Gastric ulcers and wounds are major health problems in Mali, where 75% of the population depends on traditional medicines. This thesis focuses on two plants used for treating ulcers and wounds: Cola cordifolia and Vernonia kotschyana. Traditional plant medicines are normally prepared as a decoction, extracting water soluble components. Polysaccharides are highly soluble in hot water and will therefore also be present in the prepared medicines. The fact that polysaccharides often express immunomodulating activities make them likely to be parts of the claimed activities of a medicinal plant, especially when it comes to healing of gastric ulcers and wounds. Polysaccharides can be the working components of the plant medicines, alone or in synergies with water soluble low molecular weight substances like saponins, flavonoids, alkaloids and terpenes. In this thesis, a detailed study of polysaccharide structures was related to complement fixation, macrophage activation and anti-ulcer activity. As Helicobater pylori is often implicated in gastric ulcers, two simple rapid-diagnostic tests were evaluated for H. pylori diagnosis in Mali.