Tanshinone IIA elicited vasodilation in rat coronary arteriole: Roles of nitric oxide and potassium channels

Endothelial TRPV4 channel mediates the vasodilation induced by Tanshinone IIA

Tanshinone IIA (TSA), the main lipo-soluble component from the dried rhizome of Salvia miltiorrhiza, has been shown to induce vasodilation. However, the underlying mechanisms remains unclear. This study aimed to investigate the effect of TSA on the vasodilation of small resistant arteries ex vivo. Vascular myography revealed that endothelial denudation reduced significantly the vasodilatory effect of TSA. Blocking transient receptor potential vanilloid 4 (TRPV4) channels prevented TSA-induced vasodilation. Whole-cell patch-clamp analysis revealed that the current passing through TRPV4 channels increased after TSA treatment in endothelial cells (ECs). This was attributed to reduced TRPV4 protein degradation along with its increased expression. The TRPV4 inhibitor HC-067047 lowed nitric oxide (NO) production and TSA-induced expression of endothelial nitric oxide synthase (eNOS). Moreover, it increased the production of cyclic guanosine monophosphate (cGMP) and protein kinase G (PKG). The present results indicate that TSA induces endothelium-dependent vasodilation, which is mediated by the TRPV4-NO-PKG signaling pathway. These findings highlight the potential of TSA, a compound known in traditional Chinese medicine as Danshen (Salvia miltiorrhiza), for future cardiovascular therapeutic strategies.

Bioactive components and molecular mechanisms of Salvia miltiorrhiza Bunge in promoting blood circulation to remove blood stasis

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bunge (SM) is an outstanding herbal medicine with various traditional effects, especially promoting blood circulation to remove blood stasis. It has been widely used for centuries to treat blood stasis syndrome (BSS)-related diseases. BSS is one of the basic pathological syndromes of diseases such as cardiovascular and cerebrovascular diseases in traditional East Asian medicine, which is characterized by disturbance of blood circulation. However, the bioactive components and mechanisms of SM in the treatment of BSS have not been systematically reviewed. Therefore, this article outlines the anti-BSS effects of bioactive components of SM, concentrating on the molecular mechanisms.

AIM OF THE REVIEW

To summarize the bioactive components of SM against BSS and highlight its potential targets and signaling pathways, hoping to provide a modern biomedical perspective to understand the efficacy of SM on enhancing blood circulation to remove blood stasis.

MATERIALS AND METHODS

A comprehensive literature search was performed to retrieve articles published in the last two decades on bioactive components of SM used for BSS treatment from the online electronic medical literature database (PubMed).

RESULTS

Phenolic acids and tanshinones in SM are the main bioactive components in the treatment of BSS, including but not limited to salvianolic acid B, tanshinone IIA, salvianolic acid A, cryptotanshinone, Danshensu, dihydrotanshinone, rosmarinic acid, protocatechuic aldehyde, and caffeic acid. They protect vascular endothelial cells by alleviating oxidative stress and inflammatory damage and regulating of NO/ET-1 levels. They also enhance anticoagulant and fibrinolytic capacity, inhibit platelet activation and aggregation, and dilate blood vessels. Moreover, lowering blood lipids and improving blood rheological properties may be the underlying mechanisms of their anti-BSS. More notably, these compounds play an anti-BSS role by mediating multiple signaling pathways such as Nrf2/HO-1, TLR4/MyD88/NF-κB, PI3K/Akt/eNOS, MAPKs (p38, ERK, and JNK), and Ca2+/K+ channels.

CONCLUSIONS

Both phenolic acids and tanshinones in SM may act synergistically to target different signaling pathways to achieve the effect of promoting blood circulation.

Tanshinone IIA promotes cardiac differentiation and improves cell motility by modulating the Wnt/β‑catenin signaling pathway

Although the cardiovascular pharmacological actions of Tanshinone IIA (TanIIA) have been extensively studied, research on its roles in cardiac regeneration is still insufficient. The present study employed the cardiac myoblast cell line H9c2 to evaluate the possible roles of TanIIA in cardiac regeneration. It was found that certain concentration of TanIIA inhibited cell proliferation by suppressing the expression of proteins related to the cell cycle [cyclin dependent kinase (CDK)4, CDK6 and cyclin D1] and proliferation [c-Myc, octamer-binding transcription factor 4 (Oct4) and proliferating cell nuclear antigen (PCNA)] without inducing apoptosis. In this process, the expression of cardiac troponin in the treated cells was significantly increased and the migration of the treated cells toward the wound area was significantly enhanced. Meanwhile, TanIIA inhibited the canonical signaling pathway through increasing the expression of glycogen synthase kinase 3β (GSK-3β) and adenomatous polyposis coli (APC) and increased the expression of Wnt11 and Wnt5a in the noncanonical Wnt signaling pathway. Following β-catenin agonist WAY-262611 intervention, the effect of TanIIA on the promotion of cardiac differentiation and improved cell migration was significantly reduced. In conclusion, it was hypothesized that TanIIA could promote cardiac differentiation and improve cell motility by modulating the Wnt/β-catenin signaling pathway. These results suggest that TanIIA may play beneficial roles in myocardial regeneration following stem cell transplantation.

