MyD88-dependent pro-interleukin-1β induction in dendritic cells exposed to food-grade synthetic amorphous silica.

Background: Dendritic cells (DCs) are specialized first-line sensors of foreign materials invading the organism. These sentinel cells rely on pattern recognition receptors such as Nod-like or Toll-like receptors (TLRs) to launch immune reactions against pathogens, but also to mediate tolerance to self-antigens and, in the intestinal milieu, to nutrients and commensals. Since inappropriate DC activation contributes to inflammatory diseases and immunopathologies, a key question in the evaluation of orally ingested nanomaterials is whether their contact with DCs in the intestinal mucosa disrupts this delicate homeostatic balance between pathogen defense and tolerance.

Antimalarial activity of axidjiferosides, new β-galactosylceramides from the African sponge Axinyssa djiferi.

The marine sponge, Axinyssa djiferi, collected on mangrove tree roots in Senegal, was investigated for glycolipids. A mixture containing new glycosphingolipids, named axidjiferoside-A, -B and -C, accounted for 0.07% of sponge biomass (dry weight) and for 2.

Antiproliferative activity against human non-small cell lung cancer of two O-alkyl-diglycosylglycerols from the marine sponges Myrmekioderma dendyi and Trikentrion laeve.

Glycolipids of Myrmekioderma sponges contain Myrmekiosides, a new family of glycolipids with a unique structure of mono-O-alkyl-diglycosylglycerols. This report deals with the identification and biological activity of the new Myrmekioside E from Myrmekioderma dendyi. Its structure has been elucidated from spectroscopic data and chemical degradation studies.

3-(2,4-dimethoxybenzylidene)-anabaseine: a promising candidate drug for Alzheimer's disease?

3-(2,4-dimethoxybenzylidene)-anabaseine is an analog of the paralytic alkaloid, anabaseine, from the ribbon worms Amphiporus sp., that shows numerous properties, in particular an agonist activity on alpha 7 nicotinic acetylcholine receptors. This article reviews these properties and explains to what extent they could be valuable to control symptomatology and/or neurodegeneration in Alzheimer's disease.

Cytotoxicity on human cancer cells of ophidiacerebrosides isolated from the African starfish Narcissia canariensis.

The starfish Narcissia canariensis harvested from the coasts off Dakar, Senegal, was investigated for glycolipids (GL). This report deals with the isolation, characterization and biological activity of a fraction F13-3 separated from the GL mixture and selected according to its ability to inhibit KB cell proliferation after 72 hours of treatment. Firstly, a GL mixture F13 was obtained that accounted for 1.

Demospongic acids revisited.

The well-known fatty acids with a Δ5,9 unsaturation system were designated for a long period as demospongic acids, taking into account that they originally occurred in marine Demospongia sponges. However, such acids have also been observed in various marine sources with a large range of chain-lengths (C(16)-C(32)) and from some terrestrial plants with short acyl chains (C(18)-C(19)). Finally, the Δ5,9 fatty acids appear to be a particular type of non-methylene-interrupted fatty acids (NMA FAs).

New 17-methyl-13-octadecenoic and 3,16-docosadienoic acids from the sponge Polymastia penicillus.

The phospholipid fatty acid composition of the North-East Atlantic sponge Polymastia penicillus (South Brittany, France) was investigated. Sixty fatty acids (FA) were identified as methyl esters (FAME) and N-acyl pyrrolidides (NAP) by gas chromatography-mass spectrometry (GC/MS), including eight Delta5,9 unsaturated FA and three long-chain 2-hydroxylated FA. The major phospholipid FA were palmitic (14.

Unusual sterolic mixture, and 24-isopropylcholesterol, from the sponge Ciocalypta sp. reduce cholesterol uptake and basolateral secretion in Caco-2 cells.

An unusual sterolic mixture (82.3% of 24-isopropylated sterols) and its major component, 24-isopropylcholesterol, isolated from a marine sponge, Ciocalypta sp. (Halichondriidae), reduce cholesterol uptake, basolateral secretion and ACAT-2 mRNA expression and increase the expression of ABCA1 mRNA in Caco-2 cells.

Marine metabolites overcoming or circumventing multidrug resistance mediated by ATP-dependent transporters: a new hope for patient with tumors resistant to conventional chemotherapy.

The treatment of chemoresistant tumors represents an important challenge in the field of oncology. Primary or acquired overexpression of ATP-dependent transporters, in particular P-glycoprotein (Pgp, MDR1 protein), is a major cause of multidrug resistance and reduced patient survival. Sustained efforts have thereby been undertaken to find agents overcoming this resistance.

New trends in phospholipid class composition of marine sponges.

The exceptional ability of marine sponges to adapt to often drastic changes of their environments could be due to special structural features in cell membranes, including firstly phospholipids (PL). Thus, PL class composition was investigated in marine sponges (22 species from 19 genera to 15 families) originating from various locations (East Atlantic, North Atlantic, South-West Pacific, Mediterranean Sea, Red Sea, Arabian-Persian Gulf). The quantitative determination of PL class composition was obtained by high-performance thin-layer chromatography (HPTLC) with scanning densitometry of the different spots.

Marine pharmacology: potentialities in the treatment of infectious diseases, osteoporosis and Alzheimer's disease.

