Effects of high-dilutions in behavioural models: a commentary on critical issues, from reproducibility to plausibility

Abstract

As part of a rigorous investigation into the effects of Gelsemium sempervirens on laboratory mice, we performed two complete series of experiments and published three scientific papers. A recent commentary has, however, called into question the reproducibility and validity of these findings. In this article we discuss the major issues raised by this critique within the framework of methodological aspects and the interpretation of results of high-dilution and homeopathic research. The charge of non-reproducibility is shown to be unfounded, because a same homeopathic medicine displayed the same direction of effects in two well-validated models (light-dark and open-field), albeit with nonlinear patterns. The double-blind protocols and statistics by means of ANOVA were performed appropriately and the difference between dilutions of Gelsemium (5cH, 7cH, 9cH and 30cH with variations according to model) and placebo was statistically highly significant. Our investigations brought to light some problems related with the lack of activity of buspirone and diazepam (conventional anxiolytic drugs used as control) on some behavioural parameters, suggesting that Gelsemium may have broader action, and raising doubts as to the reliability of benzodiazepines as positive controls for homeopathic treatments. Concerning the plausibility of experiments in this field, disputed on the grounds of alleged lack of dose-response effect, we note that the latter is not at all uncommon, and can be accounted for by a host of possible reasons. In conclusion, our research line showed reproducible and consistent effects of Gelsemium in laboratory mice.