Development of a test system for homeopathic preparations using impaired duckweed (Lemna gibba L.).

OBJECTIVES A bioassay with arsenic-stressed duckweed (Lemna gibba L.) was developed to study potentially regulative effects of homeopathic preparations. We compared potentized substances (nine different potency levels between 17 x and 33 x ) with two controls (unsuccussed and succussed water) regarding their influence on number- and area-related growth rate and color of fronds (leaves). Screening included 11 potentized substances: Arsenicum album, gibberellic acid, nosode, arsenic(V), phosphorus, Conchae, Acidum picrinicum, Argentum nitricum, Crotalus horridus, Hepar sulfuris, and Mercurius vivus naturalis. DESIGN Duckweed was stressed with arsenic(V) for 48 hours. Afterwards, plants grew in either potentized substances or water controls for 6 days. Growth rate and color of fronds were determined with a computerized image analysis system for different time intervals (days 0-2, 2-6, 0-6). A systematic negative control experiment with unsuccussed water was used to investigate the stability of the bioassay. All experiments were randomized and blinded. RESULTS Arsenicum album and nosode potencies increased frond number-related growth rate compared to controls (succussed water controls or pooled water controls [succussed and unsuccussed], p < 0.05, t test). Regarding color classification, no effects were observed. CONCLUSIONS The experimental setup with L. gibba stressed by arsenic(V) provides a valuable tool to investigate regulative effects of potentized substances. In order to verify the effects of Arsenicum album and nosode potencies, further independent replication experiments are necessary.