02223nas a2200217   4500008004100000022001400041245016600055210006900221260007600290300001200366490000700378520134900385653003001734653001401764653003101778653002201809653000901831100001801840700001901858856012801877       2012                        eng d  a1087-057100aPotential use of nitrate reductase as a biomarker for the identification of active and dormant inhibitors of mycobacterium tuberculosis in a THP1 infection model0 aPotential use of nitrate reductase as a biomarker for the identi  a2455 TELLER RD, THOUSAND OAKS, CA 91320 USAbSAGE PUBLICATIONS INCcAUG  a966-9730 v173 a<p>The development of a macrophage-based, antitubercular high-throughput screening system could expedite discovery programs for identifying novel inhibitors. In this study, the kinetics of nitrate reduction (NR) by Mycobacterium tuberculosis during growth in Thp1 macrophages was found to be almost parallel to viable bacilli count. NR in the culture medium containing 50 mM of nitrate was found to be optimum on the fifth day after infection with M. tuberculosis. The signal-to-noise (S/N) ratio and Z-factor obtained from this macrophage-based assay were 5.4 and 0.965, respectively, which confirms the robustness of the assay protocol. The protocol was further validated by using standard antitubercular inhibitors such as rifampicin, isoniazid, streptomycin, ethambutol, and pyrazinamide, added at their IC90 value, on the day of infection. These inhibitors were not able to kill the bacilli when added to the culture on the fifth day after infection. Interestingly, pentachlorophenol and rifampicin killed the bacilli immediately after addition on the fifth day of infection. Altogether, this assay protocol using M. tuberculosis-infected Thp-1 macrophages provides a novel, cost-efficient, robust, and easy-to-perform screening platform for the identification of both active and hypoxic stage-specific inhibitors against tuberculosis.</p>10ahigh-throughput screening10ainhibitor10aMycobacterium tuberculosis10anitrate reductase10aTHP11 aSarkar, Sampa1 aSarkar, Dhiman  uhttps://library.ncl.res.in/content/potential-use-nitrate-reductase-biomarker-identification-active-and-dormant-inhibitors-0