Salvianolic acid B protects human endothelial cells from oxidative stress damage: a possible protective role of glucose-regulated protein 78 induction

Efficacy and safety of salvianolate injection in treating acute myocardial infarction: a meta-analysis and systematic literature review

Purpose

Salvianolate for injection (SFI) is a widely used treatment for acute myocardial infarction (AMI). This study aims to assess the efficacy and safety of SFI in treating AMI by synthesizing evidence from published randomized controlled trials (RCTs).

Methods

Seven databases were searched for relevant RCTs published up to 1 July 2024. Two investigators independently conducted the literature searches, data extraction, and quality assessment. Subgroup and sensitivity analyses were performed to address potential heterogeneity. Data analyses were conducted using RevMan 5.4 software.

Result

Thirty RCTs with a total of 3,931 participants were included in the study and analyzed. The results revealed that SFI significantly reduced major adverse cardiac events (MACEs) (RR = 0.34, 95% CI: 0.24 to 0.49, p < 0.05). In addition, SFI lowered creatine kinase-MB (CK-MB) (MD = -5.65, 95% CI: -9.55 to -1.76, p < 0.05) and improved left ventricular ejection fraction (LVEF) (MD = 6.2, 95% CI: 4.82 to 7.57, p < 0.05). Further reductions were observed in C-reactive protein (CRP) (MD = -6.17, 95% CI: -8.11 to -4.23, p < 0.05), malondialdehyde (MDA) (MD = -1.95, 95% CI: -2.08 to -1.83, p < 0.05), and endothelin-1 (ET-1) (MD = -12.27, 95% CI: -17.13 to -7.40, p < 0.05). The incidence of adverse events did not significantly differ between the EG and CG [RR = 0.74, 95% CI: 0.42 to 1.33, p = 0.32].

Conclusion

This study suggests that SFI may be a promising alternative therapy for treating AMI without increasing the risk of adverse events. However, our findings may be limited by the quality of the existing studies. High-quality RCTs are needed to provide more robust evidence.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024567279.

Advances in the pharmacological effects and mechanisms of Nelumbo nucifera gaertn. Extract nuciferine

ETHNOPHARMACOLOGIC RELEVANCE

The leaves of Nelumbo nucifera Gaertn. Are recorded in the earliest written documentation of traditional Chinese medicinal as "Ben Cao Gang Mu", a medicinal herb for blood clotting, dysentery and dizziness. Nuciferine, one of N. nucifera Gaertn. leaf extracts, has been shown to possess several pharmacological properties, including but not limited to ameliorating hyperlipidemia, stimulating insulin secretion, inducing vasodilation, reducing blood pressure, and demonstrating anti-arrhythmic properties.

AIM OF THE STUDY

In light of the latest research findings on nuciferine, this article provides a comprehensive overview of its chemical properties, pharmacological activities, and the underlying regulatory mechanisms. It aims to serve as a dependable reference for further investigations into the pharmacological effects and mechanisms of nuciferine.

MATERIALS AND METHODS

Use Google Scholar, Scifinder, PubMed, Springer, Elsevier, Wiley, Web of Science and other online database search to collect the literature on extraction, separation, structural analysis and pharmacological activity of nuciferine published before November 2023. The key words are "extraction", "isolation", "purification" and "pharmacological action" and "nuciferine".

RESULTS

Nuciferine has been widely used in the treatment of ameliorating hyperlipidemia and lose weight, Nuciferine is a monomeric aporphine alkaloid extracted from the leaves of the plant Nymphaea caerulea and Nelumbo nucifera Gaertn. Nuciferine has pharmacological activities such as relaxing smooth muscles, improving hyperlipidemia, stimulating insulin secretion, vasodilation, inducing hypotension, antiarrhythmic effects, and antimicrobial and anti-HIV activities. These pharmacological properties lay a foundation for the treatment of tumors, inflammation, hyperglycemia, lipid-lowering and weight-loss, oxidative stress and other diseases with nuciferine.

CONCLUSION

Nuciferine has been clinically used to treat hyperlipidemia and aid in weight loss due to its effects on lipid levels, insulin secretion, vasodilation, blood pressure reduction, anti-tumor properties, and immune enhancement. However, other potential benefits of nuciferine have not yet been fully explored in clinical practice. Future research should delve deeper into its molecular structure, toxicity, side effects, and clinical pharmacology to uncover its full range of effects and pave the way for its safe and expanded clinical use.

Network pharmacology, molecular docking, and in vitro experimental verification of the mechanism of Guanxining in treating diabetic atherosclerosis

ETHNOPHARMACOLOGICAL RELEVANCE

Guanxinning(GXN) tablet is a patented traditional Chinese medicine widely used to prevent and treat cardiovascular diseases. However, its potential mechanism and target in anti-diabetic atherosclerosis have not been clarified.

AIM

The aim of this study was to investigate the underlying targets and mechanisms of action GXN in the treatment of diabetic atherosclerosis, employing a combination of network pharmacology, molecular docking, and in vitro experimental verification.

METHODS

We predicted the core components and targets of GXN in the treatment of diabetic atherosclerosis through various databases, and made analysis and molecular docking. In vitro, we induced injury in human umbilical vein endothelial cells using glucose/palmitate and observed the effects of GXN on cellular damage high-glucose and high-fat conditions, subsequently elucidating its molecular mechanisms.

RESULTS

A total of 14 active components and 157 targets of GXN were identified. Using the PPI network, we selected 9 core active components and 20 targets of GXN. GO functional analysis revealed that these targets were primarily associated with apoptosis signaling pathways in response to endoplasmic reticulum stress and reactive oxygen species responses. Molecular docking confirmed the strong binding affinities of the primary active components of GXN with ERN1, MAPK1 and BECN1. In vitro experiments demonstrated the ability of GXN to restore endothelial cell activity, enhance cell migration and inhibit sICAM secretion, and upregulate the expression of endoplasmic reticulum stress-related proteins (IRE1, XBP1) and autophagy-related proteins (Beclin1, LC3A, and LC3B), while simultaneously inhibiting endothelial cell apoptosis under high-glucose and high-fat conditions.

CONCLUSIONS

Our findings suggest that GXN can potentially safeguard endothelial cells from the adverse effects of high-glucose and high-fat by modulating the interactions between endoplasmic reticulum stress and autophagy. Therefore, GXN is a promising candidate for the prevention and treatment of diabetic atherosclerosis.

Artificial neuronal network analysis in investigating the relationship between oxidative stress and endoplasmic reticulum stress to address blocked vessels in cardiovascular disease

BACKGROUND

Cardiovascular disease is the leading cause of death in the world and is associated with significant morbidity. Atherosclerosis is the main cause of cardiovascular disease (CVD), including myocardial infarction (MI), heart failure, and stroke. The mechanism of atherosclerosis has not been well investigated in different aspects, such as the relationship between oxidative stress and endothelial function. This project aims to investigate whether an oxidative enzyme vascular peroxidase 1 (VPO1) and activating transcription factor 4 (ATF4) can be used as biomarkers in highlighting the pathogenesis of the disease and in evaluating the prognosis of the relationship with endoplasmic reticulum and oxidative stress. This paper used artificial neural network analysis to predict cardiovascular disease risk based on new generation biochemical markers that combine vascular inflammation, oxidative and endoplasmic reticulum stress.

METHODS

For this purpose, 80 patients were evaluated according to the coronary angiography results. hs-CRP, lipid parameters and demographic characteristics, VPO1, ATF4 and Glutathione peroxidase 1(GPx1) levels were measured.

RESULTS

We found an increase in VPO1 and hs-CRP levels in single-vessel disease as compared to controls. On the contrary, ATF4 and GPx1 levels were decreased in the same group, which was not significant. Our results showed a significant positive correlation between ATF4 and lipid parameters. A statistically significant positive correlation was also observed for VPO1 and ATF4 (r=0.367, P<0.05), and a negative correlation was found for ATF4 and GPx1 (r=-0.467, P<0.01). A significant negative relationship was noted for GPx1 and hs-CRP in two/three-vessel disease (r=-0.366, P<0.05). Artificial neural network analysis stated that body mass index (BMI) and smoking history information give us an important clue as compared to age, gender and alcohol consumption parameters when predicting the number of blocked vessels.

