TUCSON, Arizona -

A familiar herb could help fight the dreaded norovirus.

Norovirus is an intestinal illness that often affects people in nursing homes, hospitals, schools and on cruise ships. It's the leading cause of vomiting and diarrhea around the world.

A study by researchers at the University of Arizona found that a substance in oregano oil called carvacrol may be an effective weapon against norovirus.

Carvacrol gives oregano its distinctive smell and flavor. But in the lab, researchers say carvacrol also broke down the tough outer coat of the norovirus.

"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," said Dr. Kelly Bright, who led the research.

The idea is appealing. Carvacrol would be a non-toxic, harmless product to use in facilities where people may be sensitive to bleach or alcohol-based cleaners. Because carvacrol acts on the external proteins of the virus, experts say it is also unlikely that norovirus would develop resistance to it.

Unfortunately, you won't gain any protection by eating lots of pizza. Researchers say concentrated carvacrol, although non-toxic, would cause a burning sensation and numbness of the tongue.

The complete study is published in the Journal of Applied Microbiology.