| Diabetes has become the third serious diseases to human health,followed the tumor and cardiovascular diseases,but the traditional antidiabetic drugs can not meet the needs of modern society for diabetes,so it is a global concern to look for safe and effective drugs for prevention and treatment of diabetes.The results of this work were as followed:1.The best preparation process of walnut polypeptide with neutral protease in substrate concentration 2%,hydrolysis time 1 h,pH 7,the amount of enzyme for solution of walnut protein 8000 μg/g,then alkaline protease in the substrate concentration 2%,hydrolysis time 2 h,pH 9,the amount of enzyme for solution of walnut protein 10000μg/g,final degree of hydrolysis was about 40%,and the enzymatic hydrolysate of walnut polypeptide on alpha amylase inhibition rate reached 85.9%.2.The best separation conditions of the walnut polypeptide with the SuperdexTM Peptide 10/300 GL column on the enzymatic hydrolysis products were as followed: Na Cl concentration 0.15 mol/L,the sample concentration 8 mg/ml,and the flow rate 0.5 ml/min.In walnut polypeptide,the average molecular weight of JRP-1 was about 10077,the content was 38.94%,the average molecular weight of JRP-2 was about 1083,and the content was 40.92%.3.Walnut protein and polypeptide had certain antioxidant activity,and the antioxidant activity of walnut polypeptide was significantly higher than that of protein.With GSH as a positive control,the DPPH scavenging ability of walnut polypeptide was about 75%,which was that of 80% of GSH;the O2-scavenging rate of walnut polypeptide was70.70%,which was 87% of GSH;the total reduction ability of walnut protein and polypeptide was significantly lower than that of the control GSH,which that of the walnut polypeptide was almost 2 times than that of walnut protein with the same concentration;the OH clearance rate of walnut polypeptide was significantly better than that of walnut protein,which was more than 50% of GSH.Walnut protein and polypeptide have the effect of lowering blood glucose in vitrothrough promoting the utilization of glucose by Saccharomyces cerevisiae,and the effect of the polypeptide is slightly better than that of the protein.In addition,when the dosage of walnut polypeptide was 15 mg/50 ml,the promotion effect was more than 2 times than that of the blank group,and the average rate of glucose consumption of walnut polypeptide reached to 0.026 mg/（ml/h）.4.The walnut protein and polypeptide can significantly improve the ability to regulate glucose of T2 DM mice,and effectively control the glucose level,which shown good hypoglycemic effect.Additionally,the TC and TG levels in serum can significantly be reduced by treatment with walnut protein and polypeptide.Furthermore,the glucose and lipid metabolism dysfunction during the development of diabetes was improved,and the lesions of heart,liver and kidney caused by diabetes can be inhibited by walnut protein and polypeptide,which reduced the complications of diabetes. |
