Antimycobacterial and PknB Inhibitory Activities of Venezuelan Medicinal Plants

Global control and elimination of tuberculosis are hindered by the high prevalence of drug-resistant strains, making the development of new drugs to fight tuberculosis a public health priority. In this study, we evaluated 118 extracts from 58 Venezuelan plant species for their ability to inhibit the growth of Mycobacterium tuberculosis mc²6020, using the agar dilution method. Additionally, we determined the ability of these extracts to inhibit the activity of PknB protein, an essential M. tuberculosis serine/threonine kinase, using a high-throughput luminescent assay. Of the 118 extracts tested, 14 inhibited bacterial growth with a minimum inhibitory concentration ≤500 μg/ml, and 36 inhibited the kinase activity with a half-maximal inhibitory concentration <200 μg/ml. Five extracts inhibited M. tuberculosis growth and inhibited the activity of the kinase protein, suggesting that this could be the basis of their growth inhibition.