Ginseng in vascular dysfunction: A review of therapeutic potentials and molecular mechanisms

Vascular dysfunction can lead to a variety of fatal diseases, including cardiovascular and cerebrovascular diseases, metabolic syndrome, and cancer. Although a large number of studies have reported the therapeutic effects of natural compounds on vascular‐related diseases, ginseng is still the focus of research. Ginseng and its active substances have bioactive effects against different diseases with vascular dysfunction. In this review, we summarized the key molecular mechanisms and signaling pathways of ginseng, its different active ingredients or formula in the prevention and treatment of vascular‐related diseases, including cardiac‐cerebral vascular diseases, hypertension, diabetes complications, and cancer. Moreover, the bidirectional roles of ginseng in promoting or inhibiting angiogenesis have been highlighted. We systematically teased out the relationship between ginseng and vascular dysfunction, which could provide a basis for the clinical application of ginseng in the future.

Ginseng in vascular dysfunction: A review of therapeutic potentials and molecular mechanisms

Vascular dysfunction can lead to a variety of fatal diseases, including cardiovascular and cerebrovascular diseases, metabolic syndrome, and cancer. Although a large number of studies have reported the therapeutic effects of natural compounds on vascular-related diseases, ginseng is still the focus of research. Ginseng and its active substances have bioactive effects against different diseases with vascular dysfunction. In this review, we summarized the key molecular mechanisms and signaling pathways of ginseng, its different active ingredients or formula in the prevention and treatment of vascular-related diseases, including cardiac-cerebral vascular diseases, hypertension, diabetes complications, and cancer. Moreover, the bidirectional roles of ginseng in promoting or inhibiting angiogenesis have been highlighted. We systematically teased out the relationship between ginseng and vascular dysfunction, which could provide a basis for the clinical application of ginseng in the future.

Effects of Panax ginseng and ginsenosides on oxidative stress and cardiovascular diseases: pharmacological and therapeutic roles

Traditionally, Asian ginseng or Korean ginseng, Panax ginseng has long been used in Korea and China to treat various diseases. The main active components of Panax ginseng is ginsenoside, which is known to have various pharmacological treatment effects such as antioxidant, vascular easing, anti-allergic, anti-inflammatory, anti-diabetes, and anticancer. Most reactive oxygen species (ROS) cause chronic diseases such as myocardial symptoms and cause fatal oxidative damage to cell membrane lipids and proteins. Therefore, many studies that inhibit the production of oxidative stress have been conducted in various fields of physiology, pathophysiology, medicine and health, and disease. Recently, ginseng or ginsenosides have been known to act as antioxidants in vitro and in vivo results, which have a beneficial effect on preventing cardiovascular disease. The current review aims to provide mechanisms and inform precious information on the effects of ginseng and ginsenosides on the prevention of oxidative stress and cardiovascular disease in animals and clinical trials.

Characterization of hyperglycemia due to sub-chronic administration of red ginseng extract via comparative global proteomic analysis

Ginseng (Panax ginseng Meyer) is commonly used as an herbal remedy worldwide. Few studies have explored the possible physiological changes in the liver although patients often self-medicate with ginseng preparations, which may lead to exceeding the recommended dose for long-term administration. Here, we analyzed changes in the hepatic proteins of mouse livers using quantitative proteomics after sub-chronic administration of Korean red ginseng (KRG) extract (control group and 0.5, 1.0, and 2.0 g/kg KRG) using tandem mass tag (TMT) 6-plex technology. The 1.0 and 2.0 g/kg KRG groups exhibited signs of liver injury, including increased levels of aspartate transaminase (AST) and alanine aminotransferase (ALT) in the serum. Furthermore, serum glucose levels were significantly higher following KRG administration compared with the control group. Based on the upregulated proteins found in the proteomic analysis, we found that increased cystathionine beta-synthase (CBS) and cystathionine gamma-lyase (CSE) levels promoted greater hydrogen sulfide (H₂S) synthesis in the liver. This investigation provides novel evidence that sub-chronic administration of KRG can elevate H₂S production by increasing protein expression of CBS and CSE in the liver.

