Activity against multidrug‐resistant Mycobacterium tuberculosis in Mexican plants used to treat respiratory diseases

Abstract

The increase of multidrug-resistant Mycobacterium tuberculosis (MDR-TB) demands the search for alternative antimycobacterial drugs. The aim of this study was to evaluate plants used in Mexican traditional medicine to treat respiratory diseases for activity against MDR-TB. A group of 22 plants was screened for activity against Mycobacterium tuberculosis H37Rv and Mycobacterium avium at concentrations from 50 to 200 microg/mL. The antimycobacterial effect was determined by a microcolorimetric assay with Alamar blue dye. None of the aqueous extracts had antimycobacterial activity. Hexane extracts from Artemisia ludoviciana, Chamaedora tepejilote, Lantana hispida, Juniperus communis and Malva parviflora, and methanol extracts from Artemisia ludoviciana and Juniperus communis inhibited the growth of Mycobacterium tuberculosis. Mycobacterium avium was inhibited by Juniperus communis hexane extract and by Malva parviflora methanol extract. The active extracts were tested against monoresistant variants of Mycobacterium tuberculosis H37Rv (isoniazid, rifampin, streptomycin and ethambutol resistant) and the hexane extract of Lantana hispida showed the best activity. Lantana hispida hexane extract was also active against a group of MDR-TB clinical isolates. In contrast, it did not inhibit the growth of non-tuberculous mycobacteria. The hexane extract of Lantana hispida was fractionated by column chromatography and one of its fractions (FVI) inhibited the growth of all the MDR-TB clinical isolates at concentrations up to 25 microg/mL. This study supports the fact that selecting plants by ethnobotanical criteria enhances the probability of finding species with activity against mycobacteria, and our results point to Lantana hispida as an important source of potential compounds against MDR-TB.

Antioxidant, antitumor and antimicrobial activities of the crude extract and compounds of the root bark ofAllanblackia floribunda

“…The activities of all test samples against M. tuberculosis were evaluated using the Microplate Alamar Blue Assay (MABA) according to Collins and Franzblau (1997) as modified by Jimenez-Arellanes et al (2003). M. tuberculosis was cultured at 37°C in Middlebrook 7H9 broth.…”

“…Samples with detected MIC values following MABA (Collins & Franzblau, 1997;Jimenez-Arellanes et al, 2003) were assayed for their mycobactericidal effect as follows. The mycobacterial suspensions showing no growth (5 μL) were transferred from the former to a new microplate that contained 195 μL of fresh culture medium.…”

Screening of Central and South American plant extracts for antimycobacterial activity by the Alamar Blue test

“…Literature search (Van Puyvelde et al, 1994;Boily;Van Puyvelde, 1986) showed that a crude ethanolic extract of Lantana trifolia collected in Rwanda, and prepared in the same way as ours had been previously assayed for antimycobacterial activity -M. smegmatis (Boily;Van Puyvelde, 1986) and clinical strains of M. tuberculosis (Van Puyvelde et al, 1994), and similarly, no positive activity was found, corroborating with our results. However, the report on the antimycobacterial activity of another species from the genus Lantana -L. hispida (Jimenez-Arellanes et al 2003), prompted us to investigate this activity on the Lantana trifolia fractions. The active hexane and dichloromethane fractions from the leaves of Lantana trifolia, Lippia lacunosa and Lippia rotundifolia are now being submitted to bioassay-guided fractionation to locate the active(s) substance(s).…”

Antitubercular activity and phytochemical screening of selected medicinal plants

“…The activity of all phytochemicals against the aforementioned M. tuberculosis strains was tested using the microplate Alamar Blue assay described previously [14][15] . Sterile distilled water (200 ml) was poured into outer perimeter wells of the microplate.…”