Cultures of human adipocytes were pretreated with quercetin and trans-RSV followed by treatment with TNF-a. Subsequently, gene and protein markers of inflammation and insulin resistance were measured. The authors report that quercetin, and to a lesser extent trans-RSV, attenuated the TNF-a–induced expression of inflammatory genes such as interleukin (IL)-6, IL-1b, IL-8, and monocyte chemoattractant protein-1 (MCP-1) and the secretion of IL-6, IL-8, and MCP-1.
Forum members were concerned about certain aspects of the study, especially the extrapolation of in vitro results to in vivo situations. The in vitro conditions the authors describe are minimally representative of an in vivo condition. In vivo, after consumption of quercetin or resveratrol, these compounds undergo extensive metabolism, leading to glucuronidated, sulphated or methylated compounds. In a previous study, quercetin 3-glucoside was transformed to 3,4-dihydroxyphenylacetic acid, acetate and butyrate in cells from human gut; only 3'-methylquercetin has been detected in human plasma, present at a concentration of 0.1 to 0.2 µM after 3 h. The authors of the current paper are using concentrations up to 60 µM, concentrations which have not been found in vivo.
There were also concerns with the work on cell uptake of quercetin and resveratrol. Primary adipocytes were incubated with the polyphenols, but it is not clear whether or not the concentrations used were subtoxic. Our current knowledge is limited about local concentration of the molecules we are studying in subcellular compartments, their interaction with alternative targets, and eventually their transformation into products that could be more or less active on a given specific pathway. The real difficult and important issue is the identification of a reasonable convergence -- if not agreement -- between data originating from extremely distant approaches. In this case, the notion that metabolic diseases are related to a homeostatic imbalance in adipose tissue, linked to a different redox status, linked to activation of specific pathways, and that different redox sensitive polyphenols do have a protective effect, encompasses the evidence produced by extremely distant approaches.
From a clinical point of view, the role of phytochemicals acting as antioxidants and anti-inflammatory agents could be extremely important in inflammation-associated chronic conditions such as cardiovascular disease, diabetes, and cancer. Quercetin and resveratrol may indeed play an important role in this regard, and need to be investigated further to establish the clinical importance of natural dietary compounds in the prevention of chronic degenerative conditions.
Contributions to this critique by the International Scientific Forum on Alcohol Research were provided by the following members:David Vauzour, PhD
The specialists who are members of the Forum are happy to respond to questions from Health Editors regarding emerging research on alcohol and health and will offer an independent opinion in context with other research on the subject.
Contacts for EditorsProfessor R Curtis Ellison firstname.lastname@example.org
R. Curtis Ellison | EurekAlert!
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.
Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...
22.05.2017 | Event News
17.05.2017 | Event News
16.05.2017 | Event News
22.05.2017 | Materials Sciences
22.05.2017 | Life Sciences
22.05.2017 | Physics and Astronomy