Angiotensin-converting enzymes as druggable features of psychiatric and neurodegenerative disorders.

The renin-angiotensin system (RAS) plays essential roles in maintaining peripheral cardiovascular homeostasis, with its potential roles in the brain only being recognized more recently. Angiotensin-I-converting enzyme (ACE) is the main component of the RAS, and it has been implicated in various disorders of the brain. ACE and other RAS components, including the related enzyme ACE2, angiotensin peptides and their respective receptors, can participate in the pathological state, as well as with potential to contribute to neuroprotection and/or to complement existing treatments for psychiatric illness. In this narrative review, we aimed to identify the main studies describing the functions of the RAS and ACEs in the brain and their association with brain disorders. These include neurodegenerative disorders such as Parkinson's and Alzheimer's diseases, psychiatric illnesses such as schizophrenia, bipolar disorder, and depression. We also discuss the possible association of a functional polymorphism of the ACE gene with these brain diseases and the relevance of the neuroprotective and anti-inflammatory properties of ACE inhibitors (ACEis) and angiotensin receptor blockers (ARBs). Based on this, we conclude that there is significant potential value to the inclusion of ACEis and/or ARBs as a novel integrated approach for the treatment of various disorders of the brain, and particularly for psychiatric illness.

Peptide inhibitors of angiotensin-I converting enzyme based on angiotensin (1-7) with selectivity for the C-terminal domain.

The renin-angiotensin system (RAS) is a key regulator of human arterial pressure. Several of its effects are modulated by angiotensin II, an octapeptide originating from the action of angiotensin-I converting enzyme (ACE) on the decapeptide angiotensin-I. ACE possess two active sites (nACE and cACE) that have their own kinetic and substrate specificities. ACE inhibitors are widely used as the first-line treatment for hypertension and other heart-related diseases, but because they inactivate both ACE domains, their use is associated with serious side effects. Thus, the search for domain-specific ACE inhibitors has been the focus of intense research. Angiotensin (1-7), a peptide that also belongs to the RAS, acts as a substrate of nACE and an inhibitor of cACE. We have synthetized 15 derivatives of Ang (1-7), sequentially removing the N-terminal amino acids and modifying peptides extremities, to find molecules with improved selectivity and inhibition properties. Ac-Ang (2-7)-NH2 is a good ACE inhibitor, resistant to cleavage and with improved cACE selectivity. Molecular dynamics simulations provided a model for this peptide's selectivity, due to Val3 and Tyr4 interactions with ACE subsites. Val3 has an important interaction with the S3 subsite, since its removal greatly reduced peptide-enzyme interactions. Taken together, our findings support ongoing studies using insights from the binding of Ac-Ang (2-7)-NH2 to develop effective cACE inhibitors.

The potential role of sesquiterpene lactones isolated from medicinal plants in the treatment of the metabolic syndrome - A review.

Metabolic syndrome comprises a cluster of metabolic disorders related to the development of cardiovascular disease and type 2 diabetes mellitus. In latter years, plant secondary metabolites have become of special interest because of their potential role in preventing and managing metabolic syndrome. Sesquiterpene lactones constitute a large and diverse group of biologically active compounds widely distributed in several medicinal plants used for the treatment of metabolic disorders. The structural diversity and the broad spectrum of biological activities of these compounds drew significant interests in the pharmacological applications. This review describes selected sesquiterpene lactones that have been experimentally validated for their biological activities related to risk factors of metabolic syndrome, together with their mechanisms of action. The potential beneficial effects of sesquiterpene lactones discussed in this review demonstrate that these substances represent remarkable compounds with a diversity of molecular structure and high biological activity, providing new insights into the possible role in metabolic syndrome management.

Dietary Potassium Downregulates Angiotensin-I Converting Enzyme, Renin, and Angiotensin Converting Enzyme 2.

