Resveratrol and Radiation

Resveratrol is a phytochemical found in high levels in grape skins. Not only is resveratrol an antioxidant, it has some cancer preventive properties as well. In addition, there’s increasing interest in its potential use in cancer treatment. Since it’s an antioxidant, and since many chemotherapies as well as radiation act by producing free radicals that can damage cellular DNA, researchers and clinicians have been cautious about combining resveratrol with conventional treatment. Dr. Block and his research team have reviewed the clinical literature on antioxidants and chemotherapy and feel this concern is misplaced. Randomized clinical trials in which antioxidants were given with chemotherapy did not show any reduction in anticancer effects compared to chemotherapy given with no antioxidants. In addition, a new paper published in the Journal of Surgical Research recently suggested that concern about combining resveratrol with radiation therapy is similarly misplaced.

Radiation is often used when treating melanoma, both when it is localized and also for the treatment of metastatic melanoma. Researchers at the University of Missouri have already shown that resveratrol enhanced the effect of radiation on prostate cancer cells. They decided to see if resveratrol would boost the effect of radiation on the more resistant melanoma cells. Resveratrol is already known to kill cancer cells, and indeed, when cancer cells were exposed to resveratrol alone, 44% of the cancer cells died. When resveratrol and radiation were both used on melanoma cells, 65% of them died— more than is usually expected with radiation to this relatively resistant cell type.

The Missouri researchers investigated this process at a molecular level as well. Two of the ways that radiation and resveratrol could fight cancer are to slow cancer cell growth or proliferation (i.e., the rapid cell division that cancer cells undergo). Cancer cells could also be killed through cellular suicide or apoptosis. It turns out that the combination of resveratrol and radiation both slowed cancer cell proliferation and caused apoptosis. This double whammy suggests that combining resveratrol and radiation could be very helpful for tumor control. The researchers point out, though, that we need to do clinical trials to find out if this actually works, since it is not yet clear whether resveratrol can be transported effectively in the body to reach the melanoma tumors that are being treated.

Thus, this potent botanical antioxidant paradoxically increases the activity of a free-radical generating therapy. This may seem strange, but as we learn more about how antioxidants work, especially in the context of cancer, this kind of relationship is becoming more plausible. Researchers in India published a paper in April of 2012 in which they showed that resveratrol interacts with both copper and acidity to produce DNA damage and apoptosis. Cancer cells contain more copper than normal cells, and tumors are very acidic. Giving resveratrol to copper-bearing, acidic cancer cells has a very different effect from giving it to lower-copper, normal-acidity normal cells, which are not killed by resveratrol. Other work by these researchers and their colleagues have shown that the interaction of natural antioxidants like resveratrol with copper causes the production of—surprise!—free radicals, which can damage DNA and trigger apoptosis. While we don’t know exactly what is happening when resveratrol interacts with radiation, it’s tempting to think that the free radicals produced by interaction with copper add to the free radicals from radiation therapy, thus producing a synergistic anticancer effect on melanoma cells. A similar mechanism may be at work in the interactions of antioxidants and chemotherapy found by Dr. Block and his research team in their literature review. With these new data, we continue to support the use of natural antioxidants with conventional cancer treatment.

For more information on The Block Center for Integrative Cancer Treatment, call (847) 230-9107 or visit BlockMD.com.