Natural antioxidants and hypertension: promise and challenges

Evidence supporting the role of hypertension in the onset of migraine

BACKGROUND

The association between hypertension and migraine remains unclear.

OBJECTIVE

The aim of this study employ multi-layered evidence chain that revealed the association between hypertension and migraine.

METHODS

We first strictly included data from the NHANES 1999-2004 population and applied logistic regression, subgroup analysis and RCS to assess the correlation between hypertension, SBP, DBP and migraine. Meanwhile, LDSC and Mendelian randomization were conducted based on the GWAS to determine the causal relationship between hypertension and migraine. Inverse-variance weighted (IVW) was used as the primary method. Sensitivity analysis and Colocalization analysis were performed to confirm the robustness of the results. LDSC validated the genetic correlation between traits. Enrichment analysis revealed their underlying biological mechanisms.

RESULTS

After strict inclusion in NHANES, 10,743 participants were included. The logistic regression showed a significant correlation between hypertension (OR = 1.21 [95% CI, 1.08-1.36], FDR < 0.001)、DBP (OR = 1.01 [95% CI, 1.01-1.02], FDR < 0.001) and migraine. This association did not show significant group differences in subgroup. The MR results further supported the existence of a significant causal relationship between hypertension (OR = 1.77 [95% CI, 1.43-2.30], FDR < 0.001)、DBP (OR = 1.02 [95% CI, 1.01-1.03], FDR < 0.001) and migraine onset. Additionally, the RCS analysis showed a linear relationship (P non-linear = 0.897) between the two. The LDSC result showed a significant genetic correlation between the two (Rg = 0.1092, SE = 0.028, P < 0.001).

CONCLUSION

The development of migraine caused by hypertension is mainly realized through high DBP.

Protective Roles of Zinc and Selenium Against Oxidative Stress in Brain Endothelial Cells Under Shear Stress

BACKGROUND

Hypertension is a major risk factor for cerebrovascular diseases due to its damaging effects on the blood-brain barrier (BBB) and associated pathologies. Oxidative stress-induced endothelial damage plays a critical role in BBB disruption, potentially leading to cognitive impairment and neurodegeneration. In this study, we investigated the protective effects of two essential trace elements, zinc (Zn) and selenium (Se), against oxidative stress in human brain endothelial cells (HBCE5i) exposed to hypertensive shear stress. Using an innovative millifluidic system (LiveBox2), which allows for the precise simulation of continuous flow conditions, we replicated the hemodynamic forces associated with hypertension.

METHODS

Cells were treated with ZnCl2 (5-50 µM) or Na2SeO3 (50-500 nM) at concentrations selected based on previous studies and confirmed by cytotoxicity assays.

RESULTS

Our results demonstrated that shear stress significantly altered the localization of the tight junction protein zonula occludens-1 (ZO-1) and induced the nuclear translocation of the transcription factor NRF2, a hallmark of oxidative stress. Importantly, treatment with 10 µM ZnCl2 preserved ZO-1 membrane localization and prevented NRF2 translocation, as confirmed by quantitative image analysis. In contrast, Na2SeO3 did not provide comparable protection, although modest improvements in ZO-1 localization were observed in some replicates.

DISCUSSION

We discuss potential reasons for selenium's limited efficacy, including differences in bioavailability and cellular uptake. Our findings underscore zinc's promising role as a neurovascular protector and suggest that further investigation into more complex in vitro models and in vivo studies is warranted.

Effect of carotenoid supplementation on blood pressure in adults: a GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials

CONTEXT

Hypertension (HTN) is regarded as a serious public health issue throughout the world. High blood pressure (BP) may be improved by carotenoid supplementation; however, randomized controlled trials (RCTs) provide conflicting evidence.

OBJECTIVE

The aim of this study was to evaluate the effects of carotenoid supplementation on BP in RCTs by systematically review and meta-analysis.

DATA SOURCES

A comprehensive literature search was performed in the Scopus, PubMed, and Web of Science databases until October 2023, with no limitation on the date or language of publication.

DATA EXTRACTION

Studies that evaluated the net effects of carotenoids in the form of supplements on BP in adults were selected. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated on the basis of a fixed or random-effects model. Sensitivity analysis, meta-regression, publication bias, and heterogeneity were assessed using standard methods. Cochrane quality assessments were used to evaluate the included studies' bias risks. Evidence certainty was calculated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework).

DATA ANALYSIS

Reports on a total of 19 RCTs involving 1151 participants were included in this review. Carotenoid supplementation significantly reduced the systolic BP (SBP) (WMD, -2.492 mmHg; 95%CI, -4.52, -0.47; P = 0.016) and diastolic BP (DBP) (WMD, -1.60 mmHg; 95%CI, -2.73, -0.47; P = 0.005). Greater effects were observed in Asian participants, those aged >50 years, nonhealthy participants, and participants with a baseline SBP ≥130 mmHg and DBP ≥80 mmHg, at dose >10 mg. Dose-response analysis showed that carotenoid supplementation decreased SBP and DBP levels at doses of, respectively, 0-25 and 0-20 mg/d. Evidence for all SBP, DBP, and heart rate values was high quality.

CONCLUSIONS

Carotenoid supplementation had a beneficial effect on BP parameters, especially in nonhealthy study participants with high BP baseline levels.

PROSPERO REGISTRATION NO

CRD42023402740.

Towards the Development of Novel, Point-of-Care Assays for Monitoring Different Forms of Antioxidant Activity: The RoXstaTM System

(1) Background: This study set out to develop a series of simple, novel, rapid methods for assessing different forms of antioxidant activity. (2) Methods: An ABTS platform was used to engineer: (i) an electrochemical post-activation assay to assess free radical scavenging activity; (ii) an electrochemical pre-activation strategy to assesses the suppression of free radical formation; (iii) a horseradish peroxidase-mediated oxidation system to monitor hydrogen peroxide scavenging activity and (iv) a cumene peroxide-hematin system to determine the ability of samples to scavenge the mixture of organic peroxides and peroxyl and alkoxyl radicals generated in the presence of these reagents. Each assay was assessed against a panel of candidate antioxidant compounds to determine their relative activities and specificities. In addition, human semen samples were analyzed to determine how the results of these antioxidant assays correlated with semen quality. (3) Results: All 4 assays revealed dose-dependent antioxidant activity on the part of vitamin C, N-acetyl cysteine, hypotaurine, BSA, melatonin, glutathione, resveratrol and epigallocatechin gallate. The other compounds tested either completely lacked antioxidant activity or were only active in one of the assays. Using unfractionated human semen as an exemplar of biological fluids rich in antioxidants, the outputs from the individual assays were found to reflect different aspects of semen quality. When the data from all 4 assays were combined, accurate predictions were generated reflecting the importance of oxidative stress in defining semen quality as reflected by sperm count, seminal lipid aldehyde content, sperm DNA damage and free radical generation by the sperm mitochondria. (4) Conclusions: The methodologies described in this paper constitute the basis for rapid, point-of-care assessments of oxidative stress.