BACKGROUND: The importance of dietary potassium in health and disease has been underestimated compared with that placed on dietary sodium. Larger effort has been made on reduction of sodium intake and less on the adequate dietary potassium intake, although natural food contains much more potassium than sodium. The benefits of a potassium-rich diet are known, however, the mechanism by which it exerts its preventive action, remains to be elucidated. With the hypothesis that dietary potassium reduces renal vasoconstrictor components of the renin-angiotensin system in the long-term, we studied the effect of high potassium diet on angiotensin-I converting enzyme, renin, and angiotensin converting enzyme 2. METHODS: Sprague Dawley male rats on a normal sodium diet received normal potassium (0.9%, NK) or high potassium diet (3%, HK) for 4 weeks. Urine was collected in metabolic cages for electrolytes and urinary volume measurement. Renal tissue was used to analyze angiotensin-I converting enzyme, renin, and angiotensin converting enzyme 2 expression. Protein abundance analysis was done by Western blot; gene expression by mRNA levels by RT-qPCR. Renal distribution of angiotensin-I converting enzyme and renin was done by immunohistochemistry and morphometric analysis in coded samples. RESULTS: High potassium diet (4 weeks) reduced the levels of renin, angiotensin-I converting enzyme, and angiotensin converting enzyme 2. Angiotensin-I converting enzyme was located in the brush border of proximal tubules and with HK diet decreased the immunostaining intensity (P < 0.05), decreased the mRNA (P < 0.01) and the protein levels (P < 0.01). Renin localization was restricted to granular cells of the afferent arteriole and HK diet decreased the number of renin positive cells (P < 0.01) and renin mRNA levels (P < 0.01). High potassium intake decreased angiotensin converting enzyme 2 gene expression and protein levels (P < 0.01).No morphological abnormalities were observed in renal tissue during high potassium diet.The reduced expression of angiotensin-I converting enzyme, renin, and angiotensin converting enzyme 2 during potassium supplementation suggest that high dietary potassium intake could modulate these vasoactive enzymes and this effects can contribute to the preventive and antihypertensive effect of potassium.

Oligopeptidases activity in bipolar disorder: Ndel1 and angiotensin I converting enzyme.

BACKGROUND: Abnormal activity of two enzymes relevant to neurodevelopment, namely nuclear-distribution element-like 1 (Ndel1) and angiotensin I-converting enzyme (ACE), was reported in individuals with schizophrenia; to our knowledge, these oligopeptidases were never measured in bipolar disorder (BD). AIMS: Evaluate the enzyme activity of Ndel1 and ACE in euthymic individuals with BD type 1 which was compare to healthy control (HC) group. METHODS: Ndel1 and ACE activities were assessed in the serum of individuals with BD type 1 according to DSM-IV criteria (n = 70) and a HC group (n = 34). The possible differences between BD type 1 and HC groups were evaluated using Analysis of Covariance (ANCOVA), and the results were adjusted for age, gender and body mass index. RESULTS: We observed a positive correlation between Ndel1 activity and the total YMRS score in BD group (p = 0.030) and a positive correlation between ACE activity and Ham-D score (p = 0.047). ANCOVA analysis showed lower Ndel1 activity in BDs compared to HCs. Interestingly, we did not observe between-groups differences in ACE activity, despite the recognized correlation of ACE activity levels with cognitive functions, also described to be worsened in psychiatric patients. CONCLUSION: Oligopeptidases, especially Ndel1, which has been strongly correlated with neurodevelopment and brain formation, are potentially a good new target in the study of the neurobiology of BD. LIMITATIONS: The relatively small sample size did not permit to examine the cause-effect relationship of clinical dimensions of BD and the enzymatic activity.

The binding of captopril to angiotensin I-converting enzyme triggers activation of signaling pathways.

Hypertension is a global health problem, and angiotensin I (ANG I)-converting enzyme (ACE) inhibitors are largely used to control this pathology. Recently, it has been shown that ACE can also act as a transducer signal molecule when its inhibitors or substrates bind to it. This new role of ACE could contribute to understanding some of the effects not explained by its catalytic activity only. In this study, we investigated signaling pathway activation in Chinese hamster ovary (CHO) cells stably expressing ACE (CHO-ACE) under different conditions. We also investigated gene modulation after 4 h and 24 h of captopril treatment. Our results demonstrated that CHO-ACE cells when stimulated with ANG I, ramipril, or captopril led to JNK and ERK1/2 phosphorylation. To verify any physiological role at the endogenous level, we made use of primary cultures of mesangial cells from spontaneously hypertensive rats (SHR) and Wistar rats. Our results showed that ERK1/2 activation occurred mainly in primary cultures of mesangial cells from SHR rats upon captopril stimulation, suggesting that this signaling pathway could be differentially regulated during hypertension. Our results also showed that captopril treatment leads to a decrease of cyclooxygenase 2, interleukin-1ß, and ß-arrestin2 and a significant increase of AP2 gene expression levels. Our findings strengthen the fact that, in addition to the blockage of enzymatic activity, ACE inhibitors also trigger signaling pathway activation, and this may contribute to their beneficial effects in the treatment of hypertension and other pathologies.

