Hempseed protein derived antioxidative peptides: Purification, identification and protection from hydrogen peroxide-induced apoptosis in PC12 cells

Hempseeds have not been utilised to any significant extent by the industrial food markets. A novel antioxidant peptide derived from hempseed by-product was investigated. Hempseed protein isolate was prepared by alkaline extraction and subsequent isoelectric precipitation. Its enzymatic hydrolysate, obtained by Alcalase® treatment, was subjected to DA201-C macroporous absorption resin, with simultaneous desalting and concentrating of hydrophobic fragments with improved free radical-scavenging activities. The active fraction was further separated by gel filtration and reversed-phase high performance liquid chromatography to obtain two purified peptides; the peptides were characterised as NHAV and HVRETALV, by MALDI-TOF/TOF MS/MS. The protective effects of the purified peptides on hydrogen peroxide-induced cell apoptosis were investigated in rat pheochromocytoma line PC12 cells. The peptides, at a concentration of 10 μg/ml, possessed protective effects (P < 0.05) against cell death and oxidative apoptosis. The findings are significant for the discovery and development of natural antioxidants from hempseed by-products.