Discovery of Rifampicin as a New Anti-Glycating Compound by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry-Based Insulin Glycation Assay

Abstract

An in vitro insulin glycation assay was developed for screening glycation inhibitors. The assay involves the use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for monitoring the formation of glycated insulin. The assay is simple, rapid and amenable for high throughput screening. Using this assay we have discovered a strong anti-glycation activity for the anti-tuberculosis drug rifampicin. These results were compared with bovine serum albumin glucose fluorescence assay. In addition, the IC 50 of rifampicin was lower than that of aminoguanidine, a known anti-glycating agent, suggesting that rifampicin is a more potent glycation inhibitor.

Proteomic Analysis of Glycated Proteins from Streptozotocin-Induced Diabetic Rat Kidney

“…Glycation of proteins leads to formation of different kinds of AGEs such as carboxy methyl lysine (CML), pentosidine, pyralline, imidazolone B, 1-alky 2 formyl 3-4 glycyl pyralline (AFGP), and crossline (10). Glucose-derived Amadori products are thought to be potential precursors of 3-deoxyglucosone (3-DG) in vivo.…”

“…In our previous study, we have used MALDI-TOF-MS to study in vitro glycation of insulin and albumin [9,10]. In this study using Anti-AGE antibodies, we have detected the proteins modified by AGEs from the kidney of streptozotocin-induced diabetic rat by using two-dimensional electrophoresis coupled with western blot analysis.…”

The Role of Nonenzymatic Glycation and Carbonyls in Collagen Cross-Linking for the Treatment of Keratoconus

“…AG and Rif showed different inhibitory strengths in both the tensile strength and the gel electrophoresis tests; these data are consistent with a recent findings showing that Rif is a stronger AGE inhibitor than AG. 24 Free glucose in the solution with collagen type I (Fig. 4, lane 8) inhibited the formation of the highest molecular weight polymers (remaining in the sample well) but allowed the formation of polymers of approximately ␥-chain size yet did not inhibit the cross-linking-induced disappearance of the ␣1/␣2 and ␤ chains caused by CXL, suggesting that free glucose in the corneal stroma might slightly inhibit CXL compared with the pattern of cross-linking in the absence of free glucose (Fig.…”

“…24 Neither of these AGE inhibitors is known to be capable of breaking preexisting AGE-derived cross-links. 24,25 Rather, they inhibit the formation of new AGEs, possibly by reacting with the reactive carbonyl groups that AGE formation produces, thereby disabling the ability of carbonyl groups to react with amine residues.…”

“…24 Neither of these AGE inhibitors is known to be capable of breaking preexisting AGE-derived cross-links. 24,25 Rather, they inhibit the formation of new AGEs, possibly by reacting with the reactive carbonyl groups that AGE formation produces, thereby disabling the ability of carbonyl groups to react with amine residues. 26 Therefore, if the mechanism by which CXL causes cross-linking of corneas involves AGEs or reactive carbonyl groups, then the addition of an AGE inhibitor to the RF solution should significantly reduce the amount of cross-linking during CXL.…”