title: Combining metabolomic analysis and microarray gene expression analysis in the characterization of the medicinal plant Chelidonium majus L.
abstract: OBJECTIVE
  Even though herbal medicines have played an important role in disease management and health for many centuries, their present frequent use is challenged by the necessity to determine their complex composition and their multitarget mode of action. In the present study, modern methods were investigated towards their potential in the characterization of herbal substances. As a model the herbal substance Chelidonii herba was used, for which several reports on liver toxicities exist. Extracts of Chelidonii herba with different solvents were characterized phytochemically and functionally by experiments with HepG2 liver cells.
  
  
  METHODS
  Chelidonii herba was extracted with four solvents of different polarity (dichloromethane, water, ethanol, and ethanol 50% (V/V); four replicates each). The different extracts were characterized metabolomically by (1)H-NMR fingerprinting analysis and principal component analysis (PCA). The content of alkaloids was additionally determined by RP-HPLC. Functional characterization was achieved by the determination of cell proliferation and by transcriptomics techniques (Whole Genome Gene Expression Microarrays v2, Agilent Technologies) in HepG2 cells after exposure to the different extracts (four experimental replicates each).
  
  
  RESULTS
  Based on data from (1)H-NMR fingerprints and RP-HPLC analyses the different extracts showed a divergent composition of constituents depending on the solvent used. HepG2 liver cells responded differentially to the four extracts. Microarray analysis revealed a significant regulation of genes and signal cascades related to biotransformation. Also liver-toxic signal cascades were activated. Neither the activated genes nor the proliferation response could be clearly related to the differing alkaloid content of the extracts.
  
  
  CONCLUSIONS
  Different manufacturing processes lead to different herbal preparations. A systems biology approach combining a metabolomic plant analysis with a functional characterization by gene expression profiling in HepG2 cells is an appropriate strategy to characterize variations in plant extracts. Safety assessments of herbal substances may benefit from such complementary analyses.
authors.affiliation: Federal Institute for Drugs and Medical Devices, D-53175 Bonn, Germany. Electronic address: Annika.orland@rub.de.
authors.forename: A
authors.initials: A
authors.lastname: Orland
authors.affiliation: Institute of Pharmaceutical Biology, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Knapp
authors.affiliation: Institute of Pharmaceutical Biology, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany.
authors.forename: G M
authors.initials: GM
authors.lastname: König
authors.affiliation: University Clinic Centre Bonn, Medical Clinic III, Centre for Internal Medicine, D-53127 Bonn, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Ulrich-Merzenich
authors.affiliation: Federal Institute for Drugs and Medical Devices, D-53175 Bonn, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Knöß
mesh_terms: D000470:Alkaloids / Q000737:chemistry*; D049109:Cell Proliferation / Q000187:drug effects; D028281:Chelidonium / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D020869:Gene Expression Profiling; D056945:Hep G2 Cells; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D055432:Metabolomics; D020411:Oligonucleotide Array Sequence Analysis; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry
chemical_list: D000470:Alkaloids; D010936:Plant Extracts
keywords: (1)H-NMR fingerprint; Chelidonii herba; Gene expression profiling; Herbal safety