Modulation of Host Resistance by Polymeric Substances from Baptisia tinctoria and Echinacea purpurea

Abstract

Roots of the medicinal plants Baptisia tinctoria and Echinacea purpurea contain polymers and glycoproteins such as arabinogalactan proteins with immunomodulating properties. From extracts of Baptisia tinctoria, four glycoproteins were isolated with molecular weights of 58kD, 31kD, 26kD and 14kD. In extracts from Echinacea purpurea, only one glycoprotein, with a molecular weight of 40kD, was identified but these extracts also contained arabinogalactans free of proteins. In addition, as determined by an enzyme immunoassay, these compounds were much more abundant in extracts from Baptisia tinctoria than in those from Echinacea purpurea. The purified polymeric fractions stimulated spleen cells from mice, and increased Il-1 production by mouse macrophages. In-vivo treatment of mice with polymeric fractions of Baptisia tinctoria increased the number of segmented granulocytes as well as the resistance of the animals to infection with Pseudomonas aeruginosa.