Phytochemical studies of medicinal plants from Malawi

Abstract

Medicinal plants from Malawi have been analyzed phytochemically and biologically largely through collaboration with the Universities of Lausanne, Switzerland; of Rome, Italy and the Technical University of Berlin, Germany. The selection of plants for investigation has been based on interviews with traditional healers of the Herbalists Association of Malawi under the Chairmanship of Mr. James Gangire Phiri. A large percentage of the plants selected by the traditional healers gave positive leads to the activity claimed from their medicinal uses. We also used random selection based on literature reviews and chematoxonomic relationships. The studies on these plants included collection, extraction, purification, in vitro activity-guided fractionation, isolation of active principles, derivatization and further in vitro bioassays. Included here are antitumoral, antifungal, antibacterial, molluscicidal, hypoglycemic, antifeedant and, to some extent, immunostimulant activities. Depending on the activity of the compounds, some of them could be used directly after further studies on toxicity, biodegradation and efficacy through standardization. This chapter covers some of the reports on phytochemistry of medicinal plants from Malawi, with emphasis on biologically active compounds. In order to clarify the organization of this chapter, the results have been separated into three main groups: compounds exhibiting molluscicidal activity, fungitoxic natural products and miscellaneous structures