Moroccan Medicinal Plants as a Promising Source of Antitubercular Compounds: Evaluation and Comparison of their Antimycobacterial Activity

Abstract

Context/Aim: Tuberculosis remains one of the major current health challenges caused by a single infectious pathogen, Mycobacterium tuberculosis. The severity of this epidemic is mainly associated with the emergence of its multidrug-resistant and extensively drug-resistant strains against known anti-tuberculosis drugs. Hence, there is an urgent need to develop new antimycobacterial molecules to overcome this phenomenon. This study aimed to evaluate and compare the antimycobacterial activity of extracts from selected Moroccan medicinal plants. MATERIALS AND METHODS: Nine plant species were selected for this study. Three different extracts were prepared from each species using distilled water, ethanol, and ethyl acetate. The obtained twenty-seven extracts were tested for their antimycobacterial activity using the disc diffusion method and the resazurin microtiter assay against two mycobacterial strains: Mycobacterium aurum and Mycobacterium smegmatis. Finally, extracts from the active plants were subjected to qualitative and quantitative phytochemical screening. RESULTS: The studied plant extracts exhibited variable antimycobacterial activity. The MIC values ranged from 0.3 to 50 mg/mL against Mycobacterium aurum and from 0.7 to 100 mg/mL against Mycobacterium smegmatis. Among the tested extracts, the ethyl acetate extract of Marrubium vulgare showed the highest activity, with bactericidal effects reflected by MBC values of 0.7 mg/mL and 1.5 mg/mL against M. aurum and M. smegmatis, respectively. Phytochemical screening indicated that the most active extracts were rich in flavonoids. DISCUSSION: The results demonstrate a promising antimycobacterial potential of the ethyl acetate extracts from Laurus nobilis, Marrubium vulgare, and Chamaerops humilis, as indicated by significant inhibition zone diameters and low MIC/MBC values. Qualitative and quantitative phytochemical screening suggests that this activity may be associated with the high content of flavonoids in these extracts. CONCLUSION: According to these results, the studied medicinal plants appear to be a promising source for isolating and purifying new effective antitubercular compounds.