Expression of iNOS and pro-inflammatory cytokines (IL-6 and TNF-α) was induced following infection of cells with M. tuberculosis H37Rv, which was significantly (p < 0.05) suppressed by TQ (5 and 10 μg/mL) treatment at the indicated time points, as determined by qRT-PCR (Fig. 4b-4d). This evidence concerns the gene NOS2 and infection.