Effects of the herbal preparation STW 5‐II on <i>in vitro</i> muscle activity in the guinea pig stomach
Michael Schemann, Martina Landmann, O Kelber, Ramy M. Ammar, Dagmar Krueger, Klaus Michel
Abstract
Abstract Background STW 5 is a combination of nine medicinal herbal extracts and used to treat functional gastrointestinal disorders including functional dyspepsia. It has a region‐specific effect by relaxing the proximal and contracting the distal stomach. The research combination STW 5‐II (Iberogast ® Advance) lacks three herbal extracts but seems clinically as effective as STW 5. However, the action of STW 5‐II on gastric motility is unknown. Methods In vitro circular and longitudinal muscle tone and contractility were recorded from guinea pig gastric fundus and antrum with isometric force transducers. Key Results STW 5‐II decreased concentration‐dependently (64‐512 µg/ml) the tone of circular and longitudinal muscle strips from the fundus. In contrast, STW 5‐II increased concentration‐dependently contraction amplitude in antral circular and longitudinal muscle. The effects were region‐dependent but comparable in the two muscle layers. Application of 512 µg STW 5 or STW 5‐II revealed comparable effects in the fundus and antrum circular and longitudinal muscle strips. Conclusions and Interferences STW 5‐II had a region‐specific effect and relaxed the proximal stomach but increased the contractility in the antrum. It was as effective as STW 5 which may explain its comparable clinical effects in treating functional dyspepsia. Impaired accommodation may be normalized through relaxation of the fundus, while the motility‐promoting effects leading to an increase in antral motility may activate the gastric pump.