A Systematic Review on Advances in Management of Oxidative Stress-Associated Cardiovascular Diseases

Oxidative stress plays a significant role in the pathogenesis of cardiovascular diseases, such as myocardial ischemia/reperfusion injury, atherosclerosis, heart failure, and hypertension. This systematic review aims to integrate most relevant studies on oxidative stress management in cardiovascular diseases. We searched relevant literatures in the PubMed database using specific keywords. We put emphasis on those manuscripts that were published more recently and in higher impact journals. We reviewed a total of 200 articles. We examined current oxidative stress managements in cardiovascular diseases, including supplements like resveratrol, vitamins C and E, omega-3 fatty acids, flavonoids, and coenzyme-10, which have shown antioxidative properties and potential cardiovascular benefits. In addition, we reviewed the pharmacological treatments including newly discovered antioxidants and nanoparticles that show potential effects in targeting the specific oxidative stress pathways. Lastly, we examined biomarkers, such as soluble transferrin receptor, transthyretin, and cystatin C in evaluating antioxidant status and identifying cardiovascular risk. By addressing oxidative stress management and mechanisms, this paper emphasizes the importance of maintaining the balance between oxidants and antioxidants in the progression of cardiovascular diseases. This review paper is registered with the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY), registration # INPLASY202470064.

Protective effects of the R-(+)-thioctic acid treatment: possible anti-inflammatory activity on heart of hypertensive rats

BACKGROUND

In cardiovascular disease, high blood pressure is associated with oxidative stress, promoting endothelial dysfunction, vascular remodeling, and inflammation. Clinical trials are discordant that the most effective treatment in the management of hypertension seems to be the administration of anti-hypertensive drugs with antioxidant properties. The study aims to evaluate the effects of the eutomer of thioctic acid on oxidative stress and inflammation in the heart of spontaneously hypertensive rats compared to normotensive Wistar Kyoto rats.

METHODS

To study the oxidative status, the malondialdehyde and 4-hydroxynonenal concentration, protein oxidation were measured in the heart. Morphological analysis were performed. Immunohistochemistry and Western blot were done for alpha-smooth muscle actin and transforming growth factor beta to assess fibrosis; cytokines and nuclear factor kappaB to assess inflammatory processes.

RESULTS

Spontaneously hypertensive rats were characterized by hypertension with increased malondialdehyde levels in the heart. OxyBlot in the heart of spontaneously hypertensive rats showed an increase in proteins' oxidative status. Cardiomyocyte hypertrophy and fibrosis in the ventricles were associated with an increased expression of alpha-smooth muscle actin and pro-inflammatory cytokines, reduced by the eutomer of thioctic acid supplementation.

CONCLUSIONS

Based on this evidence, eutomer of thioctic acid could represent an appropriate antioxidant molecule to reduce oxidative stress and prevent inflammatory processes on the cardiomyocytes and cardiac vascular endothelium.

Mitochondrial dysfunction and its association with age-related disorders

Aging is a complex process that features a functional decline in many organelles. Various factors influence the aging process, such as chromosomal abnormalities, epigenetic changes, telomere shortening, oxidative stress, and mitochondrial dysfunction. Mitochondrial dysfunction significantly impacts aging because mitochondria regulate cellular energy, oxidative balance, and calcium levels. Mitochondrial integrity is maintained by mitophagy, which helps maintain cellular homeostasis, prevents ROS production, and protects against mtDNA damage. However, increased calcium uptake and oxidative stress can disrupt mitochondrial membrane potential and permeability, leading to the apoptotic cascade. This disruption causes increased production of free radicals, leading to oxidative modification and accumulation of mitochondrial DNA mutations, which contribute to cellular dysfunction and aging. Mitochondrial dysfunction, resulting from structural and functional changes, is linked to age-related degenerative diseases. This review focuses on mitochondrial dysfunction, its implications in aging and age-related disorders, and potential anti-aging strategies through targeting mitochondrial dysfunction.

Arterial hypertension in the chronic evolution of migraine: bystander or risk factor? An overview

BACKGROUND

Several risk factors are associated with the chronic evolution of migraine. Clinical and preclinical studies have provided data about the role of hypertension (HT) as one of the potential modifiable risk factors of chronic migraine (CM). This review is focused on the biological and clinical evidence supporting common mechanisms underlying HT and migraine and the potential role of HT in the transition from episodic to chronic migraine.

METHODS

We conducted a narrative review from a literature search covering the available evidence from studies investigating: i) the role of HT in the transition to CM in clinical practice; ii) the biological mechanisms potentially underpinning the association between HT and evolution to CM; iii) the role of antihypertensive medications in migraine prophylaxis.

RESULTS

HT proved to be at the base of multiple mechanisms underlying migraine and migraine chronicization. Endothelial dysfunction, blood-brain barrier alterations, calcitonin gene-related peptide signaling, and renin-angiotensin-aldosterone system dysregulation are involved in the worsening effect of HT on migraine frequency, and the role of HT in the transition to CM is supported by clinical observations.

CONCLUSIONS

The observed evidence supports HT contribution to CM evolution due to shared pathophysiologic mechanisms. While a bidirectional influence appears to be ascertained, data are still lacking about the one-way role of HT as direct risk factor for CM transition. Further research is needed to confirm a causal role of HT in this process.

Discovery of Potent Angiotensin-Converting Enzyme Inhibitors in Pomegranate as a Treatment for Hypertension

Pomegranate (Punica granatum L.) is associated with numerous health benefits due to its high levels of antioxidant polyphenolic substances. Since pomegranate extract has been shown to inhibit angiotensin-converting enzyme (ACE), the potential inhibitory effect of most of its main constituents against ACE is unknown. Therefore, we tested the activities of 24 major compounds, the majority of which significantly inhibited ACE. Notably, pedunculagin, punicalin, and gallagic acid were the most effective ACE inhibitors with IC₅₀ values of 0.91, 1.12, and 1.77 μM, respectively. As demonstrated in molecular docking studies, compounds block ACE by forming multiple hydrogen bonds and hydrophobic interactions with catalytic residues and zinc ions in ACE's C- and N-domains, consequently inhibiting ACE's catalytic activity. Also, the most active pedunculagin stimulated nitric oxide (NO) production, activated the endothelial nitric oxide synthase enzyme (eNOS), and significantly increased eNOS protein expression levels up to 5.3-fold in EA.hy926 cells. Furthermore, pedunculagin increased in cellular calcium (Ca²⁺) concentration promoted eNOS enzyme activation and reduced the production of reactive oxygen species (ROS). In addition, the active compounds improved glucose uptake in insulin-resistant C2C12 skeletal muscle cells in a dose-dependent manner. The results of these computational, in vitro, and cellular experiments provide further evidence to the traditional medicine that involves using pomegranates to treat cardiovascular diseases like hypertension.

Oxidative stress and metabolic syndrome in acne vulgaris: Pathogenetic connections and potential role of dietary supplements and phytochemicals

Acne vulgaris is a highly prevalent skin condition caused by androgen-induced elevated sebum secretion, abnormal keratinization, bacterial colonization, and inflammation. Current research indicates a link between acne vulgaris and the metabolic syndrome, a group of disorders that includes obesity, insulin resistance, hypertension, and dyslipidemia. This link is thought to be modulated by excessive concentrations of oxidative stress markers and chronic inflammation, which are included in the pathophysiological mechanisms shared by both conditions. Excessive generation of reactive oxygen species damages cellular components and initiates an inflammatory response, hence promoting the development of both disorders. The current narrative review focuses on the molecular implications of inflammatory, hormonal, and environmental factors in the acne-metabolic syndrome correlation. Furthermore, it outlines the current state of knowledge related to the phyto-therapeutic approach to these conditions as an adjuvant strategy to allopathic treatment, but future multicenter and larger-scale research studies are needed establish new algorithms to be included in the future management of patients with these conditions.