Exercise Reduces Insulin Resistance in Type 2 Diabetes Mellitus via Mediating the lncRNA MALAT1/MicroRNA-382-3p/Resistin Axis

Insulin resistance (IR) is the primary pathological mechanism underlying type 2 diabetes mellitus (T2DM). Here, the study aimed to ascertain whether and how exercise mediates IR in T2DM. An in vivo mouse model of high-fat diet-induced IR and an in vitro high-glucose-induced IR model were constructed. High long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) expression was detected in T2MD and was positively correlated with HOMA-IR and resistin levels. Then, short hairpin RNA targeting MALAT1 (sh-MALAT1) or pcDNA-MALAT1 was delivered into human umbilical vein endothelial cells (HUVECs) to knock down or upregulate its expression, respectively. Silencing of MALAT1 resulted in reduced levels of resistin, Ang II, tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), endothelin-1 (ET-1), and p-insulin receptor substrate-1 (p-IRS)/ISR-1, and decreased cell migration, as well as enhanced glucose uptake and levels of nitric oxide (NO) and p-Akt/Akt. In the IR mouse model, exercise was observed to downregulate MALAT1 to reduce resistin, whereby exercise reduced homeostatic model assessment-insulin resistance (HOMA-IR). Besides, exercise also elevated microRNA-382-3p (miR-382-3p) expression in the serum of IR mice. Dual-luciferase reporter and RNA binding protein immunoprecipitation (RIP) assays identified that MALAT1 could bind to miR-382-3p to upregulate resistin. Collectively, the key observations of the study provide evidence that inhibition of MALAT1 elevates miR-382-3p to repress resistin, which consequently underlies the mechanism of exercise protecting against IR, highlighting a direction for T2DM therapy development.

Decreased vasodilatory effect of Tanshinone ⅡA Sodium Sulfonate on mesenteric artery in hypertension

Tanshinone ⅡA Sodium Sulfonate (DS-201), a derivative of traditional Chinese medicinal herb Danshen, has been clinically used for various cardiovascular diseases. Previous studies showed that DS-201 induced vascular relaxation partly due to the activation of the large conductance Ca²⁺-activated potassium (BK_Ca) channels. However, the efficacy of DS-201 on the resistant vessels in hypertension remains unknown. Mesentery arteries obtained from spontaneously hypertensive rats (SHR) and hypertension patients were used in this study. The endothelium-denuded mesenteric arteries were prepared to measure the artery tension and evaluate the vasodilatory effect of DS-201. The results showed that DS-201 had a vasodilatory effect on the mesenteric artery rings pre-contracted with either phenylephrine (PE) or thromboxane mimetic U46619 in a concentration-dependent manner. However, the vasodilatory effect of DS-201 significantly decreased in hypertension than in control arteries due to a decrease in protein level of BK_Ca β1subunit. A BK_Ca channel blocker IbTX (200 nM) significantly inhibited the relaxant effect of DS-201 on non-hypertensive arteries, whereas the BK_Ca channel specific agonist NS1619 rescued the vasodilating effects of DS-201 on hypertensive vessels. These results indicate that the vasodilating effect of DS-201 is BK_Ca-dependent. This study demonstrated that DS-201 alone may not be effective for treating hypertension, but it may be considered as therapy combined with BK_Ca-agonists or methods rescuing BK_Ca functions.

Sodium Tanshinone IIA Sulfonate Prevents Angiotensin II-Induced Differentiation of Human Atrial Fibroblasts into Myofibroblasts

Differentiation of atrial fibroblasts into myofibroblasts plays a critical role in atrial fibrosis. Sodium tanshinone IIA sulfonate (DS-201), a water-soluble derivative of tanshinone IIA, has been shown to have potent antifibrotic properties. However, the protective effects of DS-201 on angiotensin II- (Ang II-) induced differentiation of atrial fibroblasts into myofibroblasts remain to be elucidated. In this study, human atrial fibroblasts were stimulated with Ang II in the presence or absence of DS-201. Then, α-smooth muscle actin (α-SMA), collagen I, and collagen III expression and reactive oxygen species (ROS) generation were measured. The expression of transforming growth factor-β1 (TGF-β1) and the downstream signaling of TGF-β1, such as phosphorylation of Smad2/3, were also determined. The results demonstrated that DS-201 significantly prevented Ang II-induced human atrial fibroblast migration and decreased Ang II-induced α-SMA, collagen I, and collagen III expression. Furthermore, increased production of ROS and expression of TGF-β1 stimulated by Ang II were also significantly inhibited by DS-201. Consistent with these results, DS-201 significantly inhibited Ang II-evoked Smad2/3 phosphorylation and periostin expression. These results and the experiments involving N-acetyl cysteine (antioxidant) and an anti-TGF-β1 antibody suggest that DS-201 prevent Ang II-induced differentiation of atrial fibroblasts to myofibroblasts, at least in part, through suppressing oxidative stress and inhibiting the activation of TGF-β1 signaling pathway. All of these data indicate the potential utility of DS-201 for the treatment of cardiac fibrosis.

