Berberine enhances the antibacterial activity of thymoquinone, carvacrol and thymol against multi-drug resistant nontuberculous mycobacteria.

The aim of this study was to investigate the activity of thymoquinone (TQ), carvacrol (CAR) and thymol (TYM) against multi-drug resistant nontuberculous mycobacteria (MDR-NTM), alone and in combination with berberine (BER). Antimicrobial activity was first evaluated at concentrations from 8 to 512 μg/mL. Each of the compounds tested exhibited good activity against nontuberculous mycobacteria (NTM) isolated from fish, with MIC values of 32-128 μg/mL. In this study, we have shown for the first time the synergistic efficacy of BER with CAR, TYM or TQ against NTM strains. Thus, the combination of these compounds with BER seems to be a new approach for combating MDR-NTM strains.