Activity of trifluoperazine against replicating, non-replicating and drug resistant M. tuberculosis

PLoS One. 2012;7(8):e44245. doi: 10.1371/journal.pone.0044245. Epub 2012 Aug 31.

Abstract

Trifluoperazine, a known calmodulin antagonist, belongs to a class of phenothiazine compounds that have multiple sites of action in mycobacteria including lipid synthesis, DNA processes, protein synthesis and respiration. The objective of this study is to evaluate the potential of TFP to be used as a lead molecule for development of novel TB drugs by showing its efficacy on multiple drug resistant (MDR) Mycobacterium tuberculosis (M.tb) and non-replicating dormant M.tb. Wild type and MDR M.tb were treated with TFP under different growth conditions of stress like low pH, starvation, presence of nitric oxide and in THP-1 infection model. Perturbation in growth kinetics of bacilli at different concentrations of TFP was checked to determine the MIC of TFP for active as well as dormant bacilli. Results show that TFP is able to significantly reduce the actively replicating as well as non-replicating bacillary load. It has also shown inhibitory effect on the growth of MDR M.tb. TFP has shown enhanced activity against intracellular bacilli, presumably because phenothiazines are known to get accumulated in macrophages. This concentration was, otherwise, found to be non-toxic to macrophage in vitro. Our results show that TFP has the potential to be an effective killer of both actively growing and non-replicating bacilli including MDR TB. Further evaluation and in vivo studies with Trifluoperazine can finally help us know the feasibility of this compound to be used as either a lead compound for development of new TB drugs or as an adjunct in the current TB chemotherapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antitubercular Agents / pharmacology*
  • Cell Line
  • Cell Survival / drug effects
  • Drug Resistance, Bacterial / drug effects*
  • Humans
  • Hydrogen-Ion Concentration / drug effects
  • Macrophages / cytology
  • Macrophages / drug effects
  • Macrophages / microbiology
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects
  • Mycobacterium tuberculosis / cytology
  • Mycobacterium tuberculosis / drug effects*
  • Mycobacterium tuberculosis / growth & development*
  • Nitric Oxide / pharmacology
  • Trifluoperazine / pharmacology*

Substances

  • Antitubercular Agents
  • Trifluoperazine
  • Nitric Oxide

Grants and funding

This work is supported by a grant received from Defence Research and Development Organization, India (No. LSRB-90/BTB/2006) and a student fellowship received from the University of Delhi. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.