title: Korean medicinal plant extracts exhibit antiviral potency against viral hepatitis.
abstract: OBJECTIVE
  Investigation of natural ethnopharmacologic extracts exhibiting antiviral potential may lead to the discovery of new therapeutics for the treatment of chronic viral hepatitis infections. Traditional Korean medicinal herbs have been identified that exhibit potency against hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. Research on the antiviral potential of naturally derived extracts is facilitated through the use of appropriate animal and liver cell culture models for these hepatotrophic pathogens. Objectives of this study were to demonstrate antiviral activity of an aqueous extract of herbal formulation KYH-1 in surrogate in vitro assays for HBV and HCV and identify mechanisms of action.
  
  
  METHODS
  Antiviral potency of KYH-1 was measured in tissue culture systems that support replication of the woodchuck hepatitis virus (WHV), and the bovine viral diarrhea virus (BVDV). These assays serve as surrogate models for HBV and HCV, respectively. A recombinant HBV polymerase gene expression assay was used to define a molecular target.
  
  
  RESULTS
  KYH-1 exhibited potent antiviral activity against WHV and to a lesser extent against BVDV. KYH-1 and its constituent components inhibited HBV polymerase priming in vitro. Additionally, KYH-1 suppressed HBV replication in a human hepatoblastoma cell line.
  
  
  CONCLUSIONS
  Evaluation of naturally derived products for antiviral activity against HBV and HCV in standardized surrogate assays provides a scientific basis for potential use as complementary or alternative medicines. This study provides significant results justifying preclinical evaluation of KYH-1 as an antiviral therapy for HBV infections.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. jrj2@cornell.edu
authors.forename: James R
authors.initials: JR
authors.lastname: Jacob
authors.forename: Brent E
authors.initials: BE
authors.lastname: Korba
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: You
authors.forename: Bud C
authors.initials: BC
authors.lastname: Tennant
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Kim
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D004279:DNA, Viral / Q000187:drug effects / Q000235:genetics; D001908:Diarrhea Viruses, Bovine Viral / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects; D017919:Hepatitis B Virus, Woodchuck / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D066298:In Vitro Techniques; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D010936:Plant Extracts