The substance can shrink breast tumours that were stimulated by progestin, a synthetic hormone used in HRT and birth control pills.
Apigenin kills cancer cells, stops them spreading, and interferes with the genetic codes that encourage cancer growth.
The research team from the University of Missouri say that apigenin injections could be a safe and effective alternative to chemotherapy, which has catastrophic side effects.
Unfortunately, apigenin's cancer-fighting qualities have been demonstrated only in mice studies, and tests on humans need to be carried out before it could become a cancer therapy, say the researchers.
(Source: Hormones and Cancer, 2012; doi: 10.1007/s12672-012-0114-x).