Investigation of peptide based antiglycation agents from various sources

Diabetes mellitus is one of the most common diseases in most of the developed countries. It can affect nearly every organ and system in the body. Hyperglycemia in diabetes causes non enzymatic glycation of proteins and leads to their structural and functional changes, resulting in diabetic complications like nephropathy, retinopathy, neuropathy, and angiopathy. Glycation of proteins starts with the formation of Shiff's base, followed by intermolecular rearrangement and conversion into Amadori products. Amadori products undergo cross linkage to form a heterogeneous protein-bound moieties, termed as advanced glycated end products (AGEs). They have been recently demonstrated to be linked to glucose auto-oxidative process and may influence the generation of oxygen free radicals. The formation of AGEs is not only linked to diabetes but also to several diseases like Alzheimer's and age related diseases. Among others deglycation process acting on Shiff bases (glycosylamines) which are the first products of the nonenzymatic glycation. The first step in this deglycation process occurs by transfer of the sugar moiety from the Shiff base to one of the low-molecular weight intracellular nucleophiles. Any agent capaple of doing this, if potent, would be very important for life-extension, since glycation in the body can only be slowed down but not stopped. There are numerous publications describing the in vitro antiglycating affect of some peptides like glutathione, carnosine and its analogs, polyamines, thiols and thiolamines. Until now many efforts have been made to seek new AGE inhibitors, in particular those from natural sources without adverse effect. In this work is to investigate peptide based antiglycation agents from various sources that inhibit AGEs formation. Among all plant peptide isolates soybean was found to be most efficient by means of antiglycating, antioxidant and metal chelatation activity.