It has been reported that ligand-mediated transcription factor peroxisome proliferator-activated receptor alpha (hPPAR alpha) is involved in hepatitis C virus (HCV) RNA replication, whereas hPPAR gamma is not, and the effect of hPPAR delta is unknown. Here, we show that hPPAR delta-selective antagonists effectively inhibit HCV RNA replication. We describe the design, synthesis and pharmacological evaluation of a series of biphenyl-4-carboxylic acid-type hPPAR delta antagonists, including previously reported compounds, as candidate anti-HCV agents. A representative compound (4c) dose-dependently inhibited HCV RNA replication (EC50 0.22 mu M), while exhibiting relatively weak cytotoxicity to the host cells (CC50 2.5 mu M). It also showed an additive and dose-dependent effect on the inhibition of HCV RNA replication by pegylated interferon alpha (Peg-IFN alpha) alone and by both Peg-IFN alpha and ribavirin (currently the clinical treatment of choice for HCV infection). Thus, combination of a hPPAR delta antagonist with current therapy may improve the efficacy of treatment for HCV infection. (C) 2013 Elsevier Ltd. All rights reserved.
It has been reported that ligand-mediated transcription factor peroxisome proliferator-activated receptor alpha (hPPAR alpha) is involved in hepatitis C virus (HCV) RNA replication, whereas hPPAR gamma is not, and the effect of hPPAR delta is unknown. Here, we show that hPPAR delta-selective antagonists effectively inhibit HCV RNA replication. We describe the design, synthesis and pharmacological evaluation of a series of biphenyl-4-carboxylic acid-type hPPAR delta antagonists, including previously reported compounds, as candidate anti-HCV agents. A representative compound (4c) dose-dependently inhibited HCV RNA replication (EC50 0.22 mu M), while exhibiting relatively weak cytotoxicity to the host cells (CC50 2.5 mu M). It also showed an additive and dose-dependent effect on the inhibition of HCV RNA replication by pegylated interferon alpha (Peg-IFN alpha) alone and by both Peg-IFN alpha and ribavirin (currently the clinical treatment of choice for HCV infection). Thus, combination of a hPPAR delta antagonist with current therapy may improve the efficacy of treatment for HCV infection. (C) 2013 Elsevier Ltd. All rights reserved.