title: Anti-influenza virus activity of Chaenomeles sinensis.
abstract: OBJECTIVE
  This investigation evaluated anti-influenza virus activity of 50% ethanol extract of the fruit of Chaenomeles sinensis K(OEHNE), which is widely used as a traditional Chinese medicine to treat throat diseases.
  
  
  METHODS
  Type A and B influenza viruses were treated with the extract at various concentrations for 1h at room temperature; then the plaque titers of the treated viruses were determined. The neutralizing component in the extract was partially purified using HP20 column chromatography.
  
  
  RESULTS
  Treatment with the extract at concentrations greater than 5mg/ml reduced the plaque titers of the both viruses to less than 10% of those of untreated viruses. The treatment inhibited viral hemagglutination activity, too. When the 50mg/ml extract was added to the culture medium after inoculation of the virus, viral NS2 protein synthesis was selectively inhibited and progeny virus was not detected in the infected cell medium. Partial purification showed that the neutralizing component consisted of high molecular weight polyphenols.
  
  
  CONCLUSIONS
  High molecular weight polyphenols in the fruits of C. sinensis neutralizes influenza virus by inhibiting hemagglutination activity and by suppressing NS2 protein synthesis.
authors.affiliation: Lotte Co Ltd, Central Laboratory, Saitama, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Sawai
authors.forename: Kazumichi
authors.initials: K
authors.lastname: Kuroda
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Shibata
authors.forename: Rieko
authors.initials: R
authors.lastname: Gomyou
authors.forename: Kenji
authors.initials: K
authors.lastname: Osawa
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D002460:Cell Line; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D005638:Fruit; D006385:Hemagglutination Inhibition Tests; D009980:Influenza A virus / Q000187:drug effects; D009981:Influenza B virus / Q000187:drug effects; D007668:Kidney / Q000187:drug effects / Q000821:virology; D010636:Phenols / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D059808:Polyphenols; D027824:Rosaceae / Q000737:chemistry*; D017361:Viral Nonstructural Proteins / Q000187:drug effects / Q000378:metabolism
chemical_list: D000998:Antiviral Agents; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D017361:Viral Nonstructural Proteins