Inhibitory effect of cinnamaldehyde, derived from Cinnamomi cortex, on the growth of influenza A/PR/8 virus in vitro and in vivo

Antiviral Res. 2007 Apr;74(1):1-8. doi: 10.1016/j.antiviral.2007.01.003. Epub 2007 Jan 26.


We have investigated the inhibitory effect of trans-cinnamaldehyde (CA), one of the principal constituents of essential oil derived from Cinnamomi cortex, on the growth of influenza A/PR/8 virus in vitro and in vivo. When 1-h drug treatment was initiated at various times post-infection (p.i.) in Madin-Darby canine kidney cells using a fixed dose of CA (40 microM), the maximum inhibitory effect (29.7% virus yield of control) was obtained when drug treatment was started at 3h p.i. Under the same treatment schedule, CA inhibited the virus growth in a dose-dependent manner (20-200 microM), and, at 200 microM, the virus yield was reduced to an undetectable level. RT-PCR and SDS-PAGE analyses showed that CA inhibited viral protein synthesis at the post-transcriptional level. In mice infected with the lung-adapted PR-8 virus, inhalation (50mg/cage/day) and nasal inoculation (250 microg/mouse/day) of CA significantly increased survival rates on the 8 days to 100% and 70%, respectively, in contrast to a survival rate of 20% in the untreated control group. Importantly, inhalation of CA caused virus yield reduction by 1 log in bronchoalveolar lavage fluid on day 6 after infection, compared with that of the untreated control group. These findings might provide further support to the empirical indication of Cinnamomi cortex-containing Kampo medicines for acute respiratory infectious diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrolein / administration & dosage
  • Acrolein / analogs & derivatives*
  • Acrolein / chemistry
  • Acrolein / pharmacology
  • Administration, Inhalation
  • Administration, Intranasal
  • Animals
  • Antiviral Agents / administration & dosage
  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacology*
  • Bronchoalveolar Lavage Fluid / virology
  • Cell Line
  • Chick Embryo
  • Cinnamomum / chemistry*
  • Dose-Response Relationship, Drug
  • Female
  • Influenza A Virus, H1N1 Subtype / drug effects*
  • Influenza A Virus, H1N1 Subtype / growth & development
  • Influenza A Virus, H3N2 Subtype / drug effects
  • Influenza A Virus, H3N2 Subtype / growth & development
  • Influenza B virus / drug effects
  • Influenza B virus / growth & development
  • Mice
  • Microbial Sensitivity Tests
  • Orthomyxoviridae Infections / drug therapy*
  • Orthomyxoviridae Infections / virology
  • Viral Proteins / biosynthesis
  • Viral Proteins / drug effects


  • Antiviral Agents
  • Viral Proteins
  • Acrolein
  • cinnamaldehyde