The study conducted at the Lombardi Comprehensive Cancer Center explains how pentameric procyanidin (pentamer), a natural compound found in cocoa, deactivates a number of proteins that likely work in concert to push a cancer cell to continually divide.
"There are all kinds of chemicals in the food we eat that potentially have effects on cancer cells, and a natural compound in chocolate may be one," said the lead author, Robert B. Dickson, Ph.D., professor of oncology.
Chocolate is made from the beans of cacao trees and is rich in natural antioxidants known as flavonoids. These antioxidants may protect cells from the damage caused by unstable molecules known as free radicals, which are thought to contribute to both heart disease and cancer development. The primary family of flavonoids contributing to the antioxidant benefit in chocolate is the procyanidins, and of the various types of procyanidins, pentamer seem to be strongest, according to a number of studies.
Given this, the Georgetown researchers looked at what happened when they used a purified preparation of pentamer on a variety of breast cancer cells, compared to treatment on normal breast cells.
What they located were two well known tumour suppressor genes as well as two other proteins known to be involved in regulating the cell cycle - the progression of a cell from a state of no action into division and growth. They specifically found that the breast cancer cells stopped dividing when treated with pentamer and that all four proteins were inactivated.
Dickson notes that "the novel aspect here is that a pattern of several regulatory proteins are jointly deactivated, probably greatly enhancing the inhibitory effect compared to targeting any one of the proteins singly. That is also why the compound seems to work on cancer cells, irrespective of whether any of these single genes are mutated, which often happens in cancer cells."
MEDICA.de; Source: Georgetown University Medical Center