title: Bioactivity-guided screening identifies pheophytin a as a potent anti-hepatitis C virus compound from Lonicera hypoglauca Miq.
abstract: Chronic hepatitis C virus (HCV) infection is a worldwide public issue. In this study, we performed bioactivity-guided screening of the Lonicera hypoglauca Miq. crude extracts to find for naturally chemical entities with anti-HCV activity. Pheophytin a was identified from the ethanol-soluble fraction of L. hypoglauca that elicited dose-dependent inhibition of HCV viral proteins and RNA expression in both replicon cells and cell culture infectious system. Computational modeling revealed that pheophytin a can bind to the active site of HCV-NS3, suggesting that NS3 is a potent molecular target of pheophytin a. Biochemical analysis further revealed that pheophytin a inhibited NS3 serine protease activity with IC(50)=0.89 microM. Notably, pheophytin a and IFNalpha-2a elicited synergistic anti-HCV activity in replicon cells with no significant cytotoxicity. This study thereby demonstrates for the first time that pheophytin a is a potent HCV-NS3 protease inhibitor and offers insight for development of novel anti-HCV regimens.
authors.affiliation: Department of Forestry, National Chung Hsing University, Taichung, Taiwan, ROC.
authors.forename: Sheng-Yang
authors.initials: SY
authors.lastname: Wang
authors.forename: Ching-Ping
authors.initials: CP
authors.lastname: Tseng
authors.forename: Keng-Chang
authors.initials: KC
authors.lastname: Tsai
authors.forename: Chia-Fan
authors.initials: CF
authors.lastname: Lin
authors.forename: Ching-Ya
authors.initials: CY
authors.lastname: Wen
authors.forename: Hsin-Sheng
authors.initials: HS
authors.lastname: Tsay
authors.forename: Naoya
authors.initials: N
authors.lastname: Sakamoto
authors.forename: Chin-Hsiao
authors.initials: CH
authors.lastname: Tseng
authors.forename: Ju-Chien
authors.initials: JC
authors.lastname: Cheng
mesh_terms: D000998:Antiviral Agents / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D020134:Catalytic Domain / Q000187:drug effects; D002460:Cell Line; D003198:Computer Simulation; D004353:Drug Evaluation, Preclinical; D016174:Hepacivirus / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology; D031239:Lonicera / Q000737:chemistry*; D008958:Models, Molecular; D010674:Pheophytins / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D014764:Viral Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D014779:Virus Replication / Q000187:drug effects; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D010674:Pheophytins; D011994:Recombinant Proteins; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C061694:pheophytin a