The Influence of Dietary Interventions on Arterial Stiffness in Overweight and Obese Subjects

Arterial stiffness is often increased in overweight/obese subjects before the development of hypertension. It is also one of the earliest indicators of increased cardiovascular disease risk and can be considered a good predictor of the development of subclinical cardiovascular dysfunction. Arterial stiffness is a significant prognostic factor influencing cardiovascular risk, which dietary habits can modify. Obese patients should use the caloric-restricted diet because it augments aortic distensibility, diminishes pulse wave velocity (PWV), and increases the activity of endothelial nitric oxide synthases. High intake of saturated fatty acids (SFA), trans fats, and cholesterol, typical for the Western diet, impairs endothelial function and raises brachial-ankle PMV. The replacement of SFA with monounsaturated (MUFA) or polyunsaturated fatty acids (PUFA) derived from seafood and plants diminishes the risk of arterial stiffness. The dairy product intake (excluding butter) decreases PWV in the general population. The high-sucrose diet causes toxic hyperglycemia and increases arterial stiffness. Complex carbohydrates with a low glycemic index (including isomaltose) should be recommended to keep vascular health. The high sodium intake (>10 g/day), particularly associated with low potassium consumption, has a deleterious effect on arterial stiffness (↑ baPWV). Since vegetables and fruits are good sources of vitamins and phytochemicals, they should be recommended in patients with high PMV. Thus, the dietary recommendation to prevent arterial stiffness should be similar to the Mediterranean diet, which is rich in dairy products, plant oils, and fish, with a minimal red meat intake and five servings of fruits and vegetables daily.

Oxidative Stress, Antioxidants and Hypertension

As a major cause of morbidity and mortality globally, hypertension remains a serious threat to global public health. Despite the availability of many antihypertensive medications, several hypertensive individuals are resistant to standard treatments, and are unable to control their blood pressure. Regulation of the renin-angiotensin-aldosterone system (RAAS) controlling blood pressure, activation of the immune system triggering inflammation and production of reactive oxygen species, leading to oxidative stress and redox-sensitive signaling, have been implicated in the pathogenesis of hypertension. Thus, besides standard antihypertensive medications, which lower arterial pressure, antioxidant medications were tested to improve antihypertensive treatment. We review and discuss the role of oxidative stress in the pathophysiology of hypertension and the potential use of antioxidants in the management of hypertension and its associated organ damage.

Neurogenic Hypertension, the Blood-Brain Barrier, and the Potential Role of Targeted Nanotherapeutics

Hypertension is a major health concern globally. Elevated blood pressure, initiated and maintained by the brain, is defined as neurogenic hypertension (NH), which accounts for nearly half of all hypertension cases. A significant increase in angiotensin II-mediated sympathetic nervous system activity within the brain is known to be the key driving force behind NH. Blood pressure control in NH has been demonstrated through intracerebrovascular injection of agents that reduce the sympathetic influence on cardiac functions. However, traditional antihypertensive agents lack effective brain permeation, making NH management extremely challenging. Therefore, developing strategies that allow brain-targeted delivery of antihypertensives at the therapeutic level is crucial. Targeting nanotherapeutics have become popular in delivering therapeutics to hard-to-reach regions of the body, including the brain. Despite the frequent use of nanotherapeutics in other pathological conditions such as cancer, their use in hypertension has received very little attention. This review discusses the underlying pathophysiology and current management strategies for NH, as well as the potential role of targeted therapeutics in improving current treatment strategies.

Supplementation with Two New Standardized Tea Extracts Prevents the Development of Hypertension in Mice with Metabolic Syndrome

Hypertension is considered to be both a cardiovascular disease and a risk factor for other cardiovascular diseases, such as coronary ischemia or stroke. In many cases, hypertension occurs in the context of metabolic syndrome (MetS), a condition in which other circumstances such as abdominal obesity, dyslipidemia, and insulin resistance are also present. The high incidence of MetS makes necessary the search for new strategies, ideally of natural origin and with fewer side effects than conventional pharmacological treatments. Among them, the tea plant is a good candidate, as it contains several bioactive compounds such as caffeine, volatile terpenes, organic acids, and polyphenols with positive biological effects. The aim of this study was to assess whether two new standardized tea extracts, one of white tea (WTE) and the other of black and green tea (CTE), exert beneficial effects on the cardiovascular alterations associated with MetS. For this purpose, male C57/BL6J mice were fed a standard diet (Controls), a diet high in fats and sugars (HFHS), HFHS supplemented with 1.6% WTE, or HFHS supplemented with 1.6% CTE for 20 weeks. The chromatography results showed that CTE is more concentrated on gallic acid, xanthines and flavan-3-ols than WTE. In vivo, supplementation with WTE and CTE prevented the development of MetS-associated hypertension through improved endothelial function. This improvement was associated with a lower expression of proinflammatory and prooxidant markers, and—in the case of CTE supplementation—also with a higher expression of antioxidant enzymes in arterial tissue. In conclusion, supplementation with WTE and CTE prevents the development of hypertension in obese mice; as such, they could be an interesting strategy to prevent the cardiovascular disorders associated with MetS.

Antihypertensive and Vasorelaxant Effects of Hibiscus rosa-sinensis through Angiotensin-Converting Enzyme-2 (ACE-2), and Ca2+ channels Pathways

AIMS

The aim of the study was to assess the antihypertensive activity of Hibiscus rosa-sinensis.

BACKGROUND

Hibiscus rosa-sinensis is used traditionally to treat hypertension.

OBJECTIVE

The goal of the study was to investigate the effect of the aqueous extract of Hibiscus rosa-sinensis flowers (AEHRS) on resting blood pressure in rats.

MATERIAL AND METHODS

In the present study, AEHRS was prepared and its antihypertensive activity was evaluated using in vivo and in vitro studies. In the in vivo study, hypertensive and normotensive rats were treated by AEHRS (100 mg/kg) orally for 6 hours in the acute treatment and for 7 days in the subchronic treatment. Systolic, diastolic, and mean arterial blood pressure values and heart rate were then recorded using a tail cuff and a computer-assisted monitoring device. To assess the vasorelaxant activity of AEHRS, isolated thoracic aortic rings were suspended in a tissue bath and changes in tension were recorded using a data acquisition system. Potential pathways involved in the vasorelaxant activity were evaluated using several standard pharmacological agents.

RESULTS

The results indicated that repeated oral administration of AEHRS during 7 days lowered systolic, diastolic, and mean arterial blood pressure in hypertensive rats without affecting normotensive rats. Furthermore, the data revealed that AEHRS exerts vasorelaxant properties via an endothelium-independent pathway. More interestingly, the study demonstrates that the vasorelaxant capacity of AEHRS seems to be exerted through the stimulation of angiotensin-converting enzyme-2 (ACE-2) and the inhibition of Ca2+ channels pathway.

CONCLUSION

The present study revealed that aqueous extract of Hibiscus rosa-sinensis has a significant antihypertensive activity and that its vasorelaxant effect may be mediated through stimulation of ACE-2, and inhibition of the Ca2+ channels.

