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Ethnopharmacological relevance Water decoctions of the root bark, stem bark and leaves of Terminalia macroptera are used by traditional healers in Mali to cure a wide range of illnesses, such as wounds, hepatitis, malaria, fever, cough and diarrhea as well as tuberculosis. Plant polysaccharides isolated from crude water extracts have previously shown effects related to the immune system. The aims of this study are comparing the properties of the polysaccharides among different plant parts, as well as relationship between chemical characteristics and complement fixation activities when the plant material has been extracted as the traditional healers do, with boiling water directly. Materials and methods Root bark, stem bark and leaves of Terminalia macroptera were extracted by boiling water, and five purified polysaccharide fractions were obtained by anion exchange chromatography and gel filtration. Chemical compositions were determined by GC of the TMS derivatives of the methyl-glycosides and the linkage determined after permethylation and GC-MS of the derived partly methylated alditol acetates. The bioactivity was determined by the complement fixation assay of the crude extracts and purified fractions. Results The acidic fraction TRBD-I-I isolated from the root bark was the most active of the fractions isolated. Structural studies showed that all purified fractions are of pectic nature, containing rhamnogalacturonan type I backbone. Arabinogalactan type II side chains were present in all fractions except TRBD-I-II. The observed differences in complement fixation activities among the five purified polysaccharide fractions are probably due to differences in monosaccharide compositions, linkage types and molecular sizes. Conclusion The crude extracts from root bark and stem bark have similar total activities, both higher than those from leaves. The root bark, leaves and stem bark are all good sources for fractions containing bioactive polysaccharides. But due to sustainability, it is prefer to use leaves rather than the other two plant parts, and then the dosage by weight must be higher when using leaves. [ABSTRACT FROM AUTHOR]

Abstract: Extracts of five medicinal plants: Boscia angustifolia, Cissus quadrangularis, Securidaca longipedunculata, Stylosanthes erecta and Trichilia emetica, used traditionally in Malian traditional medicine were screened for in vitro antiplasmodial activity and GABAA–benzodiazepine receptor binding activity. Four extracts showed significant antiplasmodial activities, with the dichloromethane extract of leaf of Securidaca longipedunculata being the most active (IC50 of 7μg/ml [95% CI: 5–9]). The dichloromethane extract of leaf of Trichilia emetica, in addition to its antiplasmodial activity (IC50: 12μg/ml [95% CI: 12–14]), exhibited a good binding activity to the GABAA–benzodiazepine receptor, while water and methanol extracts of the same plant did not show any activity. A strong GABAA-receptor complex binding activity was observed in the methanol extract of aerial part of Stylosanthes erecta. The results in this study justify some of the traditional indications of the plants investigated and may thus be candidates for Improved Traditional Medicines in Mali. [Copyright &y& Elsevier]

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]