Marjoram Relaxes Rat Thoracic Aorta Via a PI3-K/eNOS/cGMP Pathway

Phenotypic switching of vascular smooth muscle cells in atherosclerosis, hypertension, and aortic dissection

Vascular smooth muscle cells (VSMCs) play a critical role in regulating vasotone, and their phenotypic plasticity is a key contributor to the pathogenesis of various vascular diseases. Two main VSMC phenotypes have been well described: contractile and synthetic. Contractile VSMCs are typically found in the tunica media of the vessel wall, and are responsible for regulating vascular tone and diameter. Synthetic VSMCs, on the other hand, are typically found in the tunica intima and adventitia, and are involved in vascular repair and remodeling. Switching between contractile and synthetic phenotypes occurs in response to various insults and stimuli, such as injury or inflammation, and this allows VSMCs to adapt to changing environmental cues and regulate vascular tone, growth, and repair. Furthermore, VSMCs can also switch to osteoblast-like and chondrocyte-like cell phenotypes, which may contribute to vascular calcification and other pathological processes like the formation of atherosclerotic plaques. This provides discusses the mechanisms that regulate VSMC phenotypic switching and its role in the development of vascular diseases. A better understanding of these processes is essential for the development of effective diagnostic and therapeutic strategies.

The potential effect of natural antioxidants on endothelial dysfunction associated with arterial hypertension

Arterial hypertension represents a leading cause of cardiovascular morbidity and mortality worldwide, and the identification of effective solutions for treating the early stages of elevated blood pressure (BP) is still a relevant issue for cardiovascular risk prevention. The pathophysiological basis for the occurrence of elevated BP and the onset of arterial hypertension have been widely studied in recent years. In addition, consistent progress in the development of novel, powerful, antihypertensive drugs and their appropriate applications in controlling BP have increased our potential for successfully managing disease states characterized by abnormal blood pressure. However, the mechanisms responsible for the disruption of endogenous mechanisms contributing to the maintenance of BP within a normal range are yet to be fully clarified. Recently, evidence has shown that several natural antioxidants containing active ingredients originating from natural plant extracts, used alone or in combination, may represent a valid solution for counteracting the development of arterial hypertension. In particular, there is evidence to show that natural antioxidants may enhance the viability of endothelial cells undergoing oxidative damage, an effect that could play a crucial role in the pathophysiological events accompanying the early stages of arterial hypertension. The present review aims to reassess the role of oxidative stress on endothelial dysfunction in the onset and progression of arterial hypertension and that of natural antioxidants in covering several unmet needs in the treatment of such diseases.

Cardioprotective effect of Sanguisorba minor against isoprenaline-induced myocardial infarction in rats

Introduction: Oxidative stress is a major instigator of various cardiovascular diseases, including myocardial infarction (MI). Despite available drugs, there is still an increased need to look for alternative therapies or identify new bioactive compounds. Sanguisorba minor (S. minor) is a native herb characterized by its potent antioxidant activity. This study was designed to evaluate the effect of S. minor against isoprenaline-induced MI. Methods: Rats were treated with the hydro-ethanolic extract of the aerial parts of S. minor at doses of 100 or 300 mg/kg orally for 9 days. Isoprenaline was injected subcutaneously at the dose of 85 mg/kg on days 8 and 9. Then, the activities of various cardiac injury markers including cardiac troponin (cTnT), lactate dehydrogenase (LDH), creatinine kinase muscle brain (CK-MB), creatinine phosphokinase (CPK), and antioxidant enzymes in serum were determined. Malondialdehyde (MDA) and thiol content were measured in cardiac tissue, and histopathological analysis was conducted. Results: Our results show that isoprenaline increased the serum levels of cTnT, LDH, CK-MB, and CPK (p < 0.001) and elevated MDA levels (p < 0.001) in cardiac tissue. Isoprenaline also reduced superoxide dismutase (SOD), catalase, and thiol content (p < 0.001). Importantly, the extract abolished isoprenaline-induced MI by elevating SOD and catalase (p < 0.001), reducing levels of MDA, and diminishing levels of cTnT, LDH, CK-MB, and CPK cardiac markers (p < 0.001). Histopathological studies of the cardiac tissue showed isoprenaline-induced injury that was significantly attenuated by the extract. Conclusion: Our results suggest that S. minor could abrogate isoprenaline-induced cardiac toxicity due to its ability to mitigate oxidative stress.

