Ethnopharmacologically selected plants used to treat African trypanosomiasis studies on their in vitro activity and chemical composition
(2005)
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- Abstract
- African trypanosomiasis, most commonly known as "sleeping sickness" when it affects humans, is a vector-borne parasitic disease which is causing major health and economic problems in sub-Saharan Africa. The current chemotherapeutic options for human African trypanosomiasis are very limited and far from ideal (high toxicity, difficult and long administration, financial cost, increasing reports of treatment failures...) while this disease is fatal if left untreated. Therefore, there is an urgent need for new molecules that are safe, effective and cheap. Plants have always been an important source of new pharmacologically active molecules. Consequently we decided to undertake the study of plants traditionally used in Africa to treat African trypanosomiasis and investigate their antitrypanosomal activity as well as their chemical composition. Initially, we performed a screening of six plants chosen on an ethnopharmacological basis. This screening allowed us to focus our work on two plants in particular (Cassytha filiformis and Strychnos spinosa), which proved to be active on trypanosomes with a certain selectivity when considering their toxicity for mammalian cells. We showed that the alkaloid extract from Cassytha filiformis (Lauraceae) as well as some of the aporphine alkaloids isolated therefrom were active on African trypanosomes and interacted with DNA and topoisomerases. Additionally, we performed a bio-guided fractionation of the leaf dichloromethane extract from Strychnos spinosa (Loganiaceae). It allowed us to isolate for the first time in the leaves of this species several sterols and triterpenes, some of them possessing an interesting antitrypanosomal activity. We also established some structure-activity relationships for these molecules. Additionally, we showed the antitrypanosomal activity of terpenes present in the leaf essential oil of this plant. During this work, we proposed some purification procedures for several compounds (sterols and triterpenes) and developed analytical methods allowing their rapid identification in plant extracts (GC-MS, LC-MS).
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Hoet, S. (2005). Ethnopharmacologically selected plants used to treat African trypanosomiasis studies on their in vitro activity and chemical composition. https://hdl.handle.net/2078.5/110687