Ginsenosides in vascular remodeling: Cellular and molecular mechanisms of their therapeutic action

Evidence is mounting that abnormal vascular remodeling (VR) is a vital pathological event that precedes many cardiovascular diseases (CVD). This provides us with a new research perspective that VR can be a pivotal target for CVD treatment and prevention. However, the current drugs for treating CVD do not fundamentally reverse VR and repair vascular function. The reason may be that a complicated regulatory network is formed between the various signaling pathways involved in VR. Recently, ginsenoside, the main active substance of ginseng, has become increasingly the focus of many researchers for its multiple targets, multiple pathways, and few side effects. Several data have revealed that ginsenosides can improve VR caused by vasodilation dysfunction, abnormal vascular structure and blood pressure. This review is intended to discuss the therapeutic effects and mechanisms of ginsenosides in some diseases involved in VR. Besides, we herein also give a new and contradictory insight into intracellular and molecular signaling of ginsenosides in all kinds of vascular cells. Most importantly, we also discuss the feasibility of ginsenosides Rb1/Rg1/Rg3 in drug development by combining the pharmacodynamics and pharmacokinetics of ginsenosides, and provide a pharmacological basis for the development of ginsenosides in clinical applications.

Pharmacological properties of ginsenosides in inflammation-derived cancers

Ginseng is commonly used as an herbal medicine for improvement of life quality. It is also used as a supplemental medication with anti-cancer drugs to enhance chemotherapy efficacy and shows some beneficial effects. Ginsenosides, also known as saponins, are the major active pharmacological compounds found in ginseng and have been extensively using in treatment of not only cancers but also the other inflammatory diseases such as atherosclerosis, diabetes, acute lung injury, cardiovascular, and infectious diseases. The anti-cancer activities of ginsengs and ginsenosides in different types of cancers have been well studied experimentally and clinically. The major anti-cancer mechanisms of ginseng compounds include inhibition of angiogenesis and metastasis as well as induction of cell cycle arrest and apoptosis. Herein, we review and summarize the current knowledge on the pharmacological effects of ginsengs and ginseng-derived compounds in the treatment of cancers. Moreover, the molecular and cellular mechanism(s) by which ginsengs and ginsenosides modulate the immune response in cancer diseases as well as ginsengs-drugs interaction are also discussed.

Herbal Medications Used to Ameliorate Cardiac Conditions

Herbs have been used for centuries to treat various diseases, including cardiovascular disease. Herbs may be used by clients exclusively for disease management or in combination with conventional medications. This article increases provider awareness of certain herbs and their potential use by clients, as well as their impact on the cardiovascular system. It is important for the advanced practice nurse to collect information related to herb use during history retrieval. This information should prompt the nurse to discuss possible benefits and side effects that may occur taking herbs in isolation or in combination with cardiovascular prescription medications.

Chemical components of ginseng, their biotransformation products and their potential as treatment of hypertension

Ginseng is an ancient perennial herb belonging to the family Araliaceae and genus Panax which has been used for medical therapeutics for thousands of years, particularly in China and other Asian cultures although increasing interest in ginseng has recently emerged in western societies. Ginseng is a complex substance containing dozens of bioactive and potentially effective therapeutic compounds. Among the most studied are the ginsenosides, which are triterpene saponins possessing a wide array of potential therapeutic effects for many conditions. The quantity and type of ginsenoside vary greatly depending on ginseng species and their relative quantity in a given ginseng species is greatly affected by extraction processes as well as by subjecting ginseng to various procedures such as heating. Adding to the complexity of ginsenosides is their ability to undergo biotransformation to bioactive metabolites such as compound K by enteric bacteria following ingestion. Many ginsenosides exert vasodilatating effects making them potential candidates for the treatment of hypertension. Their vascular effects are likely dependent on eNOS activation resulting in the increased production of NO. One proposed end-mechanism involves the activation of calcium-activated potassium channels in vascular smooth cells resulting in reduced calcium influx and a vasodilatating effect, although other mechanisms have been proposed as discussed in this review.

The effects of ginsenosides on platelet aggregation and vascular intima in the treatment of cardiovascular diseases: From molecular mechanisms to clinical applications

Thrombosis initiated by abnormal platelet aggregation is a pivotal pathological event that precedes most cases of cardiovascular diseases (CVD). Recently, growing evidence indicates that platelet could be a potential target for CVD prevention. However, as the conventional antithrombotic management strategy, applications of current antiplatelet agents are somewhat limited by their various side effects, such as bleeding risk and drug resistance. Hence, efforts have been made to search for agents as complementary therapies. Ginsenoside, the principal active component extracted from Panax ginseng, has gained much attention for its regulations on multiple crucial events of platelet aggregation. From structural characteristics to clinical applications, this review anatomized the intrinsic structure-function relationship of antiplatelet potency of ginsenosides, and the involved signal pathways were specifically summarized. Additionally, the emphasis was placed on clinical studies that investigate the antithrombotic efficacy of ginsenosides in the treatment of CVD. Further, a broad overview of approaches for improving the bioavailability of ginsenosides was concluded. Limitations and prospects of current studies were also discussed. This study may provide some new insights into the systematic understanding of ginsenosides in CVD treatment and lay a foundation for future research.

