Novel peptides with anti-proliferation activity from the Porphyra haitanesis hydrolysate

In this study, Porphyra haitanesis protein was extracted and hydrolysed with trypsin. The gel filtration chromatography was employed to separate peptides from protein hydrolysate. Three polypeptides were isolated, which exhibited anti-proliferation activities on five cancer cells (MCF-7, HepG-2, SGC-7901, A549 and HT-29), the 1050 values were comprised within 191.61 and 316.95 mu g/mL. Subsequently, two new peptides VPGTPKNLDSPR and MPAPSCALPRSVVPPR were identified, the former displayed good inhibition activities on cancer cells MCF-7 and HepG-2, with the IC50 values of 200.97 mu g/mL and 276.85 mu g/mL, respectively, but low inhibition on normal liver cells LO-2 (7.1%), at 500 mu g/mL. Moreover, flow cytometry confirmed that cell cycle was arrested in G0/G1 phase and apoptosis was induced in MCF-7 cells treated with the synthesized peptide VPGTPKNLDSPR. Taken together, Porphyra haitanesis-derived polypeptides possessed anti-proliferation activities by arresting cell cycle and inducing apoptosis in cancer cells, which could be potential in food and pharmaceutical applications.