Anti-diabetic properties of yellowfin tuna protein hydrolysates and identification and screening of novel anti-diabetic peptides against α-amylase and DPP-IV.

Bioactive peptides derived from fishery by-products show potential in managing chronic diseases, highlighting their value in functional food and healthcare product development. This study utilized yellowfin tuna trimmings to prepare an alkaline protease hydrolysates (YTPH) and investigated its potential anti-diabetic effects in streptozotocin-induced diabetic mice. YTPH noticeably reduced random and fasting blood glucose levels, increased serum insulin levels, enhanced antioxidant enzyme activities, and alleviated liver and kidney damage. YTPH1 and YTPH2 were isolated using G-15 gel fractionation, showing considerable inhibitory activities against α-amylase (AAM) and dipeptidyl peptidase IV (DPP-IV), respectively. In silico analysis identified three bioactive peptides: GEVE, LDDVEE and VSGAELE. These peptides potentially regulate blood glucose levels through targeted inhibition of AAM or DPP-IV. This study demonstrates the potential of yellowfin tuna by-products as a source of hypoglycemic peptides and emphasizes the sustainable and comprehensive use of tuna by-products, thereby offering new functional ingredients for the development of functional food.