Quercetin Inhibited Endothelial Dysfunction and Atherosclerosis in Apolipoprotein E-Deficient Mice: Critical Roles for NADPH Oxidase and Heme Oxygenase-1

Quercetin ameliorates atherosclerosis by inhibiting inflammation of vascular endothelial cells via Piezo1 channels

BACKGROUND

Natural antioxidants, exemplified by quercetin (Qu), have been shown to exert a protective effect against atherosclerosis (AS). However, the precise pharmacological mechanisms of Qu also remain elusive.

PURPOSE

Here, we aimed to uncover the anti-atherosclerotic mechanisms of Qu.

METHODS/STUDY DESIGNS

The inflammatory cytokine expression, activity of NLRP3 inflammasome and NF-κB, as well as mechanically activated currents and intracellular calcium levels were measured in endothelial cells (ECs). In addition, to explore whether Qu inhibited atherosclerotic plaque formation via Piezo1 channels, Ldlr-/- and Piezo1 endothelial-specific knockout mice (Piezo1△EC) were established.

RESULTS

Our findings revealed that Qu significantly inhibited Yoda1-evoked calcium response in human umbilical vein endothelial cells (HUVECs), underscoring its role as a selective modulator of Piezo1 channels. Additionally, Qu effectively reduced mechanically activated currents in HUVECs. Moreover, Qu exhibited a substantial inhibitory effect on inflammatory cytokine expression and reduced the activity of NF-κB/NLRP3 in ECs exposed to ox-LDL or mechanical stretch, and these effects remained unaffected after Piezo1 genetic depletion. Furthermore, our study demonstrated that Qu substantially reduced the formation of atherosclerotic plaques, and this effect remained consistent even after Piezo1 genetic depletion.

CONCLUSION

These results collectively provide compelling evidence that Qu ameliorates atherosclerosis by inhibiting the inflammatory response in ECs by targeting Piezo1 channels. In addition, Qu modulated atherosclerosis via inhibiting Piezo1 mediated NFκB/IL-1β and NLRP3/caspase1/ IL-1β axis to suppress the inflammation. Overall, this study reveals the potential mechanisms by which natural antioxidants, such as Qu, protect against atherosclerosis.

Analysis of mechanism, therapeutic strategies, and potential natural compounds against atherosclerosis by targeting iron overload-induced oxidative stress

Ferroptosis is a novel form of cell demise characterized primarily by the reduction of trivalent iron to divalent iron, leading to the release of reactive oxygen species (ROS) and consequent induction of intense oxidative stress. In atherosclerosis (AS), highly accumulated lipids are modified by ROS to promote the formation of lipid peroxides, further amplifying cellular oxidative stress damage to influence all stages of atherosclerotic development. Macrophages are regarded as pivotal executors in the progression of AS and the handling of iron, thus targeting macrophage iron metabolism holds significant guiding implications for exploring potential therapeutic strategies against AS. In this comprehensive review, we elucidate the potential interplay among iron overload, inflammation, and lipid dysregulation, summarizing the potential mechanisms underlying the suppression of AS by alleviating iron overload. Furthermore, the application of Traditional Chinese Medicine (TCM) is increasingly widespread. Based on extant research and the pharmacological foundations of active compounds of TCM, we propose alternative therapeutic agents for AS in the context of iron overload, aiming to diversify the therapeutic avenues.

Natural Substances vs. Approved Drugs in the Treatment of Main Cardiovascular Disorders-Is There a Breakthrough?

Cardiovascular diseases (CVDs) are a group of diseases with a very high rate of morbidity and mortality. The clinical presentation of CVDs can vary from asymptomatic to classic symptoms such as chest pain in patients with myocardial infarction. Current therapeutics for CVDs mainly target disease symptoms. The most common CVDs are coronary artery disease, acute myocardial infarction, atrial fibrillation, chronic heart failure, arterial hypertension, and valvular heart disease. In their treatment, conventional therapies and pharmacological therapies are used. However, the use of herbal medicines in the therapy of these diseases has also been reported in the literature, resulting in a need for critical evaluation of advances related to their use. Therefore, we carried out a narrative review of pharmacological and herbal therapeutic effects reported for these diseases. Data for this comprehensive review were obtained from electronic databases such as MedLine, PubMed, Web of Science, Scopus, and Google Scholar. Conventional therapy requires an individual approach to the patients, as when patients do not respond well, this often causes allergic effects or various other unwanted effects. Nowadays, medicinal plants as therapeutics are frequently used in different parts of the world. Preclinical/clinical pharmacology studies have confirmed that some bioactive compounds may have beneficial therapeutic effects in some common CVDs. The natural products analyzed in this review are promising phytochemicals for adjuvant and complementary drug candidates in CVDs pharmacotherapy, and some of them have already been approved by the FDA. There are insufficient clinical studies to compare the effectiveness of natural products compared to approved therapeutics for the treatment of CVDs. Further long-term studies are needed to accelerate the potential of using natural products for these diseases. Despite this undoubted beneficence on CVDs, there are no strong breakthroughs supporting the implementation of natural products in clinical practice. Nevertheless, they are promising agents in the supplementation and co-therapy of CVDs.

