Don't tread on that dandelion as you pass by - it might one day save your life.
Scientists are taking a fresh look at weeds and common plants as a potential source for valuable new drugs and chemical compounds. The search is already under way both by private industry and public laboratories, according to Dr Robert Nash of the UK's Institute of Grassland and Environmental Research. Dr Nash was addressing a session yesterday at the British Association Festival of Science in Sheffield.
Many people were familiar with the idea that the Amazonian rain forest harboured plants that could provide important drugs, but few were aware that potentially useful chemicals were also available from common or garden weeds, trees and vegetables.
Advanced chemical analysis techniques were making it easier to find, identify and extract substances which could be useful in the fight against diseases, he said.
Even something as common as a potato could give us something new. "You can find there are chemicals in there that people didn't know about," he said. Researchers in Britain were finding thousands of promising new compounds every year, potential drugs such as taxol, the anti-cancer drug which was originally derived from the yew tree. The search was helped by folklore and old knowledge about the treatment of illness using plants, he said.
Carnations and bluebells were both once used in treatments for tuberculosis, he said, and both were now being analysed for active chemical agents that might help fight the disease. "There are a lot of chemicals in there and no one has tested them," he said.
Bluebells are also thought to contain potential anti-viral and anti-cancer chemicals. Such chemicals might provide alternative medicines that could be used against organisms that had become resistant to today's treatments.
The approach was an effort to "go back to nature to look for new medicines", stated Dr Maria Ines Chicarelli-Robinson, of Molecular Nature Ltd, a company hunting for new compounds. Plants had been used as medicines in China for 4,000 years, she said. "It is not something that hasn't been done before." Of the world's top 20 drugs, eight originally came from plants and are worth an estimated $10 billion annually. Of the top 100 drugs, about half come from plants, Dr Chicarelli-Robinson said. "In our back yard in weeds in Wales we are finding very interesting chemicals."
Harmless plant viruses may one day be harnessed to help produce vaccines, drugs and chemicals inside plants. Prof Michael Wilson of Horticultural Research International described a new technique which involves taking a piece of a common plant virus and combining it with a gene that is able to make a useful chemical.
This is used to infect a plant and the plant in turn begins to produce the chemical. "You can see that as a factory, a sunlight and water-driven factory," Prof Wilson said. The plant itself did not have to be genetically modified, and when harvested up to half its total weight was made up of the target chemical, well above what any genetically modified plant could deliver.