THE PLANTS WATER-SOLUBLE PECTIN ISOLATED FROM GENUS SAUSSUREA DC. ENHANCE FUNCTIONAL ACTIVITY OF ANTIGEN-PRESENTING CELLS

Relevance. Pectins are macromolecules containing fragments of linear and branched polysaccharides. Their immuno-modulating properties, possible mechanisms of immunostimulating and anti-inflammatory action, depending on the structure, have been actively studied recently. Purpose of the study. Determination of the relationship between the composition of pectin substances (PS) isolated from plants of the genus Saus-surea (DC.) and the ability to activate antigen-presenting cells. Material and methods. PS was obtained by dialysis against water from a previously purified aerial part of the S. controversa DC. (SC), S. salicifolia L. (SS) and leaves with petiolesof the S. frolovii Ledeb. (SF). Protein was quantified by the Lowry method. The content of uronic acids was determined in the reaction of carbohydrate oxidation products with 3,5-dimethylphenol. Molecular weight characteristics – by high-performance exclusion chromatog-raphy. Monosaccharide composition – by gas chromatography after complete acid hydrolysis of PS. NO-stimulating properties of PS were studied in a model of mature murine peritoneal macrophages using the Grace reagent. To determine the endotoxin impurity, the antibiotic polymyxin B was used. Cell proliferation was studied in the MTT test. Results. The isolated PSs are arabinogalactouronans. The content of uronic acids is 94-96%. The major component of PV SS and SF is galactose, PS SC is arabinose. Minor residues are represented by rhamnose, xylose, mannose (except for Sc), and glucose (except for SC and SF). All samples have a protein impurity of 2,5-13%. Pectin substances SF, SC, and SS increase nitrite production by macrophages by 2-10 timesdepending on the concentra-tion of substances and plant species. PS SF and SC at all doses, and PS SS at 2 μg/ml did not affect cell proliferation. Pectin substances SS in high doses reduced it by 1,2 times. The NO-stimulating properties of PS SC and SF are due to the significant endotoxin impurity. PS SS have an insignificant content and have the greatest effect on the functional activity of macrophages. Conclusion. Pectin substances from plants of the genus Saussurea, containing in varying degrees a concomitant admixture of protein and endotoxin, exhibit NO-stimulating activity, which depends on the plant species and the structure of the macromolecule.