Abstract
Critical flavonoids from Semen Hoveniae have huge potential bioactivities on hypoglycemic. A multi-index comprehensive assessment based on Analytic Hierarchy Process (AHP) method was performed to optimize the extraction process of flavonoids from Semen Hoveniae, which taking dihydromyricetin, taxifolin, myricetin and quercetin as indexes, and, then, an in vitro simulated gastrointestinal digestion model was established to investigate the changes of flavonoids contents and their antioxidant capacity before and after digestion. The results showed that three influence factors acted significantly with the order of ethanol concentration > solid-liquid ratio > ultrasound time. The optimized extraction parameters were as follows: 1:37 w/v of solid-liquid ratio, 68% of ethanol concentration and 45 min for ultrasonic time. During in vitro digestion, the order of remaining ratio of four flavonoids in the extract was dihydromyricetin > taxifolin > myricetin > quercetin in gastric digestion, and remaining ratio of taxifolin was 34.87% while others were restructured in intestinal digestion. Furthermore, the 1,1-dipheny-2-picryhydrazyl free radical (DPPH ·) scavenging ability and oxygen radical absorption capacity (ORAC) of extract were more stable in gastric digestion. After an hour's intestinal digestion, the extract had no DPPH antioxidant capacity, but amazingly, its ORAC antioxidant capacity was retained or increased, which implied that substances were transformed and more hydrogen donors were produced. This study has carried out a preliminary discussion from the perspective of extraction and put forward a new research idea, to improve the in vivo bioavailability of the critical flavonoids from Semen Hoveniae.