased antioxidant levels in NaOH-induced corrosive burns. Thus, we concluded that bromelain may protect the tongue and oesophagus tissues with its anti-inflammatory and antioxidant effects.

Bisflavonoids fraction from Araucaria bidwilli Hook., reverses hyperlipidemia induced atherosclerosis in high-fat diet induced hyperlipidemia

Background

Hyperlipidemia is a major cause for atherosclerosis which is a frontline cause for mortality in the world. Bisflavonoids are dimeric flavonoids abundant in few medicinal herbs with various pharmacological effects. However, in vivo anti-hyperlipidemic role of bisflavonoids (BFR) is limited. The present investigation is aimed to study BFR from the leaf extract ofAraucaria bidwilliiHook. in rat model of hyperlipidemia.

Results

Administration of HFD was significantly (p< 0.0001) shown to increase total cholesterol (TC), low-density lipoprotein (LDL), and triglycerides (TG) associated with decrease in HDL. BFR at two doses significantly decreased TC, LDL, and TG in HFD-fed rats. In addition, BFR significantly (p< 0.0001) decreased the MDA and significantly (p< 0.0001) increased the impaired anti-oxidant enzyme SOD and CAT in heart tissue induced by HFD. Further, 28 days administration of BFR significantly (p< 0.001) decreased HFD-induced aortic wall thickness.

Conclusion

It can be concluded that bisflavonoids fromA. bidwilliiHook. leaf extract administered to high fat-fed rats showed beneficial anti-hyperlipidemic effect by reducing lipid profiles and protecting the heart tissue from oxidative stress.

Enzymatic antioxidant system and endothelial function in patients with metabolic syndrome

BACKGROUND

This study examined the relationship between serum glutathione peroxidase 1 (GPx-1) activity and endothelial dysfunction in the subjects with and without metabolic syndrome (MetS).

METHODS

This case-control study was conducted on 76 subjects, 38 were patients with MetS and 38 were without MetS. The demographic, clinical, and laboratory features of the subjects were measured and then compared. The MetS was diagnosed according to the definitions of the National Cholesterol Education Program (NCEP) and International Diabetes Federation (IDF). Serum GPx-1 activity was measured by standard methods. Endothelial dysfunction was assessed with flow-mediated dilation (FMD) technique.

RESULTS

In case-control study of 76 subjects, all of MetS risk factors including abdominal obesity, triglyceride (TG), low serum level of high-density lipoprotein cholesterol (HDL-C), hypertension (HTN), and fasting plasma glucose (FPG) were significantly higher than healthy individuals (P < 0.050). FMD was significantly lower than normal subjects (P < 0.050). Serum GP-1 activity was significantly lower in patients with MetS compared to normal subjects (21.7 ± 13.5 vs. 79.0 ± 38.6, respectively) (P = 0.001). The value of GPx-1 was significantly correlated with diastolic blood pressure (DBP) (r = -0.249, P = 0.040), C-reactive protein (CRP) (r = -0.409, P = 0.014), and FMD (r = 0.293, P = 0.050) in patients with MetS. The results of logistic regression showed that a unite increase in CRP (mg/dl), FMD (%), and endothelin-1 (ET-1) (pg/ml) and a unit decrease in GPx significantly increased the odds ratio (OR) of MetS; after adjusting for age and sex the results remained significant except for FMD (P < 0.050)

CONCLUSION

Endothelial dysfunction is related to serum GPx-1 activity in patients with MetS. GPX-1 activity is associated with risk of cardiovascular diseases (CVDs) and peripheral vascular diseases (PVDs) in patients with MetS.

