DIQAM-Artículos
URI permanente para esta colecciónhttps://hdl.handle.net/10953/247
Examinar
Examinando DIQAM-Artículos por Materia "Antihypertensive activity"
Mostrando 1 - 3 de 3
- Resultados por página
- Opciones de ordenación
Ítem ACE-inhibitory and antihypertensive properties of a bovine casein hydrolysate(Elsevier Ltd., 2009-01-01) Miguel, Marta; Contreras, María del Mar; Recio, Isidra; Aleixandre, AmayaThe aim of this study was to investigate the potential angiotensin converting enzyme (ACE)-inhibitory activity and the antihypertensive effect, after a single oral administration, of a pepsin hydrolysed bovine casein (HBC) and a fraction with molecular mass lower than 3000 Da (HBC < 3000). ACE-inhibitory activity was measured by spectrophotometric assay. These products were orally administered by gastric intubation. The systolic (SBP) and the diastolic blood pressure (DBP) were measured in spontaneously hypertensive rats by the tail cuff method before administration and also 2, 4, 6, 8, and 24 h post-administration. HBC showed a potent ACE-inhibitory activity. This activity was 10 times higher in HBC < 3000. HBC and HBC < 3000 decreased the arterial blood pressure of the rats. The decrease in the SBP observed for HBC (400 mg/kg) or HBC < 3000 (200 mg/kg) was less pronounced than that caused by 50 mg/kg of captopril (antihypertensive positive control). However, the maximal decreases in DBP caused by HBC or HBC < 3000 were as high as the maximum decrease observed for captopril. The antihypertensive effect of these products was transient and reverted 24 h after the administration. HBC and HBC < 3000 exert antihypertensive effect caused by small peptides with ACE-inhibitory activity.Ítem Novel casein-derived peptides with antihypertensive activity(Elsevier Ltd., 2009-10) Contreras, María del Mar; Carrón, Rosalía; Montero, María José; Ramos, Mercedes; Recio, IsidraIn this study, we report novel casein-derived peptide sequences with angiotensin converting enzyme (ACE)-inhibitory activity and antihypertensive activity demonstrated in spontaneously hypertensive rats (SHR). The peptides were obtained by enzymatic hydrolysis of total isoelectric casein with pepsin. To identify ACE-inhibitory peptides, the casein hydrolysate was fractionated by semi-preparative high performance liquid chromatography, and 44 (CN) peptides contained in the active fractions were sequenced by using an ion trap mass spectrometer. Among the identified peptides, three sequences, that corresponded to αs1-CN f(90–94) (RYLGY), αs1-CN f(143–149) (AYFYPEL), and αS2-CN f(89–95) (YQKFPQY), showed IC50 values as low as 0.71 μm, 6.58 μm, and 20.08 μm, respectively. These three peptides also exerted antihypertensive activity when they were orally administered to SHR at a dose of 5 mg kg−1 of body weight. The activity of peptides RYLGY and AYFYPEL in SHR was similar to that found for tripeptide VPP when orally administered at the same dose.Ítem Stability to gastrointestinal enzymes and structure–activity relationship of β-casein-peptides with antihypertensive properties(Elsevier Inc., 2009-10) Quirós, Ana; Contreras-Gámez, María Mar; Ramos-González, Mercedes; Amigo, Lourdes; Recio, IsidraPhysiological digestion plays a key role in the formation and degradation of angiotensin-converting enzyme (ACE)-inhibitory peptides. In this study, we evaluated the impact of a simulated gastrointestinal digestion on the stability of eight peptides previously identified in fermented milk with antihypertensive activity. Two of these identified peptides with sequences LHLPLP and LVYPFPGPIPNSLPQNIPP, possess ACE-inhibitory activity in vitro and antihypertensive activity in vivo. The results showed that LHLPLP was resistant to digestive enzymes. In contrast, LVYPFPGPIPNSLPQNIPP was totally hydrolyzed and its activity decreased after incubation with pepsin and a pancreatic extract. The peptide LHLPLP was incubated with ACE and was found to be a true inhibitor of the enzyme and to exhibit a competitive inhibitor pattern. A structure–activity relationship study of this peptide was carried out by synthesizing several modified peptides related to the sequence LHLPLP. The substitution of amino acid Leu in the penultimate position by Gly improved the ACE-inhibitory activity twofold and the substitution of Pro at C-terminal position by Arg increased the activity twofold, with an IC50 of LHLPLR as low as 1.8 μM.