Absorption of aqueous extracts from Salviae Miltiorrhizae Radix et Rhizoma by everted intestinal sac method

Abstract

To study the absorptive characteristics of aqueous extracts from Salviae Miltiorrhizae Radix et Rhizoma by in vitro rat everted intestinal sac model. Three representative ingredients in aqueous extracts from Salviae Miltiorrhizae Radix et Rhizome--protocatechuic aldehyde (PAL), posmarinic acid (RA) and salvianolic acid B (SAB), were selected as the study objects. An UPLC method was established to determine and measure their cumulative absorption amount, in order to explain the absorption characteristics of ingredients in different intestinal sections. According to the experimental result, RA and SAB showed the passive absorption in ileum, which conformed to the first-order absorption rate; with low and medium doses, they showed a zero-order absorption rate in jejunum, which was reflected in the coexistence of both positive and passive absorptions; PAL showed a passive absorption manner both in ileum and jejunum. According to the experiment for absorption in different intestinal sections, RA and SAB were mainly absorbed in jejunum, while PAL was absorbed mainly in ileum. All of the three ingredients in aqueous extracts from Salviae Miltiorrhizae Radix et rhizome--PAL, RA and SAB could be absorbed in intestines, but with differences in the absorption rate and mechanism, which indicated that the intestinal absorption of aqueous extracts from Salviae Miltiorrhizae Radix et rhizome was selectivity, instead of a simple semi-permeable membrane penetration process.