Beneficial effects of flavonoids on animal models of atherosclerosis: A systematic review and meta-analysis

Atherosclerosis is the main cause of cardiovascular diseases that seriously endanger human health. The existing treatment drugs are effective, but they have some side effects. Accumulating evidence suggests that flavonoids have attracted wide attention due to their multiple cardioprotective effects and fewer side effects. PubMed, Web of Science database, Embase, and Cochrane Library were searched for studies evaluating the effects of flavonoids against atherosclerosis. 119 studies published from August 1954 to April 2023 were included. Random-effects models were performed for synthesis. Compared with the control group, flavonoids significantly reduced longitudinal and cross-sectional plaque area. The findings indicated that flavonoids significantly reduced the concentrations of serum TC, TG, and LDL-C and increased serum HDL-C concentrations. Besides, flavonoids reduced the levels of circulating pro-inflammatory factors, including TNF-α, IL-1β, and IL-6, and increased the serum IL-10 level. This study provides evidence for the potential cardiovascular benefits of flavonoids.

Cardioprotective effect of the quercetin on cardiovascular remodeling and atherosclerosis in rodents fed a high-fat diet: A systematic review

Cardiovascular diseases (CVD) are the leading cause of death globally, estimated at 17.9 million premature deaths. Several risk factors contribute to the development of CVD, including unhealthy diet rich in saturated fat. Quercetin (Q) is a important natural flavonoid with cardioprotective effect. However, it is crucial to understand and clarify which dosages and intervention times quercetin promotes better cardioprotective effects when exposed to a High-Fat Diet (HFD). We aim was to carry out a review to identify and compare experimental studies that investigated the quercetin effect on cardiac parameters in rodents fed a HFD. This literature search was performed through the specialized databases PubMed, Embase, Web of Science and Lilacs in May 2022. The following information was collected and assessed: Species of animals, dietary fat content, intervention protocol (quercetin), and main results of alterations associated with cardiac change. A total of 116 articles were selected from the database and 30 articles were included in this study. The administration form of quercetin was used in the diet supplemented in 73.4% (n = 22) of the studies. The dosage ranged between 10 and 100 mg/kg, 0.01%-0.36%, and 4-8 g/kg diet. The treatment time ranged between 14 and 63 days in 48.4% studies and most of the selected studies observed changes in the: Serum concentrations of lipids (60%, n = 18) mainly decrease in TC and TG, left ventricle (LV) (16.13%, n = 5) includes attenuation of the cardiac hypertrophy; inhibition of atherosclerotic progression (32%, n = 10) with decrease in lesions and plaque formation; improvement in the expression of gene and protein associated with cardiac functionality and oxidative stress (51.6%; n = 16). Quercetin supplementation at different concentrations/doses promotes important cardioprotective effects in experimental models exposed to a HFD. The supplemented diet was shown to be the better administration option. The methodological variation presented in the articles selected in this review proves that the most appropriate intervention protocol, as well as the most effective route of administration, promotes these effects.

Research Progress of Flavonoids Regulating Endothelial Function

The endothelium, as the guardian of vascular homeostasis, is closely related to the occurrence and development of cardiovascular diseases (CVDs). As an early marker of the development of a series of vascular diseases, endothelial dysfunction is often accompanied by oxidative stress and inflammatory response. Natural flavonoids in fruits, vegetables, and Chinese herbal medicines have been shown to induce and regulate endothelial cells and exert anti-inflammatory, anti-oxidative stress, and anti-aging effects in a large number of in vitro models and in vivo experiments so as to achieve the prevention and improvement of cardiovascular disease. Focusing on endothelial mediation, this paper introduces the signaling pathways involved in the improvement of endothelial dysfunction by common dietary and flavonoids in traditional Chinese medicine and describes them based on their metabolism in the human body and their relationship with the intestinal flora. The aim of this paper is to demonstrate the broad pharmacological activity and target development potential of flavonoids as food supplements and drug components in regulating endothelial function and thus in the prevention and treatment of cardiovascular diseases. This paper also introduces the application of some new nanoparticle carriers in order to improve their bioavailability in the human body and play a broader role in vascular protection.