Isolation of Prunin FromBauhinia variegataand Its Antioxidant Activity in Rats Fed an Atherogenic Diet

Atherosclerosis is no longer a disease attributed mainly to high cholesterol content in the body; it has come to be regarded as a chronic inflammatory disease with an autoimmune component. The purpose of this study was to investigate the effect of the prunin fraction (PF) isolated from the ethanolic extract of Bauhinia variegata against the release of various proinflammatory mediators in rats fed an atherogenic diet. The diet was administered orally to Sprague Dawley rats for 60 days to induce atherosclerosis. The blood serum of the rats was used to estimate the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), thiobarbituric acid reactive substance, catalase, total cholesterol, triglyceride, low-density lipoprotein, and high-density lipoprotein using assay kits. Other physical parameters, such as body weight, feed intake, and systolic blood pressure, were also determined during the study. The results showed a significant protective effect of the PF against diet-induced atherosclerosis by decreasing the levels of proinflammatory mediators such as TNF-α and IL-6. Rats treated with PF (20 and 40 mg/kg) showed a change in systolic blood pressure and a reduction in oxidative stress induced by the atherogenic diet. Reduction in body weight and modulation of food intake were observed in PF-treated rats, which indicated atheroprotective, hypolipidemic, and antioxidant effects. The study concludes that the atheroprotective properties of PF are due to effects on the initial phase of plaque formation to thrombus formation. This study may help researchers to find a better alternative for selecting optimal therapies and preventing plaque formation. Future Significance: This article focuses on the molecular mechanisms involved in the evolution of atherosclerotic plaques and different targets that act at the starting stage of the plaque to thrombus formation. This may pave the way for selecting optimal therapies and preventing plaque complications.

Serum uric acid as a sensitive concordant marker with lupus nephritis and new onset of renal damage: a prospective cohort study

OBJECTIVE

The objectives of this study are to assess serum different uric acid levels among systemic lupus erythematosus patients with or without active lupus nephritis in comparison to healthy controls and to study the relation of baseline uric acid levels to the development of new-onset renal damage in lupus nephritis.

METHODS

This is a case-control study followed by a prospective cohort of systemic lupus erythematosus (SLE) patients. Three groups were included; all were having normal kidney function, 25 SLE patients with recently diagnosed active lupus nephritis (LN), 26 SLE patients without LN, and 38 healthy controls. Serum uric acid (SUA)and serum creatinine were done for all groups; for SLE patients, 24-h protein in the urine, urinalysis, C3, C4 levels, anti-DNA, anti-ENA antibodies, SLE Disease Activity Index (SLEDAI), and SLICC/ACR damage index (SDI) evaluation were also calculated. Follow-up was done with clinical and laboratory assessment including SUA, with SLEDAI and SDI evaluation.

RESULTS

Serum uric acid was significantly higher in SLE patients with active LN than the other two groups (p < 0.05), a cutoff value of serum uric acid associated with lupus nephritis onset was 0.41 mmol/L with a sensitivity of 58% and specificity of 100%, however, C3 and C4 showed very low sensitivity and specificity. During follow-up, all patients with LN with baseline serum uric acid ≥ 0.52 mmol/L were associated with new-onset renal damage within 43 months.

CONCLUSIONS

High-serum uric acid levels showed a significant association with lupus nephritis onset and new onset of renal damage. Key Points • Serum uric acid is a cheap, rapid, and popular test available in most of the worldwide laboratories; its higher levels showed a significant association with lupus nephritis onset and new onset of renal damage • The current work is the largest study done on lupus nephritis with strict control to the confound risk factors that are associated with the increase of the uric acid levels; moreover, it is the first study to assess such relation in Saudi population • Uric acid could have a role in the pathogenesis of lupus nephritis patients and consequent renal damage.

The examination of the nephroprotective effect of montelukast sodium and N-acetylcysteine ın renal ıschemia with dimercaptosuccinic acid imaging in a placebo-controlled rat model

Purpose

To determine the nephroprotective effect of NAC and Montelukast Sodium administration against the development of renal damage associated with long warm renal ischemia.

Methods

Twenty-seven rats were randomly divided into 3 study groups, which received NAC, montelukast and placebo, and 3 rats were included in the sham-treated control group. Medications were given 3 days before the procedure. DMSA renal scintigraphy was performed before and after surgery. The right renal pedicle was occluded for 45 min to induce ischemia and then subjected to reperfusion for 6 h (I/R groups).

