Cardioprotection by ginseng: experimental and clinical evidence and underlying mechanisms

2018 ◽  
Vol 96 (9) ◽  
pp. 859-868 ◽  
Author(s):  
Xiaohong Tracey Gan ◽  
Morris Karmazyn
Keyword(s):  
Animal Studies ◽  
Large Scale ◽  
Clinical Evidence ◽  
Artery Bypass ◽  
Antioxidant Properties ◽  
Experimental Models ◽  
Therapeutic Effects ◽  
Ischemic And Reperfusion Injury ◽  
Underlying Mechanisms ◽  
The Many

Protection of the ischemic and reperfused myocardium represents a major therapeutic challenge. Translating results from animal studies to the clinical setting has been disappointing, yet the need for effective intervention, particularly to limit heart damage following infarction or surgical procedures such as coronary artery bypass grafting, is substantial. Among the many compounds touted as cardioprotective agents is ginseng, a medicinal herb belonging to the genus Panax, which has been used as a medicinal agent for thousands of years, particularly in Asian societies. The biological actions of ginseng are very complex and reflect composition of many bioactive components, although many of the biological and therapeutic effects of ginseng have been attributed to the presence of steroid-like saponins termed ginsenosides. Both ginseng and many ginsenosides have been shown to exert cardioprotective properties in experimental models. There is also clinical evidence that traditional Chinese medications containing ginseng exert cardioprotective properties, although such clinical evidence is less robust primarily owing to the paucity of large-scale clinical trials. Here, we discuss the experimental and clinical evidence for ginseng, ginsenosides, and ginseng-containing formulations as cardioprotective agents against ischemic and reperfusion injury. We further discuss potential mechanisms, particularly as these relate to antioxidant properties.

scholarly journals Effects and Mechanisms of Tea Regulating Blood Pressure: Evidences and Promises

Nutrients ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1115 ◽  
Author(s):  
Daxiang Li ◽  
Ruru Wang ◽  
Jinbao Huang ◽  
Qingshuang Cai ◽  
Chung S. Yang ◽  
...  
Keyword(s):  
Cardiovascular Diseases ◽  
Animal Studies ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Vascular Inflammation ◽  
Optimal Dose ◽  
Smooth Muscle Contraction ◽  
Beneficial Effects ◽  
Underlying Mechanisms

Cardiovascular diseases have overtaken cancers as the number one cause of death. Hypertension is the most dangerous factor linked to deaths caused by cardiovascular diseases. Many researchers have reported that tea has anti-hypertensive effects in animals and humans. The aim of this review is to update the information on the anti-hypertensive effects of tea in human interventions and animal studies, and to summarize the underlying mechanisms, based on ex-vivo tissue and cell culture data. During recent years, an increasing number of human population studies have confirmed the beneficial effects of tea on hypertension. However, the optimal dose has not yet been established owing to differences in the extent of hypertension, and complicated social and genetic backgrounds of populations. Therefore, further large-scale investigations with longer terms of observation and tighter controls are needed to define optimal doses in subjects with varying degrees of hypertensive risk factors, and to determine differences in beneficial effects amongst diverse populations. Moreover, data from laboratory studies have shown that tea and its secondary metabolites have important roles in relaxing smooth muscle contraction, enhancing endothelial nitric oxide synthase activity, reducing vascular inflammation, inhibiting rennin activity, and anti-vascular oxidative stress. However, the exact molecular mechanisms of these activities remain to be elucidated.

Reconciling collaborative action research with existing institutions: insights from Dutch and German climate knowledge programmes

2014 ◽  
Vol 6 (1) ◽  
pp. 89-103 ◽  
Author(s):  
Catrien Termeer ◽  
Arwin van Buuren ◽  
Joerg Knieling ◽  
Manuel Gottschick
Keyword(s):  
Climate Change ◽  
Action Research ◽  
Large Scale ◽  
Focal Point ◽  
Collaborative Action Research ◽  
Adaptation To Climate Change ◽  
Collaborative Action ◽  
Underlying Mechanisms ◽  
Set Up ◽  
The Many