Effects of superimposed pressure oscillations on a chronic sensitized airways mouse model

The hyperconstriction of airway smooth muscle (ASM) is the main driving mechanism during an asthmatic attack. The airway lumen is reduced, resistance to airflow increases, and normal breathing becomes more difficult. The tissue contraction can be temporarily relieved by using bronchodilator drugs, which induce relaxation of the constricted airways. In vitro studies indicate that relaxation of isolated, precontracted ASM is induced by mechanical oscillations in healthy subjects but not in asthmatic subjects. Further, short-term acute asthmatic subjects respond to superimposed pressure oscillations (SIPO) generated in the range of 5-15 Hz with ~50% relaxation of preconstricted sensitized airways. Mechanical oscillations, and specifically SIPO, are not widely characterized in asthmatic models. The objective of this in vivo study is to determine the effects of a range of oscillation patterns similar to our previous acute study differing from normal breathing. Both healthy and sensitized mice were observed, with their responses to SIPO treatments measured during induced bronchoconstriction resulting from acetylcholine (Ach) challenge. SIPO-generated results were compared with data from treatments using the bronchorelaxant isoproterenol (ISO). The study shows that SIPO in the range of 5-20 Hz induces relaxation in chronic sensitized airways, with significant improvements in respiratory parameters at SIPO values near 1.7 cmH₂O irrespective of the frequency of generation.

Pharmacological effects of ginseng on infectious diseases

Ginseng has been traditionally used as an herbal nutritional supplement in Asian countries, including Korea, China, Japan, and Vietnam for several millennia. Most studies have focused on the role of ginseng on anti-oxidative stress, anti-inflammatory, and anti-cancer activities. Recently, modulator activities of ginseng on the immune responses during pathogenic bacterial and viral infections and beneficial effects of ginseng in infectious diseases have been elucidated. In vivo and in vitro studies revealed the potential of ginseng extracts and ginsenosides Rg1, Rg3, Rb1, Rb2, Rb3, compound K, Re, Rd, Rh2 for treatment of several infectious diseases. The molecular mechanisms of these effects mainly involve inflammatory cytokines (TNF-α, IL-6, IL-1β, IFN-γ, IL-10), apoptotic pathway (bcl-2, bcl-xL), PI3K/Akt pathway, MAPKs pathway, JAK2/STAT5, NF-κB pathway, and the inflammasome. In this review, we will summarize the current knowledge on the effects of ginseng in the immune responses during the infections and its bioactivities on the prevention of infectious diseases as well as its underlying mechanisms. Moreover, the therapeutic potential of ginseng as an anti-bacterial and anti-viral medication and vaccine adjuvant will be discussed as well.

Stereoselective Anti-Cancer Activities of Ginsenoside Rg3 on Triple Negative Breast Cancer Cell Models

Ginsenoside Rg3 (Rg3) has two epimers, 20(S)-ginsenoside Rg3 (SRg3) and 20(R)-ginsenoside Rg3 (RRg3), and while Rg3 itself has been reported to have anti-cancer properties, few studies have been reported on the anti-cancer effects of the different epimers. The aim was to investigate the stereoselective effects of the Rg3 epimers on triple negative breast cancer (TNBC) cell lines, tested using cell-based assays for proliferation, apoptosis, cell cycle arrest, migration and invasion. Molecular docking showed that Rg3 interacted with the aquaporin 1 (AQP1) water channel (binding score -9.4 kJ mol-1). The Xenopus laevis oocyte expression system was used to study the effect of Rg3 epimers on the AQP1 water permeability. The AQP1 expression in TNBC cell lines was compared with quantitative-polymerase chain reaction (PCR). The results showed that only SRg3 inhibited the AQP1 water flux and inhibited the proliferation of MDA-MB-231 (100 μM), due to cell cycle arrest at G0/G1. SRg3 inhibited the chemoattractant-induced migration of MDA-MB-231. The AQP1 expression in MDA-MB-231 was higher than in HCC1143 or DU4475 cell lines. These results suggest a role for AQP1 in the proliferation and chemoattractant-induced migration of this cell line. Compared to SRg3, RRg3 had more potency and efficacy, inhibiting the migration and invasion of MDA-MB-231. Rg3 has stereoselective anti-cancer effects in the AQP1 high-expressing cell line MDA-MB-231.

