title: Anti-influenza viral effects of honey in vitro: potent high activity of manuka honey.
abstract: OBJECTIVE
  Influenza viruses are a serious threat to human health and cause thousands of deaths annually. Thus, there is an urgent requirement for the development of novel anti-influenza virus drugs. Therefore, the aim of this study was to evaluate the anti-influenza viral activity of honey from various sources.
  
  
  METHODS
  Antiviral activities of honey samples were evaluated using MDCK cells. To elucidate the possible mechanism of action of honey, plaque inhibition assays were used. Synergistic effects of honey with known anti-influenza virus drugs such as zanamivir or oseltamivir were tested.
  
  
  RESULTS
  Manuka honey efficiently inhibited influenza virus replication (IC50 = 3.6 ± 1.2 mg/mL; CC50 = 82.3 ± 2.2 mg/mL; selective index = 22.9), which is related to its virucidal effects. In the presence of 3.13 mg/mL manuka honey, the IC50 of zanamivir or oseltamivir was reduced to nearly 1/1000th of their single use.
  
  
  CONCLUSIONS
  Our results showed that honey, in general, and particularly manuka honey, has potent inhibitory activity against the influenza virus, demonstrating a potential medicinal value.
authors.affiliation: Laboratory of Molecular Biology of Infectious Agents, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Laboratory of Molecular Biology of Infectious Agents, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
authors.forename: Ratika
authors.initials: R
authors.lastname: Rahmasari
authors.affiliation: Laboratory of Molecular Biology of Infectious Agents, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Matsunaga
authors.affiliation: Central Research Center, AVSS Corporation, Nagasaki, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Haruyama
authors.affiliation: Laboratory of Molecular Biology of Infectious Agents, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan; Central Research Center, AVSS Corporation, Nagasaki, Japan. Electronic address: nobnob@nagasaki-u.ac.jp.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D004285:Dogs; D004357:Drug Synergism; D006722:Honey; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects / Q000254:growth & development*; D020128:Inhibitory Concentration 50; D061985:Madin Darby Canine Kidney Cells; D053139:Oseltamivir / Q000494:pharmacology*; D010948:Viral Plaque Assay; D014779:Virus Replication / Q000187:drug effects; D053243:Zanamivir / Q000494:pharmacology*
chemical_list: D000998:Antiviral Agents; D053139:Oseltamivir; D053243:Zanamivir
keywords: Anti-viral drug; Influenza virus; Manuka honey; Synergistic effect; Virucidal activity