Planta Med 2008; 74 - S-14
DOI: 10.1055/s-2008-1075157

New Results From Well-known Herbal Medicinal Products

B Kopp 1
  • 1Department of Pharmacognosy, University of Vienna, Althanstraße 14, A-1090 Vienna, Austria

Plants are used in phytotherapy for the treatment of various diseases, but often little is known about the substances causing the pharmacological effects and their mechanisms of action. Yarrow (Achillea millefolium L. s.l.) is traditionally used in the treatment of digestive complaints[1]. While the antiinflammatory activity is mediated by sesquiterpenes[2], the choleretic and spasmolytic principles of the drug are still unknown. Hence, a crude extract of yarrow was purified by solid phase extraction yielding two fractions enriched in dicaffeoylquinic acids and flavonoids, respectively. We investigated the choleretic activity of the dicaffeoylquinic acid fraction in the isolated perfused rat liver using cynarin as positive control, whereas the antispasmodic effect of the flavonoid fraction was tested on isolated terminal guinea-pig ilea. We could show both, the choleretic activity of the dicaffeoylquinic acid fraction as well as the spasmolytic activity of the flavonoid fraction, which justifies the traditional application of yarrow for the respective indications. Valeriana officinalis L. is used in phytotherapy due to its sedative and sleep enhancing effects. As one of the jointly responsible mechanisms of action for sedative substances is stimulation of the GABAA-receptor. Apolar extracts revealed high activity at the GABAA-receptor, whereas polar extracts showed no effect. Fractionation showed that apolar fractions containing high amount of sesquiterpene acids showed strong modulation: Valerenic acid showed strong stimulation, whereas acetoxyvalerenic acid inhibited the receptor3. In conclusion, valerenic acid is not only a marker for standardisation but also a potent activator of the GABAA-receptor. References: [1] Wichtl M, editor. Millefolii herba. In: Teedrogen und Phytopharmaka. 4th ed. Stuttgart: WVG, 2002: 399–403. [2] Kastner U, et al. (1993) Planta Med. 59: A669. [3] Trauner G, et al. (2008) Planta Med. in press