Antimycobacterial, Antibacterial and Antifungal Activities of the Methanolic Extract and Compounds from Garcinia Polyantha

Summary The crude methanolic extract from the stem bark of Garcinia polyantha (GPB), 5hydroxyflavone (1), 1,5-dihydroxyxanthone (2), Bangangxanthone A (3), 1,3,5trihydroxyxanthone (4) and 1,3,6,7-tretrahydroxyxanthone (5) isolated from this extract, were tested for their antimycobacterial activity against a non pathogenic Mycobacterium smegmatis, and on Mycobacterium tuberculosis using the micro-dilution and radiometric BACTEC respiratory technique respectively. The antibacterial activity against Gram-positive and negative bacteria and the antifungal activity of the above samples were also investigated. The results showed that the crude extract as well as some of the isolated compounds was active on the two tested mycobacterial species. Compound 5 showed the best activity on the two tested mycobacterial species with a recorded Minimal inhibition concentration (MIC) of 4.88 µg/ml. The results obtained also showed that GPB was active on all the 17 tested microorganisms, including nine Gram positive and four Gram-positive bacteria, and four fungi. The overall results of this study provided promising baseline information for the potential use of the studied plant in the treatment of tuberculosis, infections associated with fungi, Gram positive and Gram-negative bacteria.