[Predicting the Pharmacologic Activity of Natural Materials Based on Metabolomics]

Natural materials such as crude drugs and foods are mixtures composed of various metabolites. Metabolic profiling is often used to identify possible correlations between a compound's metabolic profile and pharmacologic activity. Direct-injection electron ionization-mass spectrometry (DI-EI-MS) is a novel metabolomics method useful for characterizing biological materials. This review demonstrates the establishment of a DI-EI-MS method for metabolic profiling using several closely related lichen species: Cladonia krempelhuberi, C. gracilis, C. pseudogymnopoda, and C. ramulosa. The qualitative DI-EI-MS method was used to profile major and/or minor constituents in extracts of lichen samples. Each lichen sample could be distinguished by altering the DI-EI-MS electron energy and examining the resulting data using one-way analysis of variance. We also attempted to predict pharmacologic activity using DI-EI-MS metabolomics. Blueberry leaf extracts inhibited the proliferation of adult T-cell leukemia (ATL) cells. Blueberry leaf extracts could be distinguished by principal component analysis based on the absolute intensity of characteristic fragment ions. Twenty cultivars were categorized into four species, and the most appropriate discriminative marker m/z value for identifying each cultivar was selected statistically. Components extracted based on DI-EI-MS analyses could be used to construct a model to predict ATL cell bioactivity. These data suggest that the novel DI-EI-MS metabolomics method is suitable for identifying species of natural materials and predicting their pharmacologic activity. This approach could enhance public health by facilitating evaluations of pharmacologic activity and functionality, leading to the elimination of counterfeit products.