CONCLUSIONS

VPO1 and ATF4 might be potential biomarkers associated with coronary artery disease, especially in the follow-up and monitoring of treatment protocols, in addition to traditional risk factors.

An injectable peptide hydrogel with excellent self-healing ability to continuously release salvianolic acid B for myocardial infarction

Drug-loaded hydrogels can improve blood supply and inhibit extracellular matrix degradation after myocardial infarction. However, due to the continual dynamic motion of cardiac tissue, the hydrogel structure cannot be reconstructed in time, causing accelerated degradation and drug burst release. Here, a novel, superior, self-healing elastin-mimic peptide hydrogel (EMH) was fabricated for the local delivery of salvianolic acid B (SaB). The self-healing ability of EMH is enhanced by SaB-loaded polydopamine nanoparticles (SaB-PDA). In vitro, the pre-hydrogel (SaB-PDA/pre-EMH) is endowed with excellent biocompatibility and a low viscosity, making it suitable for intramyocardial injection. Once injected into the myocardial infarction (MI) region, SaB-PDA/pre-EMH can form SaB-PDA/EMH with great mechanical strength under the action of upregulated transglutaminase (TGase) in heart tissue post-MI. The superior self-healing ability of SaB-PDA/EMH allows for an increase in retention time in the beating ventricular wall. Therefore, with long-term release of SaB, SaB-PDA/EMH can inhibit ventricular remodeling and promote angiogenesis for MI treatment.

Clinical effectiveness and safety of salvia miltiorrhiza depside salt combined with aspirin in patients with stable angina pectoris: A multicenter, pragmatic, randomized controlled trial

BACKGROUND

Salvia Miltiorrhiza Depside Salt (SMDS) was extracted from Salvia miltiorrhiza with high-quality control of active principles. In 2005, China's FDA approved the use of SMDS for stable angina pectoris (SAP), but the evidence of SMDS combined with aspirin remains unclear.

PURPOSE

The aim of this study was to assess the clinical effectiveness and safety of SMDS combined with aspirin in patients with SAP.

METHODS

A multicenter, pragmatic, three-armed parallel group and an individually randomized controlled superiority trial was designed. Participants aged 35 to 75 years old with SAP were recruited from four "Class Ⅲ Grade A" hospitals in China. Participants who were randomized into the SMDS group were treated with SMDS by intravenous drip. Participants in the control group received aspirin enteric-coated tablets (aspirin). Participants who were randomly assigned to the combination group received SMDS combined with aspirin. All participants received standard care from clinicians, without any restrictions. The primary outcome measure was thromboelastography (TEG). Secondary outcome measures included symptom score of the Seattle Angina Questionnaire (SAQ), visual analogue scale (VAS) score of traditional Chinese medicine (TCM) symptoms, platelet aggregation measured by light transmittance aggregometry (LTA), and fasting blood glucose. Effectiveness evaluation data were collected at baseline and ten days after treatment. Researchers followed up with participants for one month after treatment to determine whether adverse events (AEs) or adverse drug reactions (ADRs) such as bleeding tendency occurred. All statistical calculations were carried out with R 3.5.3 statistical analysis software.

RESULTS

A total of 135 participants completed follow-up data on the primary outcome after ten days of treatment. Participants in the SMDS combined aspirin group had the highest improvement rate of sensitivity in AA% [p < 0.001, 95% CI (0.00-0.00)], from 30.6% before treatment to 81.6% after treatment. Participants with drug resistance (AA% < 20%) in the SMDS combined with aspirin group also had the highest sensitivity rate [p < 0.001, 95% CI (0.00-0.00)] after treatment (accounting for 81.0% of the combination group and 60.7% of the sensitive participants). The improvement of TCM symptoms in participants treated with SMDS combined with aspirin was significantly better than that of the aspirin group [MD = 1.71, 95% CI (0.15-3.27), p = 0.032]. There were no significant differences in other indexes (R, TPI, MA, K, CI, α value) of TEG, SAQ, platelet aggregation and fasting blood glucose among the three groups. No bleeding tendency or ADRs occurred in all participants.

CONCLUSION

SMDS combined with aspirin is a clinically effective and safe intervention to treat adults aged 35 and older with SAP. This trial shows that SMDS combined with aspirin can significantly improve the sensitivity rate of AA% in TEG and the VAS score of TCM symptoms. Further large samples and high-quality research are needed to determine if certain participants might benefit more from SMDS combined with aspirin. The study protocol was registered in the Clinical Trials USA registry (registration No. NCT02694848).

Pharmacological Effects of Salvianolic Acid B Against Oxidative Damage

Salvianolic acid B (Sal B) is one of the main active ingredients of Salvia miltiorrhiza, with strong antioxidant effects. Recent findings have shown that Sal B has anti-inflammatory, anti-apoptotic, anti-fibrotic effects and can promote stem cell proliferation and differentiation, and has a beneficial effect on cardiovascular and cerebrovascular diseases, aging, and liver fibrosis. Reactive oxygen species (ROS) include oxygen free radicals and oxygen-containing non-free radicals. ROS can regulate cell proliferation, survival, death and differentiation to regulate inflammation, and immunity, while Sal B can scavenge oxygen free radicals by providing hydrogen atoms and reduce the production of oxygen free radicals and oxygen-containing non-radicals by regulating the expression of antioxidant enzymes. The many pharmacological effects of Sal B may be closely related to its elimination and inhibition of ROS generation, and Nuclear factor E2-related factor 2/Kelch-like ECH-related protein 1 may be the core link in its regulation of the expression of antioxidant enzyme to exert its antioxidant effect. What is confusing and interesting is that Sal B exhibits the opposite mechanisms in tumors. To clarify the specific target of Sal B and the correlation between its regulation of oxidative stress and energy metabolism homeostasis will help to further understand its role in different pathological conditions, and provide a scientific basis for its further clinical application and new drug development. Although Sal B has broad prospects in clinical application due to its extensive pharmacological effects, the low bioavailability is a serious obstacle to further improving its efficacy in vivo and promoting clinical application. Therefore, how to improve the availability of Sal B in vivo requires the joint efforts of many interdisciplinary subjects.

Effect of High Hydrostatic Pressure Extraction on Biological Activities and Phenolics Composition of Winter Savory Leaf Extracts

Satureja montana L. has several biological properties related to its diverse composition of secondary metabolites. Nevertheless, it has been mainly studied for its essential oil, with only a few studies on the profile and bioactivities of the bioactive compounds from its leaf extracts being reported. This work aimed to study the antioxidant activity (by oxygen radical absorbance capacity (ORAC) assay), antimicrobial minimum inhibitory and bactericidal concentrations (MIC and MBC) determination, antibiofilm (by colorimetry), impact upon DNA (anti- and pro-oxidant assay), and cytotoxicity (by cell metabolism viability assays) of S. montana extracts obtained by high-pressure-assisted extraction (HPE). The extract obtained at 348 MPa, 35% (v/v) ethanol presented the highest concentration of individual phenolic compounds, and a minimum bactericidal concentration of 20 mg/mL against Listeria monocytogenes. HPE extracts showed antioxidant activity not only in ORAC but they were also able to prevent/attenuate peroxide-induced damage upon DNA. Moreover, on its own, HPE extract induced less oxidative damage than the control extract. Concerning the cytotoxicity, HPE extracts (at 0.5 and 1.0 mg/mL) were not harmful to HT29 cell lines, while control extracts (obtained at atmospheric pressure) at higher concentrations (>1.0 mg/mL) slightly reduced the metabolism of the cells. Finally, all extracts showed inhibition of the viability of 3 cancerous cell lines (>2.0 mg/mL for Caco-2, HeLa, and TR146) to below 15%.

Salvianolic acid B improves myocardial function in diabetic cardiomyopathy by suppressing IGFBP3

BACKGROUND

Salvianolic acid B (Sal B) is the representative component of phenolic acids derived from the dried root and rhizome of Salvia miltiorrhiza Bge. (Labiatae), which has been widely used for the treatment of cardiovascular and cerebrovascular diseases. However, the effect of Sal B on diabetic cardiomyopathy (DCM) is still unclear.

