Cancer research: Blueberry leaves can help stop Hepatitis C Virus

Hepatitis C is an infectious disease affecting the liver, caused by the hepatitis C virus (HCV). In some cases, those with cirrhosis will go on to develop liver failure or other complications of cirrhosis, including liver cancer. An estimated 270-300 million people worldwide are infected with hepatitis C. Hepatitis C is a strictly human disease. No vaccine against hepatitis C is available. This virus was first isolated in 1989, and hence is a relatively new virus. It is to find vaccines that can reduce the number of people infected by preventing high risk people from getting the virus that research is targeting. There is one research that seems to have found a chemical that can stop the virus (link to article):

Hiroaki Kataoka and colleagues at the University of Miyazaki (U-M) in Japan believed that since HCV is localised in the liver and can take 20 years or more to develop into disease, a dietary supplement might help slow or stop disease progression.
So they screened nearly 300 different agricultural products for potential compounds that suppress HCV replication and uncovered a strong candidate in the leaves of rabbit-eye blueberry (native to the southeastern US). They purified the compound and identified it as proanthocyandin (a polyphenol similar to the beneficial chemicals found in grapes and wine). While proanthocyandin can be harmful, Kataoka and colleagues noted its effective concentration against HCV was 100 times less than the toxic threshold, said a U-M statement.

All such research eventually suceeds when these chemicals succeed in their trials and are rendered fit to be used in humans.