Ginsenoside Rg3, a component of ginseng, induces pro-thrombotic activity of erythrocytes via hemolysis-associated phosphatidylserine exposure

Ginseng and its active gradient, ginsenoside Rg3 (Rg3), are widely used for a variety of health benefits, but concerns over their misuses are increasing. Previously, it has been reported that Rg3 can cause hemolysis, but its health outcome remains unknown. Here, we demonstrated that Rg3 could promote the procoagulant activity of erythrocytes through the process of hemolysis, ultimately leading to increased thrombosis. In freshly isolated human erythrocytes, Rg3 caused pore formation and fragmentation of the erythrocyte membrane. Confocal microscopy observation and flow cytometric analysis revealed that remnant erythrocyte fragments after the exposure to Rg3 expressed phosphatidylserine (PS), which can promote blood coagulation through providing assembly sites for coagulation complexes. Rat in vivo experiments further confirmed that intravenous administration of Rg3 produced PS-bearing erythrocyte debris and increased thrombosis. Collectively, we demonstrated that Rg3 could induce the procoagulant activity of erythrocytes by generating PS-bearing erythrocyte debris through hemolysis, which might provoke thrombosis.

Mechanism of Beraprost Effects on Pulmonary Hypertension: Contribution of Cross-Binding to PGE2 Receptor 4 and Modulation of O2 Sensitive Voltage-Gated K+ Channels

Background: The purpose of this study is to elucidate mechanism(s) by which the orally active PGI2 analog, Beraprost (BPS), ameliorates pulmonary hypertension (PH). Prostaglandins are an important treatment for PH. Mechanisms of their action are not fully elucidated in relation to receptor subtype and effects on O2 sensitive Kv channels. Methods: Distal (3rd order and beyond) pulmonary arteries from chronically hypoxic rats and from humans with established PH were studied. Measurements included pulmonary haemodynamics and histology, vascular reactivity, prostanoid receptor expression and activity of the O2 sensitive Kv channels. Results: Prostacyclin receptor (IP), prostaglandin receptor E3 (EP3) and prostaglandin receptor E4 (EP4) are the main pulmonary artery receptor subtypes in both rat and human pulmonary arteries. Circulating levels of PGI2 and PGE2 were reduced in PH. PH was also associated with reduced receptor expression of IP but not of EP4. The effects on IP expression were overcome with BPS. Dilatory responses in PH to BPS were reduced in the presence of EP4 blockade. Expression and activity of oxygen sensitive Kv channels were reduced in pulmonary artery smooth muscle cell from rats with PH and humans with PAH and were also overcome by administration of BPS. Effects of BPS on oxygen sensitive Kv channels were reduced in the presence of EP4 blockade implicating the EP4 receptor, as well as the IP receptor, in mediating BPS effects. Conclusion: Reduced expression of pulmonary IP receptors and reduced activity of O2 sensitive Kv channels are found in PH in both humans and rats. The orally active prostacyclin analogue, BPS, is able to reverse these changes, partly through binding to the EP4 receptor.

Pharmacological and medical applications of Panax ginseng and ginsenosides: a review for use in cardiovascular diseases

Panax ginseng, also called Asian or Korean ginseng, has long been traditionally used in Korea and China to treat various diseases. The major active ingredients of P. ginseng are ginsenosides, which have been shown to have a variety of therapeutic effects, including antioxidation, anti-inflammatory, vasorelaxation, antiallergic, antidiabetic, and anticancer. To date, approximately 40 ginsenoside components have been reported. Current research is concentrating on using a single ginseng compound, one of the ginsenosides, instead of the total ginseng compounds, to determine the mechanisms of ginseng and ginsenosides. Recent in vitro and in vivo results show that ginseng has beneficial effects on cardiac and vascular diseases through efficacy, including antioxidation, control of vasomotor function, modulation of ion channels and signal transduction, improvement of lipid profiles, adjustment of blood pressure, improvement in cardiac function, and reduction in platelet adhesion. This review aims to provide valuable information on the traditional uses of ginseng and ginsenosides, their therapeutic applications in animal models and humans, and the pharmacological action of ginseng and ginsenosides.