Researchers and policymakers increasingly aim to set up collaborative research programmes to address the challenges of adaptation to climate change. This does not only apply for technical knowledge, but for governance knowledge also. Both the Netherlands and Germany have set up large-scale collaborative action research (CAR) programmes for the governance of adaptation to climate change. Despite the collaborative designs, the initial enthusiasm, the available resources and the many positive outcomes, both programmes encountered several stubborn difficulties. By comparing both programmes, this paper explores the difficulties researchers encounter, analyses the underlying mechanisms and presents some lessons. It found that many difficulties are related to the tensions that exist between the assumptions underlying the new collaborative trajectories and the logics of the existing policy and research institutions. These institutional misfits are decisive to explain ultimate difficulties and successes. Furthermore, the paper concludes that risk aversion, stereotyping and scale fixation strengthen institutional misfits; and that these misfits persist due to lacking bridging capabilities. We suggest some lessons that can help to resolve the difficulties and reconcile CAR into existing institutions: organize the knowledge arrangement as a collaborative process; construct boundary objects as focal point for collaboration; and invest in bridging capabilities.

scholarly journals Retrograde Amnesia – A Question of Disturbed Calcium Levels?

2021 ◽  
Vol 15 ◽  
Author(s):  
Dirk Montag
Keyword(s):  
Retrograde Amnesia ◽  
Traumatic Event ◽  
Neuronal Loss ◽  
Anterograde Amnesia ◽  
Experimental Models ◽  
Model Systems ◽  
Associative Memories ◽  
Specific Effects ◽  
Underlying Mechanisms ◽  
The Many

Retrograde amnesia is the inability to remember events or information. The successful acquisition and memory of information is required before retrograde amnesia may occur. Often, the trigger for retrograde amnesia is a traumatic event. Loss of memories may be caused in two ways: either by loss/erasure of the memory itself or by the inability to access the memory, which is still present. In general, memories and learning are associated with a positive connotation although the extinction of unpleasant experiences and memories of traumatic events may be highly welcome. In contrast to the many experimental models addressing learning deficits caused by anterograde amnesia, the incapability to acquire new information, retrograde amnesia could so far only be investigated sporadically in human patients and in a limited number of model systems. Apart from models and diseases in which neurodegeneration or dementia like Alzheimer’s disease result in loss of memory, retrograde amnesia can be elicited by various drugs of which alcohol is the most prominent one and exemplifies the non-specific effects and the variable duration. External or internal impacts like traumatic brain injury, stroke, or electroconvulsive treatments may similarly result in variable degrees of retrograde amnesia. In this review, I will discuss a new genetic approach to induce retrograde amnesia in a mouse model and raise the hypothesis that retrograde amnesia is caused by altered intracellular calcium homeostasis. Recently, we observed that neuronal loss of neuroplastin resulted in retrograde amnesia specifically for associative memories. Neuroplastin is tightly linked to the expression of the main Ca2+ extruding pumps, the plasma membrane calcium ATPases (PMCAs). Therefore, neuronal loss of neuroplastin may block the retrieval and storage of associative memories by interference with Ca2+ signaling cascades. The possibility to elicit retrograde amnesia in a controlled manner allows to investigate the underlying mechanisms and may provide a deeper understanding of the molecular and circuit processes of memory.

scholarly journals CFD Analysis of Mechanisms Underlying the Porosity-reducing Effect of Atomized Flows in High-pressure Die Cast Products

2020 ◽  
Vol 326 ◽  
pp. 06006
Author(s):  
Eitaro Koya ◽  
Masahiko Nakagawa ◽  
Shinya Kitagawa ◽  
Jun Ishimoto ◽  
Yoshikatsu Nakano ◽  
...  
Keyword(s):  
High Pressure ◽  
Large Scale ◽  
Open Space ◽  
Metal Flow ◽  
Two Phase ◽  
Longitudinal Vortices ◽  
Atomized Flow ◽  
Thick Part ◽  
Underlying Mechanisms ◽  
The Many

In high-pressure die casting, attention has been paid to the J factor, which is defined by the speed of the metal injected at the gate and the shape of the gate. In casting experiments using a piston die, the porosity of the product can be reduced by increasing the J factor such that the metal flow passing through the gate forms an atomized flow. To clarify the underlying mechanisms, we developed a system for simulating a two-phase flow of air and aluminum by large-scale calculations of turbulent flow. During the development of the system, we injected metal into an open space and performed imaging to confirm the state of the atomized flow. The system was then verified by reproducing the atomized flow. The analysis results visualized the many small turbulent vortices generated in the thick part far from the gate. We demonstrated that the change from small to longitudinal vortices promoted entrainment of air into the aluminum and increased the efficiency of air expulsion outside the die through an increase in the J factor.

scholarly journals Exploring the Comparative Efficacy of Metformin and Resveratrol in the Management of Diabetes-Associated Complications: A Systematic Review of Preclinical Studies

