Evaluation of the Effects of Clerodendrum polycephalum Baker Leaf Extracts on Sickle Red Blood Cells

The mortality rate for people living with sickle cell disease is high and relatively a few patients among them reach adult life, even with a high standard of medical care. Clinical manifestations of the sickle cell disease are diverse and vary, falling into three major categories: anaemia, pain related issues and organ failure. Sickle cell crises or painful episodes may be caused by blood vessel occlusion, damaged organ, triggered by membrane deformation. Patients in West Africa, where sickle cell anaemia (SCA) is prevalent, have for ages been treated with natural products especially herbs as it is still the case in rural communities. The medicinal plant Clerodendrum polycephalum used for this study is used ethno medically in treating malaria and pains associated with sickle cell disease. The leaves were collected, oven dried and macerated in methanol for 72 h. The extract was dried and reconstituted in distilled water to give concentrations 0.25 mg/mL, 0.5 mg/mL, 1 mg/mL, 2 mg/mL and 4 mg/mL. The methanol extract was further fractionated into solvents of varying polarity viz: n-hexane, dichloromethane, ethyl acetate and water. All extracts and fractions were tested for their antisickling properties using the inhibitory and reversal models. Vanillic acid and p-hydroxybenzoic acid were used as the positive controls for the inhibitory and reversal assays respectively. An attempt was made to identify the different classes of compounds present in the extract by using thin layer chromatography technique.

The methanol extract of C. polycephalum gave 55.9% inhibitory and 65.63% reversal activities at 4 mg/mL. The antisickling activities were dose-dependent and purification significantly (p<0.05) enhanced the reversal activity which was indicated in the polar fractions. This study authenticated the use of C. polycephalum in the management of pains associated with sickle cell disorder.