In a new in vitro experiment, grape seed extract caused human leukemia cells to commit cell suicide (a process known as apoptosis).
In past studies, grape seed extract has shown activity in a number of laboratory cancer cell lines, including skin, breast, colon, lung, stomach and prostate cancers. However, until now, the extract had not been tested in hematological cancers such as leukemia. In addition, the precise mechanism of action by which it has demonstrated activity against other cancer lines has never been revealed. Consequently, researchers undertook a new study on grape seed extract to determine what effects grape seed extract has on leukemia cells.
The scientists, who report their findings in Clinical Cancer Research, treated human leukemia cells with varying doses of grape seed extract. Their findings indicated that within 24 hours, 76 percent of leukemia cells had died after being exposed to the higher dose of the extract. The extract did not affect normal cells.
The researchers also investigated the cell signaling pathway associated with use of grape seed extract that led the cancer cells to commit suicide. They found that the extract activates JNK, a protein that regulates the apoptosis pathway. To confirm this finding, they used an agent to inhibit JNK and found that the grape seed was then ineffective. Additionally, they silenced the JNK gene and found that this too canceled out grape seed extract’s ability to cause cell suicide in the leukemia cells, confirming that the extract does indeed work by activating JNK.
"These results could have implications for the incorporation of agents such as grape seed extract into prevention or treatment of hematological malignancies and possibly other cancers," said the study"s lead author, Xianglin Shi, Ph.D., in a press release issued by the American Association for Cancer Research. "What everyone seeks is an agent that has an effect on cancer cells but leaves normal cells alone, and this shows that grape seed extract fits into this category." After calling for more studies to confirm the results of the findings, Shi said, “"This is a natural compound that appears to have relatively important properties