Cynarin-Rich Sunflower (Helianthus annuus) Sprouts Possess Both Antiglycative and Antioxidant Activities

The present study examined the antiglycative and antioxidant properties of four edible sprouts popular in Chinese markets. In a protein-reducing sugar model, the sunflower sprout Helianthus annuus exhibited the strongest inhibitory effects against the formation of advanced glycation end products (AGEs). At a concentration of 1.0 mg/mL, its inhibitory rate achieved 83.29%, which is stronger than that of aminoguanidine (1 mM), a well-known synthetic antiglycative agent (with an inhibitory rate of 80.88%). The antioxidant capacity of H. annuus was also much stronger than other sprout samples in terms of free radical scavenging and reducing properties. An active ingredient contributing to the observed activities was identified as cynarin (1,5-dicaffeoylquinic acid). This is the first report of the novel function of cynarin to intervene against glycoxidation. Given the key roles of AGEs and oxidation in the pathogenesis of diabetes, the sunflower sprout H. annuus rich in cynarin may be regarded as a beneficial food choice for diabetic patients.