Resveratrol, a compound found in grapes and red wine can make prostate cancer cells more susceptible to radiation and so can help in full recovery from the cancer, says a new study.

Researchers from University of Missouri found that introducing this compound during radiation therapy improved prostate cancer treatment.

"Other studies have noted that resveratrol made tumor cells more susceptible to chemotherapy, and we wanted to see if it had the same effect for radiation therapy. We found that when exposed to the compound, the tumor cells were more susceptible to radiation treatment, but that the effect was greater than just treating with both compounds separately," said Michael Nicholl, from the MU School of Medicine.

Prostate tumor cells contain two proteins - perforin and granzyme B - that can kill the cells. But these are present in small amounts in the cells.

Researchers found that when resveratrol is introduced in the cells, the proteins are highly expressed. After radiation therapy, 97 percent of the tumor cells died.

"It is critical that both proteins, perforin and granzyme B, are present in order to kill the tumor cells, and we found that the resveratrol helped to increase their activity in prostate tumor cells," Nicholl said. "Following the resveratrol-radiation treatment, we realized that we were able to kill many more tumor cells when compared with treating the tumor with radiation alone. It's important to note that this killed all types of prostate tumor cells, including aggressive tumor cells."

Resveratrol is found in grapes and in many over-the counter drugs, but the dosage required to make the radiation therapy more efficient may make people uncomfortable, researchers say.

"We don't need a large dose at the site of the tumor, but the body processes this compound so efficiently that a person needs to ingest a lot of resveratrol to make sure enough of it ends up at the tumor site. Because of that challenge, we have to look at different delivery methods for this compound to be effective," Nicholl added. "It's very attractive as a therapeutic agent since it is a natural compound and something that most of us have consumed in our lifetimes."