Endothelial dysfunction in renal arcuate arteries of obese Zucker rats: The roles of nitric oxide, endothelium-derived hyperpolarizing factors, and calcium-activated K+ channels

The roles of nitric oxide (NO), endothelium-derived hyperpolarizing factors (EDHF), and calcium-activated K⁺ (K_Ca) channels in diabetes-associated endothelial dysfunction of small renal arteries are not clear. The present study investigated acetylcholine (ACh)-induced vasorelaxation of renal arcuate arteries from obese Zucker (OZ) rats at different diabetes durations, and the relative contribution of NO, EDHF, and K_Ca channels to the endothelial dysfunction. OZ rats of 7 weeks (prediabetic stage), 12 weeks (early diabetic stage), and 20 weeks (late diabetic stage), and time-matched lean control rats, were studied. Segments of arcuate arteries (130 to 180 μm) were isolated, cannulated and pressurized. Vascular endothelial functions were tested using ACh-induced vasodilation. Our experiments demonstrated: (1) ACh-elicited vasodilation was impaired in OZ rats of 20 weeks, but not in rats of 7 and 12 weeks; (2) inhibition of NO or EDHF (contributed by epoxyeicosatrienoic acids [EETs]) production significantly decreased ACh-induced vasodilation in both lean and OZ rats of 20 weeks. The reduction of ACh-induced vasodilation by inhibition of NO or EDHF formation was less in OZ rats, as compared to lean rats; and (3) inhibition of K_Ca channels markedly reduced ACh-induced vasodilation in lean control rats, but not in OZ rats of 20 weeks. Our observations indicated that endothelium-dependent vasodilation in renal arcuate arteries is impaired in diabetes mellitus; NO and EDHF, mainly EETs, dominate the ACh-induced vasodilation in renal arcuate arteries; the contribution of NO and EETs is impaired in diabetic rats; K_Ca channels are involved in ACh-induced vasodilation; and the activity of K_Ca channels is downregulated in diabetes mellitus.

Sodium tanshinone IIA sulfonate prevents lipopolysaccharide-induced inflammation via suppressing nuclear factor-κB signaling pathway in human umbilical vein endothelial cells

Sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA, has been demonstrated to have potent anti-inflammatory properties. However, the protective effects of STS on lipopolysaccharide (LPS)-induced inflammation in endothelial cells remain to be elucidated. In the present study, human umbilical vein endothelial cells (HUVECs) were used to explore the effects of STS on LPS-induced inflammation and the molecular mechanism involved. HUVECs were pretreated with STS for 2 h, followed by stimulation with LPS. Then expression and secretion of tumor necrosis factor (TNF)-α and interleukin (IL)-1β, and the activation of nuclear factor-κB (NF-κB) were assessed. The results demonstrated that STS significantly decreased LPS-induced TNF-α and IL-1β protein expression in HUVECs. Similarly, the increased levels of TNF-α and IL-1β in cell supernatants stimulated by LPS were also significantly inhibited by STS. Furthermore, STS inhibited LPS-induced NF-κB p65 phosphorylation and nuclear translocation. All the results suggest that STS prevents LPS-induced inflammation through suppressing NF-κB signaling pathway in endothelial cells, indicating the potential utility of STS for the treatment of inflammatory diseases.

Oxidative Stress and Salvia miltiorrhiza in Aging-Associated Cardiovascular Diseases

Aging-associated cardiovascular diseases (CVDs) have some risk factors that are closely related to oxidative stress. Salvia miltiorrhiza (SM) has been used commonly to treat CVDs for hundreds of years in the Chinese community. We aimed to explore the effects of SM on oxidative stress in aging-associated CVDs. Through literature searches using Medicine, PubMed, EMBASE, Cochrane library, CINAHL, and Scopus databases, we found that SM not only possesses antioxidant, antiapoptotic, and anti-inflammatory effects but also exerts angiogenic and cardioprotective activities. SM may reduce the production of reactive oxygen species by inhibiting oxidases, reducing the production of superoxide, inhibiting the oxidative modification of low-density lipoproteins, and ameliorating mitochondrial oxidative stress. SM also increases the activities of catalase, manganese superoxide dismutase, glutathione peroxidase, and coupled endothelial nitric oxide synthase. In addition, SM reduces the impact of ischemia/reperfusion injury, prevents cardiac fibrosis after myocardial infarction, preserves cardiac function in coronary disease, maintains the integrity of the blood-brain barrier, and promotes self-renewal and proliferation of neural stem/progenitor cells in stroke. However, future clinical well-designed and randomized control trials will be necessary to confirm the efficacy of SM in aging-associated CVDs.

The Role of Complementary and Alternative Medicine for the Management of Fibroids and Associated Symptomatology

This article discusses the role of complementary and alternative medicine (CAM) in the management of fibroids and associated symptomatology. Since there is such a paucity of direct research related to fibroids, conditions that are implicated in the causation of uterine fibroids and symptomatology that CAM treatments may or have been shown to make a difference are also considered.

