An exotic mushroom widely used in oriental medicine contains chemicals that may fight breast cancer, says a new study.
Extracts of the fungus, Phellinus linteus, have been used for centuries by eastern healers, who believe it has the power to rejuvenate and extend life.
Recent research has indicated the mushroom can hold back the growth of skin, lung and prostate cancer cells.
Now, the latest research, conducted in the United States, has revealed a clue to the mechanism behind the mushroom's remarkable properties.
Scientists at the Methodist Research Institute in Indianapolis, who are working with breast-cancer cells have found evidence that the fungus blocks the activity of an enzyme called AKT.
The enzyme, a biological catalyst, is known to control signals that lead to cell growth and the development of new blood vessels feeding tumours.
Cancers need a good blood supply to survive, and send out chemical messages which promote the construction of new blood vessels, a process known as angiogenesis.
Scientists are actively exploring ways to block angiogenesis as a cancer therapy.
"We saw a number of positive results from our investigation on aggressive human breast-cancer cells, including a lower rate of uncontrolled growth of new cancer cells, suppression of their aggressive behaviour and the formation of fewer blood vessels that feed cancer cells essential nutrients," The Scotsman quoted Dr Daniel Sliva, who led the research, as saying.
"We're not yet able to apply this knowledge to modern medicine, but we're excited that we can begin to explain how this ancient medicine works by acting on specific molecules.
"We hope that our study will encourage more researchers to explore the use of medicinal mushrooms for the treatment of cancer," Sliva said.
The research appears in the British Journal of Cancer.