Background:Mycetoma is a chronic, inflammatory, granulomatous infection that is present worldwide and endemic in tropical and subtropical regions, caused by the traumatic inoculation of a fungus (eumycetoma).Sudan is the homeland of the disease. Medical treatment of eumycetoma by conventional antifungal therapies is quite disappointing. Surgical debridement may be the only solution.
Objective: This study was an attempt to find a cure for eumycetoma of natural origin.
Methods: The methanolic extracts of seven selected local plants were screened for their antimycetomal activity using the Microbroth Dilution method. All seven plant extracts were able to inhibit Madurella mycetomatis growth at a concentration of 50 µg/ml or less, point to an important property that for the first time to be disclosed. Three plant species out of the seven managed to inhibit the growth of Madurella mycetomatis at a concentration as low as 0.781 µg/ml; these were: Boswellia papyrifera, Acacia nubica and Nigella sativa. MICs of these extracts and /or fractions on 13 mycetoma strains were determined using the standard cellular viability XTT-assay.
Results: The methanolic extract from the gum resin of Boswellia papyrifera, which was fractionated using different organic solvents of variant polarities; Gas-Liquid-Chromatography hybrid Mass-Spectrophotometer (GC-MS) analysis of these fractions; showed the occurrence of four triterpenoid phytoconstituents: Beta-amyrin, Beta-amyrone, Beta-Sitosterol and Stigmatriene. On biological evaluation against 12 M. mycetomatisstrains, Stigmatriene was the best at an MIC of 32 µg/ml.
Conclusion: This is a newly discovered class of antimicrobials with potential for clinical use in the treatment of eumycetoma.