GC-MS based metabolite profiling and angiotensin I-converting enzyme inhibitory property of black tea extracts

Abstract Angiotensin I-converting enzyme inhibitors are used as therapeutic agents for the treatment of hypertension. Regular consumption of black tea (Camellia sinensis (L.) Kuntze, Theaceae) has been reported to lower blood pressure. The aims of the present work were to compare chemical composition and angiotensin I-converting enzyme inhibitory properties of infusion and decoction of four samples of black tea. GC/MS based metabolomics approach helped in identification of fifty-one metabolites including ten organic acids, one inorganic acid, sixteen amino acids, two sugars, five sugar alcohols, fifteen phenols and flavonoids, two fatty acids from infusions and decoctions of four black tea samples. Partial least squares discriminant analysis and orthogonal partial least squares discriminant analysis models showed good classification among the two groups, diffusion and infusion, based on metabolites. Both infusion and decoction inhibited the enzyme. However, the activity differed with samples. Multivariate analysis also segregated extracts on the basis of activity. Thearubigin, theaflavin, catechin inhibited the enzyme. Epicatechin, epigallocatechin gallate, gallic acid, caffeine showed lower activity.

Paramagnetic bradykinin analogues as substrates for angiotensin I-converting enzyme: Pharmacological and conformation studies.

This study uses EPR, CD, and fluorescence spectroscopy to examine the structure of bradykinin (BK) analogues attaching the paramagnetic amino acid-type Toac (2,2,6,6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid) at positions 0, 3, 7, and 9. The data were correlated with the potencies in muscle contractile experiments and the substrate properties towards the angiotensin I-converting enzyme (ACE). A study of the biological activities in guinea pig ileum and rat uterus indicated that only Toac0-BK partially maintained its native biological potency among the tested peptides. This and its counterpart, Toac3-BK, maintained the ability to act as ACE substrates. These results indicate that peptides bearing Toac probe far from the ACE cleavage sites were more susceptible to hydrolysis by ACE. The results also emphasize the existence of a finer control for BK-receptor interaction than for BK binding at the catalytic site of this metallodipetidase. The kinetic kcat/Km values decreased from 202.7 to 38.9µM-1min-1 for BK and Toac3-BK, respectively. EPR, CD, and fluorescence experiments reveal a direct relationship between the structure and activity of these paramagnetic peptides. In contrast to the turn-folded structures of the Toac-internally labeled peptides, more extended conformations were displayed by N- or C-terminally Toac-labeled analogues. Lastly, this work supports the feasibility of monitoring the progress of the ACE-hydrolytic process of Toac-attached peptides by examining time-dependent EPR spectral variations.

ACE I/D Polymorphism in Brazilian Women with Endometriosis / Polimorfismo ACE I/D em Mulheres Brasileiras com Endometriose

Endometriosis is a chronic gynecological disease that displays some features similar to malignancy, such as local invasion, aggressive spread to distant organs and angiogenesis. Polymorphisms of the ACE gene have been linked with some vascular disease. To determine the frequency of the ACE I/D polymorphism in Brazilian patients with endometriosis compared to controls. This case-control study included a total of 134 women (49 endometriosis patients and 85 controls) who had undergone a laparoscopy or laparotomy. Molecular analysis was performed by polymerase chain reaction (PCR). For the statistical analysis, the chi-square and multiple logistic regression tests were used. The I/D ACE genotype frequencies in cases and controls were, respectively: II 16.3% and 16.5%; ID 24.5% and 20%; DD 59.2% and 63.5%. There was no statistically significant difference between cases and controls, either in the genotype frequencies (χ2 = 0.385; p = 0.825) or in the allele frequencies (χ2 = 0.098; p = 0.75) of the ACE I/D polymorphism. However, the genotype distribution was not consistent with the Hardy-Weinberg equilibrium, either in patients (χ2 = 7.84; p = 0.005) or in controls (χ2 = 20.09; p <0.0001). Multiple logistic regression analysis has not shown any differences amongst groups for the polymorphism studied [(OR 1.51; CI 95% 0.52- 4.41); p=0.4523]. Despite of the small sample size, the present study suggests that I/D ACE polymorphism is not related with endometriosis in brazilian patients.(AU)

