In vitro antisickling activity of a rearranged limonoid isolated from Khaya senegalensis

We previously observed that aqueous extracts of the stem bark and leaves of Khaya senegalensis exhibited a strong antisickling activity. These results prompted us to find out the constituent(s) responsible for these propertie s using an in vitro bio-guided fractionation. The bioassay was based on sic kle cells countings, before and after deoxygenation, in blood samples taken from patients with severe sickle cell anemia and pre-incubated with the dr ugs to be tested. The main active constituent was identified as a rearrange d limonoid whose structure was recently elucidated. In comparison with pent oxifylline used as standard, the in vitro antisickling activity of this lim onoid was much higher at any concentrations and incubation conditions. In a ddition, it did not alter significantly the corpuscular indices.