Identification of oyster-derived hypotensive peptide acting as angiotensin-I-converting enzyme inhibitor

Abstract

Angiotensin-I-converting enzyme (ACE) plays a crucial role in the crisis of hypertension. Some peptides that originate from protease hydrolysates are known to suppress ACE activity in vitro and in vivo. Here, we investigated whether trypsin hydrolysate of oyster Crassostrea gigas showed hypotensive activity and ACE inhibition. The hydrolysate significantly suppressed systolic blood pressure and ACE activity in spontaneously hypertensive rats following a one-shot oral administration and a long-term feeding experiment lasting 9 weeks. Each hydrolysate from oyster tissue showed ACE inhibitory activity, indicating the hypotensive effect was due to synergism. One potent ACE inhibitory peptide, Asp-LeuThr-Asp-Tyr, was identified from the hydrolysate of the striate muscle, and the peptide exhibited hypotensive activity in vivo. Protease digestion analysis suggested that Asp-Tyr could be the real effector of this penta-peptide in vivo.

Evaluation and Identification of Potent Angiotensin-I Converting Enzyme Inhibitory Peptide Derived from Dwarf Gulper Shark (C entrophorus atromarginatus )

“…2002b; Shiozaki et al . ), antidiabetic activity (Rizkalla et al . ), anti‐obesity activity (Jung et al .…”

“…2002b), shellfish (Shiozaki et al . ) and milk (FitzGerald and Meisel ) have been reported as ACE inhibitor. Hence, this study would lead to the usage of unused shark muscles by determining procedure for ACE inhibitory hydrolysate.…”

“…There are, however, few reports about the usage of shark muscle as functional food, except for gelatin (Cho et al 2004). Some hydrolysates prepared from various bioresources are known to show biological functions, such as antihypertensive activity (Sato et al 2002b;Shiozaki et al 2010), antidiabetic activity (Rizkalla et al 2002), antiobesity activity (Jung et al 2012), antiproliferative activity (Picot et al 2006) and antioxidant activity (Chen et al 2012;Fan et al 2012). The protease hydrolysis can newly induce plenty of peptides some of which possess useful functions for human health.…”

“…The numbers of hypertensive patients are increasing all over the world. Hypertension is a serious symptom involved in many diseases, such as cerebral apoplexy and cardiac infraction (Shiozaki et al 2010). Because angiotensin-I converting enzyme is the enzyme which induces angiotensin-II, a vasopressor peptide, by the cleavage of C-terminal His-Leu of angiotensin-I, ACE inhibition is one of the major therapies for hypertension.…”

“…Although these health foods do not show very strong hypotensive effects compared with medications, they are quite useful for persons who are likely to get hypertension because of their low associated side effects. Several sources of protease hydrolysates, such as fish (Otani et al 2009), seaweed (Sato et al 2002b), shellfish (Shiozaki et al 2010) and milk (FitzGerald and Meisel 2000) have been reported as ACE inhibitor. Hence, this study would lead to the usage of unused shark muscles by determining procedure for ACE inhibitory hydrolysate.…”