Dairy Debaryomyces hansenii strains produce the antihypertensive casein-derived peptides LHLPLP and HLPLP

The ability of dairy Debaryomyces hansenii, Kluyveromyces lactis and Kluyveromyces marxianus strains to release the casein-derived antihypertensive sequences RYLGY, AYFYPEL, LHLPLP, HLPLP, VPP and/or IPP was examined. Yeast strains were grown in medium with casein as sole nitrogen source and the yeast casein hydrolysates (CSHs) were analysed by HPLC-MS/MS to search for the six antihypertensive sequences. Only LHLPLP and HLPLP were identified in CSHs and exclusively in D. hansenii Dh1 and Dh14 hydrolysates in which both antihypertensive sequences represented approximately 6 (CSH Dh1) and 10% (CSH Dh14) of total peptide content. In addition, a complete analysis of selected CSHs by HPLC-MS/MS allowed the identification of 35 (Dh1) and 46 (Dh14) additional peptides, which could also contribute to the observed in vitro ACE inhibitory potency of both hydrolysates (Dh1, IC50 = 13.6 ± 1.8 μg/mL; Dh14, IC50 = 17.5 ± 2.1 μg/mL) and might confer them multifunctional properties. Finally casein zymography revealed the presence of at least one extracellular protease with a molecular mass of about 50 kDa. In conclusion, the present study contributes to a better insight into bioactive compounds produced by dairy yeasts and shows the feasibility of D. hansenii strains to produce antihypertensive casein-derived peptides.This work was supported by grants AGL2010-21009 and AGL2011-24643 from ‘Ministerio de Educación y Ciencia – FEDER’, Consolider Ingenio 2010, Fun-C-Food, CSD2007-00063 and RETICS INVICTUS RD12/0014/0004 from ‘Instituto de Salud Carlos III’. A. García-Tejedor and L. Sánchez-Rivera are recipients of predoctoral fellowships from ‘Ministerio de Educación y Ciencia’ (BES-2011-044424) and CSIC (JAE-PreDoc), respectively.Peer reviewe

In vivo antihypertensive mechanism of lactoferrin-derived peptides: Reversion of angiotensin I- and angiotensin II-induced hypertension in Wistar rats

Novel peptides with antihypertensive effects in SHR rats have previously been identified in lactoferrin (LF) hydrolysates. To investigate their in vivo antihypertensive mechanism, we have assessed the blood pressure lowering effects of two of these LF-derived peptides (RPYL and DPYKLRP) in Wistar rats subjected to either angiotensin I- or angiotensin II-induced hypertension. Blood pressure was measured by the tail-cuff method, hypertension was induced by subcutaneous infusion of angiotensins, and then captopril, valsartan or LF-derived peptides orally administered. Angiotensin I- and angiotensin II-induced hypertension were reversed by captopril and valsartan, respectively. RPYL and DPYKLRP reversed angiotensin I-induced hypertension, while DPYKLRP but not RPYL produced a modest reversion of angiotensin II-elicited hypertension. Neither RPYL nor DPYKLRP modified normotension. Thus, in vivo ACE inhibition is involved in the antihypertensive effects of LF-derived peptides like RPYL and DPYKLRP, while inhibition of AT1 receptor-mediated vasoconstriction plays a less relevant role.This work was supported by grant AGL2010-21009 from ‘Ministerio de Educación y Ciencia – FEDER’, Consolider Ingenio 2010, Fun-C-Food, CSD2007-00063 and RETICS INVICTUS RD12/0014/0004 from ‘Instituto de Salud Carlos III’. A. García-Tejedor is recipient of a predoctoral fellowship from ‘Ministerio de Educación y Ciencia’ (BES-2011-044424).Peer reviewe

Novel Antihypertensive Lactoferrin-Derived Peptides Produced by Kluyveromyces marxianus: Gastrointestinal Stability Profile and In Vivo Angiotensin I-Converting Enzyme (ACE) Inhibition

Novel antihypertensive peptides released by Kluyveromyces marxianus from bovine lactoferrin (LF) have been identified. K. marxianus LF permeate was fractionated by semipreparative high performance liquid chromatography and 35 peptides contained in the angiotensin I-converting enzyme (ACE)-inhibitory fractions were identified by using an ion trap mass spectrometer. On the basis of peptide abundance and common structural features, six peptides were chemically synthesized. Four of them (DPYKLRP, PYKLRP, YKLRP, and GILRP) exerted in vitro inhibitory effects on ACE activity and effectively decreased systolic blood pressure after oral administration to spontaneously hypertensive rats (SHRs). Stability against gastrointestinal enzymes suggested that the sequence LRP could contribute to the in vivo effects of parental peptides. Finally, there were reductions in circulating ACE activity and angiotensin II level in SHRs after either DPYKLRP or LRP intake, thus confirming ACE inhibition as the in vivo mechanism for their antihypertensive effect.This work was supported by grant AGL2010–21009 from ‘Ministerio de Educación y Ciencia - FEDER’, Consolider Ingenio 2010, Fun-C-Food, CSD2007–00063 and RETICS INVICTUS RD12/0014/0004 from ‘Instituto de Salud Carlos III’. A.G.-T. is the recipient of a predoctoral fellowship from ‘Ministerio de Educación y Ciencia’ (BES-2011–044424).Peer reviewe