METHODS

Type 1 diabetes mellitus was induced in C57BL/6 J mice by streptozotocin (STZ) treatment, whereas meanwhile Salvianolic Acid B (Sal B (15 or 30 mg/kg/d) was intraperitoneally injected for 16 weeks. At the end of this period, cardiac function was assessed by echocardiography, and total collagen deposition was evaluated by Masson's trichrome and Picrosirius Red staining. Human umbilical vein endothelial cells exposed to hypoxia were used to investigate the effect of different doses of Sal B on angiogenesis and tube formation in vitro. Transcriptome sequencing was performed to identify potential targets of Sal B.

RESULTS

Sal B ameliorated left ventricular dysfunction and remodeling, and decreased collagen deposition in the heart of diabetic mice. Administration of Sal B increased the expression of vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) and VEGFA in a dose-dependent manner and promoted angiogenesis both in vivo and in vitro. Furthermore, Sal B reduced HG-induced insulin-like growth factor-binding protein 3 (IGFBP3) expression, induced the phosphorylation of extracellular signal-regulated protein kinase and protein kinase B (AKT) activities, enhanced cell proliferation, and activated VEGFR2/VEGFA signaling in endothelial cells. The underlying mechanisms involve SalB that enhances IGFBP3 promoter DNA methylation and induce nuclear translocation of IGFBP3 in HUVECs under hypoxia.

CONCLUSIONS

Sal B promoted angiogenesis and alleviated cardiac fibrosis and cardiac remodeling in DCM by suppressing IGFBP3.

Protective effects of salvianolic acid B against hydrogen peroxide‑induced apoptosis of human umbilical vein endothelial cells and underlying mechanisms

Salvianolic acid B (Sal B) is a water-soluble active component of Danshen and has anti-atherosclerotic effects. The present study aimed to evaluate the cytoprotective effects of Sal B against hydrogen peroxide (H₂O₂)-induced oxidative stress damage in human umbilical vein endothelial cells (HUVECs) and investigate the underlying mechanisms. It was revealed that Sal B protected the cells from H₂O₂-induced damage, as indicated by MTT results showing enhanced cell viability and by flow cytometric analysis showing reduced apoptosis of cells challenged with H₂O₂. Furthermore, as an underlying mechanism, the enhancement of autophagy was indicated to be accountable for the decrease in apoptosis, as Sal B caused the upregulation of light chain 3-II and Beclin-1, and downregulation of p62 under H₂O₂-induced oxidative stress. Finally, Sal B increased the phosphorylation of AMP kinase (AMPK) and decreased the phosphorylation of mammalian target of rapamycin (mTOR), but had no effect on the phosphorylation of AKT. In conclusion, the present study revealed that Sal B protects HUVECs from oxidative stress, at least partially by promoting autophagy via activation of the AMPK pathway and downregulation of the mTOR pathway.

A Method for Preparation of an Internal Layer of Artificial Vascular Graft Co-Modified with Salvianolic Acid B and Heparin

Studies have shown that salvianolic acid B (SAB), which is derived from Chinese salvia ( Salvia miltiorrhiza), a plant used in traditional Chinese medicine, can promote the proliferation and migration of endothelial cells. The inner layer of an artificial vascular graft was fabricated using the coaxial electrospinning method and was loaded with the anticoagulant heparin and SAB. The release of heparin and SAB was sustained for almost 30 days and without an initial burst release of SAB. Furthermore, the combined effect of SAB and heparin contributed to promoting human umbilical vein endothelial cell (HUVEC) growth and improved the blood compatibility of the graft. In addition, upregulation of GRP78 by SAB protected human endothelial cells from oxidative stress-induced cellular damage. In vivo evaluation through Masson's trichrome and H&E staining was performed after the graft was subcutaneously embedded in SD rats for 2 weeks and indicated that the graft possessed satisfactory biocompatibility and did not cause a significant immune response. Hence, the functional inner layer is promising for preventing acute thrombosis and promotes rapid endothelialization of artificial vascular grafts.

Salvia miltiorrhizaBurge (Danshen): a golden herbal medicine in cardiovascular therapeutics

Salvia miltiorrhiza Burge (Danshen) is an eminent medicinal herb that possesses broad cardiovascular and cerebrovascular protective actions and has been used in Asian countries for many centuries. Accumulating evidence suggests that Danshen and its components prevent vascular diseases, in particular, atherosclerosis and cardiac diseases, including myocardial infarction, myocardial ischemia/reperfusion injury, arrhythmia, cardiac hypertrophy and cardiac fibrosis. The published literature indicates that lipophilic constituents (tanshinone I, tanshinone IIa, tanshinone IIb, cryptotanshinone, dihydrotanshinone, etc) as well as hydrophilic constituents (danshensu, salvianolic acid A and B, protocatechuic aldehyde, etc) contribute to the cardiovascular protective actions of Danshen, suggesting a potential synergism among these constituents. Herein, we provide a systematic up-to-date review on the cardiovascular actions and therapeutic potential of major pharmacologically active constituents of Danshen. These bioactive compounds will serve as excellent drug candidates in small-molecule cardiovascular drug discovery. This article also provides a scientific rationale for understanding the traditional use of Danshen in cardiovascular therapeutics.

Salvianolic Acid B Inhibits High-Fat Diet-Induced Inflammation by Activating the Nrf2 Pathway

Salvianolic acid B (Sal B) is a major water-soluble bioactive component of Salvia miltiorrhiza, which is a traditional Chinese medicine. We investigated the ways in which Sal B affects high-fat diet (HFD)-induced immunological function disorder remission using a C57BL/6 mouse model. We gave groups of C57BL/6 mice a normal diet (Control), a normal diet supplemented with Sal B (Control + Sal B), a high-fat diet (HF), and a high-fat diet supplemented with Sal B (HF + Sal B) for 10 wk. Sal B supplementation decreased the body weight and plasma lipids, increased the fecal excretion of lipids, prevented the accumulation of chronic oxidative stress, and reversed the disproportionality of CD3⁺ CD4⁺ and CD3⁺ CD8⁺ T lymphocytes compared to HFD. We found an increase in IL-6 and TNF-α, while IL-10 decreased in plasma after the HFD and Sal B reversed the deregulation of the Thl/Th2 ratio. In addition, HFD-induced inflammation was stopped by Sal B through the downregulation of nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2), and inducible NO synthesis (iNOS), and the upregulation of nuclear factor-erythroid 2-related factor 2 (Nrf2)-regulated genes. These findings demonstrated that Sal B could effectively attenuate inflammation by activating the Nrf2-mediated antioxidant defense system.

Treatment with salvianolic acid B restores endothelial function in angiotensin II-induced hypertensive mice

Salvianolic acid B (Sal B) is one of the most abundant phenolic acids derived from the root of Danshen with potent anti-oxidative properties. The present study examined the vasoprotective effect of Sal B in hypertensive mice induced by angiotensin II (Ang II). Sal B (25mg/kg/day) was administered via oral gavage for 11days to Ang II (1.2mg/kg/day)-infused C57BL/6J mice (8-10weeks old). The vascular reactivity (both endothelium-dependent relaxations and contractions) in mouse arteries was examined by wire myography. The production of reactive oxygen species (ROS), protein level and localization of angiotensin AT₁ receptors and the proteins involved in ROS formation were evaluated using dihydroethidium (DHE) fluorescence, lucigenin-enhanced chemiluminescence, immunohistochemistry and Western blotting, respectively. The changes of ROS generating proteins were also assessed in vitro in human umbilical vein endothelial cells (HUVECs) exposed to Ang II with and without co-treatment with Sal B (0.1-10nM). Oral administration of Sal B reversed the Ang II-induced elevation of arterial systolic blood pressure in mice, augmented the impaired endothelium-dependent relaxations and attenuated the exaggerated endothelium-dependent contractions in both aortas and renal arteries of Ang II-infused mice. In addition, Sal B treatment normalized the elevated levels of AT₁ receptors, NADPH oxidase subunits (NOx-2 and NOx-4) and nitrotyrosine in arteries of Ang II-infused mice or in Ang II-treated HUVECs. In summary, the present study provided additional evidence demonstrating that Sal B treatment for 11days reverses the impaired endothelial function and with a marked inhibition of AT₁ receptor-dependent vascular oxidative stress. This vasoprotective and anti-oxidative action of Sal B most likely contributes to the anti-hypertensive action of the plant-derived compound.

