Mechanism of Action of Low Dose Preparations from <i>Coffea arabica</i>, <i>Gelsemium</i> and <i>Veratrum</i> Based on <i>in Vivo</i> and <i>in Vitro</i> Neurophysiological Findings

Abstract

Low dose remedies are widely administered in medicine. We used Tele-Stereo-EEG and the hippocampal slice preparation to measure physiological effects of orally given Coffea D6 (40 mg/kg), Gelsemium D4 (10 mg/kg) and Veratrum D6 (30 mg/kg) in rats. Adult rats were implanted with electrodes positioned stereotactically into four brain regions. Changes in field potentials were transmitted wirelessly. After frequency analysis data from 6 - 8 animals were averaged. For in vitro testing, preparations were superfused directly on hippocampal slices. Stimulation of Schaffer Collaterals by single stimuli (SS) or theta burst stimulation (TBS) resulted in stable population spike amplitudes. All three low dose preparations produced decreases of spectral power. Statistically significant changes were observed in delta, theta and alpha2 spectral power. In the hippocampal slice preparation Coffea facilitated signal transfer presumably by enhancing glutamate AMPA receptor transmission. Gelsemium showed a similar effect, but only after single shock stimulation. Opposite to this, attenuation of the electric pathway was recognized after theta burst stimulation due to AMPA receptor and glutamate metabotropic II receptor mediated transmission. Veratrum was able to attenuate glutamatergic due to receptor-mediated signalling sensitive to AMPA and NMDA. The results strongly speak in favour of the existence of biologically active molecules in these low dose preparations.