Abstract
Psychophysiological effects of Sideritis herba extracts depend on biologically active ingredients, which might be different for several botanical types of this plant. The present investigation aimed at the characterization of extracts from Sideritis scardica and Sideritis euboa in vivo and in vitro. Construction of electropharmacograms on the base of recording of electrical field potentials from four different brain regions was used to compare the possible pharmacological effects to a database of reference drugs with known clinical indications. Whereas Sideritis scardica produced decreases of spectral power in line with stimulatory frequency patterns as observed in the presence of Ginkgo biloba extract, administration of Sideritis euboa produced opposite effects. Electrical stimulation of the Schaffer Collaterals was used to elicit a pyramidal cell response called population spike in vitro. The amplitude of this spike was determined in the presence of single as well as theta burst stimuli. Direct exposure of brain matter to Sideritis scardica extract led to concentration dependent increases of the population spike amplitude under both stimulation patterns in the range from 12.5 to 100 mg/L. On the opposite, extract from Sideritis euboa did not change the electric response up to 50 mg/L. Higher concentrations of this extract attenuated the signal amplitude. A 1:1 blend of both gave intermediate results. The in vitro results are in line with the in vivo EEG recordings, where both extracts induced opposite changes of the electric power with respect to electric frequency patterns. The results from both models suggest a stimulatory and/or memory-enhancing action for the extract from Sideritis scardica but not for Sideritis euboa extract, where a more tranquillizing effect like that observed in the presence of Humulus cone extract may be expected.
Highlights
Preclinical pharmacological characterization of plant derived extracts must be seen as a special challenge since many classic animal models are not suited or at the best not sensitive enough like many behavioural models
Effects of Sideritis scardica Extract UB2010-55 Spectral frequency decreases in the presence of 50 mg/kg of Sideritis scardica UB2010-55 were dominantly seen during the first hour after administration (Figure 3)
When comparing the pattern of frequency changes of both Sideritis extracts to changes induced by other preparations a close similarity of Sideritis scardica extract to those of Gingko biloba extract (Tebonin®) and Memantine emerges, whereas the change induced by Sideritis euboa extract approached that observed in the presence of Humulus cone extract (Figure 4)
Summary
Preclinical pharmacological characterization of plant derived extracts must be seen as a special challenge since many classic animal models are not suited or at the best not sensitive enough like many behavioural models. Based on more than 20.000 hours of recording under identical experimental conditions it was recognized that synthetic drugs with similar clinical indications produced similar changes of the frequency pattern [4]. Such a pattern of drug induced frequency changes in several brain areas has been called an electropharmacogram. Feeding these data into a linear discriminant analysis resulted in a matrix of drug actions, which grouped automatically according to clinical indications. The methodology used was identical to that reported earlier [5] [6]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
