Another Danish mushroom has long been a focus of medicinal chemistry research. Siberian shamans have a tradition of ingesting Amanita muscaria (commonly known as fly agaric) in order to achieve a trance-like state. Dr. Ming Chen, an expert on traditional Chinese medicine, investigated other Danish mushrooms and found one that appears highly effective against cancerous cells. |
Researchers
at the University of Copenhagen have explored the active principles of a
Danish mushroom and found that some of the substances it contains are
particularly toxic towards cancer cells. The goal is to synthesize and
refine substances in the mushroom that may be useful in future drug
development.
Asia
has a long and proud tradition of using folk medicines based on natural
products. Many substances found in fungi are today registered as drugs
to support chemotherapy treatments for cancer—among others, the mushroom
Lentinula edodes (commonly known as Shiitake), which is the primary
ingredient in a registered drug extract on the Japanese market.
Fungi is commonly used as folk medicine in many parts of Asia
“Dr.
Ming Chen, a Chinese–Danish physician and specialist in Chinese folk
medicine, has discovered a Danish mushroom which contains toxins that
are especially effective against cancer cells. The Faculty of
Pharmaceutical Sciences has investigated the mushroom’s chemistry and,
based on the substances isolated from it, we are developing a refined
chemical compound that is even more effective and selective,” says Søren
Brøgger Christensen, professor of Natural Products Research at the
Faculty of Pharmaceutical Sciences.
The
project has received DKK 2.6 million in financial support from Protech
Investment Ltd—a spin-off company from a large Chinese producer of
natural medicines.
Screening of Danish poisonous mushrooms
Traditional
medicines derived from natural products are often based on the
experiences of several generations of shamans. Consequently these
inherited experiences are eminent sources of information in the hunt for
new active ingredients with potential for drug development. In Denmark,
mushrooms have primarily been used in food preparation, while some
species have been used as intoxicants. However, they have been largely
absent within Danish folk medicine.
This
lack of folk knowledge led Chen, a senior physician at Sønderborg
Hospital, to begin screening poisonous Danish mushrooms. After an
intense search, he discovered a particular mushroom that is
significantly more toxic towards cancer cells than benign human cells.
At the Faculty of Pharmaceutical Sciences, exchange student Xuemei Liu,
also from China, isolated the active principles.
“This
is a completely new class of natural compounds, which makes the
research results unique,” explains Christensen, who has been
collaborating with Chen since 1990, when they were both members of a
research group that worked on developing an anti-malaria drug based on
an active principle found in Chinese liquorice root.
Chemists surpass nature
When
an interesting natural substance is discovered, it must go through a
development process, in which researchers try to produce new compounds
that allow for the proper selectivity in the body and therefore have
minimal side effects.
“We
were able to isolate the mushroom’s active principles and determine
their chemical structures. The natural compounds are not useful in
themselves because their complex structure means that they cannot be
synthesised in a commercially viable manner. The problem with
sustainable production of the active substance is further complicated by
the fact that tissue of the mushroom—if it is grown from a cell
culture—does not produce the active molecule. Therefore, we attempt to
produce simple and effective analogues—that is, new compounds that have
fine-tuned the effects—so that a simplified molecule carries the same
promising properties with regard to combating cancer cells. In this
manner we use nature as an inspiration for synthetic chemistry,”
Christensen explains.
He emphasises that, as with all new drugs, using the results to develop a viable product will be a long, difficult process.
“Even
though there is a wealth of medicinal mushrooms on the Asian market, it
is unfortunately not possible to transfer Chinese folk medicine
directly to Denmark. One problem is that the active principles in
mushrooms are often tested in combination with forms of chemotherapy
that we do not use in Europe,” Christensen says.
Filed Under: Drug Discovery