A Chinese patent medicine Salvia miltiorrhiza depside salts for infusion combined with conventional treatment for patients with angina pectoris: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Currently, many trials have been conducted to investigate the beneficial and harmful effects of Salvia miltiorrhiza depside salts for infusion for treating patients with angina pectoris. It is important to systematically and criticallyevaluate the existing literature into providing a pooled effect to examine outcomes of angina pectoris with Salvia miltiorrhiza depside salts for infusion.

PURPOSE

A systematic review and meta-analysis were performed to determine the clinical curative effect and safety of Salvia miltiorrhiza depside salts for infusion for angina pectoris and provide clear evidence to inform clinical practice.

METHOD

The Cochrane Library, MEDLINE, EMBASE, and other four electronic Chinese databases were searched to identify relevant randomized controlled trials. Methodological quality and reporting quality of eligible studies was evaluated by using the Cochrane risk-of-bias tool and CONSORT for traditional Chinese medicine respectively. Meta-analysis was performed by RevMan 5.3 software.

RESULT

Fifty-six randomized controlled trials involving 5503 patients were included. Most of the trials were classified as having an unclear risk of bias because of poor reported methodology. The main outcomes are improvements in angina symptoms, ECG improvement and reduction of nitroglycerin use. CHD mortality or rate of CHD events was not reported in any trial. Meta-analysis showed that Salvia miltiorrhiza depside salts for infusion combined with conventional treatment was better than conventional treatment alone in improving angina symptoms (RR= 1.28, 95% CI 1.24 to 1.31, p < 0.00001), the frequency of angina attack (time/week)(WMD=-1.47, 95% CI -2.16 to -0.78), reducing clinical symptom scores (WMD=-0.55, 95% CI -0.57 to -0.53, p < 0.000011), increasing physical limitation scores (WMD= 7.68, 95% CI 1.48 to 13.88, p = 0.02), improving ECG (RR= 1.32,95% CI 1.27 to 1.38, p < 0.00001) and reducing dosage of nitroglycerin (RR= 1.50, 95% CI: 1.26 to 1.77, p < 0.00001). In addition, Egger's regression tests was found there was publication bias (Kendall' tau= 0.36, p < 0.01).

CONCLUSION

The current systematic review indicates relevant evidence for Salvia miltiorrhiza depside salts for infusion combined with conventional treatments treating patient with angina pectoris. However, the results should be interpreted with caution due to the low methodological quality, the risk of publication bias, lack of important clinically relevant outcomes and inadequate reporting on adverse events of the included trials. International methodological and reporting standards could help researchers conduct well designed trials and generate better evidence for Salvia miltiorrhiza depside salts for infusion.

Salvianolic Acid B (Sal B) Protects Retinal Pigment Epithelial Cells from Oxidative Stress-Induced Cell Death by Activating Glutaredoxin 1 (Grx1)

Protein glutathionylation, defined as the formation of protein mixed disulfides (PSSG) between cysteine residues and glutathione (GSH), can lead to cell death. Glutaredoxin 1 (Grx1) is a thiol repair enzyme which catalyzes the reduction of PSSG. Therefore, Grx1 exerts strong anti-apoptotic effects by improving the redox state, especially in times of oxidative stress. However, there is currently no compound that is identified as a Grx1 activator. In this study, we identified and characterized Salvianolic acid B (Sal B), a natural compound, as a Grx1 inducer, which potently protected retinal pigment epithelial (RPE) cells from oxidative injury. Our results showed that treatment with Sal B protected primary human RPE cells from H₂O₂-induced cell damage. Interestingly, we found Sal B pretreatment upregulated Grx1 expression in RPE cells in a time- and dose-dependent manner. Furthermore, NF-E2-related factor 2 (Nrf2), the key transcription factor that regulates the expression of Grx1, was activated in Sal B treated RPE cells. Further investigation showed that knockdown of Grx1 by small interfering RNA (siRNA) significantly reduced the protective effects of Sal B. We conclude that Sal B protects RPE cells against H₂O₂-induced cell injury through Grx1 induction by activating Nrf2 pathway, thus preventing lethal accumulation of PSSG and reversing oxidative damage.

Salvianolic Acid B Inhibits Aβ Generation by Modulating BACE1 Activity in SH-SY5Y-APPsw Cells

Alzheimer's disease (AD) is a neurodegenerative disease in humans. The accumulation of amyloid-β (Aβ) plays a critical role in the pathogenesis of AD. Previous studies indicated that Salvianolic acid B (SalB) could ameliorate Aβ-induced memory impairment. However, whether SalB could influence the generation of Aβ is unclear. Here, we show that SalB (25, 50, or 100 µM) reduces the generation of Aβ40 and Aβ42 in culture media by decreasing the protein expressions of BACE1 and sAPPβ in SH-SY5Y-APPsw cells. Meanwhile, SalB increases the levels of ADAM10 and sAPPα in the cells. However, SalB has no impact on the protein expressions of APP and PS1. Moreover, SalB attenuates oxidative stress and inhibits the activity of GSK3β, which might be related to the suppression of BACE1 expression and amyloidogenesis. Our study suggests that SalB is a promising therapeutic agent for AD by targeting Aβ generation.

Calreticulin protects rat microvascular endothelial cells against microwave radiation-induced injury by attenuating endoplasmic reticulum stress

OBJECTIVE

This study was designed to evaluate whether exogenous CRT was beneficial for alleviating MR-induced injury by suppressing ER stress in rat MMECs.

METHODS

MMECs were pretreated with CRT (25 pg/mL) for 12 hours, followed by the exposure to 2.856 GHz radiation at a mean power density of 30 mW/cm(2) for six minutes. MR-induced injury in MMECs was evaluated by LDH leakage, apoptosis, and cell viability analysis. The expression of GRP78, CRT, CHOP, Bcl-2, and Bax were examined by Western blot analysis to reflect ER stress response and ER stress-related apoptosis.

RESULTS

MR induced marked MMECs injury, as shown by increased LDH leakage and apoptosis rate and decreased cell viability. MR also induced excessive ER stress, characterized by increased expression of GRP78 and CRT, and ER stress-related apoptotic signaling as well, as shown by the upregulation of CHOP and Bax and the downregulation of Bcl-2. Exogenous CRT pretreatment remarkably attenuated MR-induced cell apoptosis and LDH leakage, ER stress, and activation of the ER stress-related apoptotic signaling.

CONCLUSIONS

Exogenous CRT attenuates MR-induced ER stress-related apoptosis by suppressing CHOP-mediated apoptotic signaling pathways in MMECs.

Protective Effects and Mechanisms of Salvianolic Acid B Against H₂O₂-Induced Injury in Induced Pluripotent Stem Cell-Derived Neural Stem Cells

Induced pluripotent stem cells (iPSCs) have the potential to differentiate into neural lineages. Salvianolic acid B (Sal B) is a commonly used, traditional Chinese medicine for enhancing neuroprotective effects, and has antioxidant, anti-inflammatory, and antiapoptotic properties. Here, we explore the potential mechanism of Sal B in protecting iPSC-derived neural stem cells (NSCs) against H2O2-induced injury. iPSCs were induced into NSCs, iPSC-derived NSCs were treated with 50 μM Sal B for 24.5 h and 500 μM H2O2 for 24 h. The resulting effects were examined by flow cytometry analysis, quantitative reverse-transcription polymerase chain reaction, and western blotting. Upon H2O2 exposure, Sal B significantly promoted cell viability and stabilization of the mitochondrial membrane potential. Sal B also visibly decreased the cell apoptotic ratio. In addition, Sal B markedly reduced expression of matrix metalloproteinase (MMP)-2 and -9, and phosphospecific signal transducer and activator of transcription 3 (p-STAT3), and increased the level of tissue inhibitor of metalloproteinase (TIMP)-2 in iPSC-derived NSCs induced by H2O2. These results suggest that Sal B protects iPSC-derived NSCs against H2O2-induced oxidative stress. The mechanisms of this stress tolerance may be attributed to modulation of the MMP/TIMP system and inhibition of the STAT3 signaling pathway.

