Purification and identification of anti-obesity peptides derived from Spirulina platensis

The aim of this study was to isolate and purify anti-obesity peptides from Spirulina platensis protein. Five enzymes (trypsin, alcalase, pepsin, papain and protamex) were used for hydrolysis of the extracted protein. Subsequently, ultrafiltration and gel column chromatography were employed for further purification. The inhibitory effect on pancreatic lipase and 3T3-L1 preadipocytes were evaluated. The results showed that the 3-5 kDa fraction from pepsin digest exhibited good inhibition on lipase (72%), and its chromatographed fractions displayed strong inhibition on 3T3-L1 preadipocytes (72.7-88.1%) but low inhibitory or stimulatory activities on normal liver cells L-O2 (-26.02 to 12.16%). By mass spectrometry, four novel peptides NALKCCHSCPA, LNNPSVCDCDCMMKAAR, NPVWKRK and CANPHELPNK were identified, which exhibited inhibitory effects on 3T3-L1 preadipocytes proliferation (32.29-60.08%). Moreover, NPVWKRK and CANPHELPNK also significantly decreased the accumulation of triglyceride at 600 mu g/mL (p < 0.05), up to 23.7% and 19.5%, respectively. This suggests the potential of Spirulina platensis-derived hydrolysates and peptides as anti-obesity ingredients.