Molecular Signaling Pathways Behind the Biological Effects of Salvia Species Diterpenes in Neuropharmacology and Cardiology

The genus Salvia, from the Lamiaceae family, has diverse biological properties that are primarily attributable to their diterpene contents. There is no comprehensive review on the molecular signaling pathways of these active components. In this review, we investigated the molecular targets of bioactive Salvia diterpenes responsible for the treatment of nervous and cardiovascular diseases. The effects on different pathways, including apoptosis signaling, oxidative stress phenomena, the accumulation of amyloid beta plaques, and tau phosphorylation, have all been considered to be mechanisms of the anti-Alzheimer properties of Salvia diterpenes. Additionally, effects on the benzodiazepine and kappa opioid receptors and neuroprotective effects are noted as neuropharmacological properties of Salvia diterpenes, including tanshinone IIA, salvinorin A, cryptotanshinone, and miltirone. Tanshinone IIA, as the primary diterpene of Salvia miltiorrhiza, has beneficial activities in heart diseases because of its ability to scavenge free radicals and its effects on transcription factors, such as nuclear transcription factor-kappa B (NF-κB) and the mitogen-activated protein kinases (MAPKs). Additionally, tanshinone IIA has also been proposed to have cardioprotective properties including antiarrhythmic activities and effects on myocardial infarction. With respect to the potential therapeutic effects of Salvia diterpenes, comprehensive clinical trials are warranted to evaluate these valuable molecules as lead compounds. Copyright © 2016 John Wiley & Sons, Ltd.

Molecular Mechanisms of Cardioprotective Actions of Tanshinones

Tanshinones are lipophilic compounds derived fromSalvia miltiorrhiza(Danshen) that has been widely used to treat coronary heart diseases in China. The cardioprotective actions of tanshinones have been extensively studied in various models of myocardial infarction, cardiac ischemia reperfusion injury, cardiac hypertrophy, atherosclerosis, hypoxia, and cardiomyopathy. This review outlines the recent development in understanding the molecular mechanisms and signaling pathways involved in the cardioprotective actions of tanshinones, in particular on mitochondrial apoptosis, calcium, nitric oxide, ROS, TNF-α, PKC, PI3K/Akt, IKK/NF-κB, and TGF-β1/Smad mechanisms, which highlights the potential of these compounds as therapeutic agents for treating cardiovascular diseases.

The vascular effects of sodium tanshinone IIA sulphonate in rodent and human pregnancy

Danshen, in particular its derivative tanshinone IIA (TS), is a promising compound in the treatment of cardiovascular diseases and has been used for many years in traditional Chinese medicine. Although many actions of TS have been researched, its vasodilator effects in pregnancy remain unknown. There have been a few studies that have shown the ability of TS to reduce blood pressure in women with hypertensive pregnancies; however, there are no studies which have examined the vascular effects of TS in the pregnant state in either normal or complicated pregnancies. Our aim was to determine the vasoactive role of TS in multiple arteries during pregnancy including: rat resistance (mesenteric and uterine) and conduit (carotid) arteries. Further, we aimed to assess the ability of TS to improve uterine blood flow in a rodent model of intrauterine growth restriction. Wire myography was used to assess vascular responses to the water-soluble derivative, sodium tanshinone IIA sulphonate (STS) or to the endothelium-dependent vasodilator, methylcholine. At mid-pregnancy, STS caused direct vasodilation of rat resistance (pEC₅₀ mesenteric: 4.47±0.05 and uterine: 3.65±0.10) but not conduit (carotid) arteries. In late pregnancy, human myometrial arteries responded with a similar sensitivity to STS (pEC₅₀ myometrial: 3.26±0.13). STS treatment for the last third of pregnancy in eNOS^-/- mice increased uterine artery responses to methylcholine (E_max eNOS^-/-: 55.2±9.2% vs. eNOS^-/- treated: 75.7±8.9%, p<0.0001). The promising vascular effects, however, did not lead to improved uterine or umbilical blood flow in vivo, nor to improved fetal biometrics; body weight and crown-rump length. Further, STS treatment increased the uterine artery resistance index and decreased offspring body weight in control mice. Further research would be required to determine the safety and efficacy of use of STS in pregnancy.

Screening of direct thrombin inhibitors from Radix Salviae Miltiorrhizae by a peak fractionation approach

Thrombin plays a significant role in thromboembolic disease. In this work, a peak fractionation approach combined with an activity assay method was used to screen direct thrombin inhibitors from Radix Salviae Miltiorrhizae (RSM), a famous herbal remedy for the treatment of cardiovascular diseases in China. A total of 91 fractions were collected from the RSM extract, and 19 fractions out of them showed thrombin inhibitory effects with dose-effect relationship. Among them, three compounds were unambiguously identified as 15, 16-dihydrotanshinone I, cryptotanshinone and tanshinone IIA with IC50 values of 29.39, 81.11 and 66.60μM, respectively. The three compounds were reported with direct thrombin inhibition activities for the first time and their ligand-thrombin interactions were explored by a molecular docking research. These results may contribute to explain the medical benefit of RSM for the prevention and treatment of cardiovascular diseases.

