Daiokanzoto (DKT, combination of rhubarb and glycyrrhiza), a
Kampo medicine, is clinically effective for
constipation.
Sennoside A is well known to induce
diarrhea.
Sennoside A is a
prodrug that is transformed into an active metabolite,
rheinanthrone, by intestinal bacteria. In this study, we investigated the effects of glycyrrhiza on the activity of
sennoside A metabolism in intestinal bacteria using mouse feces. A high-performance liquid chromatography (HPLC) method for the determination of
sennoside A in incubation mixture of DKT with mouse feces was established. The retention time of
sennoside A was 9.26±0.02 min with a TSKgel ODS-80TsQA column by linear gradient elution using a mobile phase containing aqueous
phosphoric acid and
acetonitrile and detection
at 265 nm. We found that the activity of
sennoside A metabolism in intestinal bacteria was significantly accelerated when glycyrrhiza,
liquiritin or
liquiritin apioside coexisted with
sennoside A, whereas that of
glycyrrhizin was not altered. This method is applicable for determination of the activity of
sennoside A metabolism by anaerobic incubation of DKT with mouse feces.