The test-tube findings are a long way from cancer patients' bedsides. But Rutgers University natural products researchers Ajay P. Singh, PhD, and Nicholi Vorsa, PhD, are optimistic.
"This has opened up exciting possibilities for therapeutic intervention associated with platinum therapy," Singh and Vorsa say in a news release.
Platinum-based chemotherapy is the mainstay of treatment for ovarian cancer. But over time, the cancers tend to become resistant to the drugs. This means increased chemotherapy dosage -- and increased toxicity to patients.
The researchers note that compounds isolated from cranberries kill human ovary, brain, and prostate cells in laboratory studies. This anticancer activity seems to come from a family of chemicals called proanthocyanidins (PACs).
These "amazing chemical entities," Singh and Vorsa suggest, are unique to cranberries and are not found in other fruits.
Exactly how the cranberry compounds work isn't known. But in their lab studies, Singh and Vorsa tested them against platinum-resistant ovarian cancer cells.
Singh and Vorsa found that in the presence of cranberry extract -- which came from a commercially available, 27% juice cranberry drink -- platinum-based chemotherapy was six times more effective against platinum-resistant ovarian cancer cells.
They will soon begin animal studies to see whether this happens outside the laboratory. For the time being, however, they warn patients not to start drinking significant quantities of cranberry juice without their doctors' permission. Cranberry juice itself, they note, is not a cure for cancer.
Singh and Vorsa reported the findings in a presentation to the 234th national meeting of the American Chemical Society.