Japanese researchers say they have found a chemical in blueberry leaves that can block the replication of the hepatitis C virus.
The discovery opens up a new avenue for treating chronic hepatitis C infections (HCV).
HCV affects 200 million people worldwide and can eventually lead to cirrhosis or liver cancer.
Currently, there is no vaccine for HCV, and though a drug regimen can clear an HCV infection, the treatment is only about 60 percent effective on average and poses a risk of severe side effects.
Because HCV is localized in the liver and can take 20 years or longer to develop into disease, researchers at University of Miyazaki believe that a dietary supplement might help slow or stop the disease's progression.
The researchers screened nearly 300 different agricultural products for potential compounds that suppress HCV replication and found one in the leaves of blueberries.
The researchers purified the compound and identified it as proanthocyanidin, a polyphenol similar to the beneficial chemicals found in grapes.
Proanthocyanidin can be harmful but researchers noted its effective concentration against HCV was 100 times less than the toxic threshold. Similar chemicals are found in many edible plants, suggesting that proanthocyanidin should be safe as a dietary supplement.
The researchers now aim to explore the detailed mechanisms of how the chemical stops HCV replication.
The study will be published in the Aug. 14 issue of The Journal of Biological Chemistry.