Effect of Micronutrients on Methylglyoxal-Mediated In Vitro Glycation of Albumin

Abstract

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.

An in vitro study reveals nutraceutical properties of Ananas comosus (L.) Merr. var. Mauritius fruit residue beneficial to diabetes

“…The chemical composition of the fractions showed the presence of sinapic acid, daucosterol and ergosterol, which are reported to have various types of therapeutic properties, such as immunomodulatory, anti‐hyperglycaemic, antifungal etc. Minerals such as sodium, potassium, calcium, magnesium, chromium and vanadium are reported to have a protective property against diabetes . AAS analysis of the fruit residue showed the presence of moderate amounts of magnesium, calcium and potassium, and traces of manganese, sodium and zinc.…”

Advanced glycation end products

“…Accordingly, an increasing list of natural antioxidants and chelating agents such as ascorbic acid, α-tocopherol, niacinamide, pyridoxal, sodium selenite, selenium yeast, trolox, rivoflavin, zink and manganese has been shown to inhibit glycation of albumin in vitro 125 . Alpha-lipoic acid was able to reverse tail tendon collagen glycation in fructose-fed rats, an effect which was attributed to its endogenous antioxidant action, its ability to recycle ascorbic acid, α-tocopherol and GSH as well as to its positive influence on glucose uptake and glycaemia 126 .…”

The role of advanced glycation end products in various types of neurodegenerative disease: a therapeutic approach

“…Binding TPP to TK activates TK and decreases the accumulation of glyceraldehyde-3-phosphate and fructose-6-phosphate formed from the glycolytic pathway, thus preventing AGE formation [129]. Secondly, thiamine can directly quench reactive carbonyls [130] due to the unique reactivity of its thiazolium nucleus [131] with a mechanism similar to that used by thiamine in enzymatic catalysis [132]. PM (4-(aminomethyl)-5-(hydroxymethyl)-2-methylpyridin-3-ol), a derivative of vitamin B6, is an effective inhibitor of both in vivo and in vitro of protein glycation and lipoxidation [133].…”