Licorice, used extensively in the Chinese traditional medicine, could help in the fight against tooth decay and gum disease.
Two substances in licorice kill the major bacteria responsible for tooth decay and gum disease, the leading causes of tooth problems, it has been reported in ACS' Journal of Natural Products.
Stefan Gafner and colleagues explain that the dried root of the licorice plant is a common treatment in Chinese traditional medicine, especially as a way to enhance the activity of other herbal ingredients or as a flavoring. Despite the popularity of licorice candy in the U.S., licorice root has been replaced in domestic candy with anise oil, which has a similar flavor. Traditional medical practitioners use dried licorice root to treat various ailments, such as respiratory and digestive problems, but few modern scientific studies address whether licorice really works. (Consumers should check with their health care provider before taking licorice root because it can have undesirable effects and interactions with prescription drugs.)
They found that two of the licorice compounds, licoricidin and licorisoflavan A, were the most effective antibacterial substances. These substances killed two of the major bacteria responsible for dental cavities and two of the bacteria that promote gum disease. One of the compounds licoricidin also killed a third gum disease bacterium. The researchers say that these substances could treat or even prevent oral infections.