Hypoglycemic Effect Of Maillard Reaction Products Of Superoxide Dismutase In Diabetic Rats

Diabetes has a serious impact on people's lives as one of the most commom chronic non-infectious diseases.And Superoxide Dismutase(SOD),as the most important antioxidant enzymes in the body,may play vital role in the treatment of diabetes.Some studies have showed that SOD extract has good hypoglycemic effect.However,Pure SOD was not used in these studies.Moreover,there are still a lot of limitations in the clinical application of SOD due to its short half-life,immunogenicity,poor cell membrane affinity and permeability and other factors,Previous researches suggest the modification of Maillard reaction may be a promising approach to overcome these shortcomings of SOD.Therefore,glucose was used to modify SOD by Maillard reaction,and the effect of Maillard reaction on the properties of SOD,as well as the hypoglycemic effect of pure native SOD and glycated SOD(SOD-G)were investigated in this thesis.Bovine blood SOD and glucose was co-incubated for Maillard reaction,then the SOD-G and native bovine blood SOD were used to treat type I and type II diabetic rats.By comparing weight,blood glucose,oral glucose tolerance,the SOD levels of tissue organs(heart,liver,kidney,pancreas,spleen and skeletal muscle)and the levels of plasma insulin(INS),glucagon(GLUCA),AMP activated protein kinase(AMPK),malondialdehyde(MDA)and blood fat,the hypoglycemic effect was comprehensively analyzed in diabetic rats administrated with native SOD or same dose of SOD-G,different doses of SOD-G,and different routes of medication(intragastric administration and dropping into mouth).It was found that SOD-G and SOD had a significant hypoglycemic effect in both types of diabetic rats,and the treatment effect was positively correlated with intragastric dosage,but different SOD had its own advantages.For type I diabetes,there were no differences between two kinds of SOD in body weight control;SOD-G hypoglycemic effect was significantly better than SOD(P<0.05);while in the OGTT test,the effect of SOD was significantly better than SOD-G(P<0.05).In tissue SOD level test,SOD levels of liver and kidney in SOD-G group were significantly lower than that in SOD group.For type II diabetes,there were no difference in controlling body weight and blood glucose.OGTT test result was opposite to type.I diabetes,SOD-G group showed better efficacy than SOD group.SOD-G could significantly reduce the level of body GLUCA(P<0.05).In the level of blood fat,SOD-G significantly improved the level of HDL-C(P<0.05),but both SOD-G and SOD had no significant difference in CHO,TG and LDL-C.Regardless of the type ?or ? diabetes,SOD and SOD-G all increased SOD activity of pancreas,and had no significant effect on skeletal muscle and heart SOD content.Both of which could effectively control INS,AMPK,MDA levels,but there was no significant difference between them.Comparison of different routes of administration showed the administration of dropping SOD-G into mouth had a significantly better effect than intragastric administration.Except pancreas SOD content and INS,AMPK,MDA levels,several indicatives of dropping into mouth even achieved equivalent effect of positive control and high dose SOD-G.These results indicated that SOD modified with Maillard reaction(SOD-G)still had obvious hypoglycemic effect,and the overall effect of SOD-G was better than SOD;the administration of dropping into mouth could play a greater efficacy.This may be due to the Maillard reaction to alter its structure,resulting in the improvement of absorption of SOD-G in the body.