Oxidative Stress-Induced Hypertension of Developmental Origins: Preventive Aspects of Antioxidant Therapy

Hypertension remains the leading cause of disease burden worldwide. Hypertension can originate in the early stages of life. A growing body of evidence suggests that oxidative stress, which is characterized as a reactive oxygen species (ROS)/nitric oxide (NO) disequilibrium, has a pivotal role in the hypertension of developmental origins. Results from animal studies support the idea that early-life oxidative stress causes developmental programming in prime blood pressure (BP)-controlled organs such as the brain, kidneys, heart, and blood vessels, leading to hypertension in adult offspring. Conversely, perinatal use of antioxidants can counteract oxidative stress and therefore lower BP. This review discusses the interaction between oxidative stress and developmental programming in hypertension. It will also discuss evidence from animal models, how oxidative stress connects with other core mechanisms, and the potential of antioxidant therapy as a novel preventive strategy to prevent the hypertension of developmental origins.

Vasorelaxant Activities and its Underlying Mechanisms of Magnolia Volatile Oil on Rat Thoracic Aorta Based on Network Pharmacology

Objective: Magnolia volatile oil (MVO) is a mixture mainly containing eudesmol and its isomers. This study was to investigate the vasorelaxant effects and the underlying mechanism of MVO in rat thoracic aortas.

Method: The present study combined gas chromatography–mass spectrometry (GC-MS) and network pharmacology analysis with in vitro experiments to clarify the mechanisms of MVO against vessel contraction. A compound–target network, compound–target–disease network, protein–protein interaction network, compound–target–pathway network, gene ontology, and pathway enrichment for hypertension were applied to identify the potential active compounds, drug targets, and pathways. Additionally, the thoracic aortic rings with or without endothelium were prepared to explore the underlying mechanisms. The roles of the PI3K-Akt-NO pathways, neuroreceptors, K⁺ channels, and Ca²⁺ channels on the vasorelaxant effects of MVO were evaluated through the rat thoracic aortic rings.

Results: A total of 29 compounds were found in MVO, which were identified by GC-MS, of which 21 compounds with a content of more than 0.1% were selected for further analysis. The network pharmacology research predicted that beta-caryophyllene, palmitic acid, and (+)-β-selinene might act as the effective ingredients of MVO for the treatment of hypertension. Several hot targets, mainly involving TNF, CHRM1, ACE, IL10, PTGS2, REN, and F2, and pivotal pathways, such as the neuroactive ligand–receptor interaction, the calcium signaling pathway, and the PI3K-Akt signaling, were responsible for the vasorelaxant effect of MVO. As expected, MVO exerted a vasorelaxant effect on the aortic rings pre-contracted by KCl and phenylephrine in an endothelium-dependent and non-endothelium-dependent manner. Importantly, a pre-incubation with indomethacin (Indo), N-nitro-L-arginine methyl ester, methylene blue, wortmannin, and atropine sulfate as well as 4-aminopyridione diminished MVO-induced vasorelaxation, suggesting that the activation of the PI3K-Akt-NO pathway and K_V channel were involved in the vasorelaxant effect of MVO, which was consistent with the results of the Kyoto Encyclopedia of Genes and the Genomes. Additionally, MVO could significantly inhibit Ca²⁺ influx resulting in the contraction of aortic rings, revealing that the inhibition of the calcium signaling pathway exactly participated in the vasorelaxant activity of MVO as predicted by network pharmacology.

Conclusion: MVO might be a potent treatment of diseases with vascular dysfunction like hypertension. The underlying mechanisms were related to the PI3K-Akt-NO pathway, K_V pathway, as well as Ca²⁺ channel, which were predicted by the network pharmacology and verified by the experiments in vitro. This study based on network pharmacology provided experimental support for the clinical application of MVO in the treatment of hypertension and afforded a novel research method to explore the activity and mechanism of traditional Chinese medicine.

Antioxidant for Neurological Diseases and Neurotrauma and Bioengineering Approaches

Antioxidants are a class of molecules with an innate affinity to neutralize reactive oxygen species (ROS), which are known to cause oxidative stress. Oxidative stress has been associated with a wide range of diseases mediated by physiological damage to the cells. ROS play both beneficial and detrimental roles in human physiology depending on their overall concentration. ROS are an inevitable byproduct of the normal functioning of cells, which are produced as a result of the mitochondrial respiration process. Since the establishment of the detrimental effect of oxidative stress in neurological disorders and neurotrauma, there has been growing interest in exploring antioxidants to rescue remaining or surviving cells and reverse the neurological damage. In this review, we present the survey of different antioxidants studied in neurological applications including neurotrauma. We also delve into bioengineering approaches developed to deliver antioxidants to improve their cellular uptake in neurological applications.

Tianma Gouteng Decoction regulates oxidative stress and inflammation in AngII-induced hypertensive mice via transcription factor EB to exert anti-hypertension effect

Hypertension is one of the important causes of cardiovascular diseases, and the imbalance of vascular homeostasis caused by oxidative stress and endothelial inflammation occurs throughout hypertension pathogenesis. Therefore, inhibiting oxidative stress and endothelial inflammation is important for treating hypertension. Tianma Gouteng Decoction (TGD) is a Chinese herbal medicine that is commonly used to treat hypertension in China, and demonstrates clinically effective antihypertensive effects. However, its blood pressure reduction mechanism remains unclear. In this study, we further determined the antihypertensive effects of TGD and revealed its underlying mechanism. We established an AngII-induced hypertension mice model, which was treated with TGD for six weeks. We monitored blood pressure, heart rate, and body weight every week. After six weeks, we detected changes in the structure and function of the heart, the structure of blood vessels, and vasomotor factors. We also detected the expression of oxidative stress and inflammation-related genes. We found that TGD can significantly reduce blood pressure, improve cardiac structure and function, and reverse vascular remodeling, which could be due to the inhibition of oxidative stress and inflammation. We also found that the effect of inhibiting oxidative stress and inflammation could be related to the up-regulation of transcription factor EB (TFEB) expression by TGD. Therefore, we used AAV9 to knock down TFEB and observe the role of TFEB in TGD's antihypertensive and cardiovascular protection properties. We found that after TFEB knockdown, the protective effect of TGD on blood pressure and cardiovascular remodeling in AngII-induced hypertensive mice was inhibited, and that it was unable to inhibit oxidative stress and inflammation. Therefore, our study demonstrated for the first time that TGD could exert anti-oxidative stress and anti-inflammatory effects through TFEB and reverse the cardiovascular remodeling caused by hypertension.

Inhibition effect of nicotinamide (vitamin B3) and reduced glutathione (GSH) peptide on angiotensin-converting enzyme activity purified from sheep kidney

Angiotensin-converting enzyme (ACE, EC 3.4.15.1) plays a significant role in blood pressure regulation and inhibition of this enzyme is one of the significant drug targets for the treatment of hypertension. In this work, ACE was purified from sheep kidneys with the affinity chromatography method in one step. The purity and molecular weight of ACE were designated using the SDS-PAGE method and observed two bands at around 60 kDa and 70 kDa on the gel. The effects of nicotinamide (vitamin B₃) and reduced glutathione (GSH) peptide on purified ACE were researched. Nicotinamide and GSH peptide on purified ACE showed an inhibition effect. IC₅₀ values for nicotinamide and GSH were calculated as 14.3 μM and 7.3 μM, respectively. Type of inhibition and K_i values for nicotinamide and GSH from the Lineweaver-Burk graph were determined. The type of inhibition for nicotinamide and GSH was determined as non-competitive inhibition. K_i value was calculated as 15.4 μM for nicotinamide and 6.7 μM for GSH. Also, GSH peptide showed higher inhibitory activity on ACE activity than nicotinamide. In this study, it was concluded that nicotinamide and GSH peptide compounds, which show an inhibition effect on ACE activity, may have both protective and therapeutic effects against hypertension.

