3 February 2000

A University of Queensland researcher has developed an experimental model showing the progression of cancer caused by bracken fern consumption.

The key to the experimental method developed by research fellow Dr Mahmood Shahin is the activation of the fern's carcinogenic compound ptaquiloside (PT) before its effects are observed.

"The method allows the cancer's development to be observed much earlier than in previous studies," Dr Shahin said.

Based on his findings he and Dr Arun Parkash from the Genetic Toxicology Group at the National Research Centre for Environmental Toxicology (NRCET) have also identified molecular bio-markers which can be used in the screening of farm animals to bracken exposure.

"Since it is now shown that PT is transferred into the meat and milk of affected animals, this technique could help prevent human exposure to bracken's cancer-causing effects," Dr Shahin said.

In the four-year study published in five international journals including Mutation Research 1999 and BBRC Journals, Dr Shahin found the cancer caused a bodily response (or mutation) in 60 percent of cases with 40 percent of these resulting in cancer in the mammary gland.

"The new method will enable better prevention and treatment programs for people affected by ptaquiloside-related cancers," he said.

Previous studies have shown a high risk and rate of cancer in people who eat young bracken, eat milk or meat from cows feeding on bracken or who live in bracken-infested areas (compound ingested from airborne pollens).

"Many Canadian and Japanese people favour the young bracken leaves for salads, pickles and soups and these populations have been found to have higher rates of stomach cancer," Dr Shahin said.

He said the experimental mechanism he developed could easily be adapted to test the effects of other compounds on animals and humans.

NRCET is jointly run by the University and Queensland Health. Established in 1991, it is funded by the NHMRC. Research is the main purpose of NRCET and information and consultancy services are provided. It offers a co-ordinated approach to problems of environmental toxicology in Australia as they affected humans and animals.

For more information, contact Dr Mahmood Shahin (telephone 07 3274 9147 at work).