Published Date: 16 April 2008
A MUSHROOM widely used in oriental medicine may combat breast cancer by slowing the growth of tumours and starving them of blood, a study has shown.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.
It is also believed to increase the number of prostate cancer cells killed by the chemotherapy drug doxorubicin.
The latest research, conducted in the United States, has revealed a clue to the mechanism behind the mushroom's remarkable properties. Working with breast-cancer cells, scientists at the Methodist Research Institute in Indianapolis 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.
Dr Daniel Sliva, who led the research, said: "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.
"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."
The research appears in the British Journal of Cancer. But Dr Lesley Walker, director of information at the charity Cancer Research UK, which owns the journal, sounded a note of caution.
She said: "Although natural products have been used to develop many important drugs, there is no guarantee that they are all safe or will be effective in the clinic.
"The results from this study are interesting, but it's certainly too early to advise people to stock up on mushrooms. Further research will be needed before we will know if mushroom extracts can be used to treat cancer patients."
Phellinus linteus is used in Chinese, Korean and Japanese medicine, where it is known as "song gen", "sang-hwang", and "meshimakobu".
Many species of mushrooms and fungi used in folk medicine for thousands of years are being studied by researchers. Maitake, shiittake, chaga and reishi are prominent among those being looked at for their potential anti-cancer, anti-viral, or immunity-enhancing properties.
Psilocybin, originally an extract of certain psychedelic mushrooms, is being studied for its ability to help people suffering from mental illness, such as obsessive-compulsive disorder.
Minute amounts have been reported to stop cluster and migraine headaches. Fly-agaric mushrooms, more commonly known as magic mushrooms, have been the subject of homeopathic remedies.
Homeopaths have long insisted on the benefits of mushrooms in treatments. Diane Goodwin, a registered homeopath in Edinburgh, said there were hundreds of remedies which involved the use of mushrooms.
She said: "The fungi we use can be for loads of different symptoms and cover lots of different types of illness. For instance, there are several remedies involving mushrooms that I tend to use for people who are suffering great anxiety."