Immunomodulatory effects of arabinogalactan-proteins from Baptisia and Echinacea.

The influences of different arabinogalactan-proteins (AGPs) on proliferation and IgM-production of mouse lymphocytes as well as nitrite- and IL6-production of mouse macrophages were investigated in vitro. AGPs have been isolated and purified from roots of Baptisia tinctoria and Echinacea pallida and suspension culture of Echinacea purpurea. Comparing the AGPs, there are differences with regard to fine structure as well as to activities. AGPs from roots of B. tinctoria and E. pallida show high activity in all test systems. AGP from cell culture of E. purpurea shows no influence on proliferation of mouse lymphocytes, only weak influence on the IgM-production of mouse lymphocytes and weak stimulation of nitrite- and IL6-production in alveolar mouse macrophage culture.

Binding studies of an arabinogalactan-protein from Echinacea purpurea to leucocytes.

Flow cytometric investigations show binding of an isolated arabinogalactan-protein (AGP) from pressed juice of the aerial parts of Echinacea purpurea to the cell surface of human leucocytes. AGP demonstrates binding to lymphocytes, monocytes and granulocytes of different donors (n=8). Competition assays with two antibodies, directed against CD4 and CD8, revealed no interaction of AGP with these receptors, leading to the conclusion that binding of AGP to leucocytes is mediated via other structures.

Characterization of an arabinogalactan-protein isolated from pressed juice of Echinacea purpurea by precipitation with the beta-glucosyl Yariv reagent.

An arabinogalactan-protein (AGP) from pressed juice of Echinacea purpurea herb was isolated from a high molecular weight fraction by precipitation with the beta-glucosyl Yariv reagent, followed by gel-permeation chromatography. It revealed characteristic features of other AGPs: i.e., a high amount of polysaccharide (83%) with a ratio of galactose to arabinose of 1.8:1, some uronic acids (4-5%), and a low protein content (7%) with high levels of serine, alanine and hydroxyproline. The molecular weight was estimated to be 1.2 x 10(6) Da. Linkage and 13C NMR analyses showed that the AGP is composed of a highly branched core polysaccharide of 3-, 6-, and 3,6-linked Galp residues with terminal Araf, GlcAp and terminal units of Araf-(1-->5)-Araf-(1-->. Partial acid hydrolysis resulted in loss of Araf residues at the periphery of the molecule. Complete loss of reactivity toward the beta-glucosyl Yariv antigen was then noticed.

The inhibiting effects of components of stinging nettle roots on experimentally induced prostatic hyperplasia in mice.

Direct implanting of fetal urogenital sinus (UGS) tissue into the ventral prostate gland of adult mice led to a 4-fold weight increase of the manipulated prostatic lobe. The induced growth could be reduced by the polysaccharide fraction (POLY-M) of the 20% methanolic extract of stinging nettle roots by 33.8%.

High molecular weight acidic polysaccharides from Malva sylvestris and Alcea rosea.

Leaves and flowers of Malva sylvestris and Alcea rosea (Malvaceae) were compared by determination of the swelling index as well as the content and viscosity of their mucilages. The investigations showed mucilage from flowers of Alcea to be superior to mucilages from leaves or flowers from Malva. High molecular weight acidic polysaccharides (HMWAPs) were isolated from the mucilages of leaves and flowers of both species. The molecular weight of all HMWAPs was in a range of 1.3 to 1.6 x 10(6) D. HMWAP-content in mucilage from flowers of Alcea was highest compared to content in mucilages from leaves or flowers from Malva. HMWAPs were found to be composed mainly of glucuronic acid, galacturonic acid, rhamnose and galactose. Methylation analysis of the carboxyl-reduced and deuterium labeled sugar derivatives of HMWAPs from flowers of Malva sylvestris ssp. mauritiana and Alcea rosea enabled elucidation of the principal structural features of both polysaccharides.

Antitumor activity of cell wall beta-1,3/1,6-glucans from Phytophthora species.

From the cell walls of various Phytophthora species (Oomycetes) different water-soluble beta-1,3/1,6-glucans were isolated and characterized. The glucans with relative molecular masses between 13 and 50 kd exhibited varying degrees of branching in the beta-1,3-linked glucan backbone ranging from 14 to 50%. The dose-dependent antitumor activity of the glucans against allogeneic sarcoma-180 was investigated. It could be demonstrated that beta-1,3/1,6-glucans with relative molecular masses below 50 kd can exhibit a prominent antitumor activity (inhibition rate up to 99%), being comparable to that of the high relative molecular mass (450 kd) beta-1,3/1,6-glucans. Biological activity of the glucans could be shown to be correlated with a low degree of branching. The most potent glucan with a degree of branching of 14% also was active against the syngeneic DBA/2-MC.SC-1 fibrosarcoma (inhibition rate up to 90%) and in combination with a suboptimum dose of diethylstilbestrol against Nobel-Nb prostate carcinoma (inhibition rate up to 90%).