RESUMEN
To study the intestinal absorptive characteristics of the ethanol extracts from Gandou decoction(GDD), everted intestinal sac models were used. The six representative ingredients (berberine hydrochloride, quercetin, kaempferide, rhein, chrysophanol, and aloe emodin) of GDD, were selected as the experimental targets to investigate the absorptive characteristics of various ingredients in different intestinal sections. The results showed that all six ingredients from GDD were detected in the intestinal sac, three active ingredients (berberine hydrochloride, quercetin, kaempferide) in high, medium and low doses had linear absorption properties in the small intestine segment, consistent with zero-order absorption rate; in addition, the absorption rate constant (Ka) of three components in jejunum and ileum were increased with the increase of the concentration of GDD (P<0.05), consistent with passive absorption. However, the Ka of rhein in jejunum and ileum showed little difference with the increase of dosage, suggesting a possibility of active transport mechanism. Chrysophanol and aloe-emodin were poorly absorbed in the two segments, which had not been detected in the previous time. The results suggested that the components of GDD were selectively absorbed in the intestinal sac, and the absorption characteristic of the ingredients were not exactly similar.