The Role Of Docosahexaenoic Acid In Prevention And Treatment Of Type 1 Diabetes Mellitus Mice And Its Possible Mechanism

Objective To explore the role of Docosahexaenoic acid in prevention and treatment of Type 1 Diabetes Mice and its possible mechanism.Methods 40 male mice were randomLy divided into 4 groups,10 mice each. Control group was given intra peritoneal injection of STZ solvent, citrate buffer,0.2mL for 5 days and DHA solvent, DMSO, 0.1mL into the colon with a mice gavage needle. Model group was given intra peritoneal injection of STZ (60mg/kg) for 5 days and DMSO 0.1mL into the colon at the same time. Prevention group was given intra peritoneal injection of STZ for 5 days while DHA 0.1mL into the colon. Treatment group was given intra peritoneal injection of STZ for 5 days. After T1DM model establishment, continuous DHA 0.1mL administration into the colon for 5 days. The four groups were observed for 25 days after administration of DHA then sacrificed. General state of mice, amount of food-and water-intake, body-weight and blood glucose were observed. Blood serum was used for measurement of insulin levels, while liver tissue were pre-prepared for measuring levels of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC), pancreas islet for structure observation and apoptosis by TUNEL, while pancreatic glucagon-like peptide-1 receptor (GLP-1R) expression by immunohistochemistry.Results In the control group, mice showed shiny hair, more active, normal state of food-and water-intake, increased body weight. While in model group mice appeared dull hair, less active, gradual polydipsia, polyphagia, polyuria, weight loss and decreased blood glucose levels. In prevention and treatment group mice had more shiny hair, more activities, increased body weight, food-and water-intake was significantly lower than that of model group, and blood glucose levels was also decreased significantly. Serum insulin, liver SOD and T-AOC levels of prevention and treatment group were slightly lower than control group, they were significantly higher than model group. In HE staining, islets morphology in prevention and treatment groups were more regular, islet cells were round or oval cytoplasmic, and borders more clearly, but a slight swelling of cytoplasm and degeneration, compared with the control group. TUNEL assay showed that in islet and around cells of prevention and treatment group, apoptosis positive cells were slightly more than that of control group, but significantly less than model group. Model group pancreatic and around tissue could be seen more apoptotic cells. In immunohistochemistry control group mice pancreas islet cells showed GLP-1R were mainly in the cytoplasm, high positive rate of brown cytoplasmic granules. The numbers of positive cells in preventive and treatment group were lower than control group, while significantly higher than model group.Conclusion DHA could effectively reduce the amount of food and water consumption and blood glucose, elevate insulin and liver SOD and T-AOC level, improve antioxidant capacity, reduce islet cell apoptosis, increase islet cells GLP-1R expression.