Quercetin Attenuates Vascular Endothelial Dysfunction in Atherosclerotic Mice by Inhibiting Myeloperoxidase and NADPH Oxidase Function

Myeloperoxidase (MPO) exhibits a unique property to use H₂O₂ to oxidize chloride and lead to the generation of a strong oxidant, hypochlorous acid (HOCl), which plays important roles in atherosclerosis. A lot of evidence indicates that quercetin, a natural polyphenol derived from human diet, effectively contributes to cardiovascular health. Herein, we found that dietary quercetin significantly inhibited vascular endothelial dysfunction and atherosclerosis in apolipoprotein E-deficient (ApoE^-/-) mice. Mechanistic studies revealed that dietary quercetin effectively suppressed the MPO level and activity in the vessels of ApoE^-/- animals, and p47phox expression and NADPH oxidase activity were simultaneously attenuated after quercetin treatment. In vascular endothelial cells, NADPH oxidase was demonstrated to be the major source of H₂O₂ formation. Moreover, quercetin effectively attenuated MPO/H₂O₂-mediated HOCl production and toxicity to human vascular endothelial cells, and this compound was not toxic. The inhibitory effect on MPO activity was likely attributed to that quercetin significantly inhibited NADPH oxidase-derived H₂O₂ formation in human endothelial cells and could act as an effective mediator for MPO intermediates, subsequently preventing HOCl production by the MPO/H₂O₂ system. Collectively, it was suggested that quercetin effectively suppressed endothelial dysfunction in atherosclerotic vasculature through the reduction of MPO/NADPH oxidase-mediated HOCl production.

Exploring the Active Compounds of Traditional Mongolian Medicine Baolier Capsule (BLEC) in Patients with Coronary Artery Disease (CAD) Based on Network Pharmacology Analysis, Molecular Docking and Experimental Validation

Objective

Baolier Capsule (BLEC) is a Traditional Mongolian Medicine comprising fifteen herbs. This study aims to illustrate the synergistic mechanism of BLEC in the treatment of Coronary Artery Disease (CAD) by using network pharmacology method, molecular docking and experimental validation.

Methods

Searching and screening the active ingredients of different herbs in BLEC and target genes related to CAD in multiple databases. Subsequently, Protein-Protein Interactions Network (PPI-Net), gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment were used to identify the key targets. AutoDock was used to verify the binding ability between the active ingredient and key target through molecular docking. Reverse Transcription-Quantitative Real-Time Polymerase Chain Reaction (RT-qPCR) was used to verify the effect of active ingredient of BLEC on the key target gene. Finally, effect of BLEC on the degree of blood lipids and atherosclerosis was validated by animal experiment.

Results

There are 144 active components and 80 CAD-related targets that are identified in BLEC in the treatment of CAD. What is more, 8 core genes were obtained by clustering and topological analysis of PPI-Net. Further, GO and KEGG analysis showed that fluid shear stress and atherosclerosis are the key pathways for BLEC to treat CAD. These results were validated by molecular docking method. In vitro, active compounds of BLEC (Quercetin, luteolin, kaempferol, naringenin, tanshinone IIA, β-carotene, 7-O-methylisomucronulatol, piperine, isorhamnetin and Xyloidone) can inhibit 8 core gene (AKT1, EGFR, FOS, MAPK1, MAPK14, STAT3, TP53 and VEGFA) expression. Moreover, BLEC not only improve blood lipid levels but also inhibit the development of atherosclerosis in ApoE-knockout mice.

Conclusion

Our research first revealed the basic pharmacological effects and related mechanisms of in the treatment of CAD. The predicted results provide some theoretical support for BLEC or its important active ingredients to treat CAD.

Polyphenols in Metabolic Diseases

Polyphenols (PPs) are a large group of phytochemicals containing phenolic rings with two or more hydroxyl groups. They possess powerful antioxidant properties, multiple therapeutic effects, and possible health benefits in vivo and in vitro, as well as reported clinical studies. Considering their free-radical scavenging and anti-inflammatory properties, these substances can be used to treat different kinds of conditions associated with metabolic disorders. Many symptoms of metabolic syndrome (MtS), including obesity, dyslipidemia, atherosclerosis, elevated blood sugar, accelerating aging, liver intoxication, hypertension, as well as cancer and neurodegenerative disorders, are substantially relieved by dietary PPs. The present study explores the bioprotective properties and associated underlying mechanisms of PPs. A detailed understanding of these natural compounds will open up new opportunities for producing unique natural PP-rich dietary and medicinal plans, ultimately affirming their health benefits.

Wax apple (Syzygium samarangense) fruit extract ameliorates endothelial dysfunction and liver damage in high cholesterol diet-fed rats

Background and aim

Wax apple fruit (Syzygium samarangense) is one of the most popular tropical fruit in Asia, and contains several essential nutrients. Therefore, this study explored the effects of the wax apple fruit extract on a high-cholesterol diet-induced vascular endothelial dysfunction and fatty liver in rats.

Experimental procedure

Male Sprague Dawley rats were fed a diet with 1.5% cholesterol (HCD) for 8 weeks, and were given wax apple fruit extract (50 and 100 mg/kg/day) orally for the last 4 weeks. After 8 weeks, blood sample, thoracic aorta, and liver were collected and processed for biochemical and histological analysis. Additionally, vascular endothelial function and the protein expression of oxidative stress markers in aortae were evaluated.