Ginsenoside F2 induces the release of mediators associated with Anaphylactoid reactions

Recently, the allergenicity of ginsenosides, as main active components in ginseng, has attracted much attention. Ginsenoside Rb1 and Rd. have been reported to induce anaphylactoid reaction. In this study, the allergenicity of a series of 20(S)-protopanaxadiol (PPD) type ginsenosides, including Rb1, Rd., F2, Compound K and 20(S)-PPD, was evaluated in rat basophilic leukemia 2H3 (RBL2H3) cells. As a result, 20(S)-PPD had no effect on the mast cell degranulation, but other components showed anaphylactoid potential to different extent. The allergenicity was stronger and stronger according to the order "Rb1, Rd., F2, Compound K". Then, F2 was further verified in RBL-2H3 cells, mouse peritoneal mast cells (MPMCs), Laboratory of Allergic Disease 2 (LAD2) human mast cells in vitro and mice in vivo. Results showed that F2 could induce a significant increase of histamine release and translocation of phosphatidylserine in RBL-2H3 cells. F2 also increased β-hexosaminidase release and the intracellular Ca²⁺ concentration of MPMCs and LAD2 cells. In addition, histamine level in serum of mice was elevated dose-dependently. Our study revealed the potential structure-allergenicity relationship of 20(S)-PPD type ginsenosides and first verified the allergenicity of ginsenoside F2. This study could guide the establishment of quality standards for safe application of ginsenoside-containing preparations.

Allergens in red ginseng extract induce the release of mediators associated with anaphylactoid reactions

BACKGROUND

Anaphylactoid reactions induced by preparations containing red ginseng have been reported. The aim of this study is to evaluate the allergenicity and screen potential allergens in red ginseng extract thoroughly.

METHODS

Red ginseng extract (RGE) and different fractions of RGE were prepared and evaluated by measuring the degranulation and viability of rat basophilic leukemia 2H3 (RBL-2H3) cells. Potential allergens were screened by RBL-2H3 cell extraction and allergenicity verified in RBL-2H3 cells, mouse peritoneal mast cells, Laboratory of Allergic Disease 2 (LAD2) human mast cells and mice, respectively.

RESULTS

80% ethanol extract of red ginseng extract induced mast cell degranulation with less cytotoxicity, but 40% ethanol extract could not. Ginsenoside Rd and 20(S)-Rg3 could induce a significant increase in β-hexosaminidase release, histamine release and translocation of phosphatidylserine in RBL-2H3 cells. Ginsenoside Rd and 20(S)-Rg3 also increased β-hexosaminidase release and the intracellular Ca²⁺ concentration in mouse peritoneal mast cells and LAD2 cells. In addition, histamine levels in serum of mice were elevated dose-dependently.

CONCLUSIONS

Ginsenoside Rd and 20(S)-Rg3 are potential allergens that induce the release of mediators associated with anaphylactoid reactions. Our study could guide optimization of methods associated with Rd/20(S)-Rg3-containing preparations and establishment of quality standards for safe application of Traditional Chinese Medicines.

Effects of ginseng on stress-related depression, anxiety, and the hypothalamic-pituitary-adrenal axis

Ginseng effectively regulates the immune response and the hormonal changes due to stress, thus maintaining homeostasis. In addition to suppressing the occurrence of psychological diseases such as anxiety and depression, ginseng also prevents stress-associated physiological diseases. Recent findings have revealed that ginseng is involved in adjusting the hypothalamic-pituitary-adrenal axis and controlling hormones, thus producing beneficial effects on the heart and brain, and in cases of bone diseases, as well as alleviating erectile dysfunction. Recent studies have highlighted the potential use of ginseng in the prevention and treatment of chronic inflammatory diseases such as diabetes, rheumatoid arthritis, and allergic asthma. However, the mechanism underlying the effects of ginseng on these stress-related diseases has not been completely established. In this review, we focus on the disease pathways caused by stress in order to determine how ginseng acts to improve health. Central to our discussion is how this effective and stable therapeutic agent alleviates the anxiety and depression caused by stress and ameliorates inflammatory diseases.

Anti-atherosclerotic plants which modulate the phenotype of vascular smooth muscle cells

BACKGROUND

Cardiovascular disease (CVD) remains the leading cause of global death, with atherosclerosis being a major contributor to this mortality. Several mechanisms are implicated in the pathogenesis of this disease. A key element in the development and progression of atherosclerotic lesions is the phenotype of vascular smooth muscle cells. Under pathophysiologic conditions such as injury, these cells switch from a contractile to a synthetic phenotype that often possesses high proliferative and migratory capacities.

PURPOSE

Despite major advances made in the management and treatment of atherosclerosis, mortality associated with this disease remains high. This mandates that other approaches be sought. Herbal medicine, especially for the treatment of CVD, has been gaining more attention in recent years. This is in no small part due to the evidence-based values associated with the consumption of many plants as well as the relatively cheaper prices, easier access and conventional folk medicine "inherited" over generations. Sections: In this review, we provide a brief introduction about the pathogenesis of atherosclerosis then we highlight the role of vascular smooth muscle cells in this disease, especially when a phenotypic switch of these cells arises. We then thoroughly discuss the various plants that show potentially beneficial effects as anti-atherosclerotic, with prime attention given to herbs and plants that inhibit the phenotypic switch of vascular smooth muscle cells.

