Assay of advanced glycation endproducts in selected beverages and food by liquid chromatography with tandem mass spectrometric detection

Abstract

Food and beverages contain protein glycation adducts--both early-stage adducts and advanced glycation endproducts. We determined the concentrations of glycation adducts in selected food and beverages by liquid chromatography with triple quadrupole mass spectrometric detection. Cola drink contained low concentrations of glycation free adducts, whereas pasteurised and sterilised milk were rich sources of heat-stable glycation adduct residues--Nepsilon-carboxymethyl-lysine and Nepsilon-carboxyethyl-lysine. Laboratory rodent food was a rich source of advanced glycation endproducts. Measurement of glycation adducts in 24 h urine samples of normal and diabetic rats indicated that < 10% of glycation adduct residue consumption was excreted. Induction of diabetes by streptozotocin led to a 2-fold increase in urinary excretion of Nepsilon-carboxymethyl-lysine and a 27-fold increase in urinary excretion of methylglyoxal-derived hydroimidazolone Ndelta-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine - the latter was decreased by high-dose thiamine therapy that also prevented the development of nephropathy. We conclude that cola drinks are a poor source of glycation adduct whereas thermally processed milk is rich in glycation adducts. Dietary glycation adducts residues probably have low bioavailability. Experimental diabetes is associated with a marked increase in exposure to endogenous formation of methylglyoxal-derived hydroimidazolone which is linked to the development of diabetic nephropathy.

Advanced Glycation End Products: A Molecular Target for Vascular Complications in Diabetes

“…Glyceraldehyde, which could be derived from glucose metabolism, is not a major sugar in vivo and its incubation with proteins will generate a large number of AGEs; in addition, there is some criticism that measurement of AGEs using liquid chromatography-tandem mass spectrometry technique may produce different results to that using ELISA (129). However, our series of studies have suggested that serum levels of glyceraldehyde-derived AGEs might be a novel biomarker for insulin resistance and vascular injury and may predict future cardiovascular events in diabetes.…”

Advanced Glycation End Products and Nephrotoxicity of High-Protein Diets

“…Detection of AGE fluorescence capacity is simple but nonspecific. Specific AGE can be identified and quantified by ELISA, HPLC, or mass spectrometry (26). …”

Improved Glycemic Control and Vascular Function in Overweight and Obese Subjects by Glyoxalase 1 Inducer Formulation

“…4E). To assess the whole-body formation of MG-H1, we measured the urinary excretion of MG-H1 free adduct, corrected for MG-H1 absorbed from food by extrapolating regression of urinary MG-H1 on urinary pyrraline in all subjects to zero pyrraline (and hence no contribution from food) (25,26) (Fig. 4F).…”