Anti-trypanosomal evaluation of Ximenia americana root bark and chromatographic-mass spectrometric profile

Medicinal plants are the richest bio-resource of drugs for traditional systems of medicine, modern medicines, food supplements, pharmaceutical intermediates and chemical entities for synthetic drugs. Human African Trypanosomiasis (HAT) is a challenging and deadly disease due to its complex epidemiology and clinical presentations.  This study was conducted to investigate anti-trypanosomal action of Ximenia americana root bark on Trypanosoma brucei brucei using various solvent extracts and to develop thin layer (TLC-MS) and liquid chromatography-mass spectrometric (LC-MS) profiles of the plant.  Soxhlet extraction was used to obtain acetone, 70% ethanol total extracts in addition to n-hexane, dichloromethane, ethyl acetate and methanol fractions by sequential extraction. The inhibitory activity of the various extracts was compared by testing against T. b. brucei using isometamidium chloride as standard drug. The most active extract was separated by solid-phase extraction (C18 stationary phase) to obtain fractions which were profiled by TLC-MS (+ESI) and LC-MS. It was observed that anti-trypanosomal activity of acetone (16.83% yield) and 70% ethanol (18.23% yield) were comparable. However, methanol extract exhibited the highest activity with 99.18%, 97.5% and 87.50% inhibition at 3 h incubation (room temperature) using 1000 µg, 500 µg and 250 µg concentrations respectively. The activities at 1000 µg for methanol extract and isometamidium chloride were comparable with 95% CI [-1.10, 1.77]. TLC-MS and LC-MS analyses suggested gallic acid, 2,3,4,5-tetrahydroxybenzoic acid, 2ʹ,5-dimethoxyflavone, quercetin, dihydroquercetin and sesquiterpene when compared with literature database. This study presents data that could be useful in standardisation and preparation of alternative medicine in the treatment of African trypanosomiasis.