Preliminary Evaluation of Hypoglycemic Activity and Its Material Basis of Ruditapes philippinarum Hydrolysate

Objective:To clarify the effect of enzymatic hydrolyzed peptides on related indexes of hypoglycemic activity and its peptide composition. Methods:Hydrolysate of R. philippinarum were prepared by acid protease treatment and separated by Sep-Pak C₁₈ solid phase extraction column under different concentrations of acetonitrile. The human dipeptidyl peptidase IV (DDP-IV) inhibition model in vitro and the HepG-2 insulin resistance (IR) model were screened to determine the active peptide fraction. Then the fraction with best activities was identified by nano liquid chromatography Q-exactive-orbitraptandem mass spectrometry (Nano LC-Orbitrap MS/MS). Results:10% acetonitrile eluting fraction had the best inhibitory effect on DPP-IV, which increased glucose uptake. Finally, a total of 114 peptides were identified from 10% acetonitrile eluting fraction by nano LC-MS/MS. Among those peptides, 83.3% of which was hydrophilic polypeptides, and 90.4% with the molecular weight was lower than 2000 Da, and most of them contained hydrophobic amino acid was at their N-terminal. Conclusion:These results suggest that the peptides from hydrolysate of R. philippinarum may exert hypoglycemic effects by inhibiting DPP-IV activity and reducing insulin resistance.