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 739 ◽  
Author(s):  
Phiwayinkosi V. Dludla ◽  
Sonia Silvestri ◽  
Patrick Orlando ◽  
Kwazi B. Gabuza ◽  
Sithandiwe E. Mazibuko-Mbeje ◽  
...  
Keyword(s):  
Antioxidant Properties ◽  
Experimental Models ◽  
Sirtuin 1 ◽  
Cochrane Library ◽  
Therapeutic Effects ◽  
Protective Effects ◽  
Metabolic Complications ◽  
Novel Therapeutic Strategies ◽  
Amp Activated Protein Kinase ◽  
Cumulative Evidence

Food-derived bioactive compounds such as resveratrol are increasingly explored for their protective effects against metabolic complications. Evidence supports the strong antioxidant properties and therapeutic effects of resveratrol in managing diabetes and its associated complications. However, evidence informing on the comparative or combination effects of this natural compound with an accomplished and well-characterized antidiabetic agent like metformin has not been revised. Thus, we conducted a comprehensive systematic search of the major electronic databases which included MEDLINE, Cochrane Library, and EMBASE. The cumulative evidence strongly supports the comparative effects of metformin and resveratrol in ameliorating diabetes-associated complications in preclinical settings. In particular, both compounds showed strong ameliorative effects against hyperglycemia, dyslipidemia, insulin resistance, a pro-inflammatory response, and lipid peroxidation in various experimental models of diabetes. Enhancing intracellular antioxidant capacity in addition to activating NAD-dependent deacetylase sirtuin-1 (SIRT1) and AMP-activated protein kinase (AMPK) are the prime mechanisms involved in the therapeutic effects of these compounds. Of interest, preclinical evidence also demonstrates that the combination treatment with these compounds may have a greater efficacy in protecting against diabetes. Thus, confirmation of such evidence in well-organized clinical trials remains crucial to uncover novel therapeutic strategies to manage diabetes and its linked complications.

scholarly journals Potentials of Raspberry Ketone as a Natural Antioxidant

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 482
Author(s):  
Sung Ho Lim ◽  
Chang-Ik Choi
Keyword(s):  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Experimental Models ◽  
Functional Health ◽  
Health Food ◽  
Pharmacological Activities ◽  
Raspberry Ketone ◽  
Effective Antioxidant ◽  
Total Antioxidant ◽  
Underlying Mechanisms

Oxidative stress is closely linked to various diseases, and many studies have been conducted to determine how to reduce this stress. In particular, efforts are being made to find potential antioxidants from natural products. Studies have shown that raspberry ketone (RK; 4-(4-hydroxyphenyl)-2-butanone) has various pharmacological activities. This review summarizes the antioxidant activities of RK and their underlying mechanisms. In several experimental models, it was proven that RK exhibits antioxidant properties through increasing total antioxidant capacity (TAC); upregulating antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT); and improving lipid peroxidation. In conclusion, research about RK’s antioxidant activities is directly or indirectly related to its other various physiological activities. Further studies at the clinical level will be able to verify the value of RK as an effective antioxidant, functional health food, and therapeutic agent.

Evolution of Metastable Structures in Bimetallic Catalysts from Microscopy and Machine-Learning Molecular Dynamics

2020 ◽  
Author(s):  
Jin Soo Lim ◽  
Jonathan Vandermause ◽  
Matthijs A. van Spronsen ◽  
Albert Musaelian ◽  
Christopher R. O’Connor ◽  
...  
Keyword(s):  
Machine Learning ◽  
Molecular Dynamics ◽  
Large Scale ◽  
Materials Science ◽  
Complete Characterization ◽  
Layer By Layer ◽  
Surface Restructuring ◽  
Metastable Structures ◽  
Mechanistic Investigation ◽  
Underlying Mechanisms

Restructuring of interface plays a crucial role in materials science and heterogeneous catalysis. Bimetallic systems, in particular, often adopt very different composition and morphology at surfaces compared to the bulk. For the first time, we reveal a detailed atomistic picture of the long-timescale restructuring of Pd deposited on Ag, using microscopy, spectroscopy, and novel simulation methods. Encapsulation of Pd by Ag always precedes layer-by-layer dissolution of Pd, resulting in significant Ag migration out of the surface and extensive vacancy pits. These metastable structures are of vital catalytic importance, as Ag-encapsulated Pd remains much more accessible to reactants than bulk-dissolved Pd. The underlying mechanisms are uncovered by performing fast and large-scale machine-learning molecular dynamics, followed by our newly developed method for complete characterization of atomic surface restructuring events. Our approach is broadly applicable to other multimetallic systems of interest and enables the previously impractical mechanistic investigation of restructuring dynamics.

