Effects of homeopathic drugs on the anxiety-like behavior in mice

Several models of anxiety-like behaviours have been developed and described in mice, essentially in order to test different anxiolytic drugs, but little is known about the effects of homeopathic medicines. Anxiety-like responses may include physiological parameters as well as behavioural changes (inhibition of ongoing behaviours, scanning, avoidance of light or of the source of danger, time spent in resting state, slow or fast movement, etc.). In our laboratory only “ethological” models are utilized, using exposure of subjects to novel environments (open field test), to unfamiliar aversive places (elevated plus-maze), or to the light/dark choice. We do not expose the animals to pain or other forms of physical stress. Aconitum, Nux vomica, Gelsemium sempervirens, Belladonna, Argentum nitricum, Tabacum, all at 5CH potency in hydroalcoholic (0.3%) solution administerd by i.p. injection, were screened for their potential effects on animal behaviour. Then, the anxiolytic-like effects of Gelsemium sempervirens 5CH were tested in various experimental settings and different mice strains (CD1, C57BL/6J, BALB/c). Control mice were treated with Ethylicum 5CH (vehicle) or with Diazepam (0.5 to 1 mg/kg) in the same hydroalcoholic (0.3%) solution used to dilute the homeopathic medicines. The test was performed with coded drugs/controls in double blind (operations and calculations). We often noted high scattering of data due to inter-individual variability, to change of illumination schedule and of strain. We have observed statistically significant effects of Gelsemium sempervirens in several “symptoms” of anxiety-like behaviour such as the time spent in the illuminated compartment in light/dark test, the decrease of resting time, the distance travelled in the open arms of the plus-maze or in the centre of the open field. The extent of responses to this medicine were in a number of cases comparable to the extent of the responses to Diazepam. Paradoxical “anxiogenic-like” (proving?) effects of Gelsemium were observed in an experiment where also Diazepam inverted its conventional action. A few significant effects of Argentum Nitricum 5CH were also observed and replications studies are now in progress