CONCLUSION

Accumulating evidence provides the justification for the use of botanicals in the treatment or prevention of atherosclerosis. However, further studies, especially clinical ones, are warranted to better define several pharmacological parameters of these herbs, such as toxicity, tolerability, and efficacy.

Review of cases of patient risk associated with ginseng abuse and misuse

Ginseng has long been used as a functional food or therapeutic supplement and it is empirically known to be safe and nontoxic. During recent decades, a number of in vitro and in vivo experiments, as well as human studies have been conducted to prove the safety of various types of ginseng samples and their components. Clinical trials, case reports, and in vitro and in vivo research articles addressing the safety, toxicity, and other adverse events of ginseng application were selected and reviewed. Patient risks associated with ginseng abuse and misuse such as affective disorder, allergy, cardiovascular and renal toxicity, genital organ bleeding, gynecomastia, hepatotoxicity, hypertension, reproductive toxicity, and anticoagulant-ginseng interaction were reviewed and summarized. There are some cases of patient risk associated with ginseng abuse and misuse depending on patients' conditions although further investigation in more cases is required to clarify these issues.

A review on the medicinal potentials of ginseng and ginsenosides on cardiovascular diseases

Ginseng is widely used for its promising healing and restorative properties as well as for its possible tonic effect in traditional medicine. Nowadays, many studies focus on purified individual ginsenoside, an important constituent in ginseng, and study its specific mechanism of action instead of whole-plant extracts on cardiovascular diseases (CVDs). Of the various ginsenosides, purified ginsenosides such as Rb1, Rg1, Rg3, Rh1, Re, and Rd are the most frequently studied. Although there are many reports on the molecular mechanisms and medical applications of ginsenosides in the treatment of CVDs, many concerns exist in their application. This review discusses current works on the countless pharmacological functions and the potential benefits of ginseng in the area of CVDs.

RESULTS

Both in vitro and in vivo results indicate that ginseng has potentially positive effects on heart disease through its various properties including antioxidation, reduced platelet adhesion, vasomotor regulation, improving lipid profiles, and influencing various ion channels. To date, approximately 40 ginsenosides have been identified, and each has a different mechanism of action owing to the differences in chemical structure. This review aims to present comprehensive information on the traditional uses, phytochemistry, and pharmacology of ginseng, especially in the control of hypertension and cardiovascular function. In addition, the review also provides an insight into the opportunities for future research and development on the biological activities of ginseng.

Dysfunction of vascular smooth muscle and vascular remodeling by simvastatin

Statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, are widely prescribed for hypercholesterolemia. With the increasing use of statins, numerous reports demonstrated that statins can cause damage to skeletal muscles. However, the toxicities of statins on vascular smooth muscle, which are essential to cardiovascular homeostasis, have not been previously described. Here, we examined the effects of simvastatin on the contractile function and the integrity of vascular smooth muscle in isolated rat thoracic aortic rings, primary cultured vascular smooth muscle cells (VSMCs) in vitro and rats in vivo. In aortic rings, simvastatin suppressed the normal agonist-induced contractile responses in time- and concentration-dependent manners (0.86 g ± 0.11 at 10 μM simvastatin for 24 h compared with 1.89 g ± 0.11 at control). The suppression persisted in the endothelium-denuded aortic rings and was irreversible even after wash-out of simvastatin. Simvastatin suppressed the contraction induced by Bay K8644, an activator of voltage-operated Ca²⁺ channel (VOCC) in rat aortic rings and abolished agonist-induced intracellular Ca²⁺ increase in VSMCs. The simvastatin-induced contractile dysfunction was reversed by the supplementation of mevalonate and geranylgeranylpyrophosphate, precursors for protein isoprenylation. Consistently, activation of RhoA, a representative isoprenylated protein, was disrupted by simvastatin in VSMCs and RhoA-mediated phosphorylation of MYPT1 and CPI-17, and tonic tension were also suppressed. Notably, prolonged treatment of simvastatin up to 48 h induced apoptosis of vascular smooth muscle in aortic rings. Most importantly, simvastatin treatment in vivo significantly attenuated the agonist-induced vasoconstriction in rats ex vivo and induced a decrease in luminal area of the vascular wall. Collectively, these results demonstrate that simvastatin can impair the normal vascular contractility by disturbing Ca²⁺ influx and RhoA activity, ultimately leading to apoptosis and structural remodeling.