Recent Progress of Research on Herbal Products Used in Traditional Chinese Medicine: the Herbs belonging to The Divine Husbandman's Herbal Foundation Canon ( Shén Nóng Běn Cǎo Jīng)

This article will review selected herbal products from Chinese Materia Medica that are used in Traditional Chinese Medicine. The herbs come from the upper, middle, and lower class medicines as listed in The Divine Husbandman's Herbal Foundation Canon (神農本草經 Shén Nóng Běn Cǎo Jīng). The review will focus on the active constituents of the herbs and their bioactivities, with emphasis on the most recent progress in research for the period of 2003 to 2011.

Phytoestrogen, tanshinone IIA diminishes collagen deposition and stimulates new elastogenesis in cultures of human cardiac fibroblasts

It has been previously reported that oral or intra-peritoneal administration of tanshinone IIA can alleviate the ventricular hypertrophy and fibrosis that develops in rats after experimental cardiac infarction. Our present studies, performed on cultures of human cardiac fibroblasts, investigated the mechanism by which tanshinone IIA produces these beneficial effects. We found that treatment of cardiac fibroblasts with 0.1-10µM tanshinone IIA significantly inhibited their deposition of collagen I, while enhancing production of new elastic fibers. Moreover, both anti-collagenogenic and pro-elastogenic effects of tanshinone IIA occurred only after selective activation of the G protein-coupled estrogen receptor (GPER). This subsequently leads to initiation of the PKA/CREB phosphorylation pathway that inversely modulated transcription of collagen I and elastin genes. Interestingly, treatment of human cardiac fibroblasts with tanshinone IIA additionally up-regulated the production of the 67-kDa elastin binding protein, which facilitates tropoelastin secretion, and increased synthesis of lysyl oxidase, catalyzing cross-linkings of tropoelastin. Moreover, tanshinone IIA also caused up-regulation in the synthesis of collagenolytic MMP-1, but down-regulated levels of elastolytic MMP-2 and MMP-9. In summary, our data validate a novel mechanism in which tanshinone IIA, interacting with a non-classic estrogen receptor, maintains the proper balance between the net deposition of collagen and elastin, allowing for optimal durability and resiliency of the newly deposited matrix.

Aqueous extract of danshen (Salvia miltiorrhiza Bunge) protects ovariectomized rats fed with high-fat diet from endothelial dysfunction

OBJECTIVE

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality in postmenopausal women. Danshen, the dried root of Salvia miltiorrhiza Bunge, has been used clinically in China to treat CVD and dyslipidemia in postmenopausal women, and its major active ingredients have been found to have an estrogenic effect. The aim of this study was to elucidate the underlying mechanism of danshen's protective effects on vascular function in an ovariectomized (OVX) hyperlipidemic rat model.

METHODS

Thirty-five 6-month-old female Sprague-Dawley rats were randomly divided into five groups: sham-operated rats with low-fat control diet + vehicle, sham-operated rats with high-fat diet (HFD) + vehicle, OVX rats with HFD + vehicle, OVX rats with HFD + 17β-estradiol (1 mg kg d, PO), and OVX rats with HFD + danshen aqueous extract (600 mg kg d, PO). After 12 weeks of treatment, gains in body weight and serum lipid profile levels in rats were measured and histological examination of livers was carried out. Vascular function was evaluated by measuring relaxation responses. Molecular mechanisms were also analyzed in isolated aorta.

RESULTS

Treatment with danshen aqueous extract reduced body weight gain, improved serum lipid profiles, and prevented formation of fatty liver induced by HFD and OVX. In addition, danshen could increase endothelial-dependent vasorelaxation and displayed vasoprotection in OVX rats fed with HFD, primarily by stimulating nitric oxide (NO) production, up-regulating the mRNA expression of endothelial NO synthase, and down-regulating the mRNA expression of tumor necrosis factor α, intercellular cell adhesion molecule-1, and vascular cell adhesion molecule-1 in the isolated aortas.

CONCLUSIONS

We conclude for the first time that danshen aqueous extract could protect OVX rats fed with HFD from endothelial dysfunction. Its effect may be related to its abilities to normalize serum lipid profiles and enhance NO availability in the vascular system. Our findings indicate that danshen aqueous extract could be a promising natural supplement for postmenopausal women for preventing CVD.

Tanshinone IIA Inhibits Angiotensin II-Induced Cell Proliferation in Rat Cardiac Fibroblasts

Tanshinone IIA extracted from Danshen, a popular medicinal herb used in traditional Chinese medicine, exhibits cardio-protective effects. However, the mechanism of its cardioprotective effect is not well established. The aims of this study were to examine whether tanshinone IIA may alter angiotensin II (Ang II)-induced cell proliferation and to identify the putative underlying signaling pathways in rat cardiac fibroblasts. Cultured rat cardiac fibroblasts were pre-treated with tanshinone IIA and stimulated with Ang II, cell proliferation and endothelin-1 (ET-1) expression were examined. The effect of tanshinone IIA on Ang II-induced reactive oxygen species (ROS) formation, and extracellular signal-regulated kinase (ERK) phosphorylation were also examined. In addition, the effect of tanshinone IIA on nitric oxide (NO) production, and endothelial nitric oxide synthase (eNOS) phosphorylation were tested to elucidate the intracellular mechanism. The increased cell proliferation and ET-1 expression by Ang II (100 nM) were partially inhibited by tanshinone IIA. Tanshinone IIA also inhibited Ang II-increased ROS formation, and ERK phosphorylation. In addition, tanshinone IIA was found to increase the NO generation, and eNOS phosphorylation. NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NOS, and the short interfering RNA transfection for eNOS markedly attenuated the inhibitory effect of tanshinone IIA on Ang II-induced cell proliferation. The results suggest that tanshinone IIA prevents cardiac fibroblast proliferation by interfering with the generation of ROS and involves the activation of the eNOS-NO pathway.

