Licorice Root Extract Shows Antitumor Activity

A substance extracted from licorice root, Licochalcone-A, has been shown to have antitumor activity in acute leukemia, breast, and prostate cancer cell lines by lowering the amount of bcl-2, a drug-resistant protein. Excess amounts of this protein are frequently associated with these cancers. These findings were presented at the International Conference on Molecular Cancer Therapeutics sponsored by the American Association of Cancer Research (AACR), National Cancer Institute (NCI), and European Organization for Research and Treatment of Cancer (EORTC).

Protein May Cause Resistance to Anticancer Agents

“Bcl-2 is a protein that seems to cause resistance to anticancer agents. By decreasing the level of bcl-2, Licochalcone-A may increase tumor sensitivity to anticancer agents,” said Robert DiPaola, MD, assistant professor of medicine at the Robert Wood Johnson Medical School and the Cancer Institute of New Jersey, and senior investigator of this study. “Interestingly, neither of its parent compounds—chalcone and estradiol—has the same effect.”

Recent studies have demonstrated that certain estrogens may regulate the cancer gene bcl-2, which is produced in excess in some cancer cells and causes resistance to chemotherapy and most other traditional cancer treatments. It is sometimes referred to as a resistance protein. Licochalcone-A belongs to a class of compounds that sometimes have both estrogenic and antitumor activity. However, this is the first time that a compound from this class has been linked directly to bcl-2 and shows antitumor activity against hormone-responsive and hormone-unresponsive tumors.