Results and conclusion

Wax apple reduced serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), aspartate aminotransferase (AST), and alanine aminotransferase (ALT), but increased high-density lipoprotein cholesterol (HDL-C) levels. Furthermore, the liver levels of TG and TC were reduced in wax apple-treated hypercholesterolemic rats. Histological studies revealed that wax apple ameliorated HCD-induced morphologic changes of aortic and liver tissues of rats. In aortic tissues, the impaired endothelium-dependent responses to acetylcholine, the reduced nitric oxide (NO) contents, the elevated endothelin (ET)-1 contents, and the increased expression of NADPH oxidase subunit p47^phox and 4-hydroxynonenal in HCD-fed rats were reversed by wax apple treatment. These results suggest that oral administration of wax apple improves vascular dysfunction and damage in hypercholesterolemic rats possibly through increasing NO bioavailability, decreasing ET-1 levels and reducing oxidative stress. Furthermore, wax apple ameliorates the HCD-induced fatty liver in rats.

Cyclodextrin-mediated conjugation of macrophage and liposomes for treatment of atherosclerosis

Current pharmacological treatments of atherosclerosis often target either cholesterol management or inflammation management, to inhibit atherosclerotic progression, but cannot lead to direct plaque lysis and atherosclerotic regression, partly due to the poor accumulation of medicine in the atherosclerotic plaques. Due to enhanced macrophage recruitment during atheromatous plaque progression, a facilely macrophage-liposome conjugate was constructed for targeted anti-atherosclerosis therapy via synergistic plaque lysis and inflammation alleviation. Endogenous macrophage is utilized as drug-transporting cell, upon membrane-modification with β-cyclodextrin (β-CD) derivative to form β-CD decorated macrophage (CD-MP). Adamantane (ADA) modified quercetin (QT)-loaded liposome (QT-NP), can be conjugated to CD-MP via host-guest interactions between β-CD and ADA to construct macrophage-liposome conjugate (MP-QT-NP). Thus, macrophage carries liposome "hand-in-hand" to significantly increase the accumulation of anchored QT-NP in the aorta plaque in response to the plaque inflammation. In addition to anti-inflammation effects of QT, MP-QT-NP efficiently regresses atherosclerotic plaques from both murine aorta and human carotid arteries via CD-MP mediated cholesterol efflux, due to the binding of cholesterol by excess membrane β-CD. Transcriptome analysis of atherosclerotic murine aorta and human carotid tissues reveal that MP-QT-NP may activate NRF2 pathway to inhibit plaque inflammation, and simultaneously upregulate liver X receptor to promote cholesterol efflux.

Quercetin Can Improve Spinal Cord Injury by Regulating the mTOR Signaling Pathway

The pathogenesis of spinal cord injury (SCI) is complex. At present, there is no effective treatment for SCI, with most current interventions focused on improving the symptoms. Inflammation, apoptosis, autophagy, and oxidative stress caused by secondary SCI may instigate serious consequences in the event of SCI. The mammalian target of rapamycin (mTOR), as a key signaling molecule, participates in the regulation of inflammation, apoptosis, and autophagy in several processes associated with SCI. Quercetin can reduce the loss of myelin sheath, enhance the ability of antioxidant stress, and promote axonal regeneration. Moreover, quercetin is also a significant player in regulating the mTOR signaling pathway that improves pathological alterations following neuronal injury. Herein, we review the therapeutic effects of quercetin in SCI through its modulation of the mTOR signaling pathway and elaborate on how it can be a potential interventional agent for SCI.

Astragali Radix-Coptis Rhizoma Herb Pair Attenuates Atherosclerosis in ApoE-/- Mice by Regulating the M1/M2 and Th1/Th2 Immune Balance and Activating the STAT6 Signaling Pathway

OBJECTIVE

Immune imbalance and the inflammatory response are associated with atherosclerosis (AS) progression. Astragali Radix and Coptis Rhizoma (ARCR) are an ancient and classic herb pair that is used in herbal medicines for the treatment of coronary heart disease. We focused on the effects and mechanisms of the ARCR herb pair attenuation of atherosclerosis in apolipoprotein E knockout (ApoE-/-) mice.

