Anthocyanin crude extracts and fractions of Annona senegalensis leaves were screened for their antisickling properties using a validated in vitro bioassay model of sickle cell anaemia. Preparative thin layer chromatography of acetylated anthocyanin crude extracts carried out with chloroform as solvent provided two active fractions named Ac 1 and Ac 2 . Fraction Ac 2 was quantitatively isolated and submitted to physicochemical investigations. Thermo-degradation kinetics of the above fraction Ac 2 at 80 °C and 100 °C revealed first order reaction with the rate constants k (s -1 ) of 8.10 10 -4 and 11.0 10 -4 , respectively. Anthocyanin crude extracts and the separated fractions showed in vitro antisickling activity. This activity justifies the use of this plant by congolese traditional healers; thus anthocyanins could be the major active principles. However, these natural pigments are unstable towards UV-vis light irradiations and heat. The conservation of this plant should then be performed in the absence of heat and/or light.

; trois plantes utilisées en médicine traditionnelle contre la drépanocytose dans la ville de Kisangani (RD Congo), a été testée en utilisant le test d'Emmel. Les résultats obtenus ont montré une activité antifalcémiante importante in vitro pour les trois plantes. Cette activité serait due aux anthocyanes. Les concentrations minimales de normalisation des drépanocytes obtenus sont de l'ordre de 8µg/ml pour les anthocyanes de ces trois plantes. Les spectres des anthocyanes ont montré une sensibilité à lumière UV et à la chaleur indiquant que ces pigments sont instables vis-à-vis de ces deux paramètres.