Cardiovascular Diseases and Panax ginseng: A Review on Molecular Mechanisms and Medical Applications

Ginseng is one of the most widely used herbal medicines and is reported to have a wide range of therapeutic and pharmacological applications. Ginseng may also be potentially valuable in treating cardiovascular diseases. Research concerning cardiovascular disease is focusing on purified individual ginsenoside constituents of ginseng to reveal specific mechanisms instead of using whole ginseng extracts. The most commonly studied ginsenosides are Rb1, Rg1, Rg3, Rh1, Re, and Rd. The molecular mechanisms and medical applications of ginsenosides in the treatment of cardiovascular disease have attracted much attention and been the subject of numerous publications. Here, we review the current literature on the myriad pharmacological functions and the potential benefits of ginseng in this area. In vitro investigations using cell cultures and in vivo animal models have indicated ginseng's potential cardiovascular benefits through diverse mechanisms that include antioxidation, modifying vasomotor function, reducing platelet adhesion, influencing ion channels, altering autonomic neurotransmitters release, and improving lipid profiles. Some 40 ginsenosides have been identified. Each may have different effects in pharmacology and mechanisms due to their different chemical structures. This review also summarizes results of relevant clinical trials regarding the cardiovascular effects of ginseng, particularly in the management of hypertension and improving cardiovascular function.

American ginseng inhibits vascular smooth muscle cell proliferation via suppressing Jak/Stat pathway

ETHNOPHARMCOLOGICAL RELEVANCE: Ginseng, a folk medicine which has been used for thousands of years in Asia, has been promoted for the treatment or prevention of health problems including cardiovascular disease. However, the molecular mechanism of ginseng-induced cardiovascular protection is unclear. Thus, we investigated signaling mechanism by which American ginseng inhibits vascular smooth muscle cell (VSMC) proliferation, a key feature of diverse vascular disease.

MATERIALS AND METHODS

A standardized crude extract of American ginseng was supplied by the National Research Council of Canada, Institute for National Measurement Standards. Rat aortic smooth muscle cells (RASMCs) were exposed to fetal bovine serum (FBS), platelet derived growth factor (PDGF), insulin, or angiotensin II (Ang II) to induce proliferation that was examined by measuring DNA synthesis and cell numbers. Western blot was applied to determine the activations of Jak, Stat, Akt, and ERK.

RESULTS

American ginseng inhibited RASMC proliferation induced by FBS, PDGF, insulin or Ang II. American ginseng slightly increased both basal and FBS-, PDGF- or Ang II-induced activities of Akt and ERK in RASMCs; however, it dramatically inhibited the activation of Jak2 and Stat3.

CONCLUSION

These results demonstrate that American ginseng inhibits VSMC proliferation through suppressing the Jak/Stat pathway.

Ginsenoside Rg3 reduces lipid accumulation with AMP-Activated Protein Kinase (AMPK) activation in HepG2 cells

Cardiovascular disease (CVD) is one of the main causes of mortality worldwide, and dyslipidemia is a major risk factor for CVD. Ginseng has been widely used in the clinic to treat CVD. Ginsenoside Rg3, one of the major active components of ginseng, has been reported to exhibit antiobesity, antidiabetic, and cardioprotective effects. However, the effect of ginsenoside Rg3 on hepatic lipid metabolism remains unclear. Therefore, we investigated whether ginsenoside Rg3 would regulate hepatic lipid metabolism with AMP-activated protein kinase (AMPK) activation in HepG2 cells. Ginsenoside Rg3 significantly reduced hepatic cholesterol and triglyceride levels. Furthermore, ginsenoside Rg3 inhibited expression of sterol regulatory element binding protein-2 (SREBP-2) and 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGCR). Ginsenoside Rg3 increased activity of AMPK, a major regulator of energy metabolism. These results suggest that ginsenoside Rg3 reduces hepatic lipid accumulation with inhibition of SREBP-2 and HMGCR expression and stimulation of AMPK activity in HepG2 cells. Therefore, ginsenoside Rg3 may be beneficial as a food ingredient to lower the risk of CVD by regulating dyslipidemia.

Procoagulant and prothrombotic effects of the herbal medicine, Dipsacus asper and its active ingredient, dipsacus saponin C, on human platelets

BACKGROUND

In spite of the growing popularity of herbal medicines and natural food supplements, their effects on cardiovascular homeostasis remain largely unknown, especially regarding pro-thrombotic risks.

OBJECTIVE

In the present study, 21 herbal tea extracts were screened for the procoagulant activities on platelets, an important promoter of thrombosis to examine if herbal medicines or natural products may have prothrombotic risks. We discovered that Dipsacus asper (DA), known to have analgesic and anti-inflammatory effects, potently induced procoagulant activities in platelets. We tried to identify the active ingredient and elucidate the underlying mechanism.