METHODS

ApoE-/- mice were fed a high-fat diet for 12 weeks to establish a model of AS. The ApoE-/- mice were randomly divided into a model group, simvastatin group (Simva), Astragali Radix group (AR), Coptis Rhizoma group (CR), Astragali Radix-Coptis Rhizoma group (ARCR), and Astragali Radix-Coptis Rhizoma + signal transducer and activator of transcription factor 6 (STAT6) inhibitor (AS1517499) group (ARCR + AS1517499). C57BL/6 mice were used as controls. Each group was administered the corresponding drugs, and mice in the model and control groups were given the same volume of normal saline once daily for 6 weeks. The body weights of the mice were observed regularly. The effect of the ARCR herb pair on lipid content in peripheral blood was evaluated using blood lipid tests. The levels of serum matrix metalloproteinase-9 (MMP-9), interleukins-12 (IL-12), IL-10, interferon-γ (IFN-γ), and IL-4 were determined to assess inflammation. Oil Red O staining, Sirius Red staining, and immunohistochemistry were used to observe changes in plaque stability. Western blotting was used to assay M1/M2 macrophages, Th1/Th2 cells, and STAT6 signaling pathway protein expression. Flow cytometry and immunofluorescence were used to detect M1/M2 macrophages and Th1/Th2 cells and reflect the immune imbalance.

RESULTS

The ARCR herb pair significantly reduced blood lipids levels and plaque vulnerability and regulated the levels of inflammatory factors and the number of M1/M2 macrophages and Th1/Th2 cells in ApoE-/- AS mice. It also decreased iNOS and T-bet protein levels and increased the Arg-1 and GATA-3 protein levels. The ARCR herb pair also increased STAT6 phosphorylation. A STAT6 inhibitor attenuated the regulation of M1/M2 and Th1/Th2 markers induced by the ARCR herb pair.

CONCLUSION

The ARCR herb pair regulates blood lipid metabolism and attenuates atherosclerosis via regulation of M1/M2 and Th1/Th2 immune balance, which is achieved partially by increasing STAT6 phosphorylation. Our study provides new evidence for the possible use of ARCR herb pair in the prevention and treatment of AS.

The Potency of Moringa oleifera Lam. as Protective Agent in Cardiac Damage and Vascular Dysfunction

Cardiac damage and vascular dysfunction due to underlying diseases, such as hypertension and cardiac thrombosis, or side effects from certain drugs may lead to critical illness conditions and even death. The phytochemical compounds in natural products are being prospected to protect the heart and vascular system from further damage. Moringa genus is a subtropical tree native to Asia and Africa, which includes 13 species; Moringa oleifera Lam. (MO) is the most cultivated for its beneficial uses. MO is also known as the “miracle tree” because it has been used traditionally as a food source and medicine to treat various diseases such as anemia, diabetes, and infectious or cardiovascular diseases. The phytochemical compounds identified in MO with functional activities associated with cardiovascular diseases are N,α-L-rhamnopyranosyl vincosamide, isoquercetin, quercetin, quercetrin, and isothiocyanate. This study aims to investigate the potency of the phytochemical compounds in MO as a protective agent to cardiac damage and vascular dysfunction in the cardiovascular disease model. This is a scoping review by studying publications from the reputed database that assessed the functional activities of MO, which contribute to the improvement of cardiac and vascular dysfunctions. Studies show that the phytochemical compounds, for example, N,α-L-rhamnopyranosyl vincosamide and quercetin, have the molecular function of antioxidant, anti-inflammation, and anti-apoptosis. These lead to improving cardiac contractility and protecting cardiac structural integrity from damage. These compounds also act as natural vasorelaxants and endothelium protective agents. Most of the studies were conducted on in vivo studies; therefore, further studies should be applied in a clinical setting.

Therapeutic Effects and Safe Uses of Plant-Derived Polyphenolic Compounds in Cardiovascular Diseases: A Review

Polyphenols have long been recognized as health-promoting entities, including beneficial effects on cardiovascular disease, but their reputation has been boosted recently following a number of encouraging clinical studies in multiple chronic pathologies, that seem to validate efficacy. Health benefits of polyphenols have been linked to their well-established powerful antioxidant activity. This review aims to provide comprehensive and up-to-date knowledge on the current therapeutic status of polyphenols having sufficient heed towards the treatment of cardiovascular diseases. Furthermore, data about the safety profile of highly efficacious polyphenols has also been investigated to further enhance their role in cardiac abnormalities. Evidence is presented to support the action of phenolic derivatives against cardiovascular pathologies by following receptors and signaling pathways which ultimately cause changes in endogenous antioxidant, antiplatelet, vasodilatory, and anti-inflammatory activities. In addition, in vitro antioxidant and pre-clinical and clinical experiments on anti-inflammatory as well as immunomodulatory attributes of polyphenols have revealed their role as cardioprotective agents. However, an obvious shortage of in vivo studies related to dose selection and toxicity of polyphenols makes these compounds a suitable target for clinical investigations. Further studies are needed for the development of safe and potent herbal products against cardiovascular diseases. The novelty of this review is to provide comprehensive knowledge on polyphenols safety and their health claims. It will help researchers to identify those moieties which likely exert protective and therapeutic effects towards cardiovascular diseases.

