Effect of buformin and metformin on formation of advanced glycation end products by methylglyoxal

The formation and accumulation of advanced glycation end products (AGE) in various tissues are known to be involved in the aging process and complications of long-term diabetes. Aminoguanidine as AGE inhibitors was first studied, and metformin as biguanide compounds have been reported to react with reactive dicarbonyl precursors such as methylglyoxal. We studied the effects of the biguanides of buformin and metformin on AGE formation by the methods of specific fluorescence, and enzyme-linked immunosorbent assay and a Western blot analysis using the anti-AGE antibody after incubating BSA or RNase with methylglyoxal. Buformin is a more potent inhibitor of AGE formation than metformin, and suggests that the amino group of buformin trap the carbonyl group of methylglyoxal to suppress formation of AGE. In addition to that of metformin, buformin may be clinically useful to prevent diabetic complications.