The idea that a mushroom can be used to treat one of the most devastating diseases to hit industrialised nations may not be as far fetched as first thought.
Many of the currently available anti-cancer agents are derived form natural products, Paclitaxel (Taxol), and camptothecin (Hycamtin) amongst many others.
Natural products have been used extensively in the Far East as a source for the generation of pharmaceutical-grade medicines to treat a wide variety of diseases, including cancer as well as nutriceuticals (dietary supplements).
The substantial range of medicinal mushroom species from which different bioactive compounds can be derived suggested that the humble mushroom could be a source of novel anti-cancer agents.
Researchers at the Boston University School of Medicine in the USA studied extracts of a type of mushroom called Phellinus linteus.
They tested its effects on prostate cancer cells and found that when it was combined with doxorubicin, a well-known cancer chemotherapy drug, it increased the number of cancer cells killed by the drug.
Studies demonstrated that low doses of doxorubicin or mushroom extract alone could not kill prostate cancer cells.
Higher doses of the drug did kill them, but combining a low dose of doxorubicin with mushroom extract killed even more cancer cells, and did not affect healthy cells.
The researchers could not be sure of how the mushroom extract, provided by Sung-Hoon Kim of Kyung Hee University, South Korea, produced its effect, although they have learned more about its activity in cells.
"This species of mushroom has been reported to have some degree of activity in cancer patients. Our aim was to study what effect, if any, extracts of Phellinus linteus have, but we also need to know precisely how it produces these effects," said lead researcher Chang-Yan Chen
"Only when we have all this information will we be able to make full, safe and effective use of these mushroom extracts in people," he added.
Their findings raise the possibility that a constituent of these mushrooms could one day be used in combination with existing chemotherapy to boost the effectiveness of treatment for some cancer patients.
It might also mean lower doses of chemotherapy would be needed to achieve the same response.
Many important drugs have been developed from natural sources. Fungi has contributed in the development of penicillin and the migraine drug ergotamine.
However compounds from natural products cannot be assumed to be safe and rigorous scientific studies are required to understand the full range of effects they produce.
Previous studies have shown that extracts of Phellinus linteus slowed tumour progression.
"The mushroom has shown promise in combination with one type of chemotherapy drug, but it is still too early to say whether it will be successful in the long run," said Richard Sullivan, director of clinical programmes at Cancer Research UK.
The study is due to be published in the >British Journal of Cancer