A endometriose é uma doença ginecológica crônica que apresenta algumas características semelhantes à malignidade, tais como invasão local, disseminação para órgãos distantes e angiogênese. Polimorfismos no gene ACE têm sido relacionados com algumas doenças vasculares. Determinar a frequência do polimorfismo ACE I/D em pacientes brasileiros com endometriose em comparação aos controles. Estudo caso-controle que incluiu um total de 134 mulheres (49 pacientes com endometriose e 85 controles) que se submeteram a uma laparoscopia ou laparotomia. A análise molecular foi realizada por Reação em Cadeia da Polimerase (PCR). A análise estatística utilizou os testes de qui-quadrado e regressão logística. As frequências genotípicas ACE I/D em casos e controles foram, respectivamente: II 16,3% e 16,5%; ID 24,5% e 20%; DD 59,2% e 63,5%. Não houve diferença estatisticamente significativa entre os casos e controles, tanto nas frequências genotípicas (χ2 = 0,385; p = 0,825) ou nas frequências alélicas (χ2 = 0,098; p = 0,75) do polimorfismo ACE I/D. Entretanto, a distribuição genotípica não foi consistente com o equilíbrio de Hardy-Weinberg, tanto nos pacientes (χ2 = 7,84; p = 0,005) ou nos controles (χ2 = 20,09; p <0,0001). A análise de regressão logística não mostrou qualquer diferença entre os grupos para o polimorfismo estudado [(OR 1,51; CI 95% 0,52-4,41); p=0,4523]. Apesar do pequeno número de amostras, o presente estudo mostra que em pacientes brasileiras o polimorfismo ACE I/D não está relacionado com endometriose.(AU)

N-domain angiotensin-I converting enzyme is expressed in immortalized mesangial, proximal tubule and collecting duct cells.

Somatic ACE (sACE) is found in glomerulus, proximal tubule and excreted in urine. We hypothesized that N-domain ACE can also be found at these sites. ACE profile was analyzed in mesangial (IMC), proximal (LLC-PK1), distal tubule (MDCK) and collecting duct (IMCD) cells. Cell lysate and culture medium were submitted to gel filtration chromatography, which separated two peaks with ACE activity from cells and medium, except from distal tubule. The first had a high molecular weight and the second, a lower one (65 kDa; N-domain ACE). We focused on N-domain ACE purification and characterization from LLC-PK1. Total LLC-PK1 N-domain ACE purification was achieved by ion-exchange chromatography, which presented only one peak with ACE activity, denominated ACE(int2A). ACE(int2A) activity was influenced by pH, NaCl and temperature. The purified enzyme was inhibited by Captopril and hydrolyzed AngI, Ang1-7 and AcSDKP. Its ability to hydrolyze AcSDKP characterized it as an N-domain ACE. ACE(int2A) also presented high amino acid sequence homology with the N-terminal part of sACE from mouse, rat, human and rabbit. The presence of secreted and intracellular N-domain ACE and sACE in IMC, LLC-PK1 and IMCD cells confirmed our studies along the nephron. We identified, purified and characterized N-domain ACE from LLC-PK1.

Serine proteases as candidates for proteolytic processing of angiotensin-I converting enzyme.