Tanshinone IIA: A Promising Natural Cardioprotective Agent

Tanshinone IIA (Tan IIA) is a member of the major lipophilic components extracted from the root of Salvia miltiorrhiza Bunge, which is currently used in China and other neighboring countries to treat patients suffering from myocardial infarction (MI), angina pectoris, stroke, diabetes, sepsis, and other conditions. However, Tan IIA is not easy to be absorbed through intestinal pathway. To raise the bioavailability of the herb, sodium tanshinone IIA sulfonate (STS) was developed. This paper discussed the pharmacology of Tan IIA, STS, and their potential cardioprotective effects.

The anti-hypertensive effect of Danshen (Salvia miltiorrhiza) and Gegen (Pueraria lobata) formula in rats and its underlying mechanisms of vasorelaxation

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Salviae miltiorrhizae (Danshen) and Radix Puerariae lobatae (Gegen) have long been used in traditional Chinese Medicine and serve as the principal herbs in treating cardiovascular disease.

AIMS OF THE STUDY

In the present study, an aqueous extract comprising Danshen and Gegen in the ratio of 7:3 (DG) was investigated for its anti-hypertension in vivo and vasodilative activities ex vivo.

MATERIALS AND METHODS

The anti-hypertensive effect of DG extract was investigated in spontaneously hypertensive rat (SHR) by measuring systolic blood pressure (SBP). Oral administration of DG extract was started at age of 6 weeks and 14 weeks for the preventive and therapeutic studies, respectively. Blood pressure was measured by tail-cuff method biweekly for 12 weeks. The ex vivo vasodilative activities of DG extract, its dependency on endothelium and the involvement of nitric oxide, prostacyclin and potassium channels were investigated using isolated rat aorta ring in organ bath.

RESULTS

For in vivo study, systolic blood pressure was significantly reduced in DG extract-treated groups (90.2 and 300 mg/kg) as compared with the SHR control in both preventive and therapeutic studies. However, DG extract was unable to suppress or delay the onset of hypertension in the preventive study. For ex vivo study, the results showed that DG extract induced a concentration-dependent relaxation in aorta and persisted response was observed with the removal of endothelium. Besides, pretreatment with a non-selective potassium channel inhibitor tetraethylammonium (TEA) also significantly inhibited DG extract-induced vasodilation. Further investigations on specific potassium channel blockers revealed that ATP-sensitive potassium (K(ATP)) channel inhibitor glibenclamide, inward rectifier potassium (Kir) inhibitor barium chloride and voltage-dependent potassium (K(v)) channel inhibitor 4-aminopyridine, but not BK(Ca) channel inhibitor iberiotoxin, exerted significant inhibition on DG extract-induced vasodilation.

CONCLUSIONS

The results of in vivo SHR animal model suggested that DG aqueous extract possessed blood pressure lowering effect on both pre- and post-hypertensive rats, which could be explained by its endothelium-independent vasodilation via the opening of K(ATP), Kir and K(v) channels.

Direct vasorelaxation by a novel phytoestrogen tanshinone IIA is mediated by nongenomic action of estrogen receptor through endothelial nitric oxide synthase activation and calcium mobilization

Salvia miltiorrhiza (Danshen) has been widely used in China and other Asian countries for treating various cardiovascular diseases resulting from its ability to improve coronary microcirculation and increase coronary blood flow. Tanshinone IIA (Tan IIA), the major active lipophilic ingredient responsible for the beneficial actions of Salvia miltiorrhiza, has been shown to induce vasodilation in coronary arteries. Because our recent study identified Tan IIA as a new member of the phytoestrogens, we hypothesized that its action might be mediated by estrogen receptor (ER) in vascular endothelial cells. The aim of the present study was to assess whether cardiovascular protection exerted by Tan IIA is mediated by the ER signal pathway and whether the genomic or nongenomic action of ER is involved within arteries and vascular endothelial cells. The effect of Tan IIA on blood vessels was investigated by vascular ring assay using endothelium-intact and endothelium-denuded rat aortas. Similar to estrogen, Tan IIA caused an nitric oxide- and endothelium-dependent relaxation, which was blocked by ER antagonist ICI 182,780. Primary cardiac microvascular endothelial cells were used as a model to study the cellular and molecular mechanisms of Tan IIA-induced vasorelaxation. We demonstrate that Tan IIA is capable of activating the estrogen receptor signal pathway, leading to increased endothelial nitric oxide synthase gene expression, nitric oxide production, ERK1/2 phosphorylation, and Ca mobilization. Collectively, these effects contribute to Tan IIA's vasodilative activity effects of y ER antagonist Cnt of cardiovascular diseases. Our findings support a continued effort in discovering and developing novel phytoestrogens as an alternative hormone replacement therapy for safer and more effective treatment of cardiovascular diseases.

