Anti-Sickle Cell Anemia and Bacterial Inhibitory Effects of <i>Uvariodendron molundense</i> (Diels) R.E.Fr. (Annonaceae) from Ubangi River Basin, DR Congo

The present study was carried out with the aim of evaluating the chemical composition and bioactivity of Uvariodendron molundense against Sickle cell disease and associated pathogenic bacteria agents. The antisickling and antibacterial activities were assessed using Emmel and micro-dilution methods respectively. The results revealed that the leaves and stem bark of U. molundense contains various secondary metabolites such as total phenols, flavonoids, anthocyanins, tannins, quinones, saponins, alkaloids, steroids, terpenoids and leuco-anthocyanins. The n-hexane (non-polar solvent) extract displayed poor yield (0.66) than the extracts obtained in the polar solvents which have a high yield (Methanol: 1.68, Ethanol: 1.46 and Ethyl acetate: 1.40). These results indicate that the abundant secondary metabolites/compounds in this plant species are those which pass easily through the polar solvents (methanol, ethanol and ethyl acetate). This is the case of phytomarkers like flavonoids and tannins (which are most concentrated in methanol) and anthocyanins which are concentrated in ethyl acetate. The extraction yield of organic/triterpenoic acids (betulinic acid rich extract) was 1.70%. All tested extracts displayed antisickling activity. At 100 μg/mL, the rates of normalization were 89% for organic extract (ED50 = 0.391 μg/ml) and 82% for anthocyanins extract (ED50 = 0.659 μg/mL). The antibacterial activity of tested extracts was very good toward Staphyloccocus areus (CMI ≤ 31.25 μg/mL) while, for Escherichia coli, only the organic extract exhibit interesting activity (CMI = 31.25 μg/mL). This study validates for the first time the in vitro antisickling activity of U. molundense. The bioactivity profiles of organic acids extract from the studied plant material indicate that they constitute promising fraction to be further investigated phytochemically for the discovery of new lead compounds for pharmaceutical application.