ABSTRACT
The rat everted intestinal sac model was adopted to investigate the absorption of total flavonoids from Coreopsis tinctoria in different intestinal segments. Cyaniding-3-O-β-D-glucoside, chlorogenic acid, flavanomarein, quercetagetin-7-O-β-D-glucoside, iso-okanin, marein and 3,5-dicaffeoylquinic acid which as the major chemical components of total flavonoids from C. tinctoria were selec-ted as the study objects to evaluate the absorption characteristics of each component in different intestinal segments. The results showed that the absorption of seven components of total flavonoids at different intestinal segments was in consistent with zero order absorption rate. The K_a of chlorogenic acid, flavanomarein, quercetagetin-7-O-β-D-glucoside, isookanin and 3,5-dicaffeoylquinic acid increased with increasing of concentration of total flavonoids(P<0.05), indicating that the intestinal absorption of these five components was passive transport. The K_a of cyaniding-3-O-β-D-glucoside and marein showed a weak concentration dependence, suggesting that the absorption of them may be an positive and passive co-existing mode. The result of absorption in different intestinal segments showed that cyaniding-3-O-β-D-glucoside, chlorogenic acid, flavanomarein, quercetagetin-7-O-β-D-glucoside, marein and 3,5-dicaffeoylquinic acid were mainly absorbed in ileum, while isookanin was mainly absorbed in jejunum. The total flavonoids of C. tinctoria are selectively absorbed in intestinal tract, the rat everted intestinal sac model can be used to evaluate the multi-component intestinal absorption characteristics of total flavonoids from C. tinctoria.