Protective effects of di- and tri-peptides containing proline, glycine, and leucine on liver enzymology and histopathology of diabetic mice

Context: Small peptides as multifunctional biomolecules can prevent the metabolic disorders such as diabetes. Objective: The purpose of this study was to investigate the effects of small peptides on the enzymes and histopathology of the liver in mice exposed to diabetes. Methods: Di- and tri-peptides containing proline, glycine, and leucine were produced by solid phase peptide synthesis (SPPS) protocol. The effects of produced peptides as well as carnosine (Ala-His) and glutathione (Glu-Cys-Gly) were evaluated on hepatic enzymes activity by enzymatic method and histopathology of liver using hematoxylin and eosin and TUNEL staining to assess histologic changes and apoptosis in diabetes induced by multiple low doses of streptozotocin (MLDS). Results: The Ala-His, Leu-Gly and Pro-Gly-Pro dipeptides had the higher protective effects against the effects of diabetes on the enzymes and histologic changes of liver in mice. Conclusion: These peptides can be raised as considerable pharmaceutical preventive agent against diabetes development.