Antiviral Therapy 2012; 17:467–476 (doi: 10.3851/IMP1937) Original article Fluoroquinolones inhibit HCV by targeting its helicase Irfan A Khan1,2, Sammer Siddiqui1, Sadiq Rehmani1, Shahana U Kazmi2, Syed H Ali1,3* 1Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan 2Department of Microbiology, University of Karachi, Karachi, Pakistan 3Department of Microbiology, Dow University of Health Sciences, Karachi, Pakistan *Corresponding author e-mail:
[email protected] Background: HCV has infected >170 million individuals of 12 different fluoroquinolones. Afterwards, Huh-7 and worldwide. Effective therapy against HCV is still lacking and Huh-8 cells were lysed and viral RNA was extracted. The there is a need to develop potent drugs against the virus. extracted RNA was reverse transcribed and quantified by In the present study, we have employed two culture models real-time quantitative PCR. Fluoroquinolones were also to test the activity of fluoroquinolone drugs against HCV: a tested on purified NS3 protein in a molecular-beacon- subgenomic replicon that is able to replicate independently based in vitro helicase assay. in the cell line Huh-8 and the Huh-7 cell culture model Results: To varying degrees, all of the tested fluoroqui- that employs cells transfected with synthetic HCV RNA to nolones effectively inhibited HCV replication in both produce the infectious HCV particles. Fluoroquinolones have Huh-7 and Huh-8 culture models. The inhibition of HCV also been shown to have inhibitory activity against certain NS3 helicase activity was also observed with all 12 of the viruses, possibly by targeting the viral helicase. To tease out fluoroquinolones.