The ubiquitous herb and pizza topping oregano has been shown to combat the norovirus, a foodborne infection responsible for winter vomiting disease as well as countless cases of food poisoning.

The new study, which is published in the Journal of Applied Microbiology, focuses on carvacrol — the primary component of oregano essential oil. In lab experiments, the substance was shown to inhibit the viral activity of norovirus, effectively killing the culture. Carvacrol does this by breaking down the tough exterior wall of the pathogen's virions, or virus particles.

Dr. Kelly Bright, a researcher at the University of Arizona and lead researcher of the study, said in a press release that the results offer a better basis for norovirus control in the food industry as well as public settings.  "Carvacrol could potentially be used as a food sanitizer and possibly as a surface sanitizer, particularly in conjunction with other antimicrobials,” she explained. “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.”

An “oregano sanitizer” based on carvacrol would come with numerous benefits. First, the substance only interacts with the external proteins of the pathogen, which means that the norovirus will probably not develop resistance. In the end, it is not the carvacrol that kills, but a secondary antimicrobial. Second, the natural, non-corrosive properties of the substance make it an ideal cleaning agent in hospitals, long-term care facilities, daycare centers, schools, and other environments where bleach and other alcohol-based cleaners may be an issue.

Oregano and Norovirus

The norovirus, which recently made headlines after it sickened over 600 passengers and crew members on a Royal Caribbean cruise ship, is described by the Centers for Disease Control and Prevention as a highly contagious infection that can spread via pretty much all vectors — touching a contaminated surface, ingestion of contaminated food or water, and contact with an infected person. It is thought to account for the majority of food poisoning cases in the U.S. with 20 million recorded illnesses annually.

Unfortunately, if you’re trying to protect yourself from food poisoning, neither pizza nor oregano will do. Instead, what you need is high-concentrate carvacrol oil — a natural product that can be found in your local health food store. “Highly purified carvacrol is commercially available,” the authors wrote in their conclusion. "Since carvacrol is a Generally Regarded As Safe (GRAS) plant antimicrobial, it may be used in applications in which other antimicrobials might not be preferred (e.g., on foods or food contact surfaces, or used in place of corrosive compounds on surfaces).”

 

Source: Bright K, Gilling D, Masaaki K, Jason T. Antiviral efficacy and mechanisms of action of organo essential oil and its primary component carvacrol against murine norovirus. Journal of Applied Microbiology. 2014.