Results

On pathological examination, the mean pathological scores of the montelukast and NAC groups were significantly lower than those of the placebo group. (p <0.05). In biochemical examination, significant differences were found in all parameter levels between the placebo group and the montelukast and NAC groups. (p <0.05) When postoperative DMSA renal scintigraphy measurements and renal function levels were compared, significant differences were found between the montelukast and NAC groups and the placebo and sham groups.

Conclusion

The administration of NAC and montelukast sodium was seen to have a nephroprotective effect against the development of renal damage associated with warm renal ischemia.

Randomized, Open-Label, Cross-Over Comparison of the Effects of Benzbromarone and Febuxostat on Endothelial Function in Patients with Hyperuricemia

Uric acid is generated with reactive oxygen species via xanthine oxidase (XO), and hyperuricemia, which is identified as the excess of uric acid in the blood, has been associated with vascular endothelial dysfunction. However, the effects of urate-lowering medicines on endothelial function have not been fully elucidated. Thus this study determined and compared the effects of benzbromarone (urate transporter 1 inhibitor) and febuxostat (XO inhibitor) on endothelial function.This randomized, cross-over, open-label study initially recruited 30 patients with hyperuricemia. They were divided into two groups, treated initially with benzbromarone or febuxostat for three months and then were switched for the next three months. Endothelial function was defined as reactive hyperemia indexes (RHI) determined using Endo-PAT 2000 before and at three and six months after medication using the two agents. Blood levels of asymmetric dimethylarginine (ADMA) and high-molecular-weight (HMW) adiponectin were also compared. We finally analyzed data from 24 patients whose endothelial function was assessed as described above.Our findings show that levels of uric acid significantly decreased, whereas those of HMW adiponectin and the RHI have significantly increased after treatment with benzbromarone. Meanwhile, in patients administered with febuxostat, uric acid levels tended to decrease and RHI significantly decreased. Neither of the two agents altered ADMA levels. The changes in RHI (P = 0.026) and HMW adiponectin levels (P = 0.001) were found to be significantly greater in patients treated with benzbromarone than febuxostat. Changes in the levels of HMW adiponectin and of uric acid were significantly correlated (r = -0.424, P = 0.039).Benzbromarone has increased adiponectin besides reducing uric acid levels, and thus, this might confer more benefits on endothelial function than febuxostat.

Revisiting pharmacology of oxidative stress and endothelial dysfunction in cardiovascular disease: Evidence for redox-based therapies

According to the latest Global Burden of Disease Study data, non-communicable diseases in general and cardiovascular disease (CVD) in particular are the leading cause of premature death and reduced quality of life. Demographic shifts, unhealthy lifestyles and a higher burden of adverse environmental factors provide an explanation for these findings. The expected growing prevalence of CVD requires enhanced research efforts for identification and characterisation of novel therapeutic targets and strategies. Cardiovascular risk factors including classical (e.g. hypertension, diabetes, hypercholesterolaemia) and non-classical (e.g. environmental stress) factors induce the development of endothelial dysfunction, which is closely associated with oxidant stress and vascular inflammation and results in CVD, particularly in older adults. Most classically successful therapies for CVD display vasoprotective, antioxidant and anti-inflammatory effects, but were originally designed with other therapeutic aims. So far, only a few 'redox drugs' are in clinical use and many antioxidant strategies have not met expectations. With the present review, we summarise the actual knowledge on CVD pathomechanisms, with special emphasis on endothelial dysfunction, adverse redox signalling and oxidative stress, highlighting the preclinical and clinical evidence. In addition, we provide a brief overview of established CVD therapies and their relation to endothelial dysfunction and oxidative stress. Finally, we discuss novel strategies for redox-based CVD therapies trying to explain why, despite a clear link between endothelial dysfunction and adverse redox signalling and oxidative stress, redox- and oxidative stress-based therapies have not yet provided a breakthrough in the treatment of endothelial dysfunction and CVD.

