BACKGROUND AND PURPOSE: This study aimed to evaluate the anti-hepatitis C virus (HCV) activity of andrographolide, a diterpenoid lactone extracted from Andrographis paniculata, and to identify the signalling pathway involved in its antiviral action. EXPERIMENTAL APPROACH: Using HCV replicon and HCVcc infectious systems, we identified anti-HCV activity of andrographolide by measuring protein and RNA levels. A reporter activity assay was used to determine transcriptional regulation of anti-HCV agents. A specific inhibitor and short hairpin RNAs were used to investigate the mechanism responsible for the effect of andrographolide on HCV replication. KEY RESULTS: In HCV replicon and HCVcc infectious systems, andrographolide time- and dose-dependently suppressed HCV replication. When combined with IFN-α, an inhibitor targeting HCV NS3/4A protease (telaprevir), or NS5B polymerase (PSI-7977), andrographolide exhibited a significant synergistic effect. Andrographolide up-regulated the expression of haeme oxygenase-1 (HO-1), leading to increased amounts of its metabolite biliverdin, which was found to suppress HCV replication by promoting the antiviral IFN responses and inhibiting NS3/4A protease activity. Significantly, these antiviral effects were attenuated by an HO-1-specific inhibitor or HO-1 gene knockdown, indicating that HO-1 contributed to the anti-HCV activity of andrographolide. Andrographolide activated p38 MAPK phosphorylation, which stimulated nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated HO-1 expression, and this was found to be associated with its anti-HCV activity. CONCLUSIONS AND IMPLICATIONS: Our results demonstrate that andrographolide has the potential to control HCV replication and suggest that targeting the Nrf2-HO-1 signalling pathway might be a promising strategy for drug development.
BACKGROUND AND PURPOSE: This study aimed to evaluate the anti-hepatitis C virus (HCV) activity of andrographolide, a diterpenoid lactone extracted from Andrographis paniculata, and to identify the signalling pathway involved in its antiviral action. EXPERIMENTAL APPROACH: Using HCV replicon and HCVcc infectious systems, we identified anti-HCV activity of andrographolide by measuring protein and RNA levels. A reporter activity assay was used to determine transcriptional regulation of anti-HCV agents. A specific inhibitor and short hairpin RNAs were used to investigate the mechanism responsible for the effect of andrographolide on HCV replication. KEY RESULTS: In HCV replicon and HCVcc infectious systems, andrographolide time- and dose-dependently suppressed HCV replication. When combined with IFN-α, an inhibitor targeting HCV NS3/4A protease (telaprevir), or NS5B polymerase (PSI-7977), andrographolide exhibited a significant synergistic effect. Andrographolide up-regulated the expression of haeme oxygenase-1 (HO-1), leading to increased amounts of its metabolite biliverdin, which was found to suppress HCV replication by promoting the antiviral IFN responses and inhibiting NS3/4A protease activity. Significantly, these antiviral effects were attenuated by an HO-1-specific inhibitor or HO-1 gene knockdown, indicating that HO-1 contributed to the anti-HCV activity of andrographolide. Andrographolide activated p38 MAPK phosphorylation, which stimulated nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated HO-1 expression, and this was found to be associated with its anti-HCV activity. CONCLUSIONS AND IMPLICATIONS: Our results demonstrate that andrographolide has the potential to control HCV replication and suggest that targeting the Nrf2-HO-1 signalling pathway might be a promising strategy for drug development.
Authors: Vincent Soriano; Eugenia Vispo; Eva Poveda; Pablo Labarga; Luz Martin-Carbonero; Jose Vicente Fernandez-Montero; Pablo Barreiro Journal: J Antimicrob Chemother Date: 2011-06-07 Impact factor: 5.790
Authors: Zhaowen Zhu; Anne T Wilson; Bruce A Luxon; Kyle E Brown; M Meleah Mathahs; Sarmistha Bandyopadhyay; Anton P McCaffrey; Warren N Schmidt Journal: Hepatology Date: 2010-12 Impact factor: 17.425