title: Antimycobacterial activity of selected medicinal plants traditionally used in Sudan to treat infectious diseases.
abstract: BACKGROUND
  The emergence of multidrug-resistant strains of Mycobacterium tuberculosis underscores the need for continuous development of new and efficient methods to determine the susceptibility of isolates of Mycobacterium tuberculosis in the search for novel antimycobacterial agents. Natural products constitute an important source of new drugs, and design and implementation of antimycobacterial susceptibility testing methods are necessary to evaluate the different extracts and compounds. In this study we have explored the antimycobacterial properties of 50 ethanolic extracts from different parts of 46 selected medicinal plants traditionally used in Sudan to treat infectious diseases.
  
  
  METHODS
  Plants were harvested and ethanolic extracts were prepared. For selected extracts, fractionation with hydrophilic and hydrophobic solvents was undertaken. A luminometry-based assay was used for determination of mycobacterial growth in broth cultures and inside primary human macrophages in the presence or absence of plant extracts and fractions of extracts. Cytotoxicity was also assessed for active fractions of plant extracts.
  
  
  RESULTS
  Of the tested extracts, three exhibited a significant inhibitory effect on an avirulent strain of Mycobacterium tubercluosis (H37Ra) at the initial screening doses (125 and 6.25µg/ml). These were bark and leaf extracts of Khaya senegalensis and the leaf extract of Rosmarinus officinalis L. Further fractions of these plant extracts were prepared with n-hexane, chloroform, ethyl acetate, n-butanol, ethanol and water, and the activity of these extracts was retained in hydrophobic fractions. Cytotoxicity assays revealed that the chloroform fraction of Khaya senegalensis bark was non-toxic to human monocyte-derived macrophages and other cell types at the concentrations used and hence, further analysis, including assessment of IC50 and intracellular activity was done with this fraction.
  
  
  CONCLUSIONS
  These results encourage further investigations to identify the active compound(s) within the chloroform fraction of Khaya senegalensis bark.
authors.affiliation: Medicinal and Aromatic Plants Research Institute, National Center for Research, P.O. Box: 2404, Khartoum 11111, Sudan; Department of Clinical Microbiology, Faculty of Medical Laboratory Sciences, Omdurman Islamic University, P.O.Box 382, Omdurman,Sudan; Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, 58185 Linkoping, Sweden.
authors.forename: Nadir
authors.initials: N
authors.lastname: Abuzeid
authors.affiliation: Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, 58185 Linkoping, Sweden.
authors.forename: Sadaf
authors.initials: S
authors.lastname: Kalsum
authors.affiliation: Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, 58185 Linkoping, Sweden.
authors.forename: Richin John
authors.initials: RJ
authors.lastname: Koshy
authors.affiliation: Department of Clinical Microbiology, Linköping University Hospital, 58185 Linkoping, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Larsson
authors.affiliation: Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, 58185 Linkoping, Sweden.
authors.forename: Mikaela
authors.initials: M
authors.lastname: Glader
authors.affiliation: Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, 58185 Linkoping, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Andersson
authors.affiliation: Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, 58185 Linkoping, Sweden.
authors.forename: Johanna
authors.initials: J
authors.lastname: Raffetseder
authors.affiliation: Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, 58185 Linkoping, Sweden.
authors.forename: Elsje
authors.initials: E
authors.lastname: Pienaar
authors.affiliation: Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, 58185 Linkoping, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Eklund
authors.affiliation: Medicinal and Aromatic Plants Research Institute, National Center for Research, P.O. Box: 2404, Khartoum 11111, Sudan.
authors.forename: Muddathir S
authors.initials: MS
authors.lastname: Alhassan
authors.affiliation: Medicinal and Aromatic Plants Research Institute, National Center for Research, P.O. Box: 2404, Khartoum 11111, Sudan.
authors.forename: Haidar A
authors.initials: HA
authors.lastname: AlGadir
authors.affiliation: Medicinal and Aromatic Plants Research Institute, National Center for Research, P.O. Box: 2404, Khartoum 11111, Sudan.
authors.forename: Waleed S
authors.initials: WS
authors.lastname: Koko
authors.affiliation: Department of Clinical Microbiology and Infectious diseases, Kalmar County Hospital, SE-391 85 Kalmar, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schön
authors.affiliation: Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur 50300, Malaysia; Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
authors.forename: M
authors.initials: M
authors.lastname: Ahmed Mesaik
authors.affiliation: Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
authors.forename: Omer M
authors.initials: OM
authors.lastname: Abdalla
authors.affiliation: Medicinal and Aromatic Plants Research Institute, National Center for Research, P.O. Box: 2404, Khartoum 11111, Sudan.
authors.forename: Asaad
authors.initials: A
authors.lastname: Khalid
authors.affiliation: Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linkoping University, 58185 Linkoping, Sweden. Electronic address: maria.lerm@liu.se.
authors.forename: Maria
authors.initials: M
authors.lastname: Lerm
mesh_terms: D000995:Antitubercular Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D020128:Inhibitory Concentration 50; D008264:Macrophages / Q000382:microbiology; D016488:Medicine, African Traditional; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D013397:Sudan
chemical_list: D000995:Antitubercular Agents; D010936:Plant Extracts
keywords: Cytotoxicity assay; Luminescence reporter assay; Mycobacterium tuberculosis; Primary human macrophages; Sudanese medicinal plants