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 <i>Rosa roxburghii</i> 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 (IC₅₀ = 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 <i>via</i> at least four hydrogen bonds and van der Waals forces, thereby altering its hydrophobic environment and secondary structure. <i>in vivo</i> 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.