Antiatherogenic and Anti-Ischemic Properties of Traditional Chinese Medicine Xinkeshu via Endothelial Protecting Function

Including herbal medicine, complementary and alternative medicine (CAM) is popular worldwide. The traditional Chinese medicine xinkeshu has been widely used to treat coronary heart disease in China. This study was designed to investigate the protective effect and probable mechanism of xinkeshu tablet to atherosclerotic myocardial ischemia rabbit. Rabbits were divided into four groups (n = 12 each) and fed with different diet for 12 weeks: Control (standard diet), Model (high-cholesterol diet), XKS (high-cholesterol diet with 184.8 mg/kg/d xinkeshu), and Atorvastatin (high-cholesterol diet with 5.0 mg/kg/d atorvastatin). Plasma lipoprotein, ECG, endothelium-dependent vessel relaxation, histomorphological study, and expressions of eNOS and VCAM-1 on coronary arteries were assessed. The findings showed that, similar to atorvastatin, xinkeshu presented significant effects on rescuing endothelium-dependent vessel relaxation, inhibiting atherosclerotic progress, preventing myocardial ischemia, and changing eNOS and VCAM-1 expression. However, xinkeshu showed no lipoprotein lowering effect in hypercholesterolemia rabbits. The results of the present study indicated that xinkeshu exerted potent antiatherogenic and anti-ischemic properties on atherosclerotic myocardial ischemia rabbit. An endothelial protecting effect may be involved in the mechanism other than antihyperlipidemic effect.

A randomized, double-blind, placebo-controlled study to evaluate the efficacy and tolerability of Fufang Danshen (Salvia miltiorrhiza) as add-on antihypertensive therapy in Taiwanese patients with uncontrolled hypertension

Hypertension generally requires the use of a combination therapy to achieve the satisfactory control of blood pressure. A traditional Chinese herb, Danshen (Salvia miltiorrhiza), has been shown to have cardioprotective effects in animals and humans. The study investigated the add-on effect of Fufang Danshen extract capsule in Taiwanese hypertensive patients with uncontrolled blood pressure. This was a double-blind, placebo-controlled, randomized, single-center study clinical trial. Fifty-five patients with uncontrolled mild to moderate hypertension were enrolled under current conventional antihypertensive treatment, randomized equally to receive a Fufang Danshen capsule (formula mixture) 1000 mg twice-daily or a placebo capsule for 12 weeks. Primary endpoints were the control rate and the response rate. By ITT analysis at week 12, the control rates were 25.5% in the Fufang Danshen group and 7.3% in the control group (p = 0.016). The response rates were 45.6% in the Fufang Danshen group and 38.2% in the placebo group (p = 0.946). A significant reduction of systolic blood pressure at week 12 was noted in the Fufang Danshen group compared with the placebo group (13.8 vs 4.2 mmHg, p = 0.005). A decrease of pulse rate was also noted in the Fufang Danshen group (- 3.2 vs +2.7/min, p = 0.027). Adverse events were not statistically different between the two groups. It was concluded that Fufang Danshen (Salvia miltiorrhiza) extract reduced systolic blood pressure and pulse rate, and was well tolerated in patients with hypertension.

Tanshinone II-A attenuates and stabilizes atherosclerotic plaques in apolipoprotein-E knockout mice fed a high cholesterol diet

Tanshinone II-A (Tan), a bioactive diterpene isolated from Salvia miltiorrhiza Bunge (Danshen), possesses anti-oxidant and anti-inflammatory activities. The present study investigated whether Tan can decrease and stabilize atherosclerotic plaques in Apolipoprotein-E knockout (ApoE(-/-)) mice maintained on a high cholesterol diet (HCD). Six week-old mice challenged with a HCD were randomly assigned to 4 groups: (a) C57BL/6J; (b) ApoE(-/-); (c) ApoE(-/-)+Tan-30 (30 mg/kg/d); (d) ApoE(-/-)+Tan-10 (10mg/kg/d). After 16 weeks of intervention, Tan treated mice showed decreased atherosclerotic lesion size in the aortic sinus and en face aorta. Furthermore, immunohistochemical analysis revealed that Tan rendered the lesion composition a more stable phenotype as evidenced by reduced necrotic cores, decreased macrophage infiltration, and increased smooth muscle cell and collagen contents. Tan also significantly reduced in situ superoxide anion production, aortic expression of NF-κB and matrix metalloproteinase-9 (MMP-9). In vitro treatment of RAW264.7 macrophages with Tan significantly suppressed oxidized LDL-induced reactive oxygen species production, pro-inflammatory cytokine (IL-6, TNF-α, MCP-1) expression, and MMP-9 activity. Tan attenuates the development of atherosclerotic lesions and promotes plaque stability in ApoE(-/-) mice by reducing vascular oxidative stress and inflammatory response. Our findings highlight Tan as a potential therapeutic agent to prevent atherosclerotic cardiovascular diseases.

