Impact of herbal substances on efflux pumps in bacterial and human cells

The rapid global expansion of multidrug (MDR) and extensively drug-resistant (XDR) bacteria reflects the urgent need of a novel course in antibiotic therapy to tackle infectious diseases such as tuberculosis [1]. Considering the rising numbers of multidrug resistance especially in mycobacteria including the Mycobacterium tuberculosis complex, they are one of the critical global health concerns [2]. Efflux pumps (EP) present one of the key strategies of bacteria to protect themselves against antimicrobials [3]. We investigated specific isolated flavonoids from Scutellaria species for their antimicrobial activity against the non-pathogenic surrogate models for Mycobacterium tuberculosis, i. e. Mycobacterium smegmatis mc2 155, Mycobacterium aurum ATCC 23366 and Mycobacterium bovis BCG ATCC 35734. The MICs of the plant compounds against the studied strains were determined using microbroth dilution and SPOTi- assays [5].