8 research outputs found
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies
There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity
Tunable Semicrystalline Thin Film Cellulose Substrate for High-Resolution, <i>In-Situ</i> AFM Characterization of Enzymatic Cellulose Degradation
In the field of enzymatic cellulose
degradation, fundamental interactions between different enzymes and
polymorphic cellulose materials are of essential importance but still
not understood in full detail. One technology with the potential of
direct visualization of such bioprocesses is atomic force microscopy
(AFM) due to its capability of real-time <i>in situ</i> investigations
with spatial resolutions down to the molecular scale. To exploit the
full capabilities of this technology and unravel fundamental enzymeâcellulose
bioprocesses, appropriate cellulose substrates are decisive. In this
study, we introduce a semicrystalline-thin-film-cellulose (SCFTC)
substrate which fulfills the strong demands on such ideal cellulose
substrates by means of (1) tunable polymorphism via variable contents
of homogeneously sized cellulose nanocrystals embedded in an amorphous
cellulose matrix; (2) nanoflat surface topology for high-resolution
and high-speed AFM; and (3) fast, simple, and reproducible fabrication.
The study starts with a detailed description of SCTFC preparation
protocols including an in-depth material characterization. In the
second part, we demonstrate the suitability of SCTFC substrates for
enzymatic degradation studies by combined, individual, and sequential
exposure to TrCel6A/TrCel7A cellulases (<i>Trichoderma reesei</i>) to visualize synergistic effects down to the nanoscale
Tunable Semicrystalline Thin Film Cellulose Substrate for High-Resolution, <i>In-Situ</i> AFM Characterization of Enzymatic Cellulose Degradation
In the field of enzymatic cellulose
degradation, fundamental interactions between different enzymes and
polymorphic cellulose materials are of essential importance but still
not understood in full detail. One technology with the potential of
direct visualization of such bioprocesses is atomic force microscopy
(AFM) due to its capability of real-time <i>in situ</i> investigations
with spatial resolutions down to the molecular scale. To exploit the
full capabilities of this technology and unravel fundamental enzymeâcellulose
bioprocesses, appropriate cellulose substrates are decisive. In this
study, we introduce a semicrystalline-thin-film-cellulose (SCFTC)
substrate which fulfills the strong demands on such ideal cellulose
substrates by means of (1) tunable polymorphism via variable contents
of homogeneously sized cellulose nanocrystals embedded in an amorphous
cellulose matrix; (2) nanoflat surface topology for high-resolution
and high-speed AFM; and (3) fast, simple, and reproducible fabrication.
The study starts with a detailed description of SCTFC preparation
protocols including an in-depth material characterization. In the
second part, we demonstrate the suitability of SCTFC substrates for
enzymatic degradation studies by combined, individual, and sequential
exposure to TrCel6A/TrCel7A cellulases (<i>Trichoderma reesei</i>) to visualize synergistic effects down to the nanoscale
Grazing-incidence in-plane X-ray diffraction on ultra-thin organic films using standard laboratory equipment
A novel grazing incidence in plane X ray diffraction setup based on a commercial four circle diffractometer with a sealed ceramic copper X ray tube, upgraded with parabolic graded multilayer X ray optics and a one dimensional position sensitive detector, is presented. The high potential of this setup is demonstrated by a phase analysis study of pentacene thin films and the determination of in plane lattice constants of pentacene mono and multilayers. The quality of the results compare well to studies performed at synchrotron radiation facilitie