Background: The medicinal properties of plants can be predicted by virtue of phylogenetic methods, which nevertheless have not been utilized to explore the regularity of skin-related bioactivities of ethnomedicinal plants. We aim to investigate the distribution of skin efficacy of Asteraceae and Ranunculales plants on the species-level Tree of Life.
Methods: The clinical efficacy data of 551 ethnomedicinal species belonging to Ranunculales, as well as 579 ethnomedicinal species of Asteraceae, were systematically collected and collated; these therapeutic data fell into 15 categories, including skin disease/cosmeceutical. The large phylogenetic tree of all China angiosperm species was used to detect the phylogenetic signals of ethnomedicinal plants by calculating the D statistic, phylogenetic diversity (PD), net relatedness index (NRI), and nearest taxon index (NTI). Of all Chinese ethnomedicinal plants of Ranunculales and Asteraceae, 339 (61.5% of all ethnomedicinal species) and 382 (66.0% of all) are used for skin problems. In Ranunculales, a clustered structure was suggested by the NRI value for skin uses. In Asteraceae, the skin utility was not clustered; Artemisia, Aster, Cremanthodium, Ligularia, and Saussurea are the most used Asteraceae genera for skin issues.
Results: The clustering structure was identified in Artemisia, and the skin efficacy in other genera was of overdispersion (NRI < 0). NTI values and D statistics largely agree with NRI. When compared with PD values of different therapeutic categories, the PD value of the skin category was relatively high in Cremanthodium, Ranunculales, Asteraceae, and Artemisia, suggesting the enormous efficacy space in the new taxa of these taxonomic groups.
Conclusion: By resolving the distribution of therapeutic effects of Ranunculales/Asteraceae taxa, the importance of phylogenetic methods in mining botanical resources with skin utilities is validated.
Keywords: Ranunculales, Asteraceae, skin efficacy, net relatedness index, nearest taxon index, phylogenetic diversity, Dstatistic.