ANTISICKLING ACTIVITY OF TERMINALIA CATAPPA LEAVES HARVESTED AT DIFFERENT STAGES OF GROWTH

The aqueous and ethanolic leaf extracts of Terminalia catappa L. family Combretaceae, a fruit bearing tree, popular in folkloric medicine for the treatment of sickle cell anaemia disease were assessed for their in-vitro anti-sickling activities. Extracts were prepared from the reddish-brown freshly fallen leaves, reddish-brown leaves and green leaves of the plant by maceration in the solvents. Phytochemical examination of the extracts showed that cardiac glycosides are present in abundance in the reddish-brown freshly fallen leaves, moderate in the reddish-brown leaves and in trace amount in the green leaves. High concentration of saponin was however observed in the green leaves, while only present in trace amount in the reddish-brown leaves and absent in the reddish-brown freshly fallen leaves. Alkaloids were detected present in all the three samples of the leaves but anthraquinones and tannins were completely absent. Antisickling activities of the extracts obtained from leaves harvested at different stages of growth (green leaves, reddish-brown leaves, reddish-brown freshly fallen leaves) were evaluated using p- hydroxybenzoic acid, (5mg/ml) and normal saline as controls. The method employed involved the inhibition of sodium metabisulphite-induced sickling of HbSS red blood cells collected from confirmed non-crisis sickle cell patients. Both the aqueous and ethanolic leaf extracts of the reddish-brown freshly fallen leaf exhibited highest antisickling activity (78% inhibition at 180 min incubation and 77% inhibition at 90 min incubation respectively). KEY WORDS: Terminalia catappa; Combretaceae; fallen leaves; sickle cell anaemia; antisickling activity. Nigerian Journal of Natural Products and Medicine Vol.7 2003: 30-3