A researcher at the University of Ulster may have found new antibiotics in exotic flora. Dick Ahlstrom reports
Plants have been doing it for millions of years. Now we are learning their secrets: how to keep bacterial attack in check using natural antibiotics.
Franklin Smyth, professor of bioanalytical chemistry at the University of Ulster, has just returned from Australia with a number of possible new antibiotics in his suitcase. He has opened up a collaboration with Dr Peter Brooks of the University of the Sunshine Coast, in Queensland; the two hope to extend the collaboration to include researchers in Chile, Mauritius and New Zealand.
"Over the past few years we have been looking at Chinese and Indian plants for new antibiotic substances. We decided to extend this to Australia," says Smyth. "It is all connected to what the natural world has been doing while we were making modern drugs. By going back to the natural world we are trying to understand how plants are able to develop resistance to infection."
The work in Australia is being aided by local knowledge of plants and their use as medicines by the Aboriginal population. As Aborigines become more Westernised, however, they are leaving behind lore built up over 40,000 years.
"Many of the traditional Aboriginal uses of plants are now lost," says Smyth. "Several reviews have attempted to record the traditional medicinal uses of Australian plants, with much of this information being collected from letters and records of early white settlers and also government reports."
This has helped the researchers to target flora for analysis. They have already found plants with very promising antibiotic properties, says Smyth. The process is relatively simple at first, but it becomes more complicated as the focus narrows to analytical chemistry. The researchers crush the plants, then use them to make extracts using a solvent such as methanol. Next they test them for antibiotic properties; if they find any, they bring in the heavy technological guns.
The technological process first involves high-performance liquid chromatography, to fractionate the molecules in the extracts. Fractions of interest are next atomised and ionised using electro-spray ionisation. These samples are then studied using mass spectrometry to determine their molecular make-up.
"In the West we have used man-made antibiotics very successfully to treat bacterial infections, but now bugs are starting to become resistant to them," Smyth says.
"We hope to find a compound that will be a natural antibiotic that will treat bacterial infections now resistant to everyday man-made antibiotics given out by GPs and help hospitals worried about the growing rise of superbugs. But it is early days yet."
An important part of the programme involves extending the reach of the research group by bringing in teams from further afield. "The use of medicines derived from plants extends across almost all cultures and over many centuries," says Smyth. "In India and China herbal medicines are still widely used, increasingly now in the West, and so we are returning to the plant world to see if we can find antibiotics that can be used effectively to treat bacterial infections."
For this reason his journey back from Australia included visits to Chile and New Zealand. The extended group of researchers is now applying for financial support to fund a more ambitious trawl for what could be life-saving plants.