ScienceDaily (Jan. 6, 2010) — Eating fruit, such as pomegranates, that contain anti-aromatase phytochemicals reduces the incidence of hormone-dependent breast cancer, according to results of a study published in the January issue of Cancer Prevention Research, a journal of the American Association for Cancer Research.

Pomegranate is enriched in a series of compounds known as ellagitannins that, as shown in this study, appear to be responsible for the anti-proliferative effect of the pomegranate.

“Phytochemicals suppress estrogen production that prevents the proliferation of breast cancer cells and the growth of estrogen-responsive tumors,” said principal investigator Shiuan Chen, Ph.D., director of the Division of Tumor Cell Biology and co-leader of the Breast Cancer Research Program at City of Hope in Duarte, Calif.

Previous research has shown that pomegranate juice — punica granatum L — is high in antioxidant activity, which is generally attributed to the fruit’s high polyphenol content. Ellagic acid found in pomegranates inhibits aromatase, an enzyme that converts androgen to estrogen. Aromatase plays a key role in breast carcinogenesis; therefore, the growth of breast cancer is inhibited.

Chen, along with Lynn Adams, Ph.D., a research fellow at Beckman Research Institute of City of Hope, and colleagues, evaluated whether phytochemicals in pomegranates can suppress aromatase and ultimately inhibit cancer growth.

After screening and examining a panel of 10 ellagitannin-derived compounds in pomegranates, the investigators found that those compounds have the potential to prevent estrogen-responsive breast cancers. Urolithin B, which is a metabolite produced from ellagic acid and related compounds, significantly inhibited cell growth.

“We were surprised by our findings,” said Chen. “We previously found other fruits, such as grapes, to be capable of the inhibition of aromatase. But, phytochemicals in pomegranates and in grapes are different.”

According to Gary Stoner, Ph.D., professor in the Department of Internal Medicine at Ohio State University, additional studies will be needed to confirm the chemopreventive action of Urolithin B against hormone-dependent breast cancer.

“This is an in vitro study in which relatively high levels of ellagitannin compounds were required to demonstrate an anti-proliferative effect on cultured breast cancer cells,” said Stoner, who is not associated with this study. “It’s not clear that these levels could be achieved in animals or in humans because the ellagitannins are not well absorbed into blood when provided in the diet.”

Stoner believes these results are promising enough to suggest that more experiments with pomegranate in animals and humans are warranted.

Powel Brown, M.D., Ph.D., medical oncologist and chairman of the Clinical Cancer Prevention Department at the University of Texas M. D. Anderson Cancer Center, agreed with Stoner’s sentiments and said these results are intriguing. He recommended that future studies focus on testing pomegranate juice for its effect on estrogen levels, menopausal symptoms, breast density or even as a cancer preventive agent.

“More research on the individual components and the combination of chemicals is needed to understand the potential risks and benefits of using pomegranate juice or isolated compounds for a health benefit or for cancer prevention,” Brown said. “This study does suggest that studies of the ellagitannins from pomegranates should be continued.”

Until then, Stoner said people “might consider consuming more pomegranates to protect against cancer development in the breast and perhaps in other tissues and organs.”

Adapted from materials provided by American Association for Cancer Research, via EurekAlert!, a service of AAAS.

ScienceDaily (Dec. 27, 2009) — A new study finds that the herb milk thistle may help treat liver inflammation in cancer patients who receive chemotherapy. Published early online in Cancer, a peer-reviewed journal of the American Cancer Society, the study indicates that the herb could allow patients to take potent doses of chemotherapy without damaging their liver.

Chemotherapy drugs frequently cause inflammation in the liver, and when they do, doctors must often lower patients’ doses or stop administering the therapies altogether. Clinical studies have investigated using milk thistle to treat liver damage from cirrhosis (from alcohol) or toxins (such as mushroom poisoning). Despite limited study data, the herb is often used for the treatment of chemotherapy associated liver problems. To test whether milk thistle could help treat chemotherapy associated liver problems, Kara Kelly, MD, of the New York-Presbyterian Hospital/Columbia University Medical Center’s Herbert Irving Comprehensive Cancer Center in New York City and colleagues conducted a randomized, controlled, double blind study in children with acute lymphoblastic leukemia (ALL), who commonly experience this side effect.

Fifty children with ALL were enrolled in the study and were randomized to receive milk thistle or placebo for 28 days. At the start of the study, all of the children had evidence of liver inflammation as measured by elevations in blood levels of the liver enzymes, aspartate amino transferase (AST) and amino alanine transferase (ALT). When the investigators performed liver function tests on the children at day 56 (28 days after receiving the herb or placebo), children receiving milk thistle had improvements in their liver enzymes compared with children receiving a placebo. Specifically, the group that took milk thistle had significantly lower levels of AST and a trend towards significantly lower levels of ALT. Taking milk thistle also seemed to help keep fewer patients from having to lower the dose of their medications: chemotherapy doses were reduced in 61 percent of the group receiving milk thistle, compared with 72 percent of the placebo group. In addition, milk thistle appeared to be safe for consumption.

The researchers also studied the effects of combining milk thistle with chemotherapy on leukemia cells grown in the laboratory. They found that milk thistle does not interfere with the cancer-fighting properties of chemotherapy.

“Milk thistle needs to be studied further, to see how effective it is for a longer course of treatment, and whether it works well in reducing liver inflammation in other types of cancers and with other types of chemotherapy,” said Dr. Kelly. “However, our results are promising as there are no substitute medications for treating liver toxicity.”

Ladas et al. A randomized, controlled, double-blind, pilot study of milk thistle for the treatment of hepatotoxicity in childhood acute lymphoblastic leukemia (ALL). Cancer, 2009; DOI: 10.1002/cncr.24723