ABSTRACT
Aim: To investigate the antisickling potentials of two Calliandra species namely C. portoricensis (Jacq) Benth and C. haematocephala Hassk in vitro. Study Design: Evaluation of antisickling activities of medicinal plants on human sickled red blood cells in vitro. Place and Duration of Study: Research Laboratory of Drug Research and Production Unit, Faculty of Pharmacy Obafemi Awolowo University, Ile Ife, Nigeria. September 2010 to November, 2011. Methodology: After obtaining ethical clearance, fresh blood samples (5ml) each were collected from confirmed sickle cell anaemia patients who were in a steady state and were attending the routine clinic. Water and 70% ethanol were used separately for the extraction of the leaves and roots of the two plants. The extracts were assessed using the inhibitory and reversal methods in vitro. Results: It was observed that there was linear increase in inhibitory and reversal activities of the ethanolic and aqueous extracts of the parts used as the concentration increased. The ethanolic root extract of C. portoricensis exhibited the highest activity for inhibitory (90.19%) and reversal activities (92.63%) both at 4mg/ml. Conclusion: Calliandra species possessed antisickling properties in vitro with C. portoricensis being the more active plant.