RESULTS

Among 10 major ingredients of DA, dipsacus saponin C (DSC) was identified as a key active ingredient in DA-induced procoagulant activities. DSC-induced procoagulant activities were achieved by the exposure of phosphatidylserine (PS) and PS-bearing microparticle generation that were caused by the alteration in the activities of phospholipid translocases: scramblase and flippase. These events were initiated by increased intracellular calcium and ATP depletion. Notably, DSC induced a series of apoptotic events including the disruption of mitochondrial membrane potential, translocation of Bax and Bak, cytochrome c release and caspase-3 activation. The key roles of apoptotic pathway and caspase activation were demonstrated by the reversal of DSC-induced PS exposure and procoagulant activities with the pretreatment of caspase inhibitors. Interestingly, EGTA reversed DSC-induced procoagulant activities and apoptotic events suggesting that an intracellular calcium increase may play a central role. These results were also confirmed in vivo where platelets of the rats exposed to DSC or DA exhibited PS exposure. Most importantly, DSC or DA administration led to increased thrombus formation.

CONCLUSION

These results demonstrate that herbal medicines or natural products such as DA or DSC might have prothrombotic risks through procoagulant activation of platelets.

Therapeutic potential of ginseng in the management of cardiovascular disorders

Although employed in Asian societies for thousands of years, the use of ginseng as an herbal medication for a variety of disorders has increased tremendously worldwide in recent years. Ginseng belongs to the genus Panax, of which there exists a variety, generally reflecting their geographic origin. North American ginseng (Panax quinquefolius) and Asian ginseng (Panax ginseng) are two such varieties possessing a plethora of pharmacological properties, which are attributed primarily to the presence of different ginsenosides that bestow these ginsengs with distinct pharmacodynamic profiles. The many cardiovascular benefits attributed to ginseng include cardioprotection, antihypertensive effects, and attenuation of myocardial hypertrophy and heart failure. Experimental studies have revealed a number of beneficial properties of ginseng, particularly in the area of cardiac protection, where ginseng and ginsenosides have been shown to protect the ischaemic and reperfused heart in a variety of experimental models. Emerging evidence also suggests that ginseng attenuates myocardial hypertrophy, thus blunting the remodelling and heart failure processes. However, clinical evidence of efficacy is not convincing, likely owing primarily to the paucity of well designed, randomized, controlled clinical trials. Adding to the complexity in understanding the cardiovascular effects of ginseng is the fact that each of the different ginseng varieties possesses distinct cardiovascular properties, as a result of their respective ginsenoside composition, rendering it difficult to assign a general, common cardiovascular effect to ginseng. Additional challenges include the identification of mechanisms (likely multifaceted) that account for the effects of ginseng and determining which ginsenoside(s) mediate these cardiovascular properties. These concerns notwithstanding, the potential cardiovascular benefit of ginseng is worthy of further studies in view of its possible development as a cardiovascular therapeutic agent, particularly as adjunctive therapy to existing medications.

Potentiation of vasoconstriction and pressor response by low concentration of monomethylarsonous acid (MMA(III))

A close link between arsenic exposure and hypertension has been well-established through many epidemiological reports, yet the mechanism underlying it remains unclear. Here we report that nanomolar concentrations of monomethylarsonous acid (MMA(III)), a toxic trivalent methylated arsenic metabolite, can potentiate agonist-induced vasoconstriction and pressor responses. In freshly isolated rat aortic ring, exposure to nanomolar MMA(III) (100-500 nM) potentiated phenylephrine (PE)-induced vasoconstriction while at higher concentrations (≥2.5 μM), suppression of vasoconstriction and apoptosis of vascular smooth muscle were observed. Potentiation of agonist-induced vasoconstriction was also observed with other contractile agonists and it was retained in endothelium-denuded aortic rings, suggesting that these events are agonist-independent and smooth muscle cell dependent. Interestingly, exposure to MMA(III) resulted in increased myosin light chain phosphorylation while PE-induced Ca2+ influx was not affected, reflecting that Ca2+ sensitization is involved. In line with this, MMA(III) enhanced agonist-induced activation of small GTPase RhoA, a key contributor to Ca2+ sensitization. Of note, treatment of MMA(III) to rats induced significantly higher pressor responses in vivo, demonstrating that this event can occur in vivo indeed. We believe that RhoA-mediated Ca2+ sensitization and the resultant potentiation of vasoconstriction by MMA(III) may shed light on arsenic-associated hypertension.