gms | German Medical Science

Tenseness, restlessness and irritability, with difficulty in falling asleep, are frequent ailments in elderly patients, while most classical sedatives are rated as potentially inadequate in elderly by the German Priscus Liste and other similar national lists. This is not the case in herbal medicines used in this indication, like Melissae folium (M), Passiflorae herba (P) and Valerianae radix (V), as their primary pharmacological effect is supposed to be anxiolytic, and not sedative like in benzodiazepines and barbituric acid derivatives.

To gain further evidence for this, hydroethanolic extracts of these three herbal substances and their combination STW 32* (P 40%, V 20%, M 40% of fluid extract) were investigated for their influence on exploratory behaviour (vigilance, rearing and locomotory activity), anxiolytic action in the elevated plus maze (EPM), social interaction test, and anti-depressive action in the tail suspension test, all in NMRI mice. Extracts were applied by oral gavage in aqueous solution with 1 % methyl cellulose 60- 70 prior to the tests, in up to 4 doses between 30 and 1040 mg/kg b.w..

The EPM test uncovered significant effects: Diazepam (1 mg/kg) increased the number of entries and the duration of stays (p≤0.05). P, 176 and 352 mg/kg b.w., was likewise anxiolytic, as well as V, 1040 mg/kg b.w. (p≤0.05), which also significantly increased the duration of the stays. STW 32, 30 mg/kg b.w., significantly increased the numbers of entries and their duration, as well as the higher doses of 120 and 240 mg/kg b.w.. In the social interaction test, for P, M, V, and the combination, the lowest significantly active doses were 88, 704, 520, and 30 mg/kg b.w., with significant effects of the combination also at the higher doses tested (60, 120 and 240 mg/kg b.w.).

The data suggest, that the sleep inducing effects of these three herbal extracts and their combination, STW 32, are due to an anxiolytic effect. As in the models of elevated plus maze and social interaction, the lowest active dose of the combination is far lower than of the combination partners tested, a synergistic effect is plausible.

*Phytonoctu, Steigerwald Arzneimittelwerk GmbH, Darmstadt, Germany