Non-Hemolytic Effect and Antiplasmodial Activity of Cassia sieberiana Root Bark on Plasmodium falciparum Isolates

Abstract

Introduction: Malaria remains endemic in Côte d’Ivoire, and Plasmodium falciparum is the predominant species associated with malaria attacks. Aims: This study evaluated the phytochemical composition, haemolytic effect, and antiplasmodial activity of an aqueous extract of Cassia sieberiana root bark against P. falciparum isolates. Methods: The aqueous extract was prepared by decoction, and selected secondary metabolites were identified using colorimetric methods. Haemolytic activity was assessed using uninfected O+ red blood cells, with phosphate-buffered saline and Triton X-100 serving as the negative and positive controls, respectively. Antiplasmodial activity was evaluated against 30 P. falciparum isolates, with quinine used as the reference antimalarial molecule. Results: The extract contained alkaloids, saponins, polyphenols, flavonoids, and catechic tannins, whereas gallic tannins, sterols and terpenes, and quinones were not detected. The measured haemolysis percentage was 0.619%. Antiplasmodial activity increased across the tested concentrations. At the highest tested concentration, the minimum and maximum IC50 values were 1.11 ± 0.00 μg/mL and 4.33 ± 0.00 μg/mL, respectively. Conclusion: Under the reported in vitro conditions, the aqueous root-bark extract showed low haemolytic activity and inhibited P. falciparum isolates. These findings provide preliminary evidence that water-extractable constituents of C. sieberiana root bark may contribute to the observed antiplasmodial activity. Further standardised studies are required to confirm the dose-response relationship, cytotoxicity, selectivity, active constituents, and possible mechanisms.