Berry Bad News for Cancer Cells
By Judy McBride
December 28, 2001
Fruits and vegetables contain a wide array of compounds--or
phytonutrients--reported to have anti-cancer activity in cell cultures. And
berries are reportedly rich in antioxidant phytonutrients.
Now, Agricultural Research
Service and Clemson University
scientists are probing an assortment of berries, as well as muscadine grapes--a
native of the Southeast--for their ability to inhibit the growth of cell lines
originally cultured from breast and cervical tumors.
Preliminary findings are very promising. But their ultimate
efficacy in people will have to be established through clinical trials.
Various extracts from muscadine grapes, raspberries and
strawberries cut the growth of breast cancer cell lines and cervical cancer
cell lines by more than half, according to
David E. Wedge,
a plant pathologist at ARS' Natural Products Utilization
Research Unit in Oxford, Miss.
Wedge and ARS chemist
Meepagala prepare extracts of the berries using various solvents and
different parts of the fruit, such as juice, skin and seeds. They send the
extracts to Lyndon L. Larcom, professor of microbiology and molecular medicine
at Clemson University in South Carolina, for assays on the cancer cell lines.
After skin cancer, breast cancer is the most frequently
diagnosed cancer in U.S. women and is second only to lung cancer in
Larcom found extracts from blueberries and blackberries
ineffective against the two cervical cancer cell lines being tested. But they
suppressed breast cancer cell growth, with each fruit suppressing a different
cell line. Larcom uses two breast cancer cell lines in these assays because
their estrogen requirements are different.
Specific muscadine grape extracts suppressed a third breast
cancer cell line much more than they suppressed a line of healthy cells from
the same donor. That means it's more selective for cancer cells.
Cancer develops in stages, according to Larcom. First, a normal
cell undergoes mutations. Then, the mutated cells must be stimulated to keep
dividing as they get cut off from the blood supply. Finally, more mutations
enable cells from a localized tumor to invade other tissues.
The findings reported here deal with suppression of the second
stage. The researchers are also assaying the berry and grape extracts for their
ability to prevent mutations.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.