title: Activity against Mycobacterium smegmatis and M. tuberculosis by extract of South African medicinal plants.
abstract: Seven ethnobotanically selected medicinal plants were screened for their antimycobacterial activity. The minimum inhibitory concentration (MIC) of four plants namely Artemisia afra, Dodonea angustifolia, Drosera capensis and Galenia africana ranged from 0.781 to 6.25 mg/mL against Mycobacterium smegmatis. G. africana showed the best activity exhibiting an MIC of 0.78 mg/mL and a minimum bactericidal concentration (MBC) of 1.56 mg/mL. The MICs of ethanol extracts of D. angustifolia and G. africana against M. tuberculosis were found to be 5.0 and 1.2 mg/mL respectively. The mammalian cytotoxicity IC(50) value of the most active antimycobacterial extract, from G. africana, was found to be 101.3 microg/mL against monkey kidney Vero cells. Since the ethanol G. africana displayed the best antimycobacterial activity, it was subjected to fractionation which led to the isolation of a flavone, 5,7,2'-trihydroxyflavone. The MIC of this compound was found to be 0.031 mg/mL against M. smegmatis and 0.10 mg/mL against M. tuberculosis. This study gives some scientific basis to the traditional use of these plants for TB-related symptoms.
authors.affiliation: Department of Plant Science, University of Pretoria, Pretoria, 0002, South Africa.
authors.forename: Sannah Patience Nkami
authors.initials: SP
authors.lastname: Mativandlela
authors.forename: Jacob Jacobus Marion
authors.initials: JJ
authors.lastname: Meyer
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Hussein
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Houghton
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Hamilton
authors.forename: Namrita
authors.initials: N
authors.lastname: Lall
mesh_terms: D019306:Artemisia / Q000737:chemistry; D029748:Caryophyllaceae / Q000737:chemistry; D031257:Droseraceae / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D020102:Mycobacterium smegmatis / Q000187:drug effects*; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D029631:Sapindaceae / Q000737:chemistry; D013019:South Africa
chemical_list: D010936:Plant Extracts