Phytochemical and Anti-sickling Activities of Terminalia catappa Linn.

Abstract

An ethnobotanical survey revealed that the dried fallen leaves of Terminalia catappa Linn. are used locally in various parts of Nigeria for the management of sickle cell anaemia. This research investigated if Terminalia catappa leaf interferes with the basic mechanism of erythrocyte sickling. Powdered dried fallen leaves of Terminalia catappa was extracted with 90% methanol by maceration. Bioactivity of the extract was studied by investigating its effect on inhibition of erythrocyte sickling
(membrane effect). Bioactivity guided fractionation showed that the highest antisickling activity in the erythrocyte sickling model resided in its triterpenoids components (fraction F3, K = 0.0037 min-1). This fraction
drastically reduced the rate of erythrocyte sickling and is very significantly more active than the control (P<0.001). Bioactivity guided separation of the extract was carried out on flash chromatography using RP18 and Silica gel stationary phases respectively. Final separation was done by HPLC on Cyanosilica column. Structural elucidation of bioactive compounds was carried out by Nuclear magnetic resonance (NMR) and mass spectrometry (MS). The most active compounds were established to be two triterpenic acids (1) 2á, 3â ,24 –Trihydroxyurs –12 – en – 28 – oic acid and (2)
2á, 3â, 24 – trihydroxy – 12, 20 (30) – ursandien – 28 – oic acid. This work therefore shows that there is a scientific basis for the application of this extract in the management of sickle cell anaemia in traditional medicine.