Morphological changes and potential inhibition of efflux pumps in Mycobacterium tuberculosis treated with Tanshinona I, Tanshinona IIA and Cryptotanshinona

Abstract

Tuberculosis is a public health problem that has been present since the dawn of humanity. Elucidated by Robert Koch, this disease has as its main pathological agent the bacillus of Mycobacterium tuberculosis, which causes an infection in the pulmonary alveoli. It stands out as a pathology for its high rate of resistance to antimicrobials and also for being the main cause of death from a single infectious agent. This resistance can be associated, for example, with bacterial efflux pumps, membrane proteins capable of decreasing the intracellular concentration of drugs when expelling them from the cell. In this work, some natural compounds were selected, with interesting previous results, for the evaluation of their activity against M. tuberculosis, they are Tanshinona I, Tanshinona IIA and Cryptotanshinona, substances isolated from Salvia miltiorrhiza, an extremely important plant in traditional Chinese medicine and that has several pharmaceutical applications, however, they have not yet been research object aganist tuberculosis bacillus. Thus, we aim to observe whether these compounds have an efflux pump inhibition activity and what morphological changes occur in the bacterial cultures exposed to them. To do that, we will use the ethidium bromide accumulation assay and scanning electron microscopy (SEM). The results obtained may indicate the potential mechanism of action of these compounds, whether or not they inhibit efflux pumps and changes in cell morphology (bubbles, wrinkling or rounding) by SEM images.