Phylogenies reveal predictive power of traditional medicine in bioprospecting

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 109; no. 39; pp. 15835 - 15840
• Main Authors: Saslis-Lagoudakis, C. Haris, Savolainen, Vincent, Williamson, Elizabeth M, Forest, Félix, Wagstaff, Steven J, Baral, Sushim R, Watson, Mark F, Pendry, Colin A, Hawkins, Julie A
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 25.09.2012; National Acad Sciences
• Subjects: Base Sequence; Biodiversity; Biological Sciences; Biological taxonomies; cross cultural studies; DNA, Plant - genetics; drugs; Ethnobotany; Flora; Flowers & plants; Genera; Herbal medicine; Humans; indigenous knowledge; International comparisons; Medicinal plants; Medicine, African Traditional; Medicine, East Asian Traditional; Molecular Sequence Data; Phylogenetics; Phylogeny; Phylogeography - methods; Phytotherapy - methods; Plant taxonomy; Plants; Plants, Medicinal - genetics; screening; Sequence Analysis, DNA; Social Sciences; Traditional medicine; New Zealand; South Africa; Nepal; Cape Province South Africa
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1202242109

There is controversy about whether traditional medicine can guide drug discovery, and investment in bioprospecting informed by ethnobotanical data has fluctuated. One view is that traditionally used medicinal plants are not necessarily efficacious and there are no robust methods for distinguishing those which are most likely to be bioactive when selecting species for further testing. Here, we reconstruct a genus-level molecular phylogenetic tree representing the 20,000 species found in the floras of three disparate biodiversity hotspots: Nepal, New Zealand, and the Cape of South Africa. Borrowing phylogenetic methods from community ecology, we reveal significant clustering of the 1,500 traditionally used species, and provide a direct measure of the relatedness of the three medicinal floras. We demonstrate shared phylogenetic patterns across the floras: related plants from these regions are used to treat medical conditions in the same therapeutic areas. This finding strongly indicates independent discovery of plant efficacy, an interpretation corroborated by the presence of a significantly greater proportion of known bioactive species in these plant groups than in random samples. We conclude that phylogenetic cross-cultural comparisons can focus screening efforts on a subset of traditionally used plants that are richer in bioactive compounds, and could revitalize the use of traditional knowledge in bioprospecting.