Effect and Mechanism of Elaeagnus angustifolia Flower and its Major Flavonoid Tiliroside on Inhibiting Non-enzymatic Glycosylation.

This study aimed to evaluate the anti-glycation ability of Elaeagnus angustifolia flowers extract, and to elucidate the mechanism with its major compound. The results indicated that E. angustifolia flowers extract and its major compound tiliroside (24.2 mg/g extract) exhibited excellent anti-glycation ability with the inhibition rate of 92.1% and 78.9% at 37.5 μg/mL, which are much higher than that of aminoguanidine (55.3% at 37.5 μg/mL). The stable tiliroside-ovalbumin (OVA) complexes were formed through a spontaneous exothermic progress in an equimolar manner, hydrophobic interaction, hydrogen bond and Van der waals forces were the major driving forces. Tiliroside could significantly ameliorate the conformation changes of OVA induced by glycation reaction, quench its fluorescence by a static mechanism, and change the micro-environment adjacent to tryptophan and tyrosine. Molecular docking revealed that the tiliroside inserted into the OVA hydrophobic pocket resulted in the formation of five hydrogen bonds. The Orbitrap MS/MS showed that tiliroside significantly suppressed the glycation of OVA, the number of glycation sites was reduced from nine to five after tiliroside was added. The above results indicated that E. angustifolia flowers and tiliroside have good anti-glycation effect and can be used as food additives to suppress undesired glycation reaction during food processing.