Research Info

The small peptides, as multifunctional biomolecules, can affect some organs and metabolic disorders. The purpose of this experiment was to investigate the effects of some small peptides on the renal enzymes and histopathology in mice exposed to diabetes. Solid phase peptide synthesis method was used to synthesis di- and tri-peptides. Diabetes was induced in mice by multiple injection of low doses of streptozotocin. The effects of the di- and tri-peptides on renal aspartate aminotransferase, alanine transaminase, alkaline phosphatase, superoxide dismutase (SOD), glutathione peroxidase, total antioxidant (TAC), and catalase activities were evaluated by enzymatic biochemical methods and malondialdehyde (MDA) by thiobarbituric acid method. Hematoxylin and eosin and TUNEL stainings performed for assessing histopathology and apoptosis of the mice kidney. Hannaneh (Leu–Gly) and carnosine (Ala–His) exhibited suppression effects on the blood glucose elevation and the severity of the renal alterations in diabetic mice. They showed a decreasing effect on diabetes-induced DNA damage (P < 0.05). Carnosine significantly prevented from MDA elevation (P < 0.05). The Pro–Pro showed a supression effect on the blood glucose elevation (P < 0.05). Glutathione (Glu–Cys–Gly) and hannaneh caused to renal tissue TAC decreasing (P < 0.05). Mice receiving Pro–Gly and Pro–Gly–Pro have lesser renal SOD compared to diabetic mice (P < 0.05). Pro– Gly–Pro significantly decreased the diabetes-induced DNA damage. Although all the treatments had significant effects on alleviating the apoptosis, but carnosine and hannaneh dipeptides had the best protective effect on the kidney. The carnosine and hannaneh dipeptides had higher reno-protective effects against renal enzymes and histologic changes in diabetic mice.