Potential therapeutic effects and applications of Eucommiae Folium in secondary hypertension

Eucommiae Folium (EF), a traditional Chinese medicine, has been used to treat secondary hypertension, including renal hypertension and salt-sensitive hypertension, as well as hypertension caused by thoracic aortic endothelial dysfunction, a high-fat diet, and oxidized low-density lipoprotein. The antihypertensive components of EF are divided into four categories: flavonoids, iridoids, lignans, and phenylpropanoids, such as chlorogenic acid, geniposide acid and pinoresinol diglucoside. EF regulates the occurrence and development of hypertension by regulating biological processes, such as inhibiting inflammation, regulating the nitric oxide synthase pathway, reducing oxidative stress levels, regulating endothelial vasoactive factors, and lowering blood pressure. However, its molecular antihypertensive mechanisms are still unclear and require further investigation. In this review, by consulting the relevant literature on the antihypertensive effects of EF and using network pharmacology, we summarized the active ingredients and pharmacological mechanisms of EF in the treatment of hypertension to clarify how EF is associated with secondary hypertension, the related components, and underlying mechanisms. The results of the network pharmacology analysis indicated that EF treats hypertension through a multi-component, multi-target and multi-pathway mechanism. In particular, we discussed the role of EF targets in the treatment of hypertension, including epithelial sodium channel, heat shock protein70, rho-associated protein kinase 1, catalase, and superoxide dismutase. The relevant signal transduction pathways, the ras homolog family member A (RhoA)/Rho-associated protein kinase (ROCK) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase/eNOS/NO/Ca²⁺ pathways, are also discussed.

•

Eucommiae Folium (EF) treats secondary hypertension via the RhoA/ROCK1 and NO/sGC/cGMP pathways.

•

EF inhibits oxidative stress and improves endothelial dysfunction to treat hypertension.

•

EF's antihypertensive components are phenylpropanoids, flavonoids, lignans, iridoids.

•

KEGG analysis showed EF treated hypertension through the MAPK and TNF signaling pathways.

Screening of potential tropical fruits in protecting endothelial dysfunction in vitro

Background

High consumption of antioxidant-rich fruits and vegetables reduces the endothelial damage involved in cardiovascular disease pathogenesis.

Objective

To evaluate the phytochemical content, antioxidant and scavenging activities (FRAP, ORAC, OH^•, HOCl, H₂O₂, and O₂ ^-), endothelial H₂O₂-cytoprotective effect, nitric oxide (NO) release activation potential, and endothelial wound healing properties of 10 tropical fruits, comprising pineapple, sugar apple, papaya fruit, longan, mangosteen, lychee, langsat, mango, rambutan, and guava.

Design

Experimental study. The experiments were conducted in vitro using endothelial cell line EA.hy926.

Results

The high performance liquid chromatography (HPLC) phytochemical analysis indicated the presence of gallic acid and quercetin in all fruits, along with the overall absence of ellagic acid. Chlorogenic acid was only detected in three fruits, that is, pineapple, ripe papaya, and guava. The antioxidant and scavenging activities of all fruits were concentration-dependent. Only the H₂O₂ scavenging activity exhibited broad positive associations with other ROS-scavenging activities. Sugar apple and unripe papaya induced a significant reduction in H₂O₂-induced cell death in endothelial cells while pineapple, sugar apple, longan, and langsat activated NO release.

Discussion

All the studied tropical fruits contained bioactive phytoantioxidants with wide ranges of antioxidant capacity and scavenging activities. The endothelial functional tests were relevant to the screening for fruits that may benefit cardiovascular health. Among the four fruits that promoted endothelial wound closure, only sugar apple and unripe papaya induced cell migration and vascular capillary-like tube formation.

Conclusion

Sugar apple and unripe papaya are potential functional fruits that can protect against oxidative cell death and enhance endothelial wound healing.

Chinese Herbal Medicines and Active Metabolites: Potential Antioxidant Treatments for Atherosclerosis

Atherosclerosis is a complex chronic disease that occurs in the arterial wall. Oxidative stress plays a crucial role in the occurrence and progression of atherosclerotic plaques. The dominance of oxidative stress over antioxidative capacity generates excess reactive oxygen species, leading to dysfunctions of the endothelium and accelerating atherosclerotic plaque progression. Studies showed that Chinese herbal medicines and traditional Chinese medicine (TCM) might regulate oxidative stress; they have already been used to treat diseases related to atherosclerosis, including stroke and myocardial infarction. This review will summarize the mechanisms of oxidative stress in atherosclerosis and discuss studies of Chinese herbal medicines and TCM preparations treating atherosclerosis, aiming to increase understanding of TCM and stimulate research for new drugs to treat diseases associated with oxidative stress.

