Antimycobacterial crude plant extracts from South, Central, and North America.

Two-hundred and thirty crude organic extracts from 118 plant species distributed among 10 families were evaluated for anti-mycobacterial activity. Activity was determined against Mycobacterium tuberculosis H(37)Rv and Mycobacterium avium using the BACTEC 460 radiorespirometric assay. At 100 μg/ml, twenty-four and ten of the extracts caused more than 95% inhibition of growth of M. tuberculosis and M. avium, respectively. The most active plant species (100% inhibition) were Borrichia frutescens, Solidago arguta, and Inula helenium against M. tuberculosis, Euthamia leptocephala against M. avium, and Erigeron strigosus and Magnolia acuminata against both mycobacteria.