Isolation, partial characterisation and immunomodulating activities of polysaccharides from Vernonia kotschyana Sch. Bip. ex Walp

The roots from Vernonia kotschyana Sch. Bip. ex Walp. (Baccharoides adoensis var. kotschyana (Sch. Bip. ex Walp.) M.A. Isawumi, G.El-Ghazaly & B. Nordenstam) (Asteraceae) are used in Malian folk medicine for the treatment of gastritis, gastro duodenal ulcers, as an aid to ameliorate digestion and as a wound healing remedy. Since a common feature among these conditions is related to immune responses, immunomodulating activities of fractions isolated from both the 50 °C and the 100 °C water extracts from Vernonia kotschyana were investigated in this study. The active principles were identified as acidic polysaccharide fractions, containing pectic arabinogalactan type II structures, which showed both complement fixing ability and T-cell independent induction of B-cell proliferation in vitro. Some activity was also observed on macrophages. The present study may provide additional support for the popular use of this plant to improve intestinal health. [Copyright &y& Elsevier]