ABSTRACT
In this study, a method for simultaneous quantitative analysis of 6 salvianolic acids and 4 tanshinones in extracts of Salviae Miltiorrhizae Radix et Rhizoma was established by ultra-high performance liquid chromatography (UHPLC). The semi-biomimetic method was applied to simulate digestion process in vitro, to explore the digestion and transport characters of oral administration through the gastrointestinal tract, and to explain the content ratio changes and bioaccessibility of active ingredients in Salviae Miltiorrhizae Radix et Rhizoma. The results showed that the 10 index components have a good linear relationship in the corresponding concentration range, and the average recovery rate was 91.35% to 105.65%. After simulated digestion in vitro, types of chemical composition in simulated gastric fluid and simulated intestinal fluid digested extracts of Salviae Miltiorrhizae Radix et Rhizoma did not change significantly. While the content ratio of salvianolic acid B and rosmarinic acid decreased, and the content ratio of protocatechuic aldehyde and danshensu increased. In the simulated gastric fluid digestion extract of Salviae Miltiorrhizae Radix et Rhizoma, the order of bioaccessibility was: danshensu (50.19%) > salvianolic acid B (33.44%) > lithospermic acid (27.34%) > salvianolic acid A (21.71%) > rosmarinic acid (12.31%). In the simulated intestinal fluid digestion extract of Salviae Miltiorrhizae Radix et Rhizoma, the order of bioaccessibility was: 15,16-dihydrotanshinone Ⅰ (5.45%) > tanshinone Ⅰ (3.67%) > cryptotanshinone (3.29%) > tanshinone ⅡA (3.01%) > salvianolic acid A (2.39%) > lithospermic acid (1.57%) > salvianolic acid B (1.02%) > danshensu (0.41%) > rosmarinic acid (0.34%). In conclusion, the UHPLC method established in this study can be applied for accurately and sensitively detecting the contents of 6 salvianolic acids and 4 tanshinones in Salviae Miltiorrhizae Radix et Rhizoma. The results of semi-biomimetic extraction showed that not all components were extracted with simulated gastric fluid and simulated intestinal fluid, especially rosmarinic acid and salvianolic acid B. Therefore, in the quality study of Salviae Miltiorrhizae Radix et Rhizoma and its extract, bioavailability should be considered at the same time when select quality markers and determine their content limits.