Antidiabetic potential of volavetki sea fish protein hydrolysates in high lipid diet and streptozotocin-induced diabetic rats

Abstract Background In the present study, the antidiabetic properties of volavetki (Panna microdon) sea fish protein hydrolysates (FPH) in high lipid diet and streptozotocin-induced type 2 diabetic rats (T2DM) were investigated through the mechanistic way using glucagon-like peptide-1 (GLP-1) agonistic and dipeptidyl peptidase-4 (DPP-4) inhibitory activities. Materials and methods There were eight groups of 5 rats each (n = 5): control, vehicle control, and other six T2DM groups consisting of one T2DM control, four T2DM groups supplemented with FPH at the doses of 12.5, 25, 50 and 75 mg/ kg b.w./day respectively for 28 days and one T2DM group treated with gliptin at the dose of 12 mg/kg b.w./day for 28 days. Results After 28 days of the experiment, T2DM group presented a significant increase in fasting blood glucose (FBG) and glycated hemoglobin (HbA1c) levels in plasma, hepatic glucose-6 phosphatase activities, level of lipid peroxidation, pancreatic DPP-4 inhibitory activities as well as a significant decrease in the levels of plasma insulin, c-peptides, GLP-1, and antioxidant activities of superoxide dismutase, catalase, glutathione and glucokinase activity in pancreas compared to control group. However, daily supplementation of FPH for 28 days improved plasma insulin, c-peptides and GLP-1 levels as well as significant decrease in plasma FBG and HbA1c levels, DPP-4 inhibitory activities, lipid peroxidation and hepatic glucose-6 phosphatase activities compared to T2DM group. FPH supplementation reduced pancreatic ROS generation and pancreatic necrosis. Conclusion Results have been presumed that antidiabetic activities were shown by various potential peptides in FPH identified by nano liquid chromatography mass spectrometry (nLC‒MS/MS) analysis.