Identification of anti-diabetes peptides from Spirulina platensis

In this study, ultrasound coupled with subcritical water (USW) technology was employed to extract S. platensis protein, and its inhibitory effect on three enzymes (α-amylase, α-glucosidase and dipeptidyl peptidase-4 (DPP-IV)) was evaluated. Subsequently, using insulin resistant-HepG2 cell model, the data presented that the USW-extracted protein significantly (p < 0.01) increased glycogen content, hexokinase and pyruvate kinase activities. Then, 11 peptides were identified from intact protein or the HPLC-separated protein fractions by LC-MS/MS. After in silico prediction, 3 peptides (GVPMPNK, RNPFVFAPTLLTVAAR and LRSELAAWSR) were synthesized, and their α-amylase, α-glucosidase and DPP-IV inhibition activities were validated. Among them, LRSELAAWSR displayed the medium activity on α-amylase (IC50 = 313.6 μg/mL), but the best activities on α-glucosidase (IC50 = 134.2 μg/mL) and DPP-IV (IC50 = 167.3 μg/mL). In summary, for the first time, anti-diabetes peptides were identified from Spirulina platensis, which are useful for functional food additives and pharmaceuticals against type 2 diabetes.Graphical abstractInhibitory effects of the identified peptides (RR, LR and GK) and drug Sitaglipin.
Source: Journal of Functional Foods - Category: Nutrition Source Type: research