Psychophysiological Effects of a Combination of Sideritis and Bacopa Extract (memoLoges®) in 32 Subjects Suffering from Mild Cognitive Impairment. A Double-Blind, Randomized, Placebo-Controlled, 2-Armed Study with Parallel Design

Mild cognitive impairment (MCI) can be regarded as a non-demented transitional stage during the development of Alzheimer’s disease. Early recognition of this stage might increase the chance of prevention by early treatment. Within a pilot study, two plant-derived preparations and mixtures thereof were tested successfully in subjects suffering from MCI. A combination of Sideritis scardica and Bacopa monnieri extract (memoLoges®) was chosen now for a repetitive dosing during 4 weeks. Thirty-two subjects aged 50 to 80 years and suffering from MCI (having a DemTect questionnaire score between 8 and 13) were recruited for intake of 2 capsules of the preparation per day. Quantitative EEG recording during relaxation and concomitant performance of three 5 minutes lasting psychometric tests (d2-concentration test, arithmetic calculation test and memory test) was achieved at the first day and one day after the last repetitive intake. Seventeen channels of EEG and one channel EOG (for artefact rejection) were recorded. After frequency analysis (FFT) current source density was calculated as reported earlier. One, two and three hours after intake of the herbal extract or placebo the whole procedure was repeated. Brain imaging was achieved by conversion of numerical values of spectral EEG power into spectral colors and additive color mixture according to RGB as used in TV settings. Intake of memoLoges® induced a trend of improvement of performance in psychometric testing (all three tests). During relaxation quantitative assessment of EEG data revealed attenuation of delta and theta spectral power in frontal brain as likewise reported in the presence of the Alzheimer drug rivastigmine, bringing the spectrum back to “normality”. During mental work memoLoges® induced statistically significant increases of beta power. Since MCI subjects produce less beta power in comparison to healthy subjects, this increase must likewise be seen as a positive effect pointing to a healthier spectrum.

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

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.