title: Antihypertensive effects of lactoferrin hydrolyzates: Inhibition of angiotensin- and endothelin-converting enzymes.
abstract: The potential of bovine lactoferrin (LF) as a source of antihypertensive peptides acting on the renin-angiotensin system (RAS) and the endothelin (ET) system as dual vasopeptidase inhibitors has been examined. For this purpose enzymatic LF hydrolyzates (LFHs) were generated by trypsin and proteinase K digestions. Permeate fractions with molecular masses lower than 3 kDa (LFH <3 kDa) were orally administered to spontaneously hypertensive rats (SHRs). Although both LFHs <3 kDa showed in vitro angiotensin I-converting enzyme (ACE)-inhibitory activity, only proteinase K LFH <3 kDa exerted an in vivo antihypertensive effect. The proteinase K LFH <3 kDa and a previously characterized pepsin LFH <3 kDa with ACE-inhibitory and antihypertensive effects were tested in ex vivo functional assays as inhibitors of ACE-dependent vasoconstriction. Pepsin LFH <3 kDa but not proteinase K LFH <3 kDa inhibited ACE-dependent vasoconstriction. When tested as inhibitors towards endothelin-converting enzyme (ECE), both LFHs <3 kDa exerted in vitro inhibitory effects on ECE activity and inhibited ECE-dependent vasoconstriction. Most abundant peptides in proteinase K LFH <3 kDa were identified by using an ion trap mass spectrometer. Based on peptide abundance, two peptides (GILRPY and REPYFGY) were chemically synthesized and their ECE-inhibitory activity was tested. Both exerted in vitro inhibitory effects on ECE activity. In conclusion, orally effective antihypertensive LFHs <3 kDa may act as dual vasopeptidase (ACE/ECE) or as single ECE inhibitors with different antivasoconstrictor effects depending on the protease used to release bioactive peptide sequences.
authors.affiliation: Departamento de Biotecnología de Alimentos, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas (CSIC), Ave. Agustín Escardino 7, 46980 Paterna, Valencia, Spain.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Fernández-Musoles
authors.forename: Juan B
authors.initials: JB
authors.lastname: Salom
authors.forename: Daniel
authors.initials: D
authors.lastname: Martínez-Maqueda
authors.forename: José Javier
authors.initials: JJ
authors.lastname: López-Díez
authors.forename: Isidra
authors.initials: I
authors.lastname: Recio
authors.forename: Paloma
authors.initials: P
authors.lastname: Manzanares
mesh_terms: D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage* / Q000737:chemistry; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000737:chemistry; D001794:Blood Pressure / Q000187:drug effects; D002339:Carotid Arteries / Q000187:drug effects / Q000201:enzymology / Q000503:physiopathology; D002417:Cattle; D016232:Endothelins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006868:Hydrolysis; D006973:Hypertension / Q000188:drug therapy* / Q000201:enzymology* / Q000503:physiopathology; D066298:In Vitro Techniques; D007781:Lactoferrin / Q000008:administration & dosage* / Q000737:chemistry; D008297:Male; D008969:Molecular Sequence Data; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D011918:Rats, Inbred SHR; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D016232:Endothelins; D007703:Peptidyl-Dipeptidase A; D007781:Lactoferrin