Barcoding sequences clearly separate Chroogomphus mediterraneus (Gomphidiaceae, Boletales) from C. rutilus, and allied species

Chroogomphus mediterraneus, a species described from the Balearic Islands, is confirmed as belonging to the genus Chroogomphus, instead of the genus Gomphidius, as it appears in taxonomic databases. Chroogomphus mediterraneus shows macroscopic features similar to Chroogomphus fulmineus and C. rutilus, species with which it has been confused in the literature. However, analyses based on comparison of barcoding sequences (internal transcribed spacers of nuclear ribosomal DNA), and a review of the morphological features, support C. mediterraneus as a separate species close to C. albipes, a gasteroid fungus, and C. confusus, a species described from Yunnan, China. Chroogomphus mediterraneus is also reported for the first time in the Iberian Peninsula.Peer reviewe

An antihypertensive lactoferrin hydrolysate inhibits angiotensin I-converting enzyme, modifies expression of hypertension-related genes and enhances nitric oxide production in cultured human endothelial cells

This study was aimed to explore whether an antihypertensive lactoferrin hydrolysate (LFH) can inhibit angiotensin I-converting enzyme (ACE) activity and modify the expression of genes related to hypertension in human umbilical vein endothelial cells (HUVEC). LFH induced significant inhibition of ACE activity but it did not affect ACE mRNA levels after 24 h of exposure. LFH treatment significantly affected the expression of genes encoding for proteins involved in nitric oxide pathway such as soluble guanylate cyclase 1 α3 subunit (GUCY1A3; 4.42-fold increase) and nitric oxide synthase trafficking (NOSTRIN; 2.45-fold decrease). Furthermore, expression of the PTGS2/COX-2 gene encoding prostaglandin-endoperoxide synthase 2 a key component of prostaglandin synthesis was significantly increased (2.23-fold). Moreover, NOSTRIN mRNA downregulation was consistent with reduced NOSTRIN protein expression and increased NO production observed in HUVEC. The present study reveals the complexity of the effects exerted by LFH opening avenues for the better understanding of its antihypertensive effects.This work was supported by grant AGL2010-21009 from ‘Ministerio de Educación y Ciencia – FEDER’, Consolider Ingenio 2010, Fun-C-Food, CSD2007-00063 and RETICS INVICTUS RD12/0014/0004 from ‘Instituto de Salud Carlos III’. A. García-Tejedor is recipient of a predoctoral fellowship from ‘Ministerio de Educación y Ciencia’ (BES-2011-044424).Peer reviewe

Antihypertensive Mechanism of Lactoferrin-Derived Peptides: Angiotensin Receptor Blocking Effect

Texto del artículo, no incluye figuras ni tablas.Looking for antihypertensive mechanisms beyond ACE inhibition, we assessed whether lactoferrin (LF)-derived peptides can act as receptor blockers to inhibit vasoconstriction induced by angiotensin II or endothelin-1. The lactoferricin B (LfcinB)-derived peptide LfcinB20–25 (RRWQWR), the low molecular weight LF hydrolysate (LFH < 3 kDa), and two peptides identified in LFH < 3 kDa (LIWKL and RPYL) were tested in ex vivo assays of vasoactive responses. The peptide RPYL was tested in radioligand receptor binding assays. Both LFH < 3 kDa and individual peptides inhibited angiotensin II-induced vasoconstriction. RPYL showed the highest ex vivo inhibitory effect and also inhibited binding of [125I]-(Sar1,Ile8)-angiotensin II to AT1 receptors. By contrast, neither LFH < 3 kDa nor RPYL inhibited endothelin-1 and depolarization-induced vasoconstrictions. In conclusion, LF-derived peptides selectively inhibit angiotensin II-induced vasoconstriction by blocking angiotensin AT1 receptors. Therefore, inhibition of angiotensin II-induced vasocontriction is suggested as a mechanism contributing along with ACE inhibition to the antihypertensive effect of some LF-derived peptides.This work was supported by Grants AGL2010-21009 from Ministerio de Educación y Ciencia – FEDER, Consolider Ingenio 2010, Fun-C-Food, CSD2007-00063, and network RETICS INVICTUS – RD12/0014/0004 from Instituto de Salud Carlos III. R. Fernández-Musoles is the recipient of a fellowship from Ministerio de Educación y Ciencia (BES-2008-004472).Peer reviewe