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At least 19 recordsLinked to original sources
PubMed1979

[Inhibition of carrageenan edema by carrageenan itself].

The influence of two kinin forming agents: iota carrageenan and ellagic acid, on the paw oedema induced by 48/80, an amino-liberator, or by carrageenan iota, has been studied, in the Rat. Ellagic acid and carrageenan, by intraperitoneal injection, reduce the paw oedema induced respectively by 48/80 and carrageenan itself. This inhibition depends on a non-specific "counter-irritation" and not on kininogen stores depletion. Ellagic acid, by intravenous injection, diminishes the oedema induced by carrageenan; swelling due to 48/80, is not affected. So kininogen activation plays some role in the inflammatory processes induced by iota carrageenan. Carrageenan by intravenous injection, suppresses his own inflammatory action but does not influence at all the similar action of 48/80. The anti-inflammatory effect of carrageenan does not exclusively depend on kininogen stores depletion.

Animals↗
PubMed2005

Production and characterization of a phage-display recombinant antibody against carrageenans: evidence for the recognition of a secondary structure of carrageenan chains present in red algae tissues.

We report the isolation, for the first time by phage display, of a scFv recombinant antibody called B3 directed against carrageenans, the major sulphated polysaccharides of red seaweeds. Immunoassays were used to characterize the binding of B3 antibodies toward the three main carrageenan forms (iota, kappa, and lambda) differing by their sulfonic ester content and the presence of 3,6-anhydrogalactose. In enzyme-linked immunoadsorbent assay (ELISA), B3 soluble scFv showed a high reactivity towards iota-carrageenan at any titer but, at high titer only, recognized also the highly sulfated lambda-form. Surface-adsorbed kappa-polymers were only recognized in presence of poly-L-lysine (PLL). The replacement of Na+ ions by K+ in the buffers had no effect on kappa-polymer detection but increased the binding of B3 antibodies toward both iota- and lambda-carrageenans, whereas addition of Ca2+ decreased sharply the recognition of the iota-form. In competitive assays, low titer B3 soluble scFv showed a iota>kappa>lambda selectivity and recognized a mixture of iota-oligomers with degrees of polymerization between 4 and 18 but not sub-fractions of 4 or 6 residues long. We suggest therefore that the B3 epitope could consist of a helical conformation of carrageenan chains. Immunofluorescence microscopy showed that, amongst other red algae, Chondrus gametophyte (containing iota-chains) was strongly recognized by B3 scFv whereas sporophytic tissues rich in lambda-carrageenans were not, assessing the preference of this probe for iota-carrageenans in situ. The high potential of the B3 recombinant probe is discussed.

Animals↗
PubMed1984

Structure-activity in the carrageenans: iota-carrageenan and experimental oedemagenic activity.

The oedemagenic activities of several iota-carrageenans from Eucheuma spinosum have been compared using the rat hindpaw model. From the parent iota-carrageenan of weight average molecular weight 541 100 an acid-degraded iota-carrageenan (Mw = 20 300) was obtained which on fractionation yielded five iota-carrageenans Mw ranging from 73 700 to 4 600. The oedemagenic activity of iota-carrageenan resided in the fraction of Mw = 73 700, the parent undegraded high molecular weight iota-carrageenan being no more active and fractions of lower molecular weight being inactive. Fractionation was based on differential solubilities of the barium salts of the fractions in water and aqueous ethanol and was probably determined by aspects of primary structure in addition to molecular weight.

Animals↗
PubMed1977

Effects of carrageenan on immune responses. Studies on the macrophage dependency of various antigens after treatment with carrageenan.

Carrageenan, a sulfated polygalactose having macrophage toxic properties, elicited a marked suppression of IgM response to T cell-dependent antigens such as sheep red blood cells (SRBC), dinitrophenylated bovine serum gamma-globulin (DNP-BGG), and trinitrophenylated concanavalin A (TNP-Con A). In contrast, carrageenan did not inhibit antibody responses to such T cell-independent antigens as trinitrophenylated DEAE-dextran (TNP-DEAE-dextran), trinitrophenylated polyvinyl pyrrolidone(TNP-PVP), and trinitrophenylated Ficoll (TNP-Ficoll). Compared to total spleen cells, spleen cells from which macrophages had been removed by adhesion to plastic Petri dishes had less effect on the production of antibody against T cell-dependent antigens, but no change or a rather stimulated effect was observed in in vitro antibiody synthesis against T cell-independent antigens. These results strongly suggest that macrophages are involved in antibody responses to T cell-dependent antigens but not in those to T cell-independent antigens. However, the antibody response to trinitrophenylated lipopolysaccharide (TNP-LPS), a T cell-independent antigen, was inhibited by carrageenan treatment, suggesting that the response is macrophage dependent. Moreover, antibody response to higher doses of dinitrophenylated phytohemagglutinin (DNP-PHA), a T cell-dependent antigen, was shown to be macrophage independent by carrageenan treatment, although the antibody response to low doses of the antigen was macrophage dependent. Considering all these results, carrageenan treatment seems to be a very useful method to determine whether immune response to various antigens are macrophage dependent or not.