Several molecules isolated from various marine organisms (microorganisms, algae, fungi, invertebrates, and vertebrates) are currently under study at an advanced stage of clinical trials, either directly or in the form of analogues deduced from structure-activity relationships. Some of them have already been marketed as drugs. The goal of this article is not to present a complete panorama of marine pharmacology but to show that new models and new mechanisms of action of marine substances bring new solutions for tackling some of the major public health problems of the 21st century.

Phospholipid fatty acids and sterols of two Cinachyrella sponges from the Saudi Arabian Red Sea: comparison with Cinachyrella species from other origins.

Phospholipid class compositions, fatty acids and sterols of the sponges Cinachyrella alloclada and C. kükenthali from the Saudi Arabian Red Sea were studied and compared with previous results for other Cinachyrella spp. collected in Senegal (East Atlantic) and New Caledonia (West Pacific).

Lu-Hf Isotope Systematics of Garnet Pyroxenites from Beni Bousera, Morocco: Implications for Basalt Origin.

Six garnet pyroxenites from Beni Bousera, Morocco, yield a mean lutetium-hafnium age of 25 +/- 1 million years ago and show a wide range in hafnium isotope compositions (varepsilonHf = -9 to +42 25 million years ago), which exceeds that of known basalts (0 to +25). Therefore, primary melts of garnet pyroxenites cannot be the source of basalts. The upper mantle may be an aggregate of pyroxenites that were left by the melting of oceanic crust at subduction zones and peridotites that were contaminated by the percolation of melts from these pyroxenites.

Sulfated compounds from marine organisms.

More than 500 sulfated compounds have been isolated from marine organisms so far but most of them originate from two phyla only, Spongia and Echinodermata. The sulfated compounds are presented according to the phyla they have been identified from and to their chemical structures. Biological activities, when available, are also given.

New unsaturated long-chain fatty acids in the phospholipids from the Axinellida sponges Trikentrion loeve and Pseudaxinella cf. lunaecharta.

In order to identify new structures and especially those involved as biosynthetic intermediates, the fatty acid composition of whole phospholipids from two Senegalese marine sponges from the order Axinellida, Trikentrion loeve and Pseudaxinella cf. lunaecharta, has been investigated by analytical gas chromatography and gas chromatography/mass spectrometry. Several new fatty acids were identified as methyl esters and N-acyl pyrrolidides, namely 16-eicosenoic, 11-tetracosenoic, 5-pentacosenoic, 11-hexacosenoic, 11-octacosenoic, 23-triacontenoic, 17,21-hexacosadienoic, 19,23-octacosadienoic, 9,23-triacontadienoic, 5,9,21-hexacosatrienoic, and 5,9,25-triacontatrienoic.

New branched-chain fatty acids from the Senegalese gorgonian Leptogorgia piccola (white and yellow morphs).

Fatty acids from total lipids of the gorgonian Leptogorgia piccola (white and yellow morphs), collected from the same area at two different periods with regard to the average water temperature, were studied. More than fifty fatty acids were identified as methyl esters and N-acyl pyrrolidides by gas chromatography and gas chromatography/mass spectrometry. Three new, branched-chain unsaturated fatty acids were identified in addition to the unusual 7-methyl-6-hexadecenoic acid, namely 10-methyl-6-hexadecenoic, 7,9-dimethyl-6-hexadecenoic, and 10-methyl-6,9-heptadecadienoic acids.

Bistramides A, B, C, D, and K: a new class of bioactive cyclic polyethers from Lissoclinum bistratum.

The isolation and characterization is described of four novel cyclic polyethers, bistramides B [2], C [3], D [4], and K [5], which are closely related to the previously reported bistramide A [1] from the New Caledonian urochordata Lissoclinum bistratum. The structures of these metabolites were defined by spectroscopic methods. The four compounds exhibited in vitro cytotoxicity toward six tumor cell lines, including the human non-small cell lung carcinoma (NSCLC-N6) line.

Effects in vitro of sulfated polysaccharide from Schizymenia dubyi (Rhodophyta, Gigartinales) on a non-small-cell bronchopulmonary carcinoma line (NSCLC-N6).

An unusual sulfated heteropolysaccharide containing uronic acids, previously isolated from the red alga Schizymenia dubyi, was studied in vitro for its effect on asynchronous cells of a human non-small-cell-bronchopulmonary carcinoma line (NSCLC-N6). Cell growth appeared to be inhibited in the G1 phase of the cell cycle, and kinetic studies in pretreated cells showed that this growth arrest was irreversible. These events are related to a terminal maturation induction.

New natural 2-acetoxy fatty acids using chemical ionization and electron impact mass spectrometry.

The phospholipids of the sponge Polymastia gleneni contain saturated long chain (C22-30)-acetoxy fatty acids. Their structures were assigned based on chromatographic and spectrometric data as well as comparison with a synthetic sample. The use of capillary gas chromatography combined with chemical ionization and electron impact mass spectrometry was instrumental in the eludication of structures, since only a very small amount of crude lipids was available.

Phospholipid studies of marine organisms: V(1) new α-methoxy acids fromHigginsia tethyoides.

The phospholipids of the demospongeHigginsia tethyoides are shown to have at least 16 long-chain α-methoxy acids, which represent a new class of fatty acids. Among them are the saturated α-methoxy acids containing 19-24 carbon atoms. The monounsaturated compounds are 2-OMe-Δ(17)-24:1, 2-OMe-Δ(18)-25:1, 2-OMeΔ(19)-26:1 and 2-OMe-Δ(21)-28:1.