A research group from the University of Arizona in the USA have found that the main active component in oregano oil, carvacrol, is able to inactivate non-enveloped mouse norovirus (a human norovirus surrogate) within an hour of exposure.
The researchers investigated the activity of both oregano oil and carvacrol against the virus. They found that both produced a reduction in virus infectivity within 15 minutes of exposure, but infectivity then remained stable on further exposure to oregano oil, whereas carvacrol produced much greater reductions after an hour.
Transmission electron microscopy revealed that both antimicrobials seemed to act directly on the virus capsid and then its RNA. Exposure to carvacrol eventually caused the capsid to disintegrate.
Lead researcher Dr Kelly Bright commented, “Carvacrol could potentially be used as a food sanitizer and possibly as a surface sanitizer, particularly in conjunction with other antimicrobials. We have some work to do to assess its potential but carvacrol has a unique way of attacking the virus, which makes it an interesting prospect.”
A report on the research is published in the Journal of Applied Microbiology and an abstract can be found here.