Activity against drug resistant‐tuberculosis strains of plants used in Mexican traditional medicine to treat tuberculosis and other respiratory diseases

Abstract

Tuberculosis (TB) kills about 3 million people per year worldwide. Furthermore, TB is an infectious disease associated with HIV patients, and there is a rise in multidrug‐resistant TB (MDR‐TB) cases around the world. There is a need for new anti‐TB agents. The study evaluated the antimycobacterial activity of nine plants used in Mexican traditional medicine to treat tuberculosis and other respiratory diseases. Nasturtium officinale showed the best activity (MIC = 100 µg/mL) against the sensitive Mycobacterium tuberculosis. The following plants were active also but at 200 µg/mL: Citrus sinensis, Citrus aurantifolia, Foeniculum vulgare, Larrea tridentata, Musa acuminata and Olea europaea. Contrary to the above data, activity against drug‐resistant variants of M. tuberculosis was more evident, e.g. N. officinale was the most potent (MIC ≤ 100 µg/mL) against the four mono‐resistant variants tested; F. vulgare and O. europaea were active against all the resistant variants (MICs ≤ 100 µg/mL). The most susceptible variant was the isoniazid resistant, being inhibited by C. aurantifolia, C. sinensis and O. europaea (MIC = 25 µg/mL). These data point to the importance of biological testing of extracts against drug‐resistant M. tuberculosis isolates, and the bioguided assay of these extracts for the identification of lead compounds against MDR‐TB isolates. Copyright © 2007 John Wiley & Sons, Ltd.