Abstract

Folk medicine reportedly uses Parquetina nigrescens L. (Asclepiadaceae) as a herbal remedy for the management of sickle cell anemia. This study was carried out to screen the leaves and stem of P. nigrescens for antisickling activity, erythrocyte membrane -stabilizing effects and any end organ toxicity. Percentage Reversal and Inhibition of Sickling parameters were analyzed on pre-sickled Hb^SS blood cell suspensions using sodium metabisulphite solution as inducer and 5 mg/ml parahydroxybenzoic acid and normal saline as positive and negative controls respectively. Effects of the plant extracts on the erythrocyte were assessed using osmotic fragility and the toxicity profile done via LD₅₀ and Sub-Acute toxicity studies on graded concentrations of extract. Results show that P. nigrescens has appreciable antisickling activity, has no toxic effect when administered at low concentrations and protects the integrity of the erythrocyte membrane as evidenced in the fragiliogram by the reduction in hemolysis of the Hb^ss cells.

Key words: Antisickling activity, membrane integrity, osmotic fragility,Parquetina nigrescens, sickle cell disease.