Production and applications of rosmarinic acid and structurally related compounds

Rosmarinic acid (α-o-caffeoyl-3,4-dihydroxyphenyllactic acid; RA) is a naturally occurring hydroxylated compound commonly found in species of the subfamily Nepetoideae of the Lamiaceae and Boraginaceae, such as Rosmarinus officinalis, Salvia officinalis, and Perilla frutescens. RA is biosynthesized from the amino acids L-phenylalanine and L-tyrosine by eight enzymes that include phenylalanine ammonia lyase and cinnamic acid 4-hydroxylase. RA can also be chemically produced by the esterification of caffeic acid and 3,4-dihydroxyphenyllactic acid. RA and its numerous derivatives containing one or two RA with other aromatic moieties are well known and include lithospermic acid, yunnaneic acid, salvianolic acid, and melitric acid. Recently, RA and its derivatives have attracted interest for their biological activities, which include anti-inflammatory, anti-oxidant, anti-angiogenic, anti-tumor, and anti-microbial functions. Clinically, RA attenuates T cell receptor-mediated signaling, attenuates allergic diseases like allergic rhinitis and asthma, and 2,4-dinitrofluorobenzene-induced atopic dermatitis-like symptoms, protects from neurotoxicity, and slows the development of Alzheimer's disease. These attributes have increased the demand for the biotechnological production and application of RA and its derivatives. The present review discusses the function and application of RA and its derivatives including the molecular mechanisms underlying clinical efficacy.

Endoplasmic reticulum stress in insulin resistance and diabetes

The endoplasmic reticulum is the main intracellular Ca(2+) store for Ca(2+) release during cell signaling. There are different strategies to avoid ER Ca(2+) depletion. Release channels utilize first Ca(2+)-bound to proteins and this minimizes the reduction of the free luminal [Ca(2+)]. However, if release channels stay open after exhaustion of Ca(2+)-bound to proteins, then the reduction of the free luminal ER [Ca(2+)] (via STIM proteins) activates Ca(2+) entry at the plasma membrane to restore the ER Ca(2+) load, which will work provided that SERCA pump is active. Nevertheless, there are several noxious conditions that result in decreased activity of the SERCA pump such as oxidative stress, inflammatory cytokines, and saturated fatty acids, among others. These conditions result in a deficient restoration of the ER [Ca(2+)] and lead to the ER stress response that should facilitate recovery of the ER. However, if the stressful condition persists then ER stress ends up triggering cell death and the ensuing degenerative process leads to diverse pathologies; particularly insulin resistance, diabetes and several of the complications associated with diabetes. This scenario suggests that limiting ER stress should decrease the incidence of diabetes and the mobility and mortality associated with this illness.

Astragalus polysaccharide inhibits isoprenaline-induced cardiac hypertrophy via suppressing Ca²⁺-mediated calcineurin/NFATc3 and CaMKII signaling cascades

Pathological cardiac hypertrophy induced by increased sympathetic drive can subsequently lead to congestive heart failure, which represents the major cause of morbidity and mortality worldwide. Astragalus polysaccharide (APS) is an active compound extracted from Chinese herb Astragalus membranaceus (AM), a frequently used "Qi-invigorating" herbal medicine in traditional medicine broadly used for the treatment of cardiovascular and other diseases. Currently, little is known about the effect of APS on cardiac hypertrophy. In the present study, we aimed to investigate its effect on cardiac hypertrophy and to clarify its possible mechanisms. In vitro cardiac hypertrophic model induced by isoprenaline (ISO) was employed to explore the anti-hypertrophic action of APS. We found that 10 μM ISO treatment for 48 h caused cultured cardiomyocytes to undergo significant increases in cell surface area, total protein content, protein synthesis as well as the expression of hypertrophic markers, including atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), which were effectively inhibited by APS in a dose dependent manner. Moreover, we found that APS pretreatment alleviated the augment of intracellular free calcium during cardiac hypertrophy induced by ISO. Our further study revealed that the upregulated expression of calcineurin, translocation of nuclear factor of activated T cells, cytoplasmic 3 (NFATc3) into nucleus and activation of calmodulin kinase II (reflected by p-CaMKII) were dose dependently suppressed by the application of APS. According to this research, APS exerted its anti-hypertrophic action via inhibiting Ca(2+)-mediated calcineurin/NFATc3 and CaMKII signaling cascades, which provided new insights into the application of APS to the therapy of heart diseases.

Rifampicin protects PC12 cells from rotenone-induced cytotoxicity by activating GRP78 via PERK-eIF2α-ATF4 pathway

Rifampicin has been proposed as a therapeutic candidate for Parkinson's disease (PD). We previously showed that rifampicin was neuroprotective in PD models in vivo and in vitro. However, the molecular mechanisms underlying are not fully elucidated. In this study, using the comprehensive proteomic analysis, we identified that the 78 kDa glucose-regulated protein (GRP78), a hallmark of the unfolded protein response (UPR), was upregulated in rifampicin-treated PC12 cells. Western blot analysis confirmed GRP78 activation. GRP78 functions cytoprotectively in stressed cells, therefore, we hypothesized that GRP78 mediated rifampicin-induced neuroprotection. Using RNA interference, we found that GRP78 gene knockdown significantly attenuated the neuroprotective effects of rifampicin. Next, we examined three UPR transducers, namely, protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol requiring kinase α (IREα) and activating transcription factor 6 (ATF 6), and how they regulated rifampicin-stimulated GRP78 expression. Our results showed that PERK, eukaryotic initiation factor 2α (eIF2α), and activating transcription factor 4 (ATF4) were activated in rifampicin-treated PC12 cells. Silencing the ATF4 gene using RNAi inhibited GRP78 stimulation. Interestingly, we did not detect significant IREα activation, X-box binding protein 1 mRNA splicing, or ATF6 cleavage up to 24 h after rifampicin treatment. Taken together, our data suggested that rifampicin induced GRP78 via the PERK-eIF2α-ATF4 pathway to protect neurons against rotenone-induced cell damage. Targeting molecules in this pathway could be a novel therapeutic approach for PD treatment.

Cardiovascular effects of salvianolic Acid B

Salvianolic acid B (SAB, Sal B) is the representative component of phenolic acids derived from the dried root and rhizome of Salvia miltiorrhiza Bge (Labiatae) which has been used widely and successfully in Asian countries for clinical therapy of various vascular disturbance-related diseases for hundreds of years. However, its exact cardioprotective components and the underlying mechanism for therapeutic basis are still poorly understood. This paper discussed and elucidated the underlying biological mechanisms and pharmacology of Sal B and their potential cardioprotective effects.

Screening and evaluation of traditional Chinese medicine by microarray expression analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza is a Chinese medicinal herb, which is widely used for the treatment of cardiovascular disorders. In this article, we investigated the effects of Salvia miltiorrhiza and its hydrophilic and lipophilic components (HCS and LCS) on human umbilical vein endothelial cells (HUVECs), and the molecular mechanism was explored by microarray gene expression profiling.

MATERIALS AND METHODS

Cell proliferation and migration were used to evaluate the angiogenic effects of HCS, LCS and total extract of Salvia miltiorrhiza (TES). Microarray technology was applied to detect the gene expression of HUVECs treated with TES, HCS and LCS. Besides, quantitative real-time PCR was used to verify the microarray results.

RESULTS

Our results showed that LCS inhibited the proliferation and migration of HUVECs, HCS promoted the proliferation and migration of HUVECs, and TES did not affect the viability of HUVECs at the concentration of 5 µg/mL. From the result of principle component analysis (PCA) of microarray data, the effect of LCS on HUVECs was significantly different from the other components. Moreover, there were more differentially expression genes in LCS group than in the other groups, which meant LCS had a strong influence on HUVECs. Compared with untreated cells, 511 significantly changed genes had been detected in LCS treated cells and 236 (approximately 46%) of them were up-regulated. The mRNA expression of IL-6 was found to be increased significantly in LCS group.

CONCLUSIONS

In Salvia miltiorrhiza, HCS and LCS had opposite effects on HUVECs. LCS showed significantly inhibitory action on HUVECs proliferation and migration. It was proposed that LCS could apply in the diseases caused by vascular anomaly hyperplasia. In the mechanism of action of LCS on HUVECs, the pathways of ErbB, MAPK, p53, oxidative phosphorylation and inflammatory response were involved.

