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Acute effect of whey peptides upon blood pressure of hypertensive rats, and relationship with their angiotensin‐converting enzyme inhibitory activity
Author(s) -
Tavares Tânia,
Sevilla MaríaÁngeles,
Montero MaríaJosé,
Carrón Rosalía,
Malcata F. Xavier
Publication year - 2012
Publication title -
molecular nutrition and food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.495
H-Index - 131
eISSN - 1613-4133
pISSN - 1613-4125
DOI - 10.1002/mnfr.201100381
Subject(s) - blood pressure , inhibitory postsynaptic potential , angiotensin converting enzyme , renin–angiotensin system , chemistry , enzyme , pharmacology , angiotensin ii , medicine , endocrinology , biochemistry
Scope: The aim of this study was to investigate the antihypertensive effect of a peptide fraction (PepC) obtained from a whey protein concentrate following hydrolysis by Cynara cardunculus , as well as of its fraction with MW below 3 kDa (PepCF). Both these concentrates encompassed peptides that exhibited potent in vitro inhibition of angiotensin‐converting enzyme (ACE): two were released from α‐lactalbumin – KGYGGVSLPEW and DKVGINYW, and one from β‐lactoglobulin – DAQSAPLRVY. Methods and results: Upon oral administration, by gastric intubation, of 400 mg/kg body weight (bw) of those peptide concentrates, or 5 mg/kg bw of the corresponding synthetic peptides, to 12 wk‐old spontaneously hypertensive rats (SHR), the systolic and diastolic blood pressures were monitored by the tail‐cuff method – before, and 2, 4, 6, 8 and 24 h afterwards. Water and zofenopril (5 mg/kg bw) – a known ACE‐inhibitor, were used as negative and positive controls, respectively. Acute administration of PepC, PepCF, KGYGGVSLPEW, DKVGINYW and DAQSAPLRVY caused antihypertensive effects in SHR; the maximum effect occurred by 4 h and 6 h after administration of the peptide concentrates and the synthetic peptides, respectively. PepC and KGYGGVSLPEW also showed ACE‐inhibitory activity in vivo: the pressor effect of angiotensin I was significantly lower, and the response to bradykinin increased when the rats were pre‐treated with either product. Conclusion: Our results strongly suggest that PepC will be effective as nutraceutical ingredient for the formulation of functional foods aimed at hypertension control.