Combining bioaffinity-ultrafiltration with in vivo and in vitro analyses to identify and characterize α-glucosidase inhibitors from Rosa roxburghii Tratt. Fruit

The fruit of Rosa roxburghii Tratt. (RRT) is frequently eaten in Guizhou Province, China. Thirty compounds from RRT fruit were identified by the bioaffinity-ultrafiltration method. Among them, quercetin, diosmetin, luteolin, and apigenin (IC 50  = 4.80 ± 0.12 μg/mL, 52.62 ± 0.26 μg/mL, 17.51 ± 0.27 μg/mL, 33.24 ± 0.32 μg/mL) exhibited significant α-glucosidase inhibitory activities. Based on multispectral and molecular docking analyses, these active compounds bind to the active site of α-glucosidase via at least four hydrogen bonds and van der Waals forces, thereby altering its hydrophobic environment and secondary structure. in vivo studies showed that compared to the AUC of postprandial glucose in the model (2809.33 ± 64.84 mM·min) and in the acarbose group (2525.40 ± 54. 28 mM·min), these compounds decreased postprandial blood glucose levels. Long-term administration of apigenin additionally improved lipid metabolic disorders. These results support the development of RRT fruit as a hypoglycemic functional food.