Antihypertensive Activity Of Peptide Fractions Prepared From Oyster Protein By Enzyme Hydrolyzation

Oyster protein powder(Oyster,Conch Ostreae)was hydrolyzed by pepsin,trypsin,proline(Maxipro)and their combination,respectively.Four kinds of protease hydrolyzates were further separated with macroporous resin(DA201-C),respectively.After being eluted with 20%,40% and 60% ethanol consecutively,some peptide fractions with different hydrophobicity were collected.After freeze drying,we obtained four kinds of bioactive peptide fraction powder,named as PEP-1(eluted from pepsin hydrolysate with 20% ethanol),PEP-2(eluted from pepsin hydrolysate with 40% ethanol),TRYP-2,(eluted from trypsin hydrolysate with 40% ethanol),and MIX-2(eluted from mixed hydrolysate with 40% ethanol).The result of cell proliferation analysis showed that the four bioactive peptides did not exhibit inhibition effecton human liver cell HLO2 proliferation at 0.2 mg/mL and 0.6 mg/mL,and the peptides can even promote it at the given concentration.The result of ACE inhibition analysis in vitro showed that PEP-1,PEP-2,TRYP-2 and MIX-2 could inhibit ACE activity with IC50 of 1.97?1.58?2.14 and 1.53 mg/mL suggesting they have an antihypertensive activity.The further lowing blood pressure effect in SHR showed that PEP-1,PEP-2 TRYP-2and MIX-2 could lower systolic blood pressure by 27.97%,18.30%,27.88% and 24.52%,respectively.It suggested that these peptide fractions could be used as potential functional ingredients in health food production.