ABSTRACT
Alafia barteri Oliv. (Apocynaceae) leaves and stems are used in ethnomedicine in South Western Nigeria for the management of sickle cell disease (SCD).
The in vitro anti-sickling activities of crude ethanolic extracts (CEE) and fractions of Alafia barteri powdered leaves and stems were evaluated using Vanillin and Phosphate Buffered Saline as positive and negative controls respectively.
The methods involved the inhibition and reversal of sodium metabisulphite induced sickling of HbSS red blood cells, obtained from confirmed non-crisis sickle cell patients.
The anti-sickling assay showed that the CEE of A. barteri leaves and its fractions (Petroleum ether and Ethyl acetate fraction) have significant inhibitory activity (p < 0.05) with percentage inhibition of 88.8, 67.3 and 53.1% respectively; CEE of A. barteri leaves and its fractions, (Ethyl acetate and Chloroform fractions) have significant reversal activity at 4 mg/ml with % reversal of 84.6, 90.2 and 86.2% respectively; while the CEE of A. barteri stems and its fractions, (Chloroform and Ethyl acetate fractions) have significant reversal activity (p < 0.05) at 4 mg / mL with percentage reversal of 59.3, 77.8 and 89.2% respectively but little inhibitory activity. Phytochemical screening of the powdered leaves and stems samples revealed the presence of alkaloids, saponins, tannins, and glycosides; with flavonoids present in leaf but absent in the stem. Further purification of the leaf extract ethyl acetate fraction using preparative thin layer chromatography (PTLC) and ultraviolet analysis revealed a major spot having absorbance of 0.265 at 404 nm wavelength, indicating a conjugated polyphenolic which might be responsible for the anti-sickling activity of the leaf.
The study has provided scientific validation for the traditional use of Alafia barteri leaf extract in the management of sickle cell anaemia.
Keywords: Anti-sickling activity, Alafia barteri leaves and stems, Phytochemical screening