Structures, and immunomodulating and anti-ulcer activities of polysaccharides from Malian medicinal plants
Appears in the following Collection
- Farmasøytisk institutt 
AbstractThe main purpose of this thesis was to evaluate the potential of pectins from the Malian medicinal tree Cola cordifolia used in the treatment of gastric ulcer and wounds. This thesis is a small contribution to the ultimate goal of providing efficient none-toxic and inexpensive medicines for the Malian population. The Department of Traditional Medicine, our collaborating partner in Bamako, wants to promote the use of renewable plant parts to guarantee a sustainable supply of medicinal plants. The structures and biological activities of the bark and leaf pectins were therefore compared in order to make recommendation on plant part substitution as debarking can damage or even kill the tree. We found that the pectins from the bark and leaves are structurally related. However, the leaf pectins are more polydisperse and heterogeneous compared to the pectins found in bark. Pectins from the bark were generally more active in the complement fixation test and the macrophage assay. Comparing the 50°C water extracts from bark and leaf in an experimental anti-ulcer model showed comparable and dose dependent inhibition of ulcer formation. However, a clinical trial is needed to evaluate the efficacy of the plant parts. Powdered roots of Vernonia kotschyana are highly valued as the improved traditional medicine “Gastrosedal”. The anti-ulcer activity of the medicine has previously been attributed to the presence of saponins. In this thesis, the anti-ulcer potential of 50°C and 100°C water extracts depleted of saponins, but high in inulin, 98% and 83% respectively, were evaluated in an experimental mouse model. The tested dose corresponded to the recommended daily intake of “Gastrosedal” and this dose showed a good inhibition of ulcer formation. We therefore concluded that inulin can also be responsible important for the anti-ulcer activity of “Gastrosedal”. In Mali, gastric ailments are rather common and contribute highly to morbidity in the country. In a previous study, Helicobacter pylori was found to be present in 95% of Malian patients with gastric ulcer. For future investigations and clinical trials, it was of interest to find a reliable and simple method for H. pylori detection. One stool and one serological based immunochromatographic method were tested, and the results showed that the sensitivity of these tests is too low in the Malian population. The low sensitivity was probably due to strain variability, in addition to high use of anti-malaria drugs, which might eradicate or lower the bio-burden of H. pylori.
List of papers
Papers 1-4 are removed due to publisher restrictions.
Paper I Ingvild Austarheim, Bjørn E. Christensen, Ida K. Hegna, Bent O. Petersen, Jens O. Duus, Ragnar Bye, Terje E. Michaelsen, Drissa Diallo, Marit Inngjerdingen & Berit S. Paulsen. Chemical and biological characterization of pectin-like polysaccharides from the bark of the Malian medicinal tree Cola cordifolia. Carbohydrate Polymers 89 (2012), 259–268. doi:10.1016/j.carbpol.2012.03.005
Paper II Ingvild Austarheim, Bjørn E. Christensen, Christian Thöle, Drissa Diallo, Marit Inngjerdingen & Berit S. Paulsen. Chemical and biological characterizations of pectins from Cola cordifolia leaves. Manuscript
Paper III Ingvild Austarheim, Haidara Mahamane, Rokia Sanogo, Adiaratou Togola, Mehdi Khaledabadi, Anne C. Vestrheim, Kari T. Inngjerdingen, Terje E. Michaelsen, Drissa Diallo & Berit S. Paulsen. Anti-ulcer polysaccharides from Cola cordifolia bark and leaves. Journal of Ethnopharmacology 143 (2012), 221–227. doi:10.1016/j.jep.2012.06.027
Paper IV Ingvild Austarheim, Cecilie S. Nergard, Rokia Sanogo, Drissa Diallo & Berit S. Paulsen. Inulin-rich fractions from Vernonia kotschyana roots have anti-ulcer activity Journal of Ethnopharmacology 144 (2012), 82–85.doi:10.1016/j.jep.2012.08.031
Paper V Ingvild Austarheim, Kari T. Inngjerdingen, Adiaratou Togola, Drissa Diallo & Berit S. Paulsen. Chromatographic immunoassays for H. pylori detection – are they reliable enough in Mali (West Africa)? Accepted for publication in PAN African Medical Journal (2013) (Ingvild Austarheim, Kari Tvete Inngjerdingen, Adiaratou Togola, Chiaka Diakité, Drissa Diallo, Berit Smestad Paulsen. Chromatographic immunoassays for Helicobacter pylori detection – are they reliable in Mali, West Africa? The Pan African Medical Journal. 2013;14:72) doi:10.11604/pamj.2013.14.72.2131