Anything New under the Sun? An Update on Modulation of Bioactive Compounds by Different Wavelengths in Agricultural Plants

Plants continuously rely on light as an energy source and as the driver of many processes in their lifetimes. The ability to perceive different light radiations involves several photoreceptors, which in turn activate complex signalling cascades that ultimately lead to a rearrangement in plant metabolism as an adaptation strategy towards specific light conditions. This review, after a brief summary of the structure and mode of action of the different photoreceptors, introduces the main classes of secondary metabolites and specifically focuses on the influence played by the different wavelengths on the content of these compounds in agricultural plants, because of their recognised roles as nutraceuticals.

Antioxidant Properties of Alpha-Lipoic (Thioctic) Acid Treatment on Renal and Heart Parenchyma in a Rat Model of Hypertension

Renal and cardiac impairments are frequent events in the presence of hypertension. Organ damage is mainly linked to oxidative stress due to high blood pressure and may be reduced by antioxidant supplementation. Alpha-lipoic acid (ALA) is one of most effective antioxidants. It is widely used as a nutritional supplement in a racemic mixture (+/–), even though the (+)-enantiomer is biologically active. This study was designed to investigate the effect of treatment with (+/–)-ALA and its enantiomers on renal and heart parenchyma in spontaneously hypertensive rats (SHR), using immunochemical and immunohistochemical techniques. The results confirmed that the oxidative mechanisms of organ alterations, due to hypertension, and characterized by glomerular and tubular lesions, left ventricular hypertrophy, and fibrosis but not by apoptosis were accompanied by proteins’ and nucleic acids’ oxidation. We found greater effectiveness of (+)-ALA compared to (+/−)-ALA in reducing oxidative stress, cardiac and renal damages in SHR. To conclude, these data propose (+)-ALA as one of the more appropriate antioxidant molecules to prevent renal and cardiac alterations associated with hypertension.

Inhibition of Angiotensin-I Converting Enzyme by Ginsenosides: Structure-Activity Relationships and Inhibitory Mechanism

Ginseng (Panax ginseng C. A. Meyer) extract has been reported to inhibit the angiotensin converting enzyme (ACE); however, the possible inhibitory action of most of its constituents (ginsenosides) against ACE remains unknown. Thus, in this study, we investigated ginsenoside derivatives' inhibitory effect on ACE. We assessed the activities of 22 ginsenosides, most of which inhibited ACE significantly. Notably, protopanaxatriol, protopanaxadiol, and ginsenoside Rh2 exhibited the most potent ACE inhibitory potential, with IC₅₀ values of 1.57, 2.22, and 5.60 μM, respectively. Further, a kinetic study revealed different modes of inhibition against ACE. Molecular docking studies have confirmed that ginsenosides inhibit ACE via many hydrogen bonds and hydrophobic interactions with catalytic residues and zinc ion of C- and N-domain ACE that block the catalytic activity of ACE. In addition, we found that the active ginsenosides stimulated glucose uptake in insulin-resistant C2C12 skeletal muscle cells in a dose-dependent manner. Moreover, the most active ginsenosides' reactive oxygen species (ROS) and peroxynitrite (ONOO^-) scavenging properties were evaluated, in which IC₅₀ values ranged from 1.44-43.83 to 2.36-39.56 μM in ONOO^- and ROS, respectively. The results derived from these computational and in vitro experiments provide additional scientific support for the anecdotal use of ginseng in traditional medicine to treat cardiovascular diseases such as hypertension.

Higher dietary total antioxidant capacity (TAC) reduces the risk of cardio-metabolic risk factors among adults: An updated systematic review and meta-analysis

Background: Numerous studies have revealed the protective role of dietary antioxidants against hypertension and diabetes. In the current systematic review and meta-analysis, we evaluated the possible role of dietary total antioxidant capacity (TAC) against metabolic parameters in the adult population. Methods: A literature search of authentic electronic resources including PubMed, Scopus, Web of Sciences, and Cochrane had been performed to retrieve the qualified observational studies that reported the mean plus/minus the SD for the parameter in subjects of the highest versus lowest dietary TAC categories up to July 2020. Results: Totally, the number of included studies was 13 for fasting blood sugar (FBS), 12 for systolic blood pressure (SBP), and 12 for diastolic blood pressure (DBP), with the participants' number of 26349. The results of the current study showed that being at highest category of TAC significantly reduces serum FBS (WMD: -2.381; CI: -3.445, -1.316; P<0.001), SBP (WMD: -1.080; CI: -1.458, -0.701; P<0.001) and DBP (WMD: -0.854; CI: -1.655, -0.052; P<0.001), while no significant difference in the serum insulin, HOMA-IR values, prevalence of type 2 diabetes (T₂DM) (P=0.37) and hypertension (HTN) (P=0.09) was observed. Subgroup analysis revealed the geographical location, dietary assessment tool, sample size, and gender as possible sources of heterogeneity. Conclusion: Higher intake of dietary TAC was associated with reduced SBP, DBP, and FBS in the current observational studies of this meta-analysis. These findings further confirm the clinical importance of dietary antioxidants in the prevention of different metabolic disorders.

Blood Pressure-Lowering Effect of Wine Lees: Dose-Response Study, Effect of Dealcoholization and Possible Mechanisms of Action

The antihypertensive effect of wine lees (WL) has been previously evidenced. In this study, the antihypertensive properties of different doses of WL were evaluated in spontaneously hypertensive rats (SHR). In addition, the blood pressure (BP)-lowering effect of dried (dealcoholized) WL powder (WLPW) and the mechanisms involved in its functionality were investigated. Furthermore, a possible hypotensive effect of WLPW was discarded in Wistar-Kyoto (WKY) rats. The administration of WL at different doses caused a dose-dependent decrease in BP of SHR up to 5.0 mL/kg bw, exhibiting the maximum decrease at 6 h post-administration. WLPW caused a greater drop in BP than WL, showing an antihypertensive effect higher and more prolonged than the drug Captopril. Moreover, the BP-lowering effect of WLPW was specific to the hypertensive state since an undesirable hypotensive effect in normotensive WKY rats was ruled out. Finally, WLPW improved oxidative stress and increased the activity of the antioxidant endogen system of SHR. These results suggest that WLPW could be used as functional ingredient for foods or nutraceuticals to ameliorate hypertension. Nevertheless, further clinical studies are needed to evaluate its long-term antihypertensive efficiency.

Attenuating Effects of Dieckol on Endothelial Cell Dysfunction via Modulation of Th17/Treg Balance in the Intestine and Aorta of Spontaneously Hypertensive Rats

Disruptions of the Treg/Th17 cell balance and gut barrier function are associated with endothelial dysfunction. Dieckol (DK) obtained from Ecklonia cava and E. cava extract (ECE) decreases blood pressure by reducing inflammation; however, it has not been elucidated whether DK or ECE modulates the Treg/Th17 balance, changes the gut epithelial barrier, or decreases endothelial cell dysfunction. We evaluated the effects of ECE and DK on gut barrier and the Treg/Th17 balance in the intestine and aorta, with regard to endothelial dysfunction, using the spontaneously hypertensive rat (SHR) model. The level of Th17 cells increased and that of Treg cells decreased in the intestine of SHRs compared to normotensive Wistar Kyoto (WKY) rat. These changes were attenuated by ECE or DK treatment. Additionally, the serum IL-17A level increased in SHRs more than WKY; this was decreased by ECE or DK treatment. The level of Treg cells decreased and that of Th17 cells increased in the aorta of SHRs. These changes were attenuated by ECE or DK treatment. The NF-κB and IL-6 levels were increased in SHRs, but these changes were reversed by ECE or DK treatment. Endothelial cell dysfunction, which was evaluated using peNOS/eNOS, nitrate/nitrite ratio, and NADPH oxidase activity, increased in the aorta of SHRs, but was decreased by ECE or DK treatment. The Treg/Th17 balance in the intestine and aorta of SHRs was attenuated and endothelial cell dysfunction was attenuated through the Th17/NF-κB/IL-6 pathway by ECE or DK.