Integration of Ecological and Engineering Aspects in Planning Large Scale Tidal Power Development in the Bay of Fundy, Canada

1984 ◽  
Vol 16 (1-2) ◽  
pp. 281-295 ◽  
Author(s):  
Donald C Gordon
Keyword(s):  
Large Scale ◽  
Feasibility Studies ◽  
Bay Of Fundy ◽  
Final Decision ◽  
Power Development ◽  
Tidal Power ◽  
History Of ◽  
Scientists And Engineers ◽  
The Many ◽  
University Scientists

Large-scale tidal power development in the Bay of Fundy has been given serious consideration for over 60 years. There has been a long history of productive interaction between environmental scientists and engineers durinn the many feasibility studies undertaken. Up until recently, tidal power proposals were dropped on economic grounds. However, large-scale development in the upper reaches of the Bay of Fundy now appears to be economically viable and a pre-commitment design program is highly likely in the near future. A large number of basic scientific research studies have been and are being conducted by government and university scientists. Likely environmental impacts have been examined by scientists and engineers together in a preliminary fashion on several occasions. A full environmental assessment will be conducted before a final decision is made and the results will definately influence the outcome.

Inflammatory Biomarkers in Atrial Fibrillation

2019 ◽  
Vol 26 (5) ◽  
pp. 837-854 ◽  
Author(s):  
Effimia Zacharia ◽  
Nikolaos Papageorgiou ◽  
Adam Ioannou ◽  
Gerasimos Siasos ◽  
Spyridon Papaioannou ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Plasma Levels ◽  
Large Scale ◽  
Inflammatory Biomarkers ◽  
Inflammatory Pathways ◽  
Inflammatory State ◽  
Anti Inflammatory ◽  
Underlying Mechanisms

During the last few years, a significant number of studies have attempted to clarify the underlying mechanisms that lead to the presentation of atrial fibrillation (AF). Inflammation is a key component of the pathophysiological processes that lead to the development of AF; the amplification of inflammatory pathways triggers AF, and, in tandem, AF increases the inflammatory state. Indeed, the plasma levels of several inflammatory biomarkers are elevated in patients with AF. In addition, the levels of specific inflammatory biomarkers may provide information regarding to the AF duration. Several small studies have assessed the role of anti-inflammatory treatment in atrial fibrillation but the results have been contradictory. Large-scale studies are needed to evaluate the role of inflammation in AF and whether anti-inflammatory medications should be routinely administered to patients with AF.

scholarly journals A Novel Unsupervised Classification Method for Sandy Land Using Fully Polarimetric SAR Data

2021 ◽  
Vol 13 (3) ◽  
pp. 355
Author(s):  
Weixian Tan ◽  
Borong Sun ◽  
Chenyu Xiao ◽  
Pingping Huang ◽  
Wei Xu ◽  
...  
Keyword(s):  
Spectral Clustering ◽  
Large Scale ◽  
Clustering Algorithm ◽  
Feature Vector ◽  
Unsupervised Classification ◽  
Classification Method ◽  
Sandy Land ◽  
Classification Methods ◽  
The Many ◽  
Representative Points

Classification based on polarimetric synthetic aperture radar (PolSAR) images is an emerging technology, and recent years have seen the introduction of various classification methods that have been proven to be effective to identify typical features of many terrain types. Among the many regions of the study, the Hunshandake Sandy Land in Inner Mongolia, China stands out for its vast area of sandy land, variety of ground objects, and intricate structure, with more irregular characteristics than conventional land cover. Accounting for the particular surface features of the Hunshandake Sandy Land, an unsupervised classification method based on new decomposition and large-scale spectral clustering with superpixels (ND-LSC) is proposed in this study. Firstly, the polarization scattering parameters are extracted through a new decomposition, rather than other decomposition approaches, which gives rise to more accurate feature vector estimate. Secondly, a large-scale spectral clustering is applied as appropriate to meet the massive land and complex terrain. More specifically, this involves a beginning sub-step of superpixels generation via the Adaptive Simple Linear Iterative Clustering (ASLIC) algorithm when the feature vector combined with the spatial coordinate information are employed as input, and subsequently a sub-step of representative points selection as well as bipartite graph formation, followed by the spectral clustering algorithm to complete the classification task. Finally, testing and analysis are conducted on the RADARSAT-2 fully PolSAR dataset acquired over the Hunshandake Sandy Land in 2016. Both qualitative and quantitative experiments compared with several classification methods are conducted to show that proposed method can significantly improve performance on classification.

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