Chemical and biological characterization of spirulina protein hydrolysates: Focus on ACE and DPP-IV activities modulation

Microalgae are considered a viable source of protein and among them spirulina (Arthrospira platensis) stands out for its exceptionally high protein content and its potential nutraceutical properties. In the present work, peptic (SP) and tryptic (ST) protein hydrolysates were produced using pepsin and trypsin, respectively. The kinetics of peptides release from the protein were investigated and the hydrolysates composition was assessed by HPLC-ESI-MS/MS, identifying 55 and 76 species-specific peptides in the SP and ST hydrolysates, respectively. The bioactivity was investigated by performing in vitro experiments and cellular assays in Caco-2 cells. SP and ST inhibited in vitro the activity of peptidyl-peptidase IV (DPP-IV) with IC50 of 3.4 and 0.1 mg/mL, respectively, and of angiotensin converting enzyme (ACE) with IC50 of 3.0 and 0.28 mg/mL. Both activities were confirmed in Caco-2 cells, although their further metabolic degradation reduced their potencies.