Effect of cooking on the content of carotenoids and tocopherols in sweet corn

Taste and nutritional value make sweet corn a valued plant and an important component of the human diet worldwide. Kernel nutritive composition of sweet corn has been reported in various papers, but a description of carotenoid and tocopherols profile, especially after cooking is scarce. Therefore, the present study was carried out to compare the carotenoid and tocopherol content in sweet corn before and after cooking. Contents of b-carotene, lutein+zeaxanthin and tocopherols (d-T, b+g-T, a-T) in the kernels of twelve sweet corn hybrids were determined by High-Performance Liquid Chromatography (HPLC) and were expressed as the mean value of three independent measurements. Both genotype and cooking affected the content of the carotenoids and tocopherols in the kernel. The highest content of total carotenoids before and after cooking was found in hybrid ZP486/1su (27.77/45.28 µg/g) whereas the lowest content was in hybrid ZP 355su (10.27 µg/g) before cooking i.e. in hybrid ZP 347su (24.55 µg/g) after cooking. The cooking resulted in a significant increase in the content of total carotenoids and tocopherols, lutein+zeaxanthin, and b-carotene in all hybrids, except the ZP504su in which the b-carotene content decreased. An increase in a-tocopherol after cooking was observed in hybrids ZP485/1su and ZP484/1su, while a decrease was in hybrids ZP481/1su, ZP486/1su and ZP477/2su. The results showed that increasing micronutrient content is genotype-dependent. This study confirmed that cooking increases the nutritional value of sweet corn and gives it additional value in terms of functional food.

Effect of cooking on the content of carotenoids and tocopherols in sweet corn

Taste and nutritional value make sweet corn a valued plant and an important component of the human diet worldwide. Kernel nutritive composition of sweet corn has been reported in various papers, but a description of carotenoid and tocopherols profile, especially after cooking is scarce. Therefore, the present study was carried out to compare the carotenoid and tocopherol content in sweet corn before and after cooking. Contents of b-carotene, lutein+zeaxanthin and tocopherols (d-T, b+g-T, a-T) in the kernels of twelve sweet corn hybrids were determined by High-Performance Liquid Chromatography (HPLC) and were expressed as the mean value of three independent measurements. Both genotype and cooking affected the content of the carotenoids and tocopherols in the kernel. The highest content of total carotenoids before and after cooking was found in hybrid ZP486/1su (27.77/45.28 µg/g) whereas the lowest content was in hybrid ZP 355su (10.27 µg/g) before cooking i.e. in hybrid ZP 347su (24.55 µg/g) after cooking. The cooking resulted in a significant increase in the content of total carotenoids and tocopherols, lutein+zeaxanthin, and b-carotene in all hybrids, except the ZP504su in which the b-carotene content decreased. An increase in a-tocopherol after cooking was observed in hybrids ZP485/1su and ZP484/1su, while a decrease was in hybrids ZP481/1su, ZP486/1su and ZP477/2su. The results showed that increasing micronutrient content is genotype-dependent. This study confirmed that cooking increases the nutritional value of sweet corn and gives it additional value in terms of functional food.

Titin and CK2α are New Intracellular Targets in Acute Insulin Application-Associated Benefits on Electrophysiological Parameters of Left Ventricular Cardiomyocytes From Insulin-Resistant Metabolic Syndrome Rats

BACKGROUND

Previous studies have demonstrated that a high-carbohydrate intake could induce metabolic syndrome (MetS) in male rats with marked cardiac functional abnormalities. In addition, studies mentioned some benefits of insulin application on these complications, but there are considerable disagreements among their findings. Therefore, we aimed to extend our knowledge on the in-vitro influence of insulin on left ventricular dysfunction and also in the isolated cardiomyocytes from MetS rats.

RESULTS

At the organ function level, an acute insulin application (100-nM) provided an important beneficial effect on the left ventricular developed pressure in MetS rats. Furthermore, to treat the freshly isolated cardiomyocytes from MetS rats with insulin provided marked recoveries in elevated resting intracellular Ca²⁺-level, as well as significant prevention of prolonged action potential through an augmentation in depressed K⁺-channel currents. Insulin also normalized the cellular levels of increased ROS and phosphorylation of PKCα, together with normalizations of apoptotic markers in MetS cardiomyocytes through the insulin-mediated regulation of phospho-Akt. Since not only elevated PKCα-activity but also reductions in phospho-Akt are key modulators of titin-based cardiomyocyte stiffening in hyperglycemia, insulin treatment of the cardiomyocytes prevented the activation of titin via the above pathways. Furthermore, CK2α-activation and NOS-phosphorylation could be prevented with insulin treatment. Mechanistically, we found that impaired insulin signaling and elevated PKCα and CK2α activities, as well as depressed Akt phosphorylation, are key modulators of titin-based cardiomyocyte stiffening in MetS rats.

CONCLUSION

We propose that restoring normal kinase activities and also increases in phospho-Akt by insulin can contribute marked recoveries in MetS heart function, indicating a promising approach to modulate titin-associated factors in heart dysfunction associated with type-2 diabetes mellitus. Graphical Abstract.

Early Origins of Hypertension: Should Prevention Start Before Birth Using Natural Antioxidants?

Hypertension may originate in early life. Reactive oxygen species (ROS) generated due to the exposure of adverse in utero conditions causes developmental programming of hypertension. These excessive ROS can be antagonized by molecules which are antioxidants. Prenatal use of natural antioxidants may reverse programming processes and prevent hypertension of developmental origin. In the current review, firstly we document data on the impact of oxidative stress in hypertension of developmental origin. This will be followed by effective natural antioxidants uses starting before birth to prevent hypertension of developmental origin in animal models. It will also discuss evidence for the common mechanisms underlying developmental hypertension and beneficial effects of natural antioxidant interventions used as reprogramming strategies. A better understanding of the reprogramming effects of natural antioxidants and their interactions with common mechanisms underlying developmental hypertension is essential. Therefore, pregnant mothers and their children can benefit from natural antioxidant supplementation during pregnancy in order to reduce their risk for hypertension later in life.

Cardiovascular and Metabolic Protection by Vitamin E: A Matter of Treatment Strategy?

Cardiovascular diseases (CVD) cause about 1/3 of global deaths. Therefore, new strategies for the prevention and treatment of cardiovascular events are highly sought-after. Vitamin E is known for significant antioxidative and anti-inflammatory properties, and has been studied in the prevention of CVD, supported by findings that vitamin E deficiency is associated with increased risk of cardiovascular events. However, randomized controlled trials in humans reveal conflicting and ultimately disappointing results regarding the reduction of cardiovascular events with vitamin E supplementation. As we discuss in detail, this outcome is strongly affected by study design, cohort selection, co-morbidities, genetic variations, age, and gender. For effective chronic primary and secondary prevention by vitamin E, oxidative and inflammatory status might not have been sufficiently antagonized. In contrast, acute administration of vitamin E may be more translatable into positive clinical outcomes. In patients with myocardial infarction (MI), which is associated with severe oxidative and inflammatory reactions, decreased plasma levels of vitamin E have been found. The offsetting of this acute vitamin E deficiency via short-term treatment in MI has shown promising results, and, thus, acute medication, rather than chronic supplementation, with vitamin E might revitalize vitamin E therapy and even provide positive clinical outcomes.

