Table 3.

Redox status of [NADH/[NAD⁺] in hypoxic nonreplicating Mtb H37Rv

Drug treatment (μM)	NAD+, μM	NADH, μM	NADH/NAD+ ratio
No drug	0.95 ± 0.11	0.3 ± 0.03	0.32 ± 0.01
Thioridazine (40)	0.72 ± 0.08	0.39 ± 0.04	0.54 ± 0.11*
Thioridazine (80)	0.66 ± 0.04*	0.56 ± 0.11*	0.85 ± 0.22*
Rifampicin (1)	0.90 ± 0.03	0.37 ± 0.03	0.41 ± 0.05
R207910 (5)	0.99 ± 0.03	0.38 ± 0.04	0.38 ± 0.05
R207910 (10)	1.16 ± 0.02	0.37 ± 0.02	0.31 ± 0.02

Hypoxic nonreplicating Mtb H37Rv was incubated with the ndh-2 inhibitor thioridazine for 3 h under anaerobic conditions before quantification of the [NADH]/[NAD⁺] ratio. The compounds were used at 2- and 4-fold of the WCC₉₀ concentration for thioridazine and R207910 and at 2-fold the WCC₉₀ concentration for rifampicin. The experiments were carried out three times in triplicate; one of the representative experiments is shown with means and standard deviations.

*Mean values are statistically different (P < 0.05) compared with the mean values of the no-drug-treated Mtb cells.