Comparative study of two bioassays with weakened duckweed and yeast treated with homeopathic preparations
Jäger Tim, Claudia Scherr, Meinhard Simon, Peter Heusser, Ursula Wolf and Stephan Baumgartner
ABSTRACT
Background: In homeopathic basic research, the question as to the most adequate test systems and apt
methodology is still open.
Aims: This investigation examined the hypothesis that more complex organisms show stronger reactions to
homeopathic remedies than less complex ones. We compared two Arsenic (As5+) stressed bioassays with
duckweed (Lemna gibba, a multi-cellular autotrophic organism) and yeast (Saccharomyces cerevisiae, a singlecellular
heterotrophic organism) regarding their response to homeopathic preparations [1].
Methods: For duckweed, growth rates of leaf area and leaf number were evaluated. For yeast, growth
kinetics were determined by measuring slope, yield and Et50 (point in time when yield was half maximum) of
the sigmoid growth curve. The experiments with duckweed and yeast were performed in parallel (same day,
same location and identical homeopathic preparations).
Results: After screening 17 substances, three homeopathic preparations (Arsenicum album, nosode,
gibberellic acid) were chosen for repeated experimental series [2]. Five independent experiments were
conducted for each remedy with both organisms in parallel. Potency levels used were in the range of 17x–33x
for duckweed and 17x–30x for yeast. To control for test system stability, systematic negative control
experiments were conducted over the complete experimentation period. All experiments were blinded and
randomized. The systematic negative control experiments did not yield any significant effects. Application of
potentized Arsenicum album in the duckweed bioassay yielded the largest effects compared to water controls
without remedies for the parameters leaf area and leaf number (p<0.001) [1, 3]. Potentized nosode
preparations also had significant effects on duckweed's leaf area and leaf number (p<0.01). Growth was
enhanced across all potency levels. In the yeast system the three homeopathic remedies did not show any
significant effects on any growth curve parameter.
Conclusions: The results obtained are in line with the hypothesis, that more complex organisms show
stronger reactions to homeopathic remedies than less complex organisms. The test system with Lemna gibba,
the stressor arsenic (As5+) and the homeopathic preparation Arsenicum album is suitable to further
investigate factors influencing the quality and effects of potentized substances