Biological Activity of Bicyclic and Tricyclic Diterpenoids from Salvia Species of Immediate Pharmacological and Pharmaceutical Interest

Diterpenoids are a class of compounds that derive from the condensation of four isoprene units that leads to a wide variety of complex chemical structures, including acyclic bi-, tri-and tetra-cyclic compounds; in Salvia species, only bi-, tri-and tetra-cyclic compounds have been found. This review covers a wide range of biological activities and mode of action of diterpenoids isolated from Salvia species that might raise some pharmacological and pharmaceutical interest.

We have produced a synoptic table where the biological activities of the main active principles are summarized. Our analysis emphasizes that diterpenoids from Salvia species continue to be a plant defence system since their antimicrobic activity. Experimental studies show that most of diterpenoids considered have cytotoxic and / or antiproliferative activity. Some of them have also cardiovascular and central effects. In a less extended manner, diterpenoids from Salvia species show gastrointestinal, urinary, antinflammatory, antidiabetic, ipolipidemic and antiaggregating effects.

In the last decade, several clinical trials have been developed in order to investigate the real value of Salvia extracts treatment; results obtained are promising and confer scientific basis in the use of medicinal plants from folk medicine.

Tanshinone IIA suppresses lung injury and apoptosis, and modulates protein kinase B and extracellular signal-regulated protein kinase pathways in rats challenged with seawater exposure

1. Tanshinone IIA (TIIA) is one of the main active components of the Chinese herb, Danshen. In the present study, we investigated the role of apoptosis in seawater exposure-induced acute lung injury (ALI), and explored the effects of TIIA on lung injury, apoptosis, and protein kinase B (Akt) and extracellular signal-regulated protein kinase (ERK) pathways in seawater-challenged rats. The rats were randomly divided into four groups: (i) naive group, no drug was given; (ii) TIIA control group, TIIA (50 mg/kg) was given intraperitoneally; (iii) seawater (SW) group, seawater (4 mL/kg) was given; and (iv) TIIA/SW group, TIIA (50 mg/kg) was injected intraperitoneally 10 min after seawater instillation. 2. The results showed that TIIA treatment significantly improved seawater exposure-induced lung histopathological changes, alleviated the decrease in PaO(2) , and reduced lung oedema, vascular leakage and cell infiltration. As shown by terminal deoxynucleotidyl transferase-mediated nick end labelling (TUNEL) assay, seawater exposure induced apoptosis in lung tissue cells. Furthermore, seawater exposure also changed apoptosis-related factors Bcl-2 and caspase-3, and caused a reduction in the activation of Akt and ERK1/2 pathways. Furthermore, TIIA treatment decreased the number of apoptotic cells, reversed changes in Bcl-2 and caspase-3, and upregulated the activation of Akt and ERK1/2 in seawater-challenged rats. 3. In conclusion, the data suggest that apoptosis might play an important role in seawater exposure-induced lung injury and that TIIA could significantly attenuate the severity of ALI and apoptosis in seawater-challenged rats, which is possibly through modulation of Akt and ERK1/2 pathways.

Tanshinone IIA modulates pulmonary vascular response to agonist and hypoxia primarily via inhibiting Ca2+ influx and release in normal and hypoxic pulmonary hypertension rats

The present study was designed to investigate the vascular effects and underlying mechanisms of tanshinone IIA on isolated rat pulmonary artery. Isometric tension was recorded in the arteries from normal and hypoxic pulmonary hypertension rats under normoxia or hypoxia condition. The results showed that tanshinone IIA exerted a biphasic effect on rat pulmonary artery. The constriction was attenuated by endothelium-denudation but was enhanced by inhibition of nitric oxide synthase. Pretreatment with tetraethylammonium (Ca2+-activated K+ channel inhibitor) upward shifted the concentration-response curve without affecting the maximum dilatation. Pretreatment with zinc protoporphyrin IX (heme oxygenase-1 inhibitor), 4-aminopyridine (KV channel inhibitor), glibenclamide (KATP channel inhibitor) or BaCl2 (inwardly rectifying K+ channel inhibitor) did not affect the vasoreactivity. Meanwhile, tanshinone IIA almost abolished vasoconstriction induced by extracellular Ca2+. Under hypoxia condition, tanshinone IIA eliminated acute hypoxia-induced initial contraction, potentiated following vasorelaxation, attenuated and reversed sustained contraction to relaxation in pulmonary artery from normal rats, and reversed phenylephrine-induced sustained constriction to sustained relaxation in remodeled pulmonary artery from hypoxic pulmonary hypertension rats. We concluded that the mild constrictive effect induced by tanshinone IIA was affected by integrity of endothelium and production of nitric oxide, while the potent dilative effect was endothelium-independent and produced primarily by inhibiting extracellular Ca2+ influx and partially by inhibiting intracellular Ca2+ release, as well as activating Ca2+-activated K+ channels. The modulation of tanshinone IIA on pulmonary vasoreactivity under both acute and chronic hypoxia condition may provide a new insight for curing hypoxic pulmonary hypertension.