Ascorbic acid partly antagonizes resveratrol mediated heme oxygenase-1 but not paraoxonase-1 induction in cultured hepatocytes - role of the redox-regulated transcription factor Nrf2

<p>Abstract</p> <p>Background</p> <p>Both resveratrol and vitamin C (ascorbic acid) are frequently used in complementary and alternative medicine. However, little is known about the underlying mechanisms for potential health benefits of resveratrol and its interactions with ascorbic acid.</p> <p>Methods</p> <p>The antioxidant enzymes heme oxygenase-1 and paraoxonase-1 were analysed for their mRNA and protein levels in HUH7 liver cells treated with 10 and 25 μmol/l resveratrol in the absence and presence of 100 and 1000 μmol/l ascorbic acid. Additionally the transactivation of the transcription factor Nrf2 and paraoxonase-1 were determined by reporter gene assays.</p> <p>Results</p> <p>Here, we demonstrate that resveratrol induces the antioxidant enzymes heme oxygenase-1 and paraoxonase-1 in cultured hepatocytes. Heme oxygenase-1 induction by resveratrol was accompanied by an increase in Nrf2 transactivation. Resveratrol mediated Nrf2 transactivation as well as heme oxygenase-1 induction were partly antagonized by 1000 μmol/l ascorbic acid.</p> <p>Conclusions</p> <p>Unlike heme oxygenase-1 (which is highly regulated by Nrf2) paraoxonase-1 (which exhibits fewer ARE/Nrf2 binding sites in its promoter) induction by resveratrol was not counteracted by ascorbic acid. Addition of resveratrol to the cell culture medium produced relatively low levels of hydrogen peroxide which may be a positive hormetic redox-signal for Nrf2 dependent gene expression thereby driving heme oxygenase-1 induction. However, high concentrations of ascorbic acid manifold increased hydrogen peroxide production in the cell culture medium which may be a stress signal thereby disrupting the Nrf2 signalling pathway.</p

Cement degradation in CO2 storage sites: a review on potential applications of nanomaterials

© 2018 The Author(s) Carbon capture and sequestration (CCS) has been employed to reduce global warming, which is one of the critical environmental issues gained the attention of scientific and industrial communities worldwide. Once implemented successfully, CCS can store at least 5 billion tons of CO2per year as an effective and technologically safe method. However, there have been a few issues raised in recent years, indicating the potential leakages paths created during and after injection. One of the major issues might be the chemical interaction of supercritical CO2with the cement, which may lead to the partial or total loss of the cement sheath. There have been many approaches presented to improve the physical and mechanical properties of the cement against CO2attack such as changing the water-to-cement ratio, employing pozzolanic materials, and considering non-Portland cements. However, a limited success has been reported to the application of these approaches once implemented in a real-field condition. To date, only a few studies reported the application of nanoparticles as sophisticated additives which can reinforce oil well cements. This paper provides a review on the possible application of nanomaterials in the cement industry where physical and mechanical characteristics of the cement can be modified to have a better resistance against corrosive environments such as CO2storage sites. The results obtained indicated that adding 0.5 wt% of Carbon NanoTubes (CNTs) and NanoGlass Flakes (NGFs) can reinforce the thermal stability and coating characteristics of the cement which are required to increase the chance of survival in a CO2sequestrated site. Nanosilica can also be a good choice and added to the cement by as much as 3.0 wt% to improve pozzolanic reactivity and thermal stability as per the reports of recent studies

Landé factor measurements in the B 3 Σ- u state of 80Se2 : a test of molecular perturbations

We have measured the Landé factor values of 180 rotational levels in the B 3Σ-u state of 80Se 2 by the Zeeman quantum beats method. Our measurements show the great sensitivity of the gJ values to molecular perturbations. A preliminary interpretation of these results is proposed.Nous avons mesuré les facteurs de Landé de 180 niveaux dans l'état B 3Σ-u de 80Se2 par la méthode des battements quantiques Zeeman. Nos mesures montrent la grande sensibilité du facteur de Landé aux perturbations moléculaires. Une interprétation préliminaire de ces résultats est proposée

Landé factors measurements in the B 3Σ- u state of 80Se2

We have measured Landé factors in several laser excited levels of the B 3Σ-u state of 80Se2. The results are in reasonably good agreement with recently published theoretical values and fine structure determinations.Nous avons mesuré les facteurs de Landé de plusieurs niveaux de l'état B 3Σ-u de 80Se2 excités par laser. Les résultats sont en assez bon accord avec les valeurs théoriques et les déterminations de structure fine récemment publiées

Étude théorique de l'effet Hanle des molécules dans le formalisme des opérateurs tensoriels irréductibles

The irreducible tensor operators formalism is applied to study the Hanle effect of molecules. The polarization rates, in zero magnetic field, of the various observable fluorescence lines are calculated. It is also shown how molecular hyperfine structures can be taken into account. Some remarks are made on a semi classical treatment in which the rotation of the molecule is treated classically.Le formalisme des opérateurs tensoriels irréductibles est appliqué à l'étude de l'effet Hanle des molécules. On calcule, en particulier, par cette méthode les taux de polarisation en champ magnétique nul des différentes raies de fluorescence que l'on est susceptible d'observer. Par ailleurs, on montre qu'il est facile de tenir compte, dans ce formalisme, de l'influence des structures hyperfines moléculaires. Quelques remarques, enfin, sont faites sur la théorie semi-classique de l'effet Hanle des molécules, théorie dans laquelle la rotation des molécules est traitée classiquement

Accessibilité des ressources numériques pour la lecture : du respect des critères au point de vue des utilisateurs

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Accessibilité des ressources numériques pour la lecture : du respect des critères au point de vue des utilisateurs

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An acoustic technique for investigating the sol–gel transition

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