Avian coronavirus infectious bronchitis virus susceptibility to botanical oleoresins and essential oils in vitro and in vivo

Virus Res. 2010 Apr;149(1):86-94. doi: 10.1016/j.virusres.2010.01.006. Epub 2010 Jan 21.


Anti-coronaviral activity of a mixture of oleoresins and essential oils from botanicals, designated QR448(a), was examined in vitro and in vivo. Treatment of avian infectious bronchitis virus (IBV) with QR448(a) reduced the virus titer as measured in two laboratory host systems, Vero E6 cells and embryonating eggs. The effect of QR448(a) on IBV in chickens was also investigated. Administering QR448(a) to chickens at a 1:20 dilution by spray, 2h before challenge with IBV was determined to be the most effective treatment. Treatment decreased the severity of clinical signs and lesions in the birds, and lowered the amount of viral RNA in the trachea. Treatment with QR448(a) protected chickens for up to 4 days post-treatment from clinical signs of disease (but not from infection) and decreased transmission of IBV over a 14-day period. Anti-IBV activity of QR448(a) was greater prior to virus attachment and entry indicating that the effect is virucidal. In addition, QR448(a) had activity against both Massachusetts and Arkansas type IB viruses, indicating that it can be expected to be effective against IBV regardless of serotype. To our knowledge, this is the first report on the in vivo use of a virucidal mixture of compounds effective against the coronavirus IBV.

MeSH terms

  • Animals
  • Antiviral Agents / pharmacology*
  • Antiviral Agents / therapeutic use*
  • Chick Embryo
  • Chickens
  • Chlorocebus aethiops
  • Coronavirus Infections / drug therapy
  • Coronavirus Infections / transmission
  • Disease Models, Animal
  • Disease Transmission, Infectious / prevention & control
  • Infectious bronchitis virus / drug effects*
  • Oils, Volatile / pharmacology*
  • Oils, Volatile / therapeutic use*
  • Plant Extracts / pharmacology*
  • Plant Extracts / therapeutic use*
  • Poultry Diseases / drug therapy
  • Treatment Outcome
  • Vero Cells
  • Virus Attachment / drug effects
  • Virus Internalization / drug effects
  • Virus Replication / drug effects


  • Antiviral Agents
  • Oils, Volatile
  • Plant Extracts
  • oleoresins