Effects of salvianolic acid B on survival, self-renewal and neuronal differentiation of bone marrow derived neural stem cells

Our previous study has demonstrated the therapeutic potential of bone marrow derived-neural stem cells (BM-NSCs) in CNS disorders; however, the beneficial effects are modest due to the poor survival and low neural differentiation frequency. Here, we demonstrate that salvianolic acid B (Sal B), a potent aqueous of a well known Chinese medicine herb, Salvia miltiorrhiza, possesses the ability to promote BM-NSCs proliferation in a dose dependent manner as verified by growth curve and Bromodeoxyuridine (BrdU) incorporation assays; While in differentiation medium, Sal B promoted nestin(+) BM-NSCs differentiated into greater numbers of NF-M(+) neurons and NG2(+) oligodendrocyte precursors, but fewer GFAP(+) astrocytes as verified by triple immunostaining and quantitative analysis; upon exposure to H(2)O(2), Sal B facilitated the cells survival, reduced LDH leakage, and inhibited apoptosis, displaying a dose-dependent neuroprotective effect on BM-NSCs. Sal B induced brain-derived neurotrophic factor (BDNF) production by BM-NSCs, which may be beneficial for the cells survival and differentiation in unfavourable environment. The collective evidence indicates that Sal B may be a potential drug to upgrade the therapeutic efficiency of BM-NSCs in CNS diseases.

Salvianolic Acid B reducing portal hypertension depends on macrophages in isolated portal perfused rat livers with chronic hepatitis

This study is aimed to investigate the effects of Sal B on portal hypertension (PH). PH with chronic hepatitis was induced by carbon tetrachloride (CCl₄) in rats. The model was confirmed with elevated portal pressures and increased serum CD163 levels. The inducible nitric oxide synthase (iNOS) or heme oxygenase-1 (HO-1) in portal triads was assessed. The isolated portal perfused rat liver (IPPRL) was performed at d₀, d₂₈, d₅₆ , and d₈₄ in the progression of chronic hepatitis. After constricting with phenylephrine, the portal veins were relaxed with Sal B. The EC₅₀ of Sal B for relaxing portal veins was −2.04 × 10⁻⁹, 7.28 × 10⁻¹¹, 1.52 × 10⁻¹¹, and 8.44 × 10⁻¹¹ mol/L at d₀, d₂₈, d₅₆, and d₈₄, respectively. More macrophages infiltrated in portal triads and expressed more iNOS or HO-1 as PH advanced. The areas under the curve (AUCs) of Sal B for reducing PH were positively correlated with the levels of iNOS or HO-1 in portal triads, and so did with serum CD163 levels. Sal B reduces PH in IPPRL with chronic hepatitis, via promoting portal relaxation due to macrophage-originated NO or CO in portal triads, partly at least.

Transgelin 2 participates in lovastatin-induced anti-angiogenic effects in endothelial cells through a phosphorylated myosin light chain-related mechanism

Background

Anti-angiogenic activity is considered to play a key role in the statin-induced anti-tumor effects. We aimed to identify new targets underlying this pleiotropic effect of lovastatin.

Methodology/Principal Findings

We investigated the inhibitory effects of lovastatin on endothelial cell biology and angiogenesis in vitro. Lovastatin at high doses inhibited endothelial cell migration and tube formation. Using two-dimensional gel electrophoresis followed by mass spectrometry, we identified the up-regulation of the actin-binding protein transgelin 2 in endothelial cells following treatment with lovastatin. Changes in transgelin 2 levels were confirmed by Western blot and confocal microscopy. We further demonstrated that the Rho signaling inactivation and actin depolymerization contributed to the up-regulation of transgelin 2. The knockdown of transgelin 2 by siRNA dramatically enhanced endothelial migration and tube formation, and meanwhile attenuated the inhibitory effects of lovastatin on cell motility. Moreover, the lovastatin-induced inhibition of myosin light chain phosphorylation was also reversed by transgelin 2 knockdown. The activation of Rho GTPase in the absence of transgelin 2 may represent a mechanism underlying the regulation of phosphorylated myosin light chain by transgelin 2.

Conclusions/Significance

These results strongly imply a novel role for transgelin 2 in the angiostatic activities of lovastatin.

Rosmarinic acid and its derivatives: biotechnology and applications

Rosmarinic acid (RA) is one of the first secondary metabolites produced in plant cell cultures in extremely high yields, up to 19% of the cell dry weight. More complex derivatives of RA, such as rabdosiin and lithospermic acid B, later were also obtained in cell cultures at high yields. RA and its derivatives possess promising biological activities, such as improvement of cognitive performance, prevention of the development of Alzheimer's disease, cardioprotective effects, reduction of the severity of kidney diseases and cancer chemoprevention. The TNF-α-induced NF-κB signaling pathway has emerged as a central target for RA. Despite these impressive activities and high yields, the biotechnological production of these metabolites on an industrial scale has not progressed. We summarized data suggesting that external stimuli, the Ca(2+)-dependent NADPH oxidase pathway and processes of protein phosphorylation/dephosphorylation are involved in the regulation of biosynthesis of these substances in cultured plant cells. In spite of growing information about pathways regulating biosynthesis of RA and its derivatives in cultured plant cells, the exact mechanism of regulation remains unknown. We suggest that further progress in the biotechnology of RA and its derivatives can be achieved by using new high-throughput techniques.

Pharmacological actions and therapeutic applications of Salvia miltiorrhiza depside salt and its active components

Salvia miltiorrhiza, a traditional medical herb known as danshen, has been widely used in China to improve blood circulation, relieve blood stasis, and treat coronary heart disease. S miltiorrhiza depside salt is a novel drug recently developed at the Shanghai Institute of Materia Medica; it contains magnesium lithospermate B (MLB) and its analogs, rosmarinic acid (RA) and lithospermic acid (LA), as active components. The drug has been used in the clinic to improve blood circulation and treat coronary heart disease. The pharmacological effects of the depside salt from S miltiorrhiza and its components have been extensively investigated. Experimental studies have demonstrated that magnesium lithospermate B possesses a variety of biological activities, especially protective effects in the cardiovascular system such as attenuation of atherosclerosis and protection against myocardial ischemia-reperfusion injury. Rosmarinic acid and lithospermic acid also show beneficial effects on the cardiovascular system. This paper reviews the recent findings regarding the mechanisms underlying the pharmacological actions of the active components of S miltiorrhiza depside salt, based on published works and our own observations.

Inhibition of Akt potentiates 2-DG-induced apoptosis via downregulation of UPR in acute lymphoblastic leukemia

The ability to pair the regulation of metabolism and cellular energetics with oncogenes and tumor suppressor genes provides cancer cells with a growth and survival advantage over normal cells. We investigated the mechanism of cell death induced by 2-deoxy-D-glucose (2-DG), a sugar analog with dual activity of inhibiting glycolysis and N-linked glycosylation, in acute lymphoblastic leukemia (ALL). We found that, unlike most other cancer phenotypes in which 2-DG only inhibits cell proliferation under normoxic conditions, ALL lymphoblasts undergo apoptosis. Bp-ALL cell lines and primary cells exhibited sensitivity to 2-DG, whereas T-ALL cells were relatively resistant, revealing phenotypic differences within ALL subtypes. Cotreatment with D-mannose, a sugar essential for N-linked glycosylation, rescues 2-DG-treated ALL cells, indicating that inhibition of N-linked glycosylation and induction of ER stress and the unfolded protein response (UPR) is the predominant mechanism of 2-DG's cytotoxicity in ALL. 2-DG-treated ALL cells exhibit upregulation of P-AMPK, P-Akt, and induction of ER stress/UPR markers (IRE1α, GRP78, P-eIF2α, and CHOP), which correlate with PARP cleavage and apoptosis. In addition, we find that pharmacologic and genetic Akt inhibition upregulates P-AMPK, downregulates UPR, and sensitizes ALL cells to remarkably low doses of 2-DG (0.5 mmol/L), inducing 85% cell death and overcoming the relative resistance of T-ALL. In contrast, AMPK knockdown rescues ALL cells by upregulating the prosurvival UPR signaling. Therefore, 2-DG induces ALL cell death under normoxia by inducing ER stress, and AKT and AMPK, traditionally thought to operate predominantly on the glycolytic pathway, differentially regulate UPR activity to determine cell death or survival.

