Le mardi 12 mai 2026, Monsieur Methodius Shinyuy LAHNGONG, titulaire d'un Master of science in biochemistry (Université de Buea - Cameroun) et d'un Certificat de formation à la recherche en sciences biomédicales et pharmaceutiques, présentera l'examen en vue de l'obtention du grade de Doctorat en sciences biomédicales et pharmaceutiques, sous la direction de Monsieur Michel FREDERICH et de Madame Gisèle ETAME LOE (Université de Douala, Cameroun).

Cette épreuve consistera en la défense publique d'une thèse intitulée : "Unraveling the Potential of Artemisia afra, Artemisia annua and Erigeron bonariensis as Culturally Sound Alternative Therapeutic Approaches Against Malaria: Efficacy, Safety and Mode of Action". 

Le jury sera composé de :

Roland MARINI DJANG'EING'A (Président), Allison LEDOUX (Secrétaire), Kris DEMEYER (VUB), Romain DUVAL (Univ. Paris Cité), Gisèle ETAME LOE (Univ. Douala), Michel FREDERICH, Stephen GHOGOMU (Univ. Buea).

Résumé de la thèse

Antimalarial drug resistance and limited access to modern therapies have stimulated renewed use of Artemisia annua and Artemisia afra and other medicinal plants as traditional remedies against malaria. However, their adoption is hampered by batch-to-batch variability, seasonal and geographical influences, post-harvest handling, authentication issues, and controversy over the presence and role of artemisinin, especially in A. afra. This project aimed to standardize, validate, and assess the safety of galenic formulations of Artemisia spp. as culturally appropriate antimalarial options for high-transmission settings.

We characterized phytochemical diversity in A. annua and A. afra collected across seasons and regions in Cameroon and evaluated post-harvest practices using HPTLC, UPLC and GC. Antiplasmodial and gametocytocidal compounds from A. afra were isolated by bioassay-guided fractionation, and an A. afra-based formulation was developed and tested in vitro, in vivo, and for sensory acceptance and toxicity. Phenolic profiles, artemisinin content and parasite metabolic responses were compared by HPLC and HPLC-MS metabolomics.

Activity and composition depended on season, origin and drying method; sun-drying yielded optimal terpene and polyphenol fingerprints. A. annua contained higher artemisinin and showed artemisinin-like metabolic signatures, whereas A. afra contained only trace artemisinin yet induced distinct parasite responses and retained dual-stage antiplasmodial activity, supporting its development as a culturally grounded antimalarial.