The Relationship Between Nutrition and Atherosclerosis

Atherosclerosis is the basic pathological process of many diseases, such as coronary atherosclerosis and stroke. Nutrients can affect the occurrence and development of atherosclerosis. At present, in nutrition science, the research on atherosclerosis focuses on which nutrients play an important role in its prevention strategy, and what are the possible mechanisms of its action. In the current study, the process of atherosclerosis can be affected by adjusting the proportion of nutrients in the diet. In this review, we pay attention to the effects of phytosterols, omega-3-polyunsaturated fatty acids, polyphenol, vitamin, and other nutrients on atherosclerosis, pay attention to their current epidemiological status, current nutritional research results, and prevention or a possible mechanism to reduce the risk of development of atherosclerosis. So that more personalized nutritional approaches may be more effective in terms of nutritional intervention responses to atherosclerosis.

Myeloperoxidase Targets Apolipoprotein A-I for Site-Specific Tyrosine Chlorination in Atherosclerotic Lesions and Generates Dysfunctional High-Density Lipoprotein

We previously demonstrated that apolipoprotein A-I (apoA-I), the major protein component of high-density lipoprotein (HDL), is an important target for myeloperoxidase (MPO)-catalyzed tyrosine chlorination in the circulation of subjects with cardiovascular diseases. Oxidation of apoA-I by MPO has been reported to deprive HDL of its protective properties. However, the potential effects of MPO-mediated site-specific tyrosine chlorination of apoA-I on dysfunctional HDL formation and atherosclerosis was unclear. Herein, Tyr192 in apoA-I was found to be the major chlorination site in both lesion and plasma HDL from humans with atherosclerosis, while MPO binding to apoA-I was demonstrated by immunoprecipitation studies in vivo. In vitro, MPO-mediated damage of lipid-free apoA-I impaired its ability to promote cellular cholesterol efflux by the ABCA1 pathway, whereas oxidation to lipid-associated apoA-I inhibited lecithin:cholesterol acyltransferase activation, two key steps in reverse cholesterol transport. Compared with native apoA-I, apoA-I containing a Tyr192 → Phe mutation was moderately resistant to oxidative inactivation by MPO. In high-fat-diet-fed apolipoprotein E-deficient mice, compared with native apoA-I, subcutaneous injection with oxidized apoA-I (MPO treated) failed to mediate the lipid content in aortic plaques while mutant apoA-I (Tyr192 → Phe) showed a slightly stronger ability to reduce the lipid content in vivo. Our observations suggest that oxidative damage of apoA-I and HDL involves MPO-dependent site-specific tyrosine chlorination, raising the feasibility of producing MPO-resistant forms of apoA-I that have stronger antiatherosclerotic activity in vivo.

Carrot Supplementation Improves Blood Pressure and Reduces Aortic Root Lesions in an Atherosclerosis-Prone Genetic Mouse Model

Epidemiological studies have shown that carrot consumption may be associated with a lower risk of developing several metabolic dysfunctions. Our group previously determined that the Bolero (Bo) carrot variety exhibited vascular and hepatic tropism using cellular models of cardiometabolic diseases. The present study evaluated the potential metabolic and cardiovascular protective effect of Bo, grown under two conditions (standard and biotic stress conditions (BoBS)), in apolipoprotein E-knockout (ApoE^−/−) mice fed with high fat diet (HFD). Effects on metabolic/hemodynamic parameters and on atherosclerotic lesions have been assessed. Both Bo and BoBS decreased plasma triglyceride and expression levels of genes implicated in hepatic de novo lipogenesis and lipid oxidation. BoBS supplementation decreased body weight gain, secretion of very-low-density lipoprotein, and increased cecal propionate content. Interestingly, Bo and BoBS supplementation improved hemodynamic parameters by decreasing systolic, diastolic, and mean blood pressure. Moreover, Bo improved cardiac output. Finally, Bo and BoBS substantially reduced the aortic root lesion area. These results showed that Bo and BoBS enriched diets corrected most of the metabolic and cardiovascular disorders in an atherosclerosis-prone genetic mouse model and may therefore represent an interesting nutritional approach for the prevention of cardiovascular diseases.

The Emerging Roles of Antioxidant Enzymes by Dietary Phytochemicals in Vascular Diseases

Vascular diseases are major causes of death worldwide, causing pathologies including diabetes, atherosclerosis, and chronic obstructive pulmonary disease (COPD). Exposure of the vascular system to a variety of stressors and inducers has been implicated in the development of various human diseases, including chronic inflammatory diseases. In the vascular wall, antioxidant enzymes form the first line of defense against oxidative stress. Recently, extensive research into the beneficial effects of phytochemicals has been conducted; phytochemicals are found in commonly used spices, fruits, and herbs, and are used to prevent various pathologic conditions, including vascular diseases. The present review aims to highlight the effects of dietary phytochemicals role on antioxidant enzymes in vascular diseases.

