Cranberry Compounds Shown to Improve Effectiveness of Chemotherapy for Ovarian Cancer

At the 234th national meeting of the American Chemical Society, researchers from Rutgers University, NJ, presented findings that suggest A-type proanthocyanidins in cranberry extract may help improve the effectiveness of platinum drugs used to fight ovarian cancer. Ovarian cancer is the seventh most common cancer and the fifth leading cause of cancer death among women in the United States, according to the Centers for Disease Control and Prevention.

Chemotherapy using platinum drugs, including cisplatin and paraplatin, is a mainstay treatment for ovarian cancer. However, cancer cells tend to develop resistance to platinum therapy, and higher doses of the drugs can cause unwanted side effects, including nerve damage and kidney failure.

For this study, the researchers treated platinum-resistant ovarian cancer cells with various doses of a purified extract of commercially available cranberry drink (containing 27% pure juice). They exposed the cells to the platinum drug paraplatin and compared them to cells that were not exposed to the extract.

Paraplatin killed six times more cancer cells that were pretreated with juice extract compared to cells that were exposed to the cancer drug alone. The extract also slowed the growth and spread of some cancer cells. The maximum amount of juice extract given to the cells was the human equivalent of about a cup of cranberry juice.

A-type proanthocyanidins are unique to cranberries and not found in other fruits. According to other research, these compounds appear to bind to and block certain tumor promoter proteins found in the ovarian cancer cells. The result is that the cancer cells become more vulnerable to attack from the platinum drugs.

The researchers consider the findings preliminary, and emphasize that cranberry extract is not a cure for cancer.