title: Antimycobacterial screening of traditional medicinal plants using the microplate resazurin assay.
abstract: Multidrug-resistant Mycobacterium tuberculosis strains have rapidly become a global health concern. North American First Nations communities have used traditional medicines for generations to treat many pulmonary infections. In this study, we evaluated the antimycobacterial activity of 5 medicinal plants traditionally used as general therapeutics for pulmonary illnesses and specifically as treatments for tuberculosis. Aqueous extracts of Aralia nudicaulis, Symplocarpus foetidus, Heracleum maximum, Juniperus communis, and Acorus calamus were screened for antimycobacterial activity against Bacillus Calmette-Guérin, Mycobacterium avium, and M. tuberculosis H37Ra using the colorimetric microplate resazurin assay. Extracts of Acorus calamus and H. maximum root demonstrated significant antimycobacterial activity comparable to that of the rifampin control (2 microg/mL). Evaluation of the cytotoxicity of these 2 extracts using the MTT assay also showed that the extracts were less toxic to 3 human cell lines than was the DMSO positive control. This study demonstrates that aqueous extracts of the roots of H. maximum and Acorus calamus possess strong in vitro antimycobacterial activity, validates traditional knowledge, and provides potential for the development of urgently needed novel antituberculous therapeutics.
authors.affiliation: Department of Medicine, Saint John Regional Hospital, Canada.
authors.forename: Duncan
authors.initials: D
authors.lastname: Webster
authors.forename: Timothy D G
authors.initials: TD
authors.lastname: Lee
authors.forename: Jill
authors.initials: J
authors.lastname: Moore
authors.forename: Tracy
authors.initials: T
authors.lastname: Manning
authors.forename: Dennis
authors.initials: D
authors.lastname: Kunimoto
authors.forename: Darren
authors.initials: D
authors.lastname: LeBlanc
authors.forename: John A
authors.initials: JA
authors.lastname: Johnson
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Gray
mesh_terms: D000995:Antitubercular Agents / Q000302:isolation & purification / Q000494:pharmacology*; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D006801:Humans; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D009162:Mycobacterium avium / Q000187:drug effects* / Q000378:metabolism; D009163:Mycobacterium bovis / Q000187:drug effects* / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000378:metabolism; D010078:Oxazines / Q000378:metabolism; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism; D014966:Xanthenes / Q000378:metabolism
chemical_list: D000995:Antitubercular Agents; D010078:Oxazines; D010936:Plant Extracts; D013778:Tetrazolium Salts; D013844:Thiazoles; D014966:Xanthenes; C005843:resazurin; C022616:thiazolyl blue