Generation of a Bovine Serum Albumin-Diligand Complex for the Protection of Bioactive Quercetin and Suppression of Heme Toxicity

As an abundant protein in milk and blood serum, bovine serum albumin (BSA) contains various sites to bind a lot of bioactive components, generating BSA-monoligand complex. Demonstration of the interaction between BSA and bioactive components (such as heme, flavonoids) is important to develop effective carrier for the protection of bioactive ligands and to reduce cytotoxicity of heme. Herein, the bindings of BSA to quercetin and/or heme were investigated by multispectroscopic and molecular docking methods. The fluorescence of protein was significantly quenched by both quercetin and heme in a static mode (i.e., generation of BSA-ligand complex). Although quercetin had lower affinity to protein than heme, the interactions of both compounds with protein did locate in site I (i.e., subdomain IIA). BSA-diligand complex was successfully generated after the coaddition of quercetin and heme. The cytotoxicity of free heme to endothelial cells was reduced in the BSA-diligand complex relative to that of heme or BSA-monoligand complex, while the stability of bioactive quercetin was promoted in the complex relative to free flavonoid. The complex provided a better inhibition on the cytotoxicity of heme than BSA-monoligand complex, in which the copresence of quercetin played a vital role.

Quercetin Attenuated Myeloperoxidase-Dependent HOCl Generation and Endothelial Dysfunction in Diabetic Vasculature

Myeloperoxidase (MPO)-dependent hypochlorous acid (HOCl) generation plays crucial roles in diabetic vascular complications. As a natural polyphenol, quercetin has antioxidant properties in various diabetic models. Herein, we investigated the therapeutic mechanism for quercetin on MPO-mediated HOCl generation and endothelial dysfunction in diabetic vasculature. In vitro, the presence of MPO could amplify high glucose-induced endothelial dysfunction which was significantly inhibited by the NADPH oxidase inhibitor, HOCl or H₂O₂ scavengers, revealing the contribution of MPO/H₂O₂/HOCl to vascular endothelial injury. Furthermore, quercetin effectively inhibited MPO/high glucose-mediated HOCl generation and cytotoxicity to vascular endothelial cells. The inhibitive effect on MPO activity was related to the fact that quercetin reduced high glucose-induced H₂O₂ generation in endothelial cells and directly acted as a competitive substrate for MPO, thus limiting MPO/H₂O₂-dependent HOCl production. Moreover, quercetin could attenuate HOCl-caused endothelial dysfunction in endothelial cells and isolated aortas. In vivo, dietary quercetin significantly inhibited aortic endothelial dysfunction in diabetic mice, while this compound simultaneously suppressed vascular MPO expression and activity. Therefore, it was demonstrated herein that quercetin inhibited endothelial injury in diabetic vasculature via suppression of MPO/high glucose-dependent HOCl formation.

Systematic Pharmacology and GEO Database Mining Revealed the Therapeutic Mechanism of Xuefu Zhuyu Decoration for Atherosclerosis Cardiovascular Disease

Background: Xuefu Zhuyu decoration (XFZYD), as a traditional Chinese compound recipe, has been used to treat atherosclerosis cardiovascular disease (ASCVD) for thousands of years in China, but its effective compounds and underlying treatment molecular mechanism remains promiscuous, which severely limits its clinical application. Methods: The effective components and their targets of XFZYD were predicted and screened based on the Traditional Chinese Medicine System Pharmacology (TCMSP) database. The candidate therapeutic targets of ASCVD were screened by Pharmacogenomics Knowledgebase (PharmGKB) and Comparative Toxicogenomics Database (CTD). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses for target proteins were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) database. Differentially expressed genes were identified using the GEO2R online tool. Molecular docking was performed by Schrodinger software. To assess the efficacy of the prediction, human umbilical vein endothelial cells (HUVECs) treated with the effective compound of XFZYD were used as the in vitro model. Results: A total of 108 effective compounds (including quercetin) and 137 candidate therapeutic targets were identified. Analyzing the relationships among effective compounds, candidate therapeutic targets, and signaling pathways, the therapy mechanisms of XFZYD were mainly reflected in the protection of vascular endothelium, anti-inflammatory, antioxidant stress, etc. Accordingly, we found the effective compound of XFZYD (quercetin) decreased intracellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) expressions and pro-inflammatory cytokines in HUVECs treated with lipopolysaccharide (LPS), and reduced the adhesion function of HUVECs with monocytes. The inhibitor of the predicted target protein (PTGS2) could further reduce the expressions of VCAM-1, ICAM-1, and TNF-α induced by LPS, and inhibit the adhesion function of HUVECs with monocytes, while PTGS2 agonists partially counteracted the protective effect of quercetin. Conclusions: In this study, the effective components and potential therapeutic targets of XFZYD for ASCVD treatment were explored from the perspective of systemic pharmacology. The effective component quercetin was verified to protect endothelial cells by reducing endothelial inflammatory response and impeding the attachment of monocytes against the predicted therapeutic target PTGS2.