Cardioprotective Effects of Vitex negundo: A Review of Bioactive Extracts and Compounds

There has been accumulating interest in the application of medicinal plants as alternative medicine to treat various diseases and/or to develop modern medicines. Vitex negundo is one of such medicinal plants that has been of interest to many researchers and has been of use in traditional medicine. V. negundo is found in Sri Lanka, Madagascar, Malaysia, India, China, The Philippines and East Africa. Therapeutic properties of V. negundo have previously been reviewed. Different parts, preparations and bioactive components of V. negundo possess potential protective and therapeutic effects against cardiovascular disease and related conditions as demonstrated in previous studies. We review the present state of scientific knowledge on the potential use of V. negundo and some of its bioactive components in protecting against cardiovascular diseases and related pathologies. Previous studies in animal and non-animal experimental models, although limited in number and vary in design, seem to support the cardioprotective effect of V. negundo and some of its active components. However, there is need for further preclinical and clinical studies to validate the use of V. negundo and its active constituents in protection and treatment of cardiovascular diseases. Additionally, since only a few V. negundo compounds have been evaluated, specific cardioprotective effects or mechanisms and possible side effects of other V. negundo compounds need to be extensively evaluated.

Spicy and Aromatic Plants for Meat and Meat Analogues Applications

Aromatic and spicy plants are an important factor that contributes not only to improving the taste of meat, meat products, and meat analogues, but also to increasing the nutritional value of the products to which they are added. The aim of this paper is to present the latest information on the bioactive antioxidant and antimicrobial properties of the most commonly used herbs and spices (parsley, dill, basil, oregano, sage, coriander, rosemary, marjoram, tarragon, bay, thyme, and mint) used in the meat and meat analogues industry, or proposed to be used for meat analogues.

Marjoram extract prevents ischemia reperfusion-induced myocardial damage and exerts anti-contractile effects in aorta segments of male wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Marjoram (Origanum majorana L.) is an herb traditionally used as a medicine in different countries, as Morocco and Iran, because of its beneficial cardiovascular effects. Some studies suggest that these effects are due, at least in part, to the presence of phenolic compounds such as rosmarinic acid (RA) and luteolin.

AIM OF THE STUDY

To analyze the possible cardiprotective effects of a marjoram extract (ME) reducing myocardial damage after coronary ischemia-reperfusion (IR) and its possible antihypertensive effects reducing the response of aorta segments to the vasoconstrictors noradrenaline (NA) and endothelin-1 (ET-1).

MATERIALS AND METHODS

Male Wistar rats (300g) were used. After sacrifice, the heart was immediately removed and mounted in a perfusion system (Langendorff). The aorta was carefully dissected and cut in 2 mm segments to perform vascular reactivity experiments.

RESULTS

In the heart, ME perfusion after IR reduced heart rate and prevented IR-induced decrease of cardiac contractility, possibly through vasodilation of coronary arteries and through the upregulation of antioxidant markers in the myocardium that led to reduced apoptosis of cardiomyocytes. In the aorta, ME decreased the vasoconstrictor response to NA and ET-1 and exerted a potent anti-inflammatory and antioxidant effect. Neither RA nor 6-hydroxi-luteolin-O-glucoside, major compounds of this ME, were effective in improving cardiac contractility after IR or attenuating vasoconstriction to NA and ET-1 in aorta segments.

CONCLUSION

In conclusion, ME reduces the myocardial damage induced by IR and the contractile response to vasoconstrictors in the aorta. Thus, it may be useful for the treatment of cardiovascular diseases such as myocardial infarction and hypertension.

Herbs and their bioactive ingredients in cardio-protection: Underlying molecular mechanisms and evidences from clinical studies

BACKGROUND

Medicinal plants or herbs produce a bounty of bioactive phytochemicals. These phytochemicals can influence a variety of physiological events related to cardiovascular health through multiple underlying mechanisms, such as their role as antioxidative, anti-ischemic, anti-proliferative, hypotensive, anti-thrombotic, and anti-hypercholesterolemic agents.

