Effect of micronutrients on methylglyoxal-mediated in vitro glycation of albumin.

Nonenzymatic glycation of long-lived proteins has been implicated in several complications related to age and diabetes. Dicarbonyl compounds such as methylglyoxal (MGO) have been identified as the predominant source for the formation of advanced glycation end-products (AGEs) in various tissues. We investigated the effect of 13 micronutrients on MGO-mediated in vitro glycation of bovine serum albumin (BSA), as formation of AGEs and protein carbonyls. BSA (10 mg/ml) was incubated at 37°C with 100 mM MGO for 24 hours, in presence of ascorbic acid, Trolox (water-soluble α-tocopherol analog), β-carotene, retinol, riboflavin, thiamin, folic acid, niacin, pyridoxine, zinc, iron, manganese, and selenium. Fluorescence was measured at the wavelength pair of 370 and 440 nm as an index of the formation of AGEs and spectra were recorded for promising interactions at λex=280 nm and λex=370 nm. Within four standard antiglycating agents, aminoguanidine showed highest inhibitory response for BSA glycation followed by quercetin, gallic acid, and tannic acid. Promising antiglycation potential was seen for Trolox, riboflavin, Zn, and Mn as evidenced by decrease in the formation of AGEs and protein carbonyls.