Reproducibility of the effects of homeopathically potentised Argentum nitricum on the growth of Lemna gibba L. in a randomised and blinded bioassay

Homeopathy. 2017 Aug;106(3):145-154. doi: 10.1016/j.homp.2017.04.001. Epub 2017 May 9. . Majewsky V1, Scherr C2, Schneider C3, Arlt SP4, Baumgartner S5. Author information 1 Institute of Complementary Medicine, University of Bern, Fabrikstrasse 8, 3012 Bern, Switzerland; Clinic for Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, Königsweg 65 (Haus 27), 14163 Berlin, Germany. Electronic address: veramajewsky@hotmail.com. 2 Institute of Complementary Medicine, University of Bern, Fabrikstrasse 8, 3012 Bern, Switzerland; Hiscia Institute, Society for Cancer Research, Kirschweg 9, 4144 Arlesheim, Switzerland. Electronic address: c.scherr@vfk.ch. 3 Research Institute of Organic Agriculture FiBL, Ackerstrasse, Postfach, 3070 Frick, Switzerland. Electronic address: claudia.schneider@fibl.org. 4 Clinic for Animal Reproduction, Faculty of Veterinary Medicine, Freie Universität Berlin, Königsweg 65 (Haus 27), 14163 Berlin, Germany. Electronic address: sebastian.arlt@fu-berlin.de. 5 Institute of Complementary Medicine, University of Bern, Fabrikstrasse 8, 3012 Bern, Switzerland; Hiscia Institute, Society for Cancer Research, Kirschweg 9, 4144 Arlesheim, Switzerland; Institute of Integrative Medicine, University of Witten-Herdecke, Gerhard-Kienle-Weg 4, 58313 Herdecke, Germany. Electronic address: stephan.baumgartner@uni-wh.de. Abstract BACKGROUND: A previous study reported a significant statistical interaction between experiment date and treatment effect of Argentum nitricum 14x-30x on the growth rate of duckweed (Lemna gibba L.). The aim of the present study was to investigate the stability of the test system and intra-laboratory reproducibility of the effects found. METHODS: Duckweed was treated with A. nitricum potencies (14x-30x) as well as succussed and unsuccussed water controls. The outcome parameter area-related growth rate for day 0-7 was determined by a computerised image analysis system in two series of independent randomised and blinded experiments. Systematic negative control (SNC) experiments were carried out to investigate test system stability. Statistical analysis was performed with full two-way analysis of variance (ANOVA) and protected Fisher's Least Significant Difference (LSD) test. RESULTS: In the first repetition series we found a significant treatment effect (p = 0.016), while in the second series no effect was observed. The negative control experiments showed that the experimental system was stable. An a posteriori subgroup analysis concerning gibbosity revealed the importance of this growth state of L. gibba for successful reproduction of the statistically significant interaction in the original study; flat: no interaction (p = 0.762); slight gibbosity: no interaction (p = 0.356); medium gibbosity: significant interaction (p = 0.031), high gibbosity: highly significant interaction (p = 0.005). CONCLUSIONS: With the original study design (disregarding gibbosity status of L. gibba) results of the original study could not be reproduced sensu stricto. We conclude that the growth state gibbosity is crucial for successful reproduction of the original study. Different physiological states of the test organisms used for bioassays for homeopathic basic research must carefully be considered. Copyright © 2017 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved. KEYWORDS: Duckweed; Homeopathy; Plants; Reproducibility; Silver nitrate PMID: 28844287 DOI: 10.1016/j.homp.2017.04.001