Methanol extract of Caesalpinia benthamiana normalizes blood pressure and attenuates oxidative stress in uninephrectomized hypertensive rats

OBJECTIVES

Hypertension is the number one risk factor and primary contributor of cardiovascular diseases. Caesalpinia benthamiana is a valuable medicinal plant with unvalidated anti-hypertensive activity. This study was carried out to explore the antihypertensive effect of C. benthamiana on uninephrectomized hypertensive rats.

METHODS

Fifty rats were grouped into five groups, each containing 10 animals: Group A-normal control (normotensive); B-uninephrectomized control; C-uninephrectomized treated with 50 mg/kg C. benthamiana extract; D-uninephrectomized treated with 100 mg/kg C. benthamiana; and E- uninephrectomized treated with 10 mg/kg of Lisinopril.

RESULTS

Significant increases were observed in systolic, diastolic and mean blood pressure of uninephrectomized control rats. Furthermore, markers of oxidative stress (malondialdehyde, hydrogen peroxide, protein carbonyl, myeloperoxidase and the advanced oxidative protein products) increased significantly while antioxidant status (reduced glutathione, glutathione peroxidase, glutathione S-transferase and superoxide dismutase), reduced significantly in uninephrectomized hypertensive rats. Histopathology revealed thrombosis and occlusion of coronary vessels in the heart, and congestion in the kidney. However, the observed high blood pressure parameters were remarkably normalized together with reduction in markers of oxidative stress and improvement in antioxidant defence system of uninephrectomized hypertensive rats treated with C. benthamiana extract similar to normotensive rats.

CONCLUSIONS

C. benthamiana extract exhibited antihypertensive action, strong antioxidant ability, attenuated oxidative stress-mediated hypertension and lessened the development of cardiac and renal damage associated with hypertension induced by uninephrectomy and high dietary intake of salt. Together, C. benthamiana extract might be useful in the management of hypertension due to volume overload in the cardiovascular system.

A greater burden of atrial fibrillation is associated with worse endothelial dysfunction in hypertension

Atrial fibrillation (AF) and hypertension often co-exist and both are associated with endothelial dysfunction. We hypothesised that AF would further worsen endothelium-dependent flow-mediated dilatation (FMD) in hypertension patients compared to those without AF. In a cross-sectional comparison, we measured brachial artery diameter at rest and during reactive hyperaemia following 5 min of arterial occlusion in two patient groups: AF (and hypertension) (n = 61) and hypertension control groups (n = 33). The AF (and hypertension) subgroups: permanent AF (n = 30) and paroxysmal AF (n = 31) were also assessed. The permanent AF patients received heart rate and blood pressure (BP) control optimisation and were then followed up after eight weeks for repeat FMD testing. There was no significant difference in FMD between AF (and hypertension) group and hypertension control group (4.6%, 95% CI [2.6-5.9%] vs 2.6%, 95% CI [1.9-5.3%]; p = 0.25). There was a significant difference in FMD between permanent AF and paroxysmal AF groups (3.1%, 95% CI [2.3-4.8%] vs 5.9%, 95% CI [4.0-8.1%]; p = 0.02). Endothelium-dependent FMD response showed a non-significant improvement trend following eight weeks of heart rate and BP optimisation (3.1%, 95% CI [2.3-4.8%] (baseline) vs 5.2%, 95% CI [3.9-6.5%] (follow up), p = 0.09). Presence of AF generally does not incrementally worsen endothelial dysfunction in hypertension patients, although the duration and frequency of AF (paroxysmal AF to permanent AF) does lead to worsening endothelial function. Eight weeks of BP optimisation did not significantly improve endothelial dysfunction as measured by FMD.

Quercetin improves vascular endothelial function through promotion of autophagy in hypertensive rats

AIMS

Endothelial dysfunction is a hallmark of hypertension. Herein, we assessed the effect of quercetin, a common dietary antioxidant, on endothelial function of spontaneously hypertensive rats (SHRs), and investigated the underlying molecular mechanisms.

MAIN METHODS

The Wistar-Kyoto (WKY) and SHR rats were administered vehicle (1% w/v methyl cellulose) or quercetin (10 mg/kg body weight) by oral gavage once a day for 6 weeks. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured with a tail-cuff system. Functional of rat mesenteric arterioles was assessed by the temperature-controlled myograph. A dose-response curve was generated by the cumulative addition of acetylcholine (ACh) or sodium nitroprusside (SNP). NO production in the culture medium was assessed by measuring the concentration of nitrite, a stable metabolite of NO, using a modified Griess reagent.

KEY FINDINGS

Quercetin improved endothelial function and decreased blood pressure in SHRs. Endothelial autophagy, an important cellular homeostatic process, was increased in the early phase of treatment, and decreased in the late phase of treatment. Quercetin promoted autophagy in cultured endothelial cells under both normal and oxidative stress conditions. Pharmacological inhibition of autophagy aggravated endothelial dysfunction in quercetin-treated endothelial cells under oxidative stress, and attenuated the antihypertensive and endothelial protective effects of quercetin in SHRs.

SIGNIFICANCE

Quercetin protects endothelial function in hypertensive rats through promotion of autophagy. Thus, autophagy could serve as a potential therapeutic target for hypertension.

Nitric oxide and oxidative stress pathways do not contribute to sex differences in renal injury and function in Dahl SS/Jr rats

The burden of hypertension in the United States is increasing and yields significant morbidity and mortality, and sex differences in hypertension are widely recognized. Reduced nitric oxide (NO) bioavailability and increased oxidative stress are known to contribute to the pathogenesis of hypertensive renal injury, and but their contributions to sex differences in injury progression of are undefined. Our purpose was to test the hypothesis that male hypertensive rats have accelerated renal injury compared to females and to determine the contributions of the nitric oxide pathway and oxidative stress in these differences. Male and female Dahl SS/Jr rats, a model that spontaneously develops hypertension with age, were allowed to age on a 0.3% NaCl diet until 3 or 6 months of age, at which points blood pressure was measured and plasma, tissue, and urine were collected. While no significant sex differences in blood pressure were present at either time point, renal injury measured by urine protein excretion was more severe (male = 44.9 ± 6; female = 15±3 mg/day/100 g bw, p = .0001), and renal function was reduced (male = 0.48 ± 0.02; female = 0.7 ± 0.03 ml min-1  g-1 kw, p = .001) in males compared to females with age. Both male and female rats exhibited reduced nitric oxide metabolites (3 months: male = 0.65 ± 0.1; female = 0.74 ± 0.3; 6 months: male = 0.16 ± 0.1; female = 0.41 ± 0.1 ml min-1  g-1 kw, p, age = 0.02, p, sex = 0.3). Levels of urinary TBARS were similar (3 months: male = 20±1.5; female = 23±1.8; 6 months: male = 26±4.8; female = 23±4.7µM day g-1 kw, p, age = 0.4, p, sex = 0.9), extracellular superoxide dismutase (EC SOD) mRNA was greater in females (3 months: male = 0.35 ± 0.03; female = 1.4 ± 0.2; 6 months: male = 0.4 ± 0.05; female = 1.3 ± 0.1 normalized counts, p, age = 0.7, p, sex < 0.0001), but EC SOD protein expression was not different (3 months: male = 0.01 ± 0.002; female = 0.01 ± 0.002; 6 months: male = 0.02 ± 0.004; female = 0.01 ± 0.002 relative density, p, age = 0.2, p, sex = 0.8). These data support the presence of significant sex differences in renal injury and function in the Dahl S rat and identify a need for further study into the mechanisms involved.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

