Content Differences of Active Ingredients in Different Flower Colors of Carthamus tinctorius L. and Their α-Glucosidase Inhibitory Effects Based on Network Pharmacology and Molecular Docking

This study investigated the content differences of major active ingredients in red, yellow, and white flowers of Carthamus tinctorius L. from Yumin County, Xinjiang, and evaluated their α-glucosidase inhibitory effects using high-performance liquid chromatography (HPLC), network pharmacology, molecular docking, and in vitro enzyme assays. HPLC analysis revealed that red safflower had the highest content of Hydroxysafflor yellow A (HSYA), while white safflower exhibited the highest levels of kaempferol and kaempferol-3-O-rutinoside. Network pharmacology identified 21 core targets and multiple pathways related to type 2 diabetes and insulin resistance. Molecular docking indicated that kaempferol-3-O-rutinoside had the lowest binding energy (−9.3 kcal/mol). However, in vitro assays showed that kaempferol exhibited the strongest α-glucosidase inhibition (half maximal inhibitory concentration (IC50) = 0.1768 mg/mL), followed by HSYA and kaempferol-3-O-rutinoside. Among extracts, white safflower demonstrated the highest inhibitory activity (IC50 = 0.5485 mg/mL). In conclusion, flower color significantly influences the chemical composition and hypoglycemic potential of safflower. White safflower extract exhibited the strongest α-glucosidase inhibitory activity among the three flower color extracts. This study identifies kaempferol as the key active ingredient for safflower’s α-glucosidase inhibitory activity, providing a scientific basis for developing Yumin safflower as hypoglycemic functional food.