In vitro inhibition of human influenza A virus infection by fruit-juice concentrate of Japanese plum (Prunus mume SIEB. et ZUCC)

Biol Pharm Bull. 2008 Mar;31(3):511-5. doi: 10.1248/bpb.31.511.


Using a plaque reduction assay, treatment of human influenza A viruses with the fruit-juice concentrate of Japanese plum (Prunus mume SIEB. et ZUCC) showed strong in vitro anti-influenza activity against human influenza A viruses before viral adsorption, but not after viral adsorption, with 50% inhibitory concentration (IC50) values against A/PR/8/34 (H1N1) virus, A/Aichi/2/68 (H3N2) virus and A/Memphis/1/71 (H3N2) virus of 6.35+/-0.17, 2.84+/-1.98 and 0.53+/-0.10 microg/ml, respectively. The plum-juice concentrate exhibited hemagglutination activity toward guinea pig erythrocytes. Its hemagglutination activity was inhibited by the monosaccharide N-acetylneuraminic acid and a sialoglycoprotein (fetuin), but not by the other tested monosaccharides (mannose, galactose, glucose and N-acetylglucosamine), suggesting the presence of a lectin-like molecule(s) in the Japanese plum-juice concentrate. Our findings suggest that the fruit-juice concentrate of Japanese plum may prevent and reduce infection with human influenza A virus, possibly via inhibition of viral hemagglutinin attachment to host cell surfaces by its lectin-like activity.

MeSH terms

  • Animals
  • Beverages*
  • Cell Line
  • Dogs
  • Dose-Response Relationship, Drug
  • Erythrocytes / virology
  • Fruit / chemistry*
  • Guinea Pigs
  • Hemagglutination, Viral / drug effects
  • Influenza A virus / drug effects*
  • Influenza A virus / enzymology
  • Influenza A virus / growth & development
  • Influenza A virus / pathogenicity
  • Monosaccharides / pharmacology
  • Neuraminidase / antagonists & inhibitors
  • Plant Extracts / pharmacology*
  • Prunus / chemistry*
  • Viral Plaque Assay


  • Monosaccharides
  • Plant Extracts
  • Neuraminidase