Animals↗
PubMed2001

Analysis of carrageenans by matrix-assisted laser desorption/ionization and electrospray ionization mass spectrometry. I. kappa-Carrageenans.

Matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) mass spectra of small kappa-carrageenans are reported and discussed. MALDI spectra can be obtained in both positive and negative ion mode. In the absence of extraneous metal ions, positive ions are formed by the attachment of one Na(+) ion to the carrageenan, whereas for negative ions one Na(+) ion is detached from the sulfate group. Multiply charged species are not observed in MALDI. Intense ESI spectra can be obtained in negative ion mode and now multiply charged species are seen. Alkali exchange experiments show that in these small carrageenan anions one, but only one, alkali metal ion is bound in a bidentate coordination with two ionic sulfate groups. G2-type ab initio calculations on model ions HO(-) [M(+)] (-)OH (M = Li, Na, K, Cs), as well as arguments based on a simple Coulombic interaction model, show that the bidentate stabilization energy drops rapidly as the size of the alkali cation increases. Exchange of Na(+) with Li(+) leads to expulsion of the Na(+) ion generating, in ESI, intense multiply charged anions. An attempt is made to rationalize this behavior in terms of hydration effects.

Carrageenan↗
PubMed1993

Room temperature, low-field 13C-n.m.r. spectra of degraded carrageenans: Part III. Autohydrolysis of a lambda carrageenan and of its alkali-treated derivative.

Autohydrolysis of lambda and theta carrageenans produces degraded products which are useful for 13C-n.m.r. spectroscopy, with low-field equipment and at room temperature. Data obtained from these spectra are doubly valuable as they are used for the structural study of parent carrageenans and to investigate the reactions carried out during autohydrolysis.

Carbohydrate Sequence↗
PubMed2004

Modified carrageenan. 2. Hydrolyzed crosslinked kappa-carrageenan-g-PAAm as a novel smart superabsorbent hydrogel with low salt sensitivity.

A novel pH-responsive superabsorbing hydrogel based on K-carrageenan (kappaC) was prepared through polyacrylamide crosslinking grafting followed by alkaline hydrolysis. The hydrogel structure was confirmed using FT-IR spectroscopy. The hydrolysis conditions were systematically optimized to obtain a hydrogel with maximum swelling capacity. Thus, the reaction variables, including the hydrolysis time and temperature, concentration of sodium hydroxide, amount of hydrogel hydrolyzed and post-neutralization pH, were optimized. The swelling measurements of the hydrogels were conducted in 0.15 M aqueous solutions of LiCl, NaCl, KCI, CaCl2 and AlCl3. As observed for the hydrolyzed hydrogel (H-carragPAM), it was found that a 'charge screening' action of small cations and carboxylate anions affected the swelling in univalent salt solutions. In the case of the non-hydrolyzed hydrogel (carragPAM), however, a converse trend was observed. As a result, carragPAM and H-carragPAM superabsorbent hydrogels showed a maximum swelling of 45 and 135 g/g in LiCl and KCl solutions, respectively. Due to the high swelling capacity in salt solutions, the hydrogels may be referred to as anti-salt superabsrbents. The swelling of superabsorbing hydrogels was examined in buffer solutions with pH values ranging between 1 and 13. The H-carragPAM hydrogel exhibited a pH-responsie character so that a swelling-deswelling pulsatile behavior was recorded at pH 4 and 9. The swelling kinetics of H-carragPAM were preliminary investigated.

Absorption↗
PubMed1998

On the employment of lambda carrageenan in a matrix system. III. Optimization of a lambda carrageenan-HPMC hydrophilic matrix.

The lambda carrageenan/HPMC ratio in matrix tablets has been optimized in order to obtain pH-independent release profiles of chlorpheniramine maleate, a freely soluble drug. Release profiles in acidic (pH1.2) and neutral (pH 6.8) media were fitted according to the Weibull and the power law models. Model independent parameters(t50% and the percentage of drug released after 2 h) were also calculated. The Weibull parameters were found suitable to describe the dependence of the release profiles on matrix composition. Preparation and testing of the optimized formulation showed linear and pH-independent release profiles lasting about 24 h, in good accordance with the values predicted by the optimization procedure.

Carrageenan↗