The use of PEGylated liposomes to prolong the circulation lifetime of salvianolic acid B

The clinical application of salvianolic acid B (Sal B), a potential therapeutic agent for cardiovascular diseases isolated from Salvia miltiorrhiza, is greatly restricted by its short half-life and low bioavailability. To improve therapeutic effects and prolong the systemic circulation time of Sal B, liposomes, composed of soybean phosphatidylcholine and cholesterol were prepared by reverse-phase evaporation method. In addition, polyethylene glycol 2000-disteroylphosphoethanolamine (PEG-DSPE 2000) was included to give steric barrier to liposomes. A central composite design was employed to optimize liposomal formulation with high encapsulation efficiency and small particle size. Physicochemical characteristics such as particle size, zeta potential, encapsulation efficiency and in vitro release were investigated. In vivo pharmacokinetic properties of Sal B in beagle dogs and the effect of PEG on the blood circulation time of Sal B-loaded liposomes were also evaluated. An optimized formulation with encapsulation efficiency of 73.68% and mean particle size of 136.6nm were developed. Encapsulation of Sal B into conventional and PEGylated liposomes could prolong the half-life of Sal B by 5.8- and 17.5-fold and enhance the AUC(0-t) of Sal B by 6.7- and 13.3-fold compared with free Sal B, respectively. Therefore, the use of PEGylated liposomes could prolong the circulation time in blood and longevity effect of liposomes on Sal B was increased by PEG.

The most negatively charged low-density lipoprotein L5 induces stress pathways in vascular endothelial cells

BACKGROUND/AIMS

L5, the most negatively charged species of low-density lipoprotein (LDL), has been implicated in atherogenesis by inducing apoptosis of endothelial cells (ECs) and inhibiting the differentiation of endothelial progenitor cells. In this study, we compared the effects of LDL charge on cellular stress pathways leading to atherogenesis.

METHODS

We isolated L5 and L1 (the least negatively charged LDL) from the plasma of patients with familial hypercholesterolemia and used JC-1 staining to examine the effects of L5 and L1 on the mitochondrial membrane potential (DCm) in human umbilical vein ECs (HUVECs). Additionally, we characterized the gene expression profiles of 7 proteins involved in various types of cellular stress.

RESULTS

The DCm was severely compromised in HUVECs treated with L5. Furthermore, compared with L1, L5 induced a decrease in mRNA and protein expression of the endoplasmic reticulum (ER) chaperone proteins ORP150, Grp94, and Grp58, mitochondrial proteins Prdx3 and ATP synthase, and an increase in the expression of the pro-inflammatory protein hnRNP C1/C2.

CONCLUSIONS

Our work suggests that L5, but not L1, may promote the destruction of ECs that occurs during atherogenesis by causing mitochondrial dysfunction and modulating the expression of key proteins to promote inflammation, ER dysfunction, oxidative stress, and apoptosis.

Curcumin induces autophagy to protect vascular endothelial cell survival from oxidative stress damage

Our study first proposed that curcumin could protect human endothelial cells from the damage caused by oxidative stress via autophagy. Furthermore, our results revealed that curcumin causes some novel cellular mechanisms that promote autophagy as a protective effect. Pretreatment with curcumin remarkably improves the survival of human umbilical vein endothelial cells (HUVECs) from H 2O 2-induced viability loss, which specifically evokes an autophagic response. Exposed to H 2O 2, curcumin-treated HUVECs upregulate the level of microtubule-associated protein 1 light chain 3-II (LC3-II), the number of autophagosomes, and the degradation of p62. We show that this compound promotes BECN1 expression and inhibits the phosphatidylinositol 3-kinase (PtdIns3K)-AKT-mechanistic target of rapamycin (MTOR) signaling pathway. Curcumin can also reverse FOXO1 (a mediator of autophagy) nuclear localization along with causing an elevated level of cytoplasmic acetylation of FOXO1 and the interaction of acetylated FOXO1 and ATG7, under the circumstance of oxidative stress. Additionally, knockdown of FOXO1 by shRNA inhibits not only the protective effects that curcumin induced, but the autophagic process, from the quantity of LC3-II to the expression of RAB7. These results suggest that curcumin induces autophagy, indicating that curcumin has the potential for use as an autophagic-related antioxidant for prevention and treatment of oxidative stress. These data uncover a brand new protective mechanism involving FOXO1 as having a critical role in regulating autophagy in HUVECs, and suggest a novel role for curcumin in inducing a beneficial form of autophagy in HUVECs, which may be a potential multitargeted therapeutic avenue for the treatment of oxidative stress-related cardiovascular diseases.

A novel bridge between oxidative stress and immunity: the interaction between hydrogen peroxide and human leukocyte antigen G in placental trophoblasts during preeclampsia

OBJECTIVE

The aim of this study was to investigate a possible association between hydrogen peroxide and human leukocyte antigen G (HLA-G) in preeclampsia.

STUDY DESIGN

We explored the correlation between HLA-G and hydrogen peroxide in preeclamptic (n = 30) and normotensive (n = 30) placentas, which was confirmed by in vitro experiments. Furthermore, RNA interference was used to explore the influence of HLA-G on the proliferation, apoptosis and invasion of HTR-8/SVneo cells when exposed to hydrogen peroxide.

RESULTS

We found an inverse correlation between hydrogen peroxide and HLA-G expression in preeclamptic placentas. High levels of hydrogen peroxide could down-regulate HLA-G expression in HTR-8/SVneo. Compared with HLA-G knockdown HTR-8/SVneo, increased proliferation inhibition, higher apoptosis, and decreased cell invasion were found in the cell expressing HLA-G when exposed to hydrogen peroxide.

CONCLUSION

Our findings highlight that high levels of hydrogen peroxide can down-regulate HLA-G expression in trophoblasts during preeclampsia and trophoblasts expressing HLA-G are vulnerable to oxidative stress.

Salvianolic acid B suppresses maturation of human monocyte-derived dendritic cells by activating PPARγ

BACKGROUND AND PURPOSE

Salvianolic acid B (Sal B), a water-soluble antioxidant derived from a Chinese medicinal herb, is known to be effective in the prevention of atherosclerosis. Here, we tested the hypothesis that the anti-atherosclerotic effect of Sal B might be mediated by suppressing maturation of human monocyte-derived dendritic cells (h-monDC).

EXPERIMENTAL APPROACH

h-monDC were derived by incubating purified human monocytes with GM-CSF and IL-4. h-monDC were pre-incubated with or without Sal B and stimulated by oxidized low-density lipoprotein (ox-LDL) in the presence or absence of PPARγ siRNA. Expression of h-monDC membrane molecules (CD40, CD86, CD1a, HLA-DR) were analysed by FACS, cytokines were measured by elisa and the TLR4-associated signalling pathway was determined by Western blotting.

KEY RESULTS

Ox-LDL promoted h-monDC maturation, stimulated CD40, CD86, CD1a, HLA-DR expression and IL-12, IL-10, TNF-α production; and up-regulated TLR4 signalling. These effects were inhibited by Sal B. Sal B also triggered PPARγ activation and promoted PPARγ nuclear translocation, attenuated ox-LDL-induced up-regulation of TLR4 and myeloid differentiation primary-response protein 88 and inhibited the downstream p38-MAPK signalling cascade. Knocking down PPARγ with the corresponding siRNA blocked these effects of Sal B.

CONCLUSIONS AND IMPLICATIONS

Our data suggested that Sal B effectively suppressed maturation of h-monDC induced by ox-LDL through PPARγ activation.

Endothelial dysfunction in diabetes mellitus: possible involvement of endoplasmic reticulum stress?

