Folk remedy stands up to science probe

British wild flowers and plants used for centuries in folk medicine have genuine medical properties, scientists at the Royal Botanic Gardens, Kew, have found.

The active ingredients of several herbal remedies have been isolated by Kew researchers systematically investigating the potential medicinal properties of the British flora.

Plants such as common figwort, long used as a poultice to dress wounds and skin diseases, contain chemical compounds that really do stimulate wound healing, the scientists have discovered.

Others such as bugle and wild clary contain compounds that may help with inflammatory diseases such as rheumatoid arthritis, or with the uptake of drugs, while bluebells contain compounds that may be used to inhibit the action of viruses.

Led by Professor Monique Simmonds of Kew's Jodrell Laboratory, the researchers have screened more than 60 species of British flowering plants, from stinging nettles to wild basil.

Professor Simmonds says they have not yet found a new wonder drug - but with every plant looked at they have found either a new biological use for the plant, a compound not found in that plant before, or an entirely new compound.

It is the search for wonder drugs that has led to an intense scientific scrutiny of wild flowers and plants in recent years, especially those from the rainforest.

A spectacular discovery that has caught the world's attention is the rosy periwinkle of Madagascar, which proved to be the source of two compounds, vincristine and vinblastine, which have had enormous success in treating cancers such as Hodgkin's disease and childhood leukaemia. Global sales of these drugs now top $100 million a year.

Kew has already had success in finding new drugs from foreign plants; in collaborative projects with other laboratories Professor Simmonds' biological interactions department has identified a potential anti-HIV drug, castanospermine, from an Australian tree, the Moreton Bay chestnut, and a potential anti-cancer compound, tricin, from the bran of a strain of wild rice. Work is continuing on the development of both.

The immediate aim, she says, is pure science: to explain how the traditional medicinal properties of plants actually work, rather than to discover new drugs, although if a "magic bullet" were chanced upon she would by no means ignore it.

The project, in collaboration with King's College, London, is part-financed by the GlaxoSmithKline foundation, but the giant pharmaceutical multinational has no rights over any discoveries.

"Granny was told modern approaches were best," said Professor Simmonds. "But there may have been true wisdom in what Granny did."