Browsing by Author "Wabo Fotso, Ghislain"

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    Callistemon Citrinus (Curtis) Skeels as A Source of Antitubercular Compounds
    (Research Square, 2021) Bunalema, Lydia; Wabo Fotso, Ghislain; Waako, Paul; Yeboah, Samuel
    Tuberculosis (TB) is still a principal cause of death in the world. There is considerable emphasis for search of novel drugs against TB due to increased Mycobacterium tuberculosis drug resistance and co infection with Human Immunodeficiency virus (HIV) that are challenging to treat. Callistemon citrinus (Curtis) skeels is one of the medicinal plants that are used in treatment of tuberculosis by local communities in Uganda. Though crude extracts from the plant have shown antimycobacterial activity invitro, the specific phytochemicals responsible for this activity are not known. The study aimed at isolating and characterizing compounds from C. citrinus and testing the compounds on different strains of M. tuberculosis.
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    Potential of Zanthoxylum leprieurii as a source of active compounds against drug resistant Mycobacterium tuberculosis
    (BMC complementary and alternative medicine, 2017) Bunalema, Lydia; Wabo Fotso, Ghislain; Waako, Paul; Tabuti, John; Yeboah, Samuel O.
    Tuberculosis (TB) is still a global health problem mainly due to development of resistance and co-infection with the Human immune Virus (HIV). Treatment of multi and extensively drug resistant TB requires use of second line drugs which are less efficacious, expensive and very toxic. This has necessitated a need to search for new treatment regimens especially from medicinal plants. Zanthoxylum leprieurii, a plant species fromRutaceae is used locally in the treatment of tuberculosis in Uganda. The aim of the study was to isolate, identify and characterize bio active compounds from Z. leprieurii stem bark with antimycobacterial activity. Methods: Crude extracts, fractions and compounds from air dried stem bark of Z. leprieurii were tested against pan sensitive (H37rv), isoniazid resistant (TMC 301) and rifampicin resistant (TMC 331) strains of M. tuberculosis using micro plate alamar blue assay. Isolation of active compounds was done by using column chromatography and thin layer chromatography. They were analysed using nuclear magnetic resonance spectroscopy and mass spectroscopy. Results: The methanol extract had minimum inhibitory concentrations (MIC) of 47.5, 75.3 and 125.0 μg/ml on the pan sensitive strain, rifampicin resistant and isozianid resistant strains of M. tuberculosis respectively. The chloroform extract had MIC values of 260 μg/ml agnaist the pan sensitive strain and 156 μg/ml on the rifampicin resistant strain. Of the sixteen fractions from the methanol extract, fraction Za4 (MIC = 6.3 μg/mL, 23.0 μg/mL, 11.7 μg/mL) and Za6 (MIC = 11.7 μg/mL 31.2 μg/ml, 31.2 μg/ml) were the most active. Three acridone alkaloids; hydroxy-1, 3-dimethoxy-10-methyl-9-acridone (1), 1-hydroxy-3-methoxy-10-methyl-9-acridone (2) and 3-hydroxy-1, 5, 6-trimethoxy-9-acridone (3) were isolated fromZa4 and Za6. TheMIC of compound 3 was found to be 5.1 μg/ml, 4.5 μg/ml and 3.9 μg/ml on H37rv, TMC 331 and TMC 301 while that of 1 was found to be 1.5 μg/ml, 8.3 μg/ml and 3.5 μg/ml respectively. Conclusion: The results of this study suggest that Z. leprieurii is active on resistant strains of M. tuberculosis and could be a potential source of new leads against resistant tuberculosis. It also verifies the local use of the plant in treatment of tuberculosis.