Somatic angiotensin-I converting enzyme (sACE) is a broadly distributed peptidase which plays a role in blood pressure and electrolyte homeostasis by the conversion of angiotensin I into angiotensin II. N-domain isoforms (nACE) with 65 and 90 kDa have been described in body fluids, tissues and mesangial cells (MC), and a 90 kDa nACE has been described only in spontaneously hypertensive rats. The aim of this study was to investigate the existence of proteolytic enzymes that may act in the hydrolysis of sACE generating nACEs in MC. After the confirmation of the presence of ACE sheddases in Immortalized MC (IMC), we purified and characterized these enzymes using fluorogenic substrates specifically designed for ACE sheddases. Purified enzyme identified as a serine protease by N-terminal sequence was able to generate nACE. In the present study, we described for the first time the presence of ACE sheddases in IMC, identified as serine proteases able to hydrolyze sACE in vitro. Further investigations are necessary to elucidate the mechanisms responsible for the expression and regulation of ACE sheddases in MC and their roles in the generation of nACEs, especially the 90 kDa form possibly related to hypertension.

Effects of hydrolysis and digestion in vitro on the activity of bovine plasma hydrolysates as inhibitors of the angiotensin I converting enzyme

The angiotensin I-converting enzyme (ACE) inhibiting activity of bovine plasma hydrolyzates obtained by Alcalase 2.4 L at different degrees of hydrolysis (DH) was evaluated. For the evaluation of ACE inhibition (ACEI), Hippuryl-His-Leu was used as substrate and the amount of hippuric acid liberated by non-inhibiting ACE was determined by spectrophotometry at 228 nm. The results showed that the enzymatic hydrolysis increased the ACEI activity as compared with the un-hydrolyzed plasma. The highest activity was onbtained with a DH of 6.7%. The peptide fractions with the maximum activity were isolated using ultrafiltration membranes, ion exchange chromatography and high performance liquid chromatography on reverse phase (RP-HPLC). The fraction with highest ACEI activity, showed an IC50 of 0.18 mg/mL and contained peptides with sequences AGATGVTISGAG, YSRRHPEYAVS, Q(K)AW and L(l)I(I)VR, which were determined by MALDI-TOF-TOF. It was also found that after submitting such fraction to digestive conditions in vitro, the ACEI activity remained constant.

Proline rich-oligopeptides: diverse mechanisms for antihypertensive action.

Bradykinin-potentiating peptides from Bothrops jararaca (Bj) discovered in the early 1960s, were the first natural inhibitors of the angiotensin-converting enzyme (ACE). These peptides belong to a large family of snake venom proline-rich oligopeptides (PROs). One of these peptides, Bj-PRO-9a, was essential for defining ACE as effective drug target and development of captopril, an active site-directed inhibitor of ACE used worldwide for the treatment of human arterial hypertension. Recent experimental evidences demonstrated that cardiovascular effects exerted by different Bj-PROs are due to distinct mechanisms besides of ACE inhibition. In the present work, we have investigated the cardiovascular actions of four Bj-PROs, namely Bj-PRO-9a, -11e, -12b and -13a. Bj-PRO-9a acts upon ACE and BK activities to promote blood pressure reduction. Although the others Bj-PROs are also able to inhibit the ACE activity and to potentiate the BK effects, our results indicate that antihypertensive effect evoked by them involve new mechanisms. Bj-PRO-11e and Bj-PRO-12b involves induction of [Ca(2+)]i transients by so far unknown receptor proteins. Moreover, we have suggested argininosuccinate synthetase and M3 muscarinic receptor as targets for cardiovascular effects elicited by Bj-PRO-13a. In summary, the herein reported results provide evidence that Bj-PRO-mediated effects are not restricted to ACE inhibition or potentiation of BK-induced effects and suggest different actions for each peptide for promoting arterial pressure reduction. The present study reveals the complexity of the effects exerted by Bj-PROs for cardiovascular control, opening avenues for the better understanding of blood pressure regulation and for the development of novel therapeutic approaches.

Peptides with angiotensin I converting enzyme (ACE) inhibitory activity generated from porcine skeletal muscle proteins by the action of meat-borne Lactobacillus.