Bioenergetics and translational metabolism: implications for genetics, physiology and precision medicine

It is now becoming clear that human metabolism is extremely plastic and varies substantially between healthy individuals. Understanding the biochemistry that underlies this physiology will enable personalized clinical interventions related to metabolism. Mitochondrial quality control and the detailed mechanisms of mitochondrial energy generation are central to understanding susceptibility to pathologies associated with aging including cancer, cardiac and neurodegenerative diseases. A precision medicine approach is also needed to evaluate the impact of exercise or caloric restriction on health. In this review, we discuss how technical advances in assessing mitochondrial genetics, cellular bioenergetics and metabolomics offer new insights into developing metabolism-based clinical tests and metabolotherapies. We discuss informatics approaches, which can define the bioenergetic-metabolite interactome and how this can help define healthy energetics. We propose that a personalized medicine approach that integrates metabolism and bioenergetics with physiologic parameters is central for understanding the pathophysiology of diseases with a metabolic etiology. New approaches that measure energetics and metabolomics from cells isolated from human blood or tissues can be of diagnostic and prognostic value to precision medicine. This is particularly significant with the development of new metabolotherapies, such as mitochondrial transplantation, which could help treat complex metabolic diseases.

Quercetin improves endothelial insulin sensitivity in obese mice by inhibiting Drp1 phosphorylation at serine 616 and mitochondrial fragmentation

Studies have shown that endothelial insulin resistance induced by oxidative stress contributes to vascular dysfunction in metabolic disorders. Quercetin, a natural antioxidant, has been recently shown to exert protective effects on endothelial function. However, the effects of quercetin on endothelial insulin resistance and its underlying mechanism are unclear. Here, we found that chronic oral treatment of obese mice with quercetin increased vascular endothelial insulin sensitivity, accompanied by alleviated mitochondrial fragmentation as revealed by confocal imaging. In addition, western blot analysis showed that quercetin treatment suppressed the levels of dynamin-related protein 1 (Drp1) and phosphorylation at serine 616 in endothelial cells of obese mice. Mechanistically, quercetin specifically suppressed Drp1 phosphorylation at serine 616, whereas it showed little effects on the Drp1 level and its phosphorylation at serine 637 in cultured endothelial cells under oxidative stress. Furthermore, our results also showed that quercetin suppressed Drp1 phosphorylation at serine 616 by inhibiting PKCδ as revealed by western blot analysis. Knockdown of PKCδ with siRNA alleviated the protective effects of quercetin on endothelial-mitochondrial dynamics and insulin sensitivity. These results suggest that chronic oral treatment with quercetin exerts endothelial protective effects through inhibition of PKCδ and the resultant mitochondrial fragmentation.

Quantification of Alpha Lipoic Acid in Pharmaceutical Products by HPLC with Pulsed Amperometric Detection at a Gold Electrode

Background:

Alpha-lipoic acid (ALA) has become a common ingredient in food supplements and multivitamin formulas. ALA is widely used as therapy for preventing diabetic polyneuropathies, scavenges free radicals, and restores intracellular glutathione levels. This study aimed to develop a simple and fast analytical method to determine ALA content in dietary supplements using highperformance liquid chromatography with pulsed amperometric detection (HPLC PAD).

Methods:

ALA was analyzed by HPLC in a mobile phase composed of 25 mmol/L potassium phosphate in 50% (v/v) acetonitrile (pH 4.0) and PAD at a gold electrode (vs. solid-phase hydrogen reference electrode). The PAD cycle was performed by applying a detection potential (E1) of +0.7 V for 0.4 s, an oxidation potential (E2) of +1.0V for 0.4 s and a reduction potential (E3) of -0.2 V for 1.2 s.

Results:

The runtime method was shown a rapid procedure for the analysis of α-lipoic acid. The sampling rate of 8 injections per hour was attained and measurements of the reproducibility of successive injections (20 µL) showed an RSD of 1.89% for 16 successive injections. The method presented low quantification limit of 0.21 mg/L. The industrialized ALA-based supplements ranged from to 97.8 to 104.1%, while manipulated capsules ranged from 69.2 to 95.4%.

Conclusion:

Electrochemical detector has been presented as an effective alternative for ALA determination, which has weakly UV-absorbing. This detection has the benefits of sensitivity, simplicity and low costs. The developed HPLC-DAD method proposes to be analytical tool applicable to quality control of ALA supplements.

Antioxidant properties of probucol released from mesoporous silica

Antioxidants play a vital role in scavenging reactive oxygen species (ROS) produced by the reduction of molecular oxygen from various cellular mechanisms. Under oxidative stress, an increase in the levels of ROS overwhelms the antioxidant response, causing oxidative damage to biological molecules, and leading to the development of various diseases. Drug compounds with potent antioxidant properties are typically poorly water soluble and highly hydrophobic. An extreme case is Probucol (PB), a potent antioxidant with reported water solubility of 5 ng/ml, and oral bioavailiability of <10%. In this study, PB was loaded in mesoporous silica at various drug loadings to understand the changes to the physical properties of the loaded drug, and it's in vitro drug release. Further in vitro studies were conducted in endothelial and microglia cell models to compare the free radical scavening efficiency of ascorbic acid, PB, and PB release from mesoporous silica particles. Out of the three different mesostructured particles studied, the maximum loading of PB was achieved for large pore mesoporous particles (SBA-15) at 50 wt% drug loading, before complete pore filling was observed. For all materials, loadings above complete pore filling resulted in the recrystallization of PB on the external surface. In vitro drug release measurements showed a rapid dissolution rate at low drug loadings compared to a bimodal release profile of amorphous and crystalline drug at higher drug loadings. PB loaded in mesoporous particle was shown to enhance the antioxidant response to extracellular ROS in the endothelial cell line model, and to intracellular ROS in the microglia cell model. Our results indicate that the antioxidant properties of PB can be significantly improved by using mesoporous silica as a delivery vehicle.

Oxidative stress and vascular stiffness in hypertension: A renewed interest for antioxidant therapies?

Since the first successful launch of the Veterans Administration(VA) cooperative studies in the late 1960s, the increasing access to blood pressure lowering medications has significantly contributed to improving longevity and quality of life in hypertensive patients. Since then, insights into the pathogenesis of hypertension have shown a mechanistic role for reactive oxygen species (ROS) in all phases of disease progression, suggesting the potential utility of antioxidant therapies to counteract symptoms and, at the same time, treat a fundamental mechanism of the disease. Despite these progresses, hypertension still remains the main contributor to the global incidence of cardiovascular disease and the leading cause of morbidity and mortality worldwide. We here briefly review and update the role of ROS and ROS-dependent metalloproteinase activation in the maladaptive remodeling of the vascular wall in hypertension. Such understanding should provide new Potential sites of action for antioxidant therapies as an integrated therapeutic approach to hypertension and its consequences.