title: Pathway-focused bioassays and transcriptome analysis contribute to a better activity monitoring of complex herbal remedies.
abstract: BACKGROUND
  Transcriptome analysis in combination with pathway-focused bioassays is suggested to be a helpful approach for gaining deeper insights into the complex mechanisms of action of herbal multicomponent preparations in living cells. The polyherbalism based concept of Tibetan and Ayurvedic medicine considers therapeutic efficacy through multi-target effects. A polyherbal Indo-Tibetan preparation, Padma 28, approved by the Swiss drug authorities (Swissmedic Nr. 58436), was applied to a more detailed dissection of mechanism of action in human hepatoma HepG2 cells. Cell-free and cell-based assays were employed to evaluate the antioxidant capacity. Genome-wide expression profiling was done by applying Human Genome U133 Plus 2.0 Affymetrix arrays. Pathway- and network-oriented analysis elucidated the affected biological processes. The results were validated using reporter gene assays and quantitative real-time PCR.
  
  
  RESULTS
  To reveal the direct radical scavenging effects of the ethanolic extract of the Indo-Tibetan polyherbal remedy Padma 28, an in vitro oxygen radical absorbance capacity assay (ORAC) was employed, which resulted in a peroxyl-radical scavenging activity of 2006 ± 235 μmol TE/g. Furthermore, the antioxidant capacity of Padma 28 was analysed in living HepG2 cells, by measuring its scavenging potential against radical induced ROS. This formulation showed a considerable antioxidant capacity by significantly reducing ROS levels in a dose-dependent manner.Integrated transcriptome analysis revealed a major influence on phase I and phase II detoxification and the oxidative stress response. Selected target genes, such as heme oxygenase 1, were validated in qPCR experiments. Network analysis showed 18 interrelated networks involved in important biological functions such as drug and bio-molecule metabolism, molecular transport and cellular communication. Some molecules are part of signaling cascades that are active during development and morphogenesis or are involved in pathological conditions and inflammatory response.
  
  
  CONCLUSIONS
  The identified molecular targets and pathways suggest several mechanisms that underlie the biological activity of the preparation. Although extrapolation of these findings to the in vivo situation is not possible, the results obtained might be the basis for further investigations and new hypotheses to be tested. This study demonstrates the potential of the combination of focused and unbiased research strategies in the mode of action analysis of multicomponent herbal mixtures.
authors: Division of Medical Biochemistry, Innsbruck Medical University, Center for Chemistry and Biomedicine, Innrain 80-82, Innsbruck, Austria.
authors: Angela
authors: A
authors: Klein
authors: Oliver A
authors: OA
authors: Wrulich
authors: Marcel
authors: M
authors: Jenny
authors: Peter
authors: P
authors: Gruber
authors: Kathrin
authors: K
authors: Becker
authors: Dietmar
authors: D
authors: Fuchs
authors: Johanna M
authors: JM
authors: Gostner
authors: Florian
authors: F
authors: Uberall
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001681:Biological Assay; D049109:Cell Proliferation / Q000187:drug effects; D020869:Gene Expression Profiling; D053263:Gene Regulatory Networks / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism; D056945:Hep G2 Cells; D029001:Herbal Medicine; D006801:Humans; D038861:Medicine, Tibetan Traditional; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D000975:Antioxidants; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D010936:Plant Extracts; C066069:Padma 28; D051547:Heme Oxygenase-1