The vascular complications of diabetes mellitus impose a huge burden on the management of this disease. The higher incidence of cardiovascular complications and the unfavorable prognosis among diabetic individuals who develop such complications have been correlated to the hyperglycemia-induced oxidative stress and associated endothelial dysfunction. Although antioxidants may be considered as effective therapeutic agents to relieve oxidative stress and protect the endothelium, recent clinical trials involving these agents have shown limited therapeutic efficacy in this regard. In the recent past experimental evidence suggest that endoplasmic reticulum (ER) stress in the endothelial cells might be an important contributor to diabetes-related vascular complications. The current paper contemplates the possibility of the involvement of ER stress in endothelial dysfunction and diabetes-associated vascular complications.

Salvianolic acid B inhibits the TLR4-NFκB-TNFα pathway and attenuates neonatal rat cardiomyocyte injury induced by lipopolysaccharide

OBJECTIVE

To investigate the role of the TLR4-NFκB-TNFα inflammation pathway on: lipopolysaccharide (LPS)-induced neonatal rat cardiomyocyte injury and the possible protective effects of salvianolic acid B (Sal B).

METHODS

Wistar rat (1-2 days old) cardiomyocytes were isolated and cultured. Sal B 10(-5)mol/L, 10(-6)mol/L and 10(-7)mol/L were pre-treated for 6 h in the culture medium. LPS (1 μg/mL) was added to mol/the culture medium and kept for 6 h to induce inflammation injury. The concentration of lactate dehydrogenase (LDH) in the supernatant was detected by spectrophotometry. The concentrations of tumor necrosis factor α (TNFα) and heat shock protein 70 (HSP70) in the supernatant were detected by enzyme linked immunosorbent assay. The protein expressions of toll, such as receptor 4 (TLR4) and nuclear factor kappa B (NFκB) were detected by immunohistochemistry. The mRNA expressions of TLR4 and NFκB were detected by real-realtime reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

(1) The concentrations of LDH and: TNFα in the LPS control group were significantly higher than those in the control group (561.41±67.39 U/L and 77.94±15.08 pg/mL, versus 292.13±26.02 U/L and 25.39±16.53 pg/mL, respectively, P<0.01, P<0.05). Compared with the LPS control group, the concentrations of LDH and TNFα were significantly decreased in the Sal B 10(-5)mol/L pre-treated group (451.76±83.96 U/L and 34.00±10.38 pg/mL, respectively, P<0.05). (2) The TLR4 and NFκB protein expression area in the LPS control group were significantly higher than those in the control group (1712.41±410.12 μm(2) and 2378.15±175.29 μm(2), versus 418.62±24.42 μm(2) and 1721.74±202.87 μm(2), respectively, P<0.01). The TLR4 and NFκB protein expression internal optical density (IOD) values in the LPS control group were also significantly higher than those in the control group (3.06±0.33 and 7.20±1.04, versus 0.91±0.21 and 4.24±0.48, respectively, P<0.05 and P<0.01). Compared with the LPS control group, the TLR4 and NFκB protein expression areas were significantly decreased in the Sal B 10(-5)mol/L pre-treated group (1251.54±133.82 μm(2) and 1996.37±256.67 μm(2), respectively, P<0.05), the TLR4 and NFκB protein expression IOD values were also significantly decreased in the Sal B 10(-5)mol/L pre- mol/pretreated group (1.92±0.28 and 5.17±0.77, respectively, treated P<0.05). (3) The TLR4 and NFκB mRNA expressions (2(-ΔΔ)CT value) in the LPS control group were significantly higher than those in the control group (3.16±0.38 and 5.03±0.43 versus 1.04±0.19 and 1.08±0.21, respectively, P<0.01). Compared with the LPS control group, the TLR4 and NFκB mRNA expressions (2(-ΔΔ) -CT value) were significantly decreased in the Sal B 10(-5)mol/L pre- mol/pretreated group (1.34±0.22 and 1.74±0.26, respectively, treated P<0.05). The concentration of HSP70 did not show any <statistical differences in all groups (P>0.05).

CONCLUSIONS

The TLR4-NFκB-TNFα pathway was quickly activated: and was independent of HSP70 in the early phase of neonatal cardiomyocyte injury induced by LPS. The protective effects of Sal B may be through inhibiting the TLR4-NFκB-TNFα pathway and are dose-dependent.

Imperatorin prevents cardiac hypertrophy and the transition to heart failure via NO-dependent mechanisms in mice

Augmented endothelial nitric oxide (NO) synthase (eNOS) signaling has been reported to be associated with improvements in cardiac remodeling, and NO levels have been shown to be related to cardiac hypertrophy and heart failure. Imperatorin, a dietary furanocoumarin, has been shown to prevent cardiac hypertrophy in the spontaneous hypertension rats (SHR). Thus, we aimed to clarify whether imperatorin attenuates both cardiac hypertrophy and heart failure via the NO-signaling pathway. In neonatal mouse cardiac myocytes, imperatorin inhibited protein synthesis stimulated by either isoproterenol or phenylephrine, which was unchanged by NG-nitro-L-arginine methyl ester (L-NAME). Four weeks after transverse aortic constriction (TAC) on Kunming (KM) male mice, the ratio of heart weight to body weight was lower after imperatorin treatment than in controls (6.60 ± 0.35 mg/g in TAC, 4.54 ± 0.29 mg/g with imperatorin 15 mg kg(-1)d(-1), ig, P<0.01); similar changes in the ratio of lung weight to body weight (7.30 ± 0.85 mg/g in TAC, 5.42 ± 0.51 mg/g with imperatorin 15 mg kg(-1)d(-1), ig) and the myocardial fibrosis. All of these improvements were blunted by L-NAME. Imperatorin treatment significantly activated phosphorylation of eNOS. Myocardial mRNA levels of natriuretic peptide precursor type B and protein inhibitor of NO synthase, which were increased in the TAC mice, were decreased in the imperatorin-treated ones. Imperatorin can attenuate cardiac hypertrophy both in vivo and in vitro, and halt the process leading from hypertrophy to heart failure by a NO-mediated pathway.

Venous and arterial endothelial proteomics: mining for markers and mechanisms of endothelial diversity

Endothelial cells (ECs) line the inside of arterial and venous blood vessels in a continuous monolayer and have the important function of responding to environmental cues to regulate vascular tone and new blood vessel formation. They also have well-defined roles in supporting tumorigenesis, and alterations in their function lead to cardiovascular disease. Consequently, ECs have been studied extensively as a cellular model of both normal and abnormal physiology. Despite their importance and the increased utility of proteomic tools in medical research, there are relatively few publications on the topic of vascular endothelial proteomics. A thorough search of the literature mined 52 publications focused exclusively on arterial and/or venous endothelial proteomics. These studies mostly relied upon examination of whole-cell lysates from cultured human umbilical vein ECs to investigate in vitro effects of various molecules, such as VEGF in the context of altering human umbilical vein EC functions related to angiogenesis. Only a few of these publications focused solely on a proteomic characterization of ECs and our analysis further revealed a lack of published studies incorporating proteomic analysis of freshly isolated ECs from tissues or in vitro conditions that mimic in vivo variables, such as oxygen tension and shear stress. It is the purpose of this article to account for the diversity of vascular EC proteomic investigations and comment on the issues that have been and should be addressed in future work.

MEK/ERK pathway mediates cytoprotection of salvianolic acid B against oxidative stress-induced apoptosis in rat bone marrow stem cells

To improve the survival and/or differentiation of grafted BMSCs (bone marrow stem cells) represents one of the challenges for the promising cell-based therapy. Considerable reports have implicated Sal B (salvianolic acid B), a potent aqueous extract of Salvia miltiorrhiza, in enhancing the survival of cells under various conditions. In this study, we investigated the effect of Sal B on H₂O₂-induced apoptosis in rat BMSCs, focusing on the survival signalling pathways. Results indicated that the MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] inhibitor (PD98059) and 10 μM Sal B remarkably prevented BMSCs from H₂O₂-induced apoptosis through attenuating caspase-3 activation, which is accompanied by the significant up-regulation of Bcl-2. In addition, the ROS (reactive oxygen species) accumulation was also reduced after Sal B treatment. Furthermore, Sal B inhibited the ERK1/2 phosphorylations stimulated by H₂O₂. Taken together, our results showed that H₂O₂-induced apoptosis in BMSCs via the ROS/MEK/ERK1/2 pathway and Sal B may exert its cytoprotection through mediating the pathway.