Angiotensin I converting enzyme (ACE) inhibitory activity of peptides derived from the hydrolysis of sarcoplasmic and myofibrillar porcine proteins by the action of Lactobacillus sakei CRL1862 and Lactobacillus curvatus CRL705 (whole cells+cell free extracts) was investigated at 30°C for 36 h. The protein hydrolysates were subjected to RP-HPLC in order to fractionate the extracts for further evaluation of ACE inhibitory activity. Bioactive fractions were only found from the hydrolysis of sarcoplasmic proteins by both assayed lactobacilli strains. Identification of peptides contained in the bioactive fractions was carried out by tandem mass spectrometry using a nanoLC-ESI-QTOF instrument and the mascot search engine. From the four most active fractions obtained, a total of eighteen and fifty peptides were characterized from L. sakei CRL1862 and L. curvatus CRL705 protein hydrolysates, respectively. The sequence FISNHAY was generated by the proteolytic activity of the two lactobacilli species. Sequence similarity analyses between the peptides identified in this study and those previously identified as ACE inhibitory peptides and detailed in the BIOPEP database were outlined. Results suggest that meat-borne Lactobacillus were able to generate peptides with ACE inhibitory activity, highlighting their potential to be used in the development of functional fermented products. BIOLOGICAL SIGNIFICANCE: The results of this study would enable the obtention of porcine functional foods by applying lactic acid bacteria generating bioactive peptides. ACE inhibitory peptides obtained by the hydrolytic action of L. curvatus CRL705 and L. sakei CRL1862 on sarcoplasmic proteins were analyzed. Among them, the peptide FISNHAY exhibited the highest activity and its sequence has not yet been reported.

Vascular reactivity and ACE activity response to exercise training are modulated by the +9/-9 bradykinin B2 receptor gene functional polymorphism.

The bradykinin receptor B2 (BDKRB2) gene +9/-9 polymorphism has been associated with higher gene transcriptional activity, and characteristics of cardiovascular phenotypes and physical performance. We hypothesized that vasodilation and ACE activity response to exercise training is modulated by BDKRB2 gene. We genotyped 71 healthy volunteers were genotyped for the BDKRB2 gene polymorphism. Heart rate (HR), mean blood pressure (MBP), and forearm blood flow (FBF) were evaluated. Angiotensin-I converting enzyme (ACE) activity was measured by fluorescence. Aerobic training was performed for 16 wk. All variables were reassessed after completion of the training period. In pretraining period, HR, MBP, FBF, and forearm vascular conductance (FVC) were similar among all genotypes. After physical training, the FBF and the FVC response during handgrip exercise such as area under the curve were higher in -9/-9 carriers than the other two groups. However, there were no changes in HR and MBP for all three groups. In addition, in posttraining period the decrease in ACE activity was higher in the -9/-9 group than the other two groups. These results suggest that reflex muscle vasodilation and ACE activity in response to exercise training are modulated by BDKRB2 gene +9/-9 polymorphism in healthy individuals.

The chronic blockade of angiotensin I-converting enzyme eliminates the sex differences of serum cytokine levels of spontaneously hypertensive rats

Sex hormones modulate the action of both cytokines and the renin-angiotensin system. However, the effects of angiotensin I-converting enzyme (ACE) on the proinflammatory and anti-inflammatory cytokine levels in male and female spontaneously hypertensive rats (SHR) are unclear. We determined the relationship between ACE activity, cytokine levels and sex differences in SHR. Female (F) and male (M) SHR were divided into 4 experimental groups each (n = 7): sham + vehicle (SV), sham + enalapril (10 mg/kg body weight by gavage), castrated + vehicle, and castrated + enalapril. Treatment began 21 days after castration and continued for 30 days. Serum cytokine levels (ELISA) and ACE activity (fluorimetry) were measured. Male rats exhibited a higher serum ACE activity than female rats. Castration reduced serum ACE in males but did not affect it in females. Enalapril reduced serum ACE in all groups. IL-10 (FSV = 16.4 ± 1.1 pg/mL; MSV = 12.8 ± 1.2 pg/mL), TNF-α (FSV = 16.6 ± 1.2 pg/mL; MSV = 12.8 ± 1 pg/mL) and IL-6 (FSV = 10.3 ± 0.2 pg/mL; MSV = 7.2 ± 0.2 pg/mL) levels were higher in females than in males. Ovariectomy reduced all cytokine levels and orchiectomy reduced IL-6 but increased IL-10 concentrations in males. Castration eliminated the differences in all inflammatory cytokine levels (IL-6 and TNF-α) between males and females. Enalapril increased IL-10 in all groups and reduced IL-6 in SV rats. In conclusion, serum ACE inhibition by enalapril eliminated the sexual dimorphisms of cytokine levels in SV animals, which suggests that enalapril exerts systemic anti-inflammatory and anti-hypertensive effects.