PURPOSE

The purpose of this review is to summarize and connect evidences supporting the use of phytotherapy in the management of some of the most common cardiovascular impairments, molecular mechanisms underlying cardio-protection mediated by herbs, and clinical studies which are positively linked with the use of herbs in cardiovascular biology. Additionally, we also describe several adverse effects associated with some of the herbal plants and their products to provide a balanced set of studies in favor or against phytotherapy in cardiovascular health that may help global discourses on this matter.

METHODS

Studies relating to the use of medicinal plants were mined by strategically searching scientific databases including Google Scholar, PubMed and Science Direct. Investigations involving approximately 175 articles including reviews, research articles, meta-analyses, and cross-sectional and observational studies were retrieved and analyzed in line with the stated purpose of this study.

RESULTS

A positive correlation between the use of medicinal plants and cardiovascular health was observed. While maintaining cardiovascular physiology, medicinal plants and their derivatives seem to govern a variety of cellular mechanisms involved in vasoconstriction and vasorelaxation, which in turn, are important aspects of cardiovascular homeostasis. Furthermore, a variety of studies including clinical trials, cross-sectional studies, and meta-analyses have also supported the anti-hypertensive and thus, cardio-protective effects, of medicinal plants. Apart from this, evidence is also available for the potential drawbacks of several herbs and their products indicating that the unsupervised use of many herbs may lead to severe health issues.

CONCLUSIONS

The cardio-protective outcomes of medicinal plants and their derivatives are supported by ever-increasing studies, while evidences exist for the potential drawbacks of some of the herbs. A balanced view about the use of medicinal plants and their derivative in cardiovascular biology thus needs to be outlined by researchers and the medical community. The novelty and exhaustiveness of the present manuscript is reflected by the detailed outline of the molecular basis of "herbal cardio-protection", active involvement of several herbs in ameliorating the cardiovascular status, adverse effects of medicinal plants, and the clinical studies considering the use of phytotherapy, all on a single platform.

Flavonoids in adipose tissue inflammation and atherosclerosis: one arrow, two targets

Flavonoids are polyphenolic compounds naturally occurring in fruits and vegetables, in addition to beverages such as tea and coffee. Flavonoids are emerging as potent therapeutic agents for cardiovascular as well as metabolic diseases. Several studies corroborated an inverse relationship between flavonoid consumption and cardiovascular disease (CVD) or adipose tissue inflammation (ATI). Flavonoids exert their anti-atherogenic effects by increasing nitric oxide (NO), reducing reactive oxygen species (ROS), and decreasing pro-inflammatory cytokines. In addition, flavonoids alleviate ATI by decreasing triglyceride and cholesterol levels, as well as by attenuating inflammatory mediators. Furthermore, flavonoids inhibit synthesis of fatty acids and promote their oxidation. In this review, we discuss the effect of the main classes of flavonoids, namely flavones, flavonols, flavanols, flavanones, anthocyanins, and isoflavones, on atherosclerosis and ATI. In addition, we dissect the underlying molecular and cellular mechanisms of action for these flavonoids. We conclude by supporting the potential benefit for flavonoids in the management or treatment of CVD; yet, we call for more robust clinical studies for safety and pharmacokinetic values.

Phytochemical constituents, biological activities, and health-promoting effects of the genus Origanum

