Chromatography fractions from the ethyl acetate fraction of Harungana madagascariensis Lam. Ex Poiret fruits (Hypericaceae) inhibited the growth of Mycobacterium tuberculosis

Abstract

The economic burden of drug resistant tuberculosis strain is enormous due to its being one of the leading cause of global mortality. New treatments that are faster, simpler and affordable are urgently needed. Thus this research aimed to validate that the ethyl acetate fraction from the Nigeria variety of Harungana madagascariensis contain secondary metabolites with anti-Mycobacterium tuberculosis activity. The fruit of H. madagascariensis was extracted with 70% aqueous ethanol by cold maceration. The crude aqueous ethanol extract was defatted with n-hexane by partitioning and the aqueous portion further partitioned with ethyl acetate to give ethyl acetate portion (EAP) used in this study. Fractionation of EAP was done using chromatographic techniques. Phytochemical screening of the fractions was done using standard methods. Anti- Mycobacterium tuberculosis screening was done using Lowestein Jensen(LJ) method (test fractions stock solution 1mg/ml diluted to a 0.01mg/ml in the LJ medium while isoniazid, dihydrostreptomycin, ethambutol and rifampicin at their reported minimum inhibition concentrations(MIC) were used as reference anti-TB drugs). Four (4) chromatography fractions (EAF1 –EAF4) were obtained. All fractions were found to contain phenolics with anthraquinone present in EAF2 and EAF3. Fractions EAF3 and EAF4 inhibited the growth of the Mycobacteria tuberculosis. This preliminary screening validates the use of H. madagascariensis in traditional medicine and as a potential source of natural products with anti-Mycobacterium tuberculosis activity as well as a good source of anthraquinone.