Inhibición de la Enzima Convertidora de Angiotensina I con hidrolizados proteicos de Jatropha curcas / Angiotensin I-Converting Enzyme inhibition with protein hydrolysates from Jatropha curcas / InibiþÒo da Enzima Conversora de Angiotensina I com hidrolisados proteicos de Jatropha curcas

Se evaluó la actividad inhibitoria in vitro de los hidrolizados proteínicos obtenidos a partir de la harina desgrasada y del aislado proteínico provenientes del grano de Jatropha curcas L. sobre la actividad de la enzima convertidora de angiotensina I (ECA-1), con la finalidad de emplearlos en un futuro para la formulación de alimentos funcionales. Los hidrolizados fueron obtenidos empleando alcalasa y el sistema enzimático pepsina-pancreatina. Se calculó la concentración media inhibitoria (IC50) para medir el grado de inhibición de la actividad enzimática de ECA-1. Fueron seleccionados los hidrolizados con el menor tiempo de hidrólisis (60 min) para evaluar la bioactividad, dado que las cinéticas de hidrólisis enzimática de la harina desgrasada y del aislado proteínico no encontraron diferencias significativas en el grado de hidrólisis para los tiempos de reacción en cada sistema (60, 90 y 120 min). Los valores de IC50 que presentaron el mejor efecto de inhibición sobre la ECA-I fueron 2,8 y 7,0 Ag/mL, obtenidos a partir del aislado proteínico con la enzima alcalasa y con el sistema secuencial pepsina-pancreatina, respectivamente. Los hidrolizados de J. curcas podrían ser incorporados en la elaboración de alimentos funcionales y ser aplicados en tratamientos para personas con hipertensión por su efecto inhibitorio sobre la ECA-I.(AU)

In vitro angiotensin I-converting enzyme (ACE) inhibitory activity was evaluated in protein hydrolysates from defatted meal and protein isolate from Jatropha curcas L. Seed, in order to determine their potential inclusion in functional food formulation. Hydrolysates were produced using Alcalase« or a sequential pepsin-pancreatin enzymatic system. Mean inhibitory concentration (IC50) was used to measure the degree of ACE enzymatic activity inhibition. Bioactivity was evaluated in the hydrolysates with the lowest hydrolysis time (60 min) given that no differences in degree of hydrolysis in terms of reaction time in each system were observed (60, 90 and 120 min) in the enzymatic hydrolysis kinetics for the defatted meal and protein isolate. The protein isolate exhibited the highest inhibitory effect, as seen in the IC50 values: 2.8 Ag/mL in the alcalase system and 7.0 Ag/mL in the pepsin-pancreatin system. Hydrolysates from J. curcas seed exhibit ACE inhibition and could be incorporated into functional foods or treatments for those suffering hypertension.(AU)

Foi avaliada a atividade inibitória in vitro dos hidrolisados proteicos obtidos a partir da farinha desengordurada e do isolado proteico provenientes do grÒo de Jatropha curcas L. sobre a atividade da enzima conversora de angiotensina I (ECA-1), com o objetivo de utilizá-los num futuro para a formulaþÒo de alimentos funcionais. Os hidrolisados foram obtidos usando alcalase e o sistema enzimático pepsina-pancreatina. Foi calculada a concentraþÒo média inibitória (IC50) para medir o grau de inibiþÒo da atividade enzimática da ECA-1. Foram selecionados os hidrolisados com o menor tempo de hidrólise (60 min.) para avaliar a bioatividade visto que as cinéticas de hidrólise enzimática da farinha desengordurada e do isolado proteico nÒo encontraram diferenþas significativas no grau de hidrólise para os tempos de reaþÒo para cada sistema (60, 90 e 120 min.). Os valores de IC50 que apresentaram o melhor efeito de inibiþÒo sobre a ECA-I foram 2.8 e 7.0 Ag/mL obtidos a partir do isolado proteico com a enzima alcalase e com o sistema sequencial pepsina-pancreatina respectivamente. Os hidrolisados de J. curcas poderiam ser incorporados na elaboraþÒo de alimentos funcionais e ser aplicados em tratamentos para pessoas com hipertensÒo por seu efeito inibitório sobre a ECA-I.(AU)

