Vasorelaxing and antihypertensive activities of synthesized peptides derived from computer-aided simulation of pepsin hydrolysis of yam dioscorin.

Yin-Shiou Lin,Wen-Chi Hou,Guei-Jane Wang,Hong-Jen Liang,Yeh-Lin Lu

doi:10.1186/s40529-014-0049-3

Abstract

BackgroundWe reported that yam dioscorin and its peptic hydrolysates exhibited ACE inhibition and antihypertensive effects on SHRs, however, the active peptides are not really isolated until now. Using ACE inhibitory screenings, two penta-peptides, KTCGY and KRIHF, were selected for ex vivo and in vivo experiments.ResultsKTCGY, KRIHF, and captopril were shown to have similar vasodilating effects against phenylephrine (PE)-induced tensions in rat endothelium-dependent thoracic aortic rings, however, KTCGYKTCGY (two-repeated KTCGY) and TCGYTCGY (two-repeated TCGY) were showed endothelium-independent vasodilating effects against PE-induced tensions. KTCGY, KRIHF (10 or 20 mg/kg), and captopril (10 mg/kg) were used to evaluate antihypertensive activity during 24-h after a single oral administration to spontaneously hypertensive rats (SHRs). The KTCGY and KRIHF showed significantly different and reduced the systolic blood pressure of SHRs compared to the blank.ConclusionsThese results suggest that KTCGY and KRIHF may contribute important roles in yam dioscorin for regulating blood pressure in vivo.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-014-0049-3) contains supplementary material, which is available to authorized users.

Highlights

We reported that yam dioscorin and its peptic hydrolysates exhibited angiotensin I converting enzyme (ACE) inhibition and antihypertensive effects on spontaneously hypertensive rats (SHRs), the active peptides are not really isolated until now
We reported that yam dioscorin and its peptic hydrolysates exhibited ACE inhibitory activity (Hsu et al 2002) and antihypertensive activity (Lin et al 2006) using SHRs as models, the active peptides are not really isolated until now
It is suggested that KTCGY and KRIHF show vasodilating effects and can reduce SHR’s systolic blood pressure (SBP) which may contribute important roles in yam dioscorin for regulating blood pressure in vivo

Summary

Introduction

We reported that yam dioscorin and its peptic hydrolysates exhibited ACE inhibition and antihypertensive effects on SHRs, the active peptides are not really isolated until now. Fujita et al (2000) found that the octapeptides of FFGRCVSP (IC50 = 0.4 μM) and ERKIKVYL (IC50 = 1.2 μM) were potent ACE inhibitors, but none of them were effective in spontaneously hypertensive rats (SHRs) to reduce the blood pressure. These potential ACE inhibitory peptides were further hydrolyzed by the rat’s gastrointestinal proteases and lose their antihypertensive effects on SHR in vivo. It is suggested that KTCGY and KRIHF show vasodilating effects and can reduce SHR’s systolic blood pressure (SBP) which may contribute important roles in yam dioscorin for regulating blood pressure in vivo

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Discussion

Conclusion