Cardiovascular safety risks associated with gout treatments

INTRODUCTION

Uric acid is the final byproduct of purine metabolism. The loss of the enzyme that hydrolyzes uric acid to allantoin was lost, leading to a decrease in uric acid excretion and its further accumulation. The buildup of uric acid leads to damage in different organ systems, including the cardiovascular system. With the increasing burden of cardiovascular disease worldwide, a growing body of evidence has addressed the relationship between urate, cardiovascular outcomes, and gout medication cardiovascular safety. Areas covered: We discuss the most common gout therapies used for the reduction of serum urate and management of gout flares in different observational and clinical trials and their effects on different aspects of cardiovascular disease. We selected the most representative clinical studies that evaluated cardiovascular outcomes with each gout therapy as well as recommendation given by the most representative guidelines from Rheumatology societies for the management of gout.

EXPERT OPINION

The treatment of gout reduces joint damage and it can also lessen CV morbidity. Allopurinol shows CV safety profile when compared to other ULTs. Evidence supporting CV safety with the use of colchicine and IL-1 agents is promising and research needs to be conducted to further assess this outcome.

Hempseed (Cannabis sativa) lipid fractions alleviate high-fat diet-induced fatty liver disease through regulation of inflammation and oxidative stress

Diet and lifestyle-induced dysregulated lipid metabolism have been implicated in fatty liver disease. Chronic redox modulation and hepatic inflammation are key pathological mediators and hallmarks of fatty liver disease associated liver steatosis and steatohepatitis. In this context, owing to the beneficial phytochemical properties such as optimal omega-6: omega-3 PUFA ratio of hempseed, we aimed to explore its potential anti-inflammatory and antioxidant properties against high-fat diet (HFD)-induced experimental model of fatty liver disease. The hempseed lipid fractions (HEMP) were prepared and their ameliorating effects on HFD induced morphological changes, lipid profiles, liver function markers (LFT), markers of oxidative stress and inflammation were studied. Results indicated that HEMP administration to hypercholesterolemic rats resolved the morphological, histopathological, and biochemical indicators of fatty liver diseases. Further, the mechanistic evidence revealed that these hepatoprotective effects of HEMP are mediated through inhibition of oxidative stress and inflammatory mediators such as Cox-2, hPGDS, mPGES, IL-4, TNF-α and sEH. In conclusion, current study suggests the plausible antioxidant and anti-inflammatory role of HEMP in alleviating pathophysiological conditions including fatty liver disease, where oxidative stress and inflammation are key mediators.

The interaction between dietary Non-Enzymatic Antioxidant Capacity (NEAC) with variants of Melanocortin-4 receptor (MC4R) 18q21.23-rs17782313 locus on hypothalamic hormones and cardio-metabolic risk factors in obese individuals from Iran

Background: In the current study, we aimed to evaluate the interaction between dietary Non-Enzymatic Antioxidant Capacity (NEAC) and rs17782313 polymorphism on hypothalamic hormones and cardio-metabolic risk factors. Methods: A total of 287 subjects (aged 20-50 years, 147 males and 140 females) enrolled in the cross-sectional study. Dietary NEAC was assessed using databases of NEAC measurements compiled from outcomes for three different analyses: oxygen radical absorbance capacity (ORAC), ferric reducing-antioxidant power (FRAP), and total radical-trapping antioxidant parameter (TRAP) and genotyping for the near MC4R rs17782313 was carried out by Polymerase chain reaction-restriction fragments length polymorphism (PCR-RFLP) method. Results: The significant interactions were found between adherence to the dietary NEAC and MC4R rs17782313 in relation to high-density lipoprotein-cholesterol (HDL-C), glucose, α-melanocyte stimulating hormone (α-MSH), insulin and quantitative insulin sensitivity check index (QUICKI) (P _Interaction = 0.03, 0.01, 0.04, 0.04 and 0.04, respectively). In homozygous subjects for the minor allele, the serum insulin level and QUICKI in participants with the highest adherence to TRAP were significantly higher than those with the lowest adherence (p < 0.001). There was a significant inverse association between high ORAC score and risk of metabolic syndrome even after adjusting for potential confounders (OR: 0.33; 95%CI:0.13-0.81) and also a significant inverse association between high NEAC (ORAC, FRAP and TRAP assays) score and high triglyceride (TG) level was found in obese adults. Conclusion: In conclusion, our study found for the first time that the NEAC significantly interacts with the rs17782313 genotypes to influence several metabolic risk factors in obesity.