Crude extracts and pure compounds evaluations

Bruxelles Woluwe

Plants used in traditional medicine in different countries are obtained through research collaborations (Marocco, Benin, Congo Democratic Republic, Rwanda, Madagascar, Mauritius in Africa, Vietnam in Asia, Peru, Bolivia and Brazil in South America). The first step is the selection on an ethnopharmacological basis and a literature survey. Different extracts are prepared and pharmacologically evaluated according to their traditional use(s). Several properties are analysed in collaboration with other teams who developed suitable pharmacological tests (LDRI, other UCL or Belgian partners): antimicrobial, immunostimulating, anti-angiogenic, anti-inflammatory, antihypertensive, anti-coagulant, antioxidant and antiplasmodial activities, as well as inhibition of A-Beta formation, while tests for antitrypanosomal, cytotoxic and antileishmanial properties are now developed in the lab.

Crude extracts are first evaluated by in vitro tests and their cytoxicity assessed on cancer and non-cancer cell lines.





The originality of our works is that we do not just realise screenings. The most promising extracts are also tested in vivo to assess their activity and eventual toxicity. The mode of administration is chosen according to the nature of the extract but most of them are given by oral route.
Several extracts possessing biological activities in vitro were identified (cfr publications).
The activities of the most interesting ones as well as purified compounds were also analysed in vivo. Results indicate that extracts of Croton zambesicus and Marrubium vulgare showed, in vivo, antihypertensive properties but some extracts of Croton zambesicus also showed toxicities. Extracts from i.e. Keetia leucantha and Acanthospermum hispidum as well as isolated triterpenic esters proved to have antimalarial activities on mice infected by Plasmodium berghei. Efficient extracts on mice infected with Trypanosoma brucei were also identified and their highest tolerated dose determined.





Our researches also led us to identify further in vivo toxic compounds from nutrient rich seeds of Pachyrhizus species, consumed in certain parts of Asia.
Our research on antimicrobial plants allowed us to identify some promosing plant extracts and natural compounds reducing the resistance of methicillin resistant Staphylococcus aureus (collaboration with F.Van Bambeke).