Applications of metabolimcs to medicinal plants for scientific study and drug discovery

The term “metabolomics” was developed 10 years ago to describe the untargeted identification and quantification of all of the small metabolites in a biological sample. Over the last decade, researchers have been working to develop methodological approaches, standards, data analysis tools and new technologies that enable metabolome studies. Medicinal plants are ideal candidates for investigations by metabolomics as research questions often involve quantification multiple bioactive or marker compounds, synergy between molecules and complex interactions within a system. It has been estimated an average leaf sample could contain up to 30,000 compounds; the vast majority of which have never been isolated, identified or described. In metabolomic profiles we have observed 2,500 compounds in St. John's wort, 4,800 in Scutellaria baicalensis, and 5,200 in cranberries. By comparing metabolomes of different extracts and focusing the statistical analysis on unknowns in each sample, we have identified previously undiscovered compounds required for medicinal activity leading us to propose an alternate "Metabolomics-Based Drug Discovery Pipeline". Key factors for success are production of standardized active plant extracts and statistical methods to evaluate data quality thereby minimizing potential false discovery. This approach has the advantage of providing basic chemical information on compounds not sufficiently stable to withstand purification processes and could lead to a greater understandings of chemical synergy and the interactions of medicinal plants with human metabolism.