title: The use of plant-based bioassays in homeopathic basic research.
abstract: OBJECTIVE
  The objective was to evaluate homeopathic basic research studies that use plant-based bioassays. With this in view, a compilation was made of the findings of three systematic literature reviews covering plant-based bioassays in the three fields of healthy, abiotically, or biotically stressed plants. This compilation focused on investigations using advanced experimental methods and detailed descriptions, also with the aim of supporting the design of future experiments.
  
  
  METHODS
  Publications included had to report on studies into the effects of homeopathic preparations on whole plants, seeds, plant parts and cells. Outcomes had to be measured by established procedures and statistically evaluated. A Manuscript Information Score (MIS) was applied using predefined criteria to identify publications with sufficient information for adequate interpretation (MIS ≥ 5). Additional evaluation focused on the use of adequate controls to investigate specific effects of homeopathic preparations, and on the use of systematic negative control (SNC) experiments to ensure the stability of the bioassay. Only a fraction of the studies reported here were performed with 'ultra high' dilutions, whereas other studies were performed with moderate or high dilutions.
  
  
  RESULTS
  A total of 157 publications were identified, describing a total of 167 experimental studies. 84 studies included statistics and 48 had a MIS ≥ 5, thus allowing adequate interpretation. 29 studies had adequate controls to identify specific effects of homeopathic preparations, and reported significant effects of decimal and centesimal homeopathic potencies, including dilution levels beyond Avogadro's number. 10 studies reported use of SNC experiments, yielding evidence for the stability of the experimental set-up.
  
  
  CONCLUSIONS
  Plant models appear to be a useful approach for investigating basic research questions relating to homeopathic preparations, but more independent replication trials are needed in order to verify the results found in single experiments. Adequate controls and SNC experiments should be implemented on a routine basis to exclude false-positive results.
authors.affiliation: Institute of Integrative Medicine, University of Witten-Herdecke, Germany; Center for Complementary Medicine, Department of Environmental Health Sciences, Medical Center, University of Freiburg, Germany; Institute of Complementary Medicine IKOM, University of Bern, Switzerland. Electronic address: tim.jaeger@uni-wh.de.
authors.forename: Tim
authors.initials: T
authors.lastname: Jäger
authors.affiliation: Society for Cancer Research, Hiscia Institute, Arlesheim, Switzerland.
authors.forename: Claudia
authors.initials: C
authors.lastname: Scherr
authors.affiliation: Society for Cancer Research, Hiscia Institute, Arlesheim, Switzerland.
authors.forename: Devika
authors.initials: D
authors.lastname: Shah
authors.affiliation: Clinic for Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Majewsky
authors.affiliation: Institute of Complementary Medicine IKOM, University of Bern, Switzerland.
authors.forename: Ursula
authors.initials: U
authors.lastname: Wolf
authors.affiliation: Department of Agro-Environmental Science and Technology, University of Bologna, Italy.
authors.forename: Lucietta
authors.initials: L
authors.lastname: Betti
authors.affiliation: Institute of Integrative Medicine, University of Witten-Herdecke, Germany; Center for Complementary Medicine, Department of Environmental Health Sciences, Medical Center, University of Freiburg, Germany; Society for Cancer Research, Hiscia Institute, Arlesheim, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Baumgartner
mesh_terms: D001681:Biological Assay / Q000379:methods* / Q000706:statistics & numerical data; D006705:Homeopathy / Q000379:methods*; D006801:Humans; D010937:Plant Growth Regulators / Q000494:pharmacology; D018514:Plant Structures; D012107:Research Design
chemical_list: D010937:Plant Growth Regulators
keywords: Agriculture; Basic research; Field trials; Homeopathy; Impaired plants; Noxa; Phytopathological models; Potentisation; Review