Then, 30 mL of freshly prepared 0.01% resazurin solution (Acros, NJ, USA) was added to each well and the plates were reincubated at 35 8C for 24 h for visual readings. A color change from blue to pink indicated mycobacterial
growth, and the MIC was interpreted as the lowest extract concentration that prevented the color change. A control contain-
ing 2.5% (v/v) DMSO was included to detect inhibitory effects on M. tuberculosis growth. All experiments were performed in