In vitro anti-sickling effect of crude and partially purified fractions of methanolic extract of Steculia setigera leaf on human sickled red blood cells

Abstract

Sickle cell anaemia is a very important genetic disease affecting populace of the sub Saharan Africa. There is a strong need for discovery of cheap and readily available remedies for management of this disease. This research work assesses the ability of the crude methanolic extract, ethylacetate, n-hexane, butanol, and aqueous fractions of Sterculia setigera to reverse sickled human red blood cells in vitro after inducing hypoxia in erythrocytes using sodium metabisulphite. Generally, the results showed that anti-sickling activity was both concentration- and time-dependent, except for some concentrations and time intervals where the percentage of unsickled erythrocytes were abnormally higher or lower than expected. These exceptions were reflected in crude methanolic extract at 0.3 mg/ml, n-hexane fraction at 0.1 mg/ml, ethylacetate fraction at 0.2 mg/ml, butanol fraction at 0.3 mg/ml, aqueous fraction at 0.3 mg/ml with percentage unsickled erythrocytes of 29.68±1.62 %, 15.39±2.81 %, 13.01±1.62 %, 21.73±1.4 %, and 8.68±1.83 %, respectively. At the lowest concentration of 0.1mg/ml, n-hexane fraction showed the highest number of percentage unsickled erythrocytes of 76.04±1.48 %. However, at 0.3 mg/ml, ethylacetate fraction seems to have the highest anti-sickling activity of 86.01±1.69 %. Qualitative phytochemical screening revealed the presence of important phytochemicals such as alkaloids, flavonoids, steroids, tannins, saponins and cardiac glycosides. However, anthraquinones were consistently absent in the extract and all the fractions. These results goes to show that S. Setigera leaf extract possess anti-sickling properties and hence validates the usefulness of this plant in the management of sickle cell anaemia by traditional healers.

Keywords: S. setigera, Sickle cell anaemia, Erythrocyte, phytochemical screening, Antisickling effect