The ethanolamide metabolite of DHA, docosahexaenoylethanolamine, shows immunomodulating effects in mouse peritoneal and RAW264.7 macrophages: evidence for a new link between fish oil and inflammation

Several mechanisms have been proposed for the positive health effects associated with dietary consumption of long-chain n-3 PUFA (n-3 LC-PUFA) including DHA (22 : 6n-3) and EPA (20 : 5n-3). After dietary intake, LC-PUFA are incorporated into membranes and can be converted to their corresponding N-acylethanolamines (NAE). However, little is known on the biological role of these metabolites. In the present study, we tested a series of unsaturated NAE on the lipopolysaccharide (LPS)-induced NO production in RAW264.7 macrophages. Among the compounds tested, docosahexaenoylethanolamine (DHEA), the ethanolamide of DHA, was found to be the most potent inhibitor, inducing a dose-dependent inhibition of NO release. Immune-modulating properties of DHEA were further studied in the same cell line, demonstrating that DHEA significantly suppressed the production of monocyte chemotactic protein-1 (MCP-1), a cytokine playing a pivotal role in chronic inflammation. In LPS-stimulated mouse peritoneal macrophages, DHEA also reduced MCP-1 and NO production. Furthermore, inhibition was also found to take place at a transcriptional level, as gene expression of MCP-1 and inducible NO synthase was inhibited by DHEA. To summarise, in the present study, we showed that DHEA, a DHA-derived NAE metabolite, modulates inflammation by reducing MCP-1 and NO production and expression. These results provide new leads in molecular mechanisms by which DHA can modulate inflammatory processes

Expression of an expansin carbohydrate-binding module affects xylem and phloem formation

Expansins are believed to be involved in disrupting the non-covalent adhesion of cellulose to matrix polysaccharides, thereby promoting wall creep. We have targeted a putative potato expansin (EXPA)carbohydrate-binding module (CBM) to the cell walls of tobacco plants. Histological examinations and electron microscopy indicated that 30% of the xylem cells of the transgenic stems with high expressionof the expansin CBM are wider (radial surface area) than those of the controls. Similarly, 37% of the xylem cells of the stems of the high expressers have thinner cell walls than those of the controls. Therewere no such phenotypes in the low and none expressers, as well as in the control plants. The transgenic tobacco plants expressing the potato expansin CBM did not exhibit marked change in plant morphology. Analysis of cellulose content in the stem cell walls was similar between the high expresser of the transgene and the control plants. Nonetheless, our results taken together demonstrate that expansin CBM alone can bring about changes in the plant cell walls

Interaction of iron(III) with taste enhancers:Potential of Fe(III) salts with inosine monophosphate or guanosine monophosphate for food fortification

Iron interactions in iron-fortified savory concentrates lead to undesirable discoloration, even when poorly-water soluble iron salts such as ferric pyrophosphate (Fe4PP3) are used. This is the first study to comprehensively investigate the interaction of Fe(III) with three common taste enhancers: glutamate (Glu), inosine monophosphate (IMP), and guanosine monophosphate (GMP). The stability of the complexes of Fe(III) with IMP or GMP is higher compared to that with Glu. Neutrality of IMP or GMP species with Fe(III) at pH 3–8 resulted in precipitation. This property was exploited to synthesize Fe(III) salts of IMP or GMP (i.e. Fe2IMP3 and Fe2GMP3) by aqueous chemical precipitation. Iron dissolution from Fe2IMP3 and Fe2GMP3 was up to twenty-fold higher at gastric pH (1–3), indicative of better bio-accessibility, and up to fifteen-fold lower at food pH (3–7), indicative of decreased reactivity in food, compared to Fe4PP3. Consequently, Fe2IMP3 and Fe2GMP3, compared to Fe4PP3, led to less discoloration in combination with the poorly soluble phenolics that are commonly present in savory concentrates. We conclude that Fe(III) salts of IMP or GMP can potentially serve as iron fortificants due to their increased solubility at gastric pH (1–3), decreased iron dissolution at food pH (3–7), and decreased reactivity at food pH.</p

Interactions of Natural Flavones with Iron Are Affected by 7-O-Glycosylation, but Not by Additional 6″-<i>O</i>-Acylation

In iron-fortified bouillon, reactivity of the iron ion with (acylated) flavone glycosides from herbs can affect product color and bioavailability of iron. This study investigates the influence of 7-O-glycosylation and additional 6″-O-acetylation or 6″-O-malonylation of flavones on their interaction with iron. Nine (6″-O-acylated) flavone 7-O-apiosylglucosides were purified from celery (Apium graveolens), and their structures were elucidated by mass spectrometry (MS) and nuclear magnetic resonance (NMR). In the presence of iron, a bathochromic shift and darker color were observed for the 7-O-apiosylglucosides compared to the aglycon of flavones that only possess the 4-5 site. Thus, the ability of iron to coordinate to the flavone 4-5 site is increased by 7-O-glycosylation. For flavones with an additional 3′-4′ site, less discoloration was observed for the 7-O-apiosylglucoside compared to the aglycon. Additional 6″-O-acylation did not affect the color. These findings indicate that model systems used to study discoloration in iron-fortified foods should also comprise (acylated) glycosides of flavonoids.</p

Prescription of inhalers in asthma and COPD : Towards a rational, rapid and effective approach

Peer reviewedPublisher PD