Abstract: The present study aimed to evaluate the effect of peptides produced by enzymatic hydrolysis of tuna pancreatic proteins on body weight, fasting serum insulin (FINS), glycated hemoglobin (HbA1c), and serum lipid levels of db/db diabetic mice for the purpose of providing theoretic evidence for the development of new healthy foods from tuna pancreas. Methods: Ten male Db/m mice were used as blank control group. A total of 30 male leptin gene knockout db/db mice were divided into model control group, positive drug control group and experimental group. The mice in the experimental group were gavaged with the peptides derived from tuna pancreatic proteins. After 10 weeks, the body weight, FINS, HbA1c, and serum lipid biochemical indexes in all groups of mice were examined. The gene expression levels in the kidney were evaluated using gene chip technology. Results: In comparison with the control group, the experimental group demonstrated a significant decrease in body weight, FINS, HbA1c, serum total cholesterol, triglyceride and low-density lipoprotein cholesterol levels and an obvious increase in high-density lipoproteincholesterol. The gene expression levels in experimental group were also significantly different from those in the control group. A total of 678 differentially expressed genes were found, 161 of which were up-regulated and 517 of which were down-regulated. Conclusion: The peptides derived from tuna pancreatic proteins by enzymatic hydrolysis can effectively control body weight, FINS, HbA1c and serum lipid levels in db/db diabetic mice, likely by decreasing the expression of aldosterone synthase gene (CYP11B1).

Key words: tuna pancreas, enzymatic hydrolysate, diabetes, db/db mice, CYP11B1