The Influence of Water-Soluble Polysaccharides of Crataegus sanguinea Pall. on Nitric Oxide Production by Macrophages.

The in vitro addition of water-soluble polysaccharides isolated from the leaves of Crataegus sanguinea Pall. to culture of mouse peritoneal macrophages induced classical activation of antigen-presenting cells by increasing NO synthase activity and reducing arginase expression.

Study of Immunotropic Properties of Water-Soluble Polysaccharides Isolated from Conium maculatum Grass.

Addition of water-soluble polysaccharides isolated from Conium maculatum L. to the mouse peritoneal macrophage culture induces classical activation of antigen-presenting cells due to an increase in NO synthase activity and a decrease in arginase expression.

Effects of Humic Acids Isolated from Peat of Various Origin on in Vitro Production of Nitric Oxide: a Screening Study.

A screening study of biological activity of native humic acids isolated from peat was performed; several physical and chemical parameters of their structures were studied by UV- and infrared spectroscopy. Spectroscopy yielded similar shape of light absorption curves of humic acids of different origin, which can reflect similarity of general structural principles of these substances. Alkaline humic acids have more developed system of polyconjugation, while molecular structures of pyrophosphate humic acids were characterized by higher aromaticity and condensation indexes. Biological activity of the studied humic acids was assessed by NO-stimulating capacity during their culturing with murine peritoneal macrophages in a wide concentration range. It was shown that due to dose-dependent enhancement of NO production humic acids can change the functional state of macrophages towards development of pro-inflammatory properties. These changes were associated with high activity of humic acids isolated by pyrophosphate extraction, which allows considering effects of isolation method on biological activity.

Immunotropic Properties of Immobilized Interferon-α2b.

Course treatment with IFN-α2b immobilized on polyethylene glycol stimulates phagocytic activity of peritoneal macrophages and neutrophils, enhances humoral immune response in CBA/CaLac mice, stimulates IL-4 synthesis, and suppresses IFN-γ production by mitogenstimulated splenocytes from experimental animals.

Effects of Water-Soluble Polysaccharides with Different Chemical Structure, Isolated from Acorus calamus L. and Trifolium pratense L., on Nitric Oxide Production: A Screening Study.

Screening study of the effects of sweet flag (Acorus calamus L.) rhizome and clover (Trifolium pratense L.) aerial part on the production of NO by mouse macrophages was carried out. The polysaccharides were separated by ion exchange chromatography into fractions differing by monomeric composition and ramification type and were used in concentrations of 20, 40, and 100 µg/ml. Four fractions of Acorus calamus L. (PSF-101, PSF-102, PSF-103, and PSF-105), used in different concentrations, moderately stimulated nitrite production by macrophages. Three of five Trifolium pratense L. polysaccharides (PS62-3, PS62-4, and PS62-5) exhibited a significant specific effect on NO production. Rhamnogalactouronans from clover PS63-3 in all concentrations and from PS62-5 in a concentration of 100 µg/ml exhibited the highest activity, comparable to the NO-stimulatory activity of the reference LPS, while polysaccharide PS62-3 in a concentration of 40 µg/ml exhibited even higher activity.

[Effect of plant polysaccharides on TH1-dependent immune response: screening investigation].

We have studied the influence of water-soluble polysaccharides isolated from Tussilago farfara L. leaves, Betula verrucosa Ehrh. leaves, Calendula officinalis L. flowers, Acorus calamus rhizomes, Inula helenium L. rhizomes, overground part of Trifolium pretense L., and overground part ofArtemisia absinthium L., on Thl immune response induced by sheep red blood cells and on NO production by murine peritoneal macrophages in vitro. All the investigated polysaccharides have stimulated a Th1 response. Polysaccharides isolated from Betula verrucosa leaves did not influence NO synthesis, while polysaccharides of Tussilago farfara leaves and Acorus calamus rhizomes stimulated NO synthase of murine macrophages on a level comparable with that of lipopolysaccharides (LPS). Polysaccharides from Inula helenium rhizomes, Calendula officinalis flowers, and overground parts of Trifolium pretense and Artemisia absinthium also stimulated NO production, but to a lower extent in comparison to LPS.

Water-soluble polysaccharide obtained from Acorus calamus L. classically activates macrophages and stimulates Th1 response.

A pectic polysaccharide was isolated from the rhizomes of Acorus calamus L. The main component of its carbohydrate chain was represented by residues of D-galacturonic acid (>85%). In addition, this polysaccharide contained residues of galactose, arabinose, xylose and rhamnose (<10%). Structural analysis of pectic polysaccharide from A.calamus L. with NMR spectroscopy indicated that it contains the regions of a linear 1,4-alpha-D-galactopyranosyluronan, which represents a major component of the macromolecule. A considerable amount of galacturonic acid residues was not methoxylated. We demonstrate here that the pectic polysaccharide from A. calamus L. in low concentrations was able to stimulate in vitro IL-12 and nitric oxide production by murine macrophages. It also induced TNF-alpha secretion by human peripheral blood mononuclear cells, reduced arginase activity but did not affect IL-10 secretion by murine macrophages or human peripheral blood mononuclear cells. The IL-12 and NO-stimulating effects on murine macrophages were similar to that of LPS. In addition, the polysaccharide promoted in vivo Th1 immune response in mice which were immunized with sheep red blood cells (DTH and quantity of plaque-forming cells) and down regulated serum level of IgG1 and IgE during Th2-depend immune response induced by ovalbumin. The PS increased Th1-induced edema and suppressed Th2-induced paw swelling in adoptive systems. Our results suggest that the pectic polysaccharide from A. calamus L. represents a promising immunomodulating agent that stimulates M1-polarized macrophages and promotes Th1-oriented adaptive immune response. We propose that this polysaccharide could be potentially applied for treatment of infectious, oncological diseases or for immunoglobulin-E-mediated disorders.