Anthocyanins in blackcurrant effectively prevent the formation of advanced glycation end products by trapping methylglyoxal

Carbonyl stress is the major consequence for advanced glycation end products (AGEs). Polyphenols have been shown to inhibit the formation of AGEs. However, little is known about whether anthocyanins contribute to trapping methylglyoxal (MGO) and reducing carbonyl stress. Blackcurrant (Ribes nigrum) extract (BE) is known to have high content of anthocyanins. When an aliquot of 7.5 mg/mL BE sample was incubated with 2.9 mM MGO in pH 7.4 phosphate buffer solution (PBS) for an hour, 36.75% MGO decrease was observed. The BE extract sample was separated and purified by Sephadex LH-20 and reverse phase C18 column chromatography. Delphinidin-3-rutinoside (D3R) and cyanidin-3-rutinoside (C3R) were identified as major pigments in BE sample. Some 71.45 and 78.72% of D3R and C3R, respectively, remained when they were incubated alone in a phosphate buffer solution at 37 °C for 1 h, but only 2.48 and 1.83% of D3R and C3R, respectively, remained when individually incubated with MGO. D3R- and C3R-mono-MGO adducts were characterized by HPLC-MSn.