Origanum species are mostly distributed around the Mediterranean, Euro-Siberian, and Iran-Siberian regions. Since time immemorial, the genus has popularly been used in Southern Europe, as well as on the American continent as a spice now known all over the world under the name "oregano" or "pizza-spice." Origanum plants are also employed to prepare bitter tinctures, wines, vermouths, beer, and kvass. The major components of Origanum essential oil are various terpenes, phenols, phenolic acids, and flavonoids with predominant occurrence of carvacrol and thymol (with reasonable amounts of p-cymen and -terpinene) or of terpinene-4-ol, linalool, and sabinene hydrate. Many species of Origanum genus are used to treat kidney, digestive, nervous, and respiratory disorders, spasms, sore throat, diabetes, lean menstruation, hypertension, cold, insomnia, toothache, headache, epilepsy, urinary tract infections, etc. Origanum essential oil showed potent bioactivities owing to its major constituents' carvacrol, thymol, and monoterpenes. Several preclinical studies evidenced its pharmacological potential as antiproliferative or anticancer, antidiabetic, antihyperlipidemic, anti-obesity, renoprotective, antiinflammatory, vasoprotective, cardioprotective, antinociceptive, insecticidal, and hepatoprotective properties. Its nanotechnological applications as a promising pharmaceutical in order to enhance the solubility, physicochemical stability, and the accumulation rate of its essential oils have been investigated. However, Origanum has been reported causing angioedema, perioral dermatitis, allergic reaction, inhibition of platelet aggregation, hypoglycemia, and abortion. Conclusive evidences are still required for its clinical applications against human medical conditions. Toxicity analyses and risk assessment will aid to its safe and efficacious application. In addition, elaborate structure-activity studies are needed to explore the potential use of Origanum-derived phytochemicals as promising drug candidates.

The Mitochondria: A Target of Polyphenols in the Treatment of Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) is a constellation of symptoms consisting of ventricular dysfunction and cardiomyocyte disarray in the presence of diabetes. The exact cause of this type of cardiomyopathy is still unknown; however, several processes involving the mitochondria, such as lipid and glucose metabolism, reactive oxygen species (ROS) production, apoptosis, autophagy and mitochondrial biogenesis have been implicated. In addition, polyphenols have been shown to improve the progression of diabetes. In this review, we discuss some of the mechanisms by which polyphenols, particularly resveratrol, play a role in slowing the progression of DCM. The most important intermediates by which polyphenols exert their protective effect include Bcl-2, UCP2, SIRT-1, AMPK and JNK1. Bcl-2 acts to attenuate apoptosis, UCP2 decreases oxidative stress, SIRT-1 increases mitochondrial biogenesis and decreases oxidative stress, AMPK increases autophagy, and JNK1 decreases apoptosis and increases autophagy. Our dissection of these molecular players aims to provide potential therapeutic targets for the treatment of DCM.

The hypertensive potential of estrogen: An untold story

Cardiovascular disease (CVD) is the major cause of morbidity and mortality worldwide. The implication of estrogen in this disease has been extensively studied. While the vast majority of published research argue for a cardioprotective role of estrogen in vascular inflammation such as in atherosclerosis, the role of estrogen in hypertension remains far from being resolved. The vasorelaxant effect of estrogen has already been well-established. However, emerging evidence supports a vasoconstrictive potential of this hormone. It has been proposed that the microenvironment dictates the effect of estrogen-induced type 1 nitric oxide synthase-1 (nNOS) on vasotone. Indeed, depending on nNOS product, nitric oxide or superoxide, estrogen can induce vasodilation or vasoconstriction, respectively. In this review, we discuss the evidence supporting the vasorelaxant effects of estrogen, and the molecular players involved. Furthermore, we shed light on recent reports revealing a vasoconstrictive role of estrogen, and speculate on the underlying signaling pathways. In addition, we identify certain factors that can account for the discrepant estrogenic effects. This review emphasizes a yin-yang role of estrogen in regulating blood pressure.

KCNQ5 activation is a unifying molecular mechanism shared by genetically and culturally diverse botanical hypotensive folk medicines

Botanical folk medicines have been used throughout human history to treat common disorders such as hypertension, often with unknown underlying mechanisms. Here, we discovered that hypotensive folk medicines from a genetically diverse range of plant species each selectively activated the vascular-expressed KCNQ5 potassium channel, a feature lacking in the modern synthetic pharmacopeia, whereas nonhypotensive plant extracts did not. Analyzing constituents of the hypotensive Sophora flavescens root, we found that the quinolizidine alkaloid aloperine is a KCNQ-dependent vasorelaxant that potently and isoform-selectively activates KCNQ5 by binding near the foot of the channel voltage sensor. Our findings reveal that KCNQ5-selective activation is a defining molecular mechanistic signature of genetically diverse traditional botanical hypotensives, transcending plant genus and human cultural boundaries. Discovery of botanical KCNQ5-selective potassium channel openers may enable future targeted therapies for diseases including hypertension and KCNQ5 loss-of-function encephalopathy.