Search results for "acids"
showing 10 items of 3520 documents
Inhibition of Rac1 signaling by lovastatin protects against anthracycline-induced cardiac toxicity
2011
Normal tissue damage limits the efficacy of anticancer therapy. For anthracyclines, the clinically most relevant adverse effect is cardiotoxicity. The mechanisms involved are poorly understood and putative cardioprotectants are controversially discussed. Here, we show that the lipid-lowering drug lovastatin protects rat H9c2 cardiomyoblasts from doxorubicin in vitro. Protection by lovastatin is related to inhibition of the Ras-homologous GTPase Rac1. It rests on a reduced formation of DNA double-strand breaks, resulting from the inhibition of topoisomerase II by doxorubicin. Doxorubicin transport and reactive oxygen species are not involved. Protection by lovastatin was confirmed in vivo. I…
Fatty acid composition as biomarkers of freshwater microalgae: analysis of 37 strains of microalgae in 22 genera and in seven classes
2013
The fatty acid (FA) composition of algae is an important determinant of their food quality for consumers, and FAs can also be used as biomarkers for biochemical and energetic pathways in food webs. FA analyses of 7 freshwater algal classes and 37 strains showed clear similarity within classes and strong differences amongst classes. Class was a dominant factor (66.4%) explaining variation in FA signatures of microalgae. The 7 algal classes comprised 4 separate groups according to their FA profiles: (1) Chlorophyceae and Trebouxiophyceae, (2) Bacillariophyceae, (3) Cryptophyceae, Chrysophyceae, and Raphidophyceae, and (4) Euglenophyceae. Each group had a characteristic FA composition, althoug…
The Missing Member of the Partially O-Alkylated Resorcinarene Family: Synthesis and Conformation of Methyl Tetramethoxy Resorcinarene
2013
An improved Lewis acid catalyzed synthesis method for methyl tetramethoxy resorcinarene is described, which produced the missing lower rim methyl derivative of this partially O-alkylated resorcinarene family. Structural characterization by means of variable temperature NMR experiments and single crystal X-ray diffraction studies furthermore revealed that the resorcinarene core adopts different conformations in the solid state and in solution. peerReviewed
Dietary fatty acids in the retina: beyond DHA, is EPA the underestimate intermediate?
2016
Dietary fatty acids in the retina: beyond DHA, is EPA the underestimate intermediate?. 12. congress of the international society for the study of fatty acids and lipids
Inhibition of small G proteins of the Rho family by statins orClostridium difficiletoxin B enhances cytokine-mediated induction of NO synthase II
2000
In order to investigate the involvement of Ras and/or Rho proteins in the induction of the inducible isoform of nitric oxide synthase (NOS II) we used HMG-CoA reductase inhibitors (statins) and Clostridium difficile toxin B (TcdB) as pharmacological tools. Statins indirectly inhibit small G proteins by preventing their essential farnesylation (Ras) and/or geranylgeranylation (Rho). In contrast, TcdB is a glucosyltransferase and inactivates Rho-proteins directly. Human A549/8- and DLD-1 cells as well as murine 3T3 fibroblasts were preincubated for 18 h with statins (1–100 μM) or TcdB (0.01–10 ng ml−1). Then NOS II expression was induced by cytokines. NOS II mRNA was measured after 4–8 h by R…
Activation of astroglial phospholipase D activity by phorbol ester involves ARF and Rho proteins.
2000
Primary cultures of rat cortical astrocytes express phospholipase D (PLD) isoforms 1 and 2 as determined by RT-PCR and Western blot. Basal PLD activity was strongly (10-fold) increased by 4beta-phorbol-12beta,13alpha-dibutyrate (PDB) (EC(50): 56 nM), an effect which was inhibited by Ro 31-8220 (0.1-1 microM), an inhibitor of protein kinase C (PKC), and by brefeldin A (10-100 microg/ml), an inhibitor of ADP-ribosylating factor (ARF) activation. Pretreatment of the cultures with Clostridium difficile toxin B-10463 (0.1-1 ng/ml), which inactivates small G proteins of the Rho family, led to a breakdown of the astroglial cytoskeleton; concomitantly, PLD activation by PDB was reduced by up to 50%…
Metabotropic glutamate receptors activate phospholipase D in astrocytes through a protein kinase C-dependent and Rho-independent pathway.
2003
Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors that mediate phospholipase D (PLD) activation in brain, but the mechanism underlying this response remains unclear. Here we used primary cultures of astrocytes as a cell model to explore the mechanism that links mGluRs to PLD. Glutamate activated both phospholipase C (PLC) and PLD with equal potency and this effect was mimicked by L-cysteinesulfinic acid, a putative neurotransmitter previously shown to activate mGluRs coupled to PLD, but not PLC, in adult brain. PLD activation by glutamate was dependent on Ca(2+) mobilization and fully blocked by both protein kinase C (PKC) inhibitors and PKC down-regulation, suggesti…
Inhibition of Rho modulates cytokine-induced prostaglandin E2 formation in renal mesangial cells.
2003
Stimulation of rat mesangial cells for 24 h with interleukin-1β(IL-1β) plus forskolin (Fk) leads to a marked increase in prostaglandin E 2 (PGE 2 ) synthesis. This effect is further enhanced by the small G-protein Rho inhibitor toxin A. A similar increase in PGE 2 formation is obtained with Y27632, a Rho-dependent kinase inhibitor, and with lovastatin, a hydroxymethylglutaryl-coenzyme A inhibitor which depletes cells from geranylgeranyl moieties and thus blocks Rho activation. In parallel to the increased PGE 2 synthesis, a potentiation of IL-1β-induced secretory group IIA phospholipases A 2 (sPLA 2 -IIA) protein expression also occurs by Rho inhibition. However, only toxin A triggers an in…
NMR-based quantification of rosmarinic and carnosic acids, GC-MS profile and bioactivity relevant to neurodegenerative disorders of Rosmarinus offici…
2013
Abstract A comparative study of phytochemicals content and biological properties of eight Rosmarinus officinalis (rosemary) populations (RO1–RO8) collected in different areas of Tunisia was carried out. Two of the main rosemary constituents, rosmarinic and carnosic acids, were quantified by an NMR technique. Carnosic acid content was higher than that of rosmarinic acid. The non-polar constituents were examined by GC and GC–MS. Total phenols and flavonoids content were also determined in order to discuss the possible correlation between these phytochemicals and bioactivity. Antioxidant activity was investigated through different in vitro assays. Sample RO3 from a sub-humid area showed the hi…
Salivary lipolytic activity seems to modulate the basal free fatty acid concentration in human saliva
2017
The perception of fat is a complex sensation that involves various sensory modalities, such as texture, aroma and taste. Taste perception is supported by the discovery of fatty acid receptors in the tongue papillae. However, dietary fat is mainly composed of esterified fatty acids, whereas only free fatty acids can bind to taste receptors. In this context, the literature often mentioned the necessity and efficiency of a salivary lipolytic activity to hydrolyse the esterified fatty acids present in foods and enable fat perception. We made a complementary hypothesis in which salivary lipolytic activity is also involved in regulating the basal level of salivary fatty acids in saliva. To test t…