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Posts in ‘red grapes’

Cancer Treatment: How Eating Fruit And Vegetables Can Improve Cancer Patients’ Response To Chemotherapy

Oct 29

ScienceDaily (Oct. 24, 2008) — The leading cause of death in all cancer patients continues to be the resistance of tumor cells to chemotherapy, a form of treatment in which chemicals are used to kill cells.

Now a study by UC Riverside biochemists that focuses on cancer cells reports that ingesting apigenin – a naturally occurring dietary agent found in vegetables and fruit – improves cancer cells’ response to chemotherapy.

Xuan Liu, a professor of biochemistry, and Xin Cai, a postdoctoral researcher working in her lab, found that apigenin localizes tumor suppressor p53, a protein, in the cell nucleus – a necessary step for killing the cell that results in some tumor cells responding to chemotherapy.

The study, published in the online early edition of the Proceedings of the National Academy of Sciences, provides a novel approach to conquer tumor resistance to chemotherapy, and suggests an avenue for developing safe chemotherapy via naturally occurring agents.

Normally, cells have low levels of p53 diffused in their cytoplasm and nucleus. When DNA in the nucleus is damaged, p53 moves to the nucleus where it activates genes that stop cell growth and cause cell death. In this way, p53 ensures that cells with damaged DNA are killed.

In many cancers, p53 is rendered inactive by a process called cytoplasmic sequestration. Apigenin is able to activate p53 and transport it into the nucleus, resulting in a stop to cell growth and cell death.

“In therapy you want to kill cancer cells,” explained Cai, the first author of the research paper. “But to stop cell growth and to kill the cell, p53 first needs to be moved to the cell’s nucleus to function. Apigenin is very effective in localizing p53 this way.”

Apigenin is mainly found in fruit (including apples, cherries, grapes), vegetables (including parsley, artichoke, basil, celery), nuts and plant-derived beverages (including tea and wine). It has been shown by researchers to have growth inhibitory properties in several cancer lines, including breast, colon, skin, thyroid and leukemia cells. It has also been shown to inhibit pancreatic cancer cell proliferation.

“Our study advocates the inclusion of vegetables and fruit in our daily diet to help prevent cancer,” said Liu, the research paper’s coauthor.

The National Institutes of Health supported the five-year study.

Next in their research Liu and Cai plan to design therapies for cancer by finding compounds that are like, but perform better than, apigenin.


Adapted from materials provided by University of California - Riverside

Cancer Preventive Properties Identified In Resveratrol, Found In Red Wine, Red Grapes

Aug 22

ScienceDaily (July 7, 2008) — Early laboratory research has shown that resveratrol, a common dietary supplement, suppresses the abnormal cell formation that leads to most types of breast cancer, suggesting a potential role for the agent in breast cancer prevention. Resveratrol is a natural substance found in red wine and red grapes. It is sold in extract form as a dietary supplement at most major drug stores.

“Resveratrol has the ability to prevent the first step that occurs when estrogen starts the process that leads to cancer by blocking the formation of the estrogen DNA adducts. We believe that this could stop the whole progression that leads to breast cancer down the road,” said Eleanor G. Rogan, Ph.D., a professor in the Eppley Institute for Research in Cancer and Allied Diseases at the University of Nebraska Medical Center.

Rogan was the lead author of the report that was published in the July 2008 issue of Cancer Prevention Research, a journal of the American Association for Cancer Research.

For the current study, Rogan and colleagues measured the effect of resveratrol on cellular functions known to contribute to breast cancer.

The formation of breast cancer is a multi-step process which differs depending on type of disease, a patient’s genetic makeup and other factors. However, scientists know that many breast cancers are fueled by increased estrogen, which collects and reacts with DNA molecules to form adducts. Rogan and colleagues found that resveratrol was able to suppress the formation of these DNA adducts.

“This is dramatic because it was able to be done with fairly low concentrations of resveratrol to stop the formation of these DNA adducts in the cells we studied,” said Rogan. Although researchers experimented with up to 100 µmol/L of resveratrol, the suppression of DNA adducts was seen with 10 µmol/L. A glass of red wine contains between 9 and 28 µmol/L of resveratrol.

The researchers also found that resveratrol suppressed the expression of CYP1B1 and the formation of 2,3,7,8-Tetrachlorodibenzo-p-dioxin, two known risk factors for breast cancer.

Rogan said resveratrol works by inducing an enzyme called quinone reductase, which reduces the estrogen metabolite back to inactive form. By making estrogen inactive, resveratrol decreases the associated risk.

The current study was conducted in laboratory cultures, and will need to be confirmed in larger human trials, Rogan said.


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