Choleretic effects of yarrow (Achillea millefolium s.l.) in the isolated perfused rat liver.

Different species from the Achillea millefolium aggregate are used against gastrointestinal and hepato-biliary disorders in traditional European medicine. In this work, a fraction enriched in dicaffeoylquinic acids (DCCAs) and luteolin-7-O-beta-D-glucuronide was investigated on its choleretic effect in the isolated perfused rat liver (IPRL) compared to cynarin (1,3-DCCA), the main choleretic compound of Cynara scolymus L. A fraction containing 3,4-, 3,5- and 4,5-DCCA and luteolin-7-O-beta-D-glucuronide was prepared by solid phase extraction from a 20% methanolic extract of yarrow. A total amount of 48.8% DCCAs and 3.4% luteolin-7-O-beta-D-glucuronide was determined by HPLC analysis with cynarin as internal standard. IPRL experiments revealed a dose-dependant increase in bile flow (23-44-47%) by the Achillea fraction. Choleresis was two- to three-fold higher than that of cynarin. The combined effect of DCCAs and luteolin-7-O-beta-D-glucuronide stimulated bile flow more effectively than the single compound cynarin. Due to their polar structure, these compounds are quantitatively extracted into teas and tinctures; hence, they seem to be the choleretic active principles in the traditional application forms of yarrow.