Sourcing drugs from traditional medicines, known as bioprospecting, has been given a boost by a study showing three geographically-separate cultures using similar plants for similar medicinal purposes.
A team of researchers led by Dr Julie Hawkins of the University of Reading collated information on medicinal plant use from New Zealand, Nepal and South Africa, recording what plants were used to treat what conditions, then used genetic data to build up a phylogenetic, or family tree of the samples.
The study, published in the Proceedings of the National Academy of Sciences, also found that closely-related plants often share medicinal properties.
"Our study is unique in being a phylogenetic analysis of traditionally used plants spanning whole floras and different cultures," the researchers write.
"We demonstrate shared phylogenetic patterns across the floras: related plants from these regions are used to treat medical conditions in the same therapeutic areas."
The phylogenetic analysis revealed 'hot nodes' of plants used in traditional medicine - clusters of closely-related plants all sharing similar medicinal properties.
The findings support the somewhat neglected approach of using traditional medicine to guide the search for new medicinal compounds, and suggests that scientists looking for new medicines might benefit from focusing their search on the relatives of known medicinal plants.
The researchers say the current approach to bioprospecting tends to involve a scattergun approach of random collection and analysis of enormous quantities of samples.
"Automated high-throughput screening has enabled the rapid testing of thousands of samples against specific targets and requires little or no previous knowledge of the medicinal uses of the plant," they write.
"We propose a more sophisticated framework of identifying plants with high medicinal potential based on traditional medicine, combining two criteria: phylogenetic signal and cross-cultural agreement."
Associate Professor Joanna Jamie, co-director of the Indigenous Bioresources Research Group at Macquarie University in Sydney, says the study highlights the benefit of developing strong relationships with custodians of traditional knowledge.
"It's a partnership, capacity-building, and the term 'bioprospecting' doesn't give that justice," says Jamie.
While the pharmaceutical industry has had some success with its large-scale approach to the challenge, Jamie believes there is a shift towards engaging with traditional knowledge.
"There has certainly been a lot of papers that now show that natural products are still where you get the majority of new medicines and traditional medicine is a big part of how we've identified the natural products," Jamie says.
Reference: Biana Nogrady. ABC Science. 11.9.12.