Inhibición de la Enzima Convertidora de Angiotensina I con hidrolizados proteicos de Jatropha curcas / Angiotensin I-Converting Enzyme inhibition with protein hydrolysates from Jatropha curcas / Inibição da Enzima Conversora de Angiotensina I com hidrolisados proteicos de Jatropha curcas

Se evaluó la actividad inhibitoria in vitro de los hidrolizados proteínicos obtenidos a partir de la harina desgrasada y del aislado proteínico provenientes del grano de Jatropha curcas L. sobre la actividad de la enzima convertidora de angiotensina I (ECA-1), con la finalidad de emplearlos en un futuro para la formulación de alimentos funcionales. Los hidrolizados fueron obtenidos empleando alcalasa y el sistema enzimático pepsina-pancreatina. Se calculó la concentración media inhibitoria (IC50) para medir el grado de inhibición de la actividad enzimática de ECA-1. Fueron seleccionados los hidrolizados con el menor tiempo de hidrólisis (60 min) para evaluar la bioactividad, dado que las cinéticas de hidrólisis enzimática de la harina desgrasada y del aislado proteínico no encontraron diferencias significativas en el grado de hidrólisis para los tiempos de reacción en cada sistema (60, 90 y 120 min). Los valores de IC50 que presentaron el mejor efecto de inhibición sobre la ECA-I fueron 2,8 y 7,0 µg/mL, obtenidos a partir del aislado proteínico con la enzima alcalasa y con el sistema secuencial pepsina-pancreatina, respectivamente. Los hidrolizados de J. curcas podrían ser incorporados en la elaboración de alimentos funcionales y ser aplicados en tratamientos para personas con hipertensión por su efecto inhibitorio sobre la ECA-I.

In vitro angiotensin I-converting enzyme (ACE) inhibitory activity was evaluated in protein hydrolysates from defatted meal and protein isolate from Jatropha curcas L. Seed, in order to determine their potential inclusion in functional food formulation. Hydrolysates were produced using Alcalase® or a sequential pepsin-pancreatin enzymatic system. Mean inhibitory concentration (IC50) was used to measure the degree of ACE enzymatic activity inhibition. Bioactivity was evaluated in the hydrolysates with the lowest hydrolysis time (60 min) given that no differences in degree of hydrolysis in terms of reaction time in each system were observed (60, 90 and 120 min) in the enzymatic hydrolysis kinetics for the defatted meal and protein isolate. The protein isolate exhibited the highest inhibitory effect, as seen in the IC50 values: 2.8 µg/mL in the alcalase system and 7.0 µg/mL in the pepsin-pancreatin system. Hydrolysates from J. curcas seed exhibit ACE inhibition and could be incorporated into functional foods or treatments for those suffering hypertension.

Foi avaliada a atividade inibitória in vitro dos hidrolisados proteicos obtidos a partir da farinha desengordurada e do isolado proteico provenientes do grão de Jatropha curcas L. sobre a atividade da enzima conversora de angiotensina I (ECA-1), com o objetivo de utilizá-los num futuro para a formulação de alimentos funcionais. Os hidrolisados foram obtidos usando alcalase e o sistema enzimático pepsina-pancreatina. Foi calculada a concentração média inibitória (IC50) para medir o grau de inibição da atividade enzimática da ECA-1. Foram selecionados os hidrolisados com o menor tempo de hidrólise (60 min.) para avaliar a bioatividade visto que as cinéticas de hidrólise enzimática da farinha desengordurada e do isolado proteico não encontraram diferenças significativas no grau de hidrólise para os tempos de reação para cada sistema (60, 90 e 120 min.). Os valores de IC50 que apresentaram o melhor efeito de inibição sobre a ECA-I foram 2.8 e 7.0 µg/mL obtidos a partir do isolado proteico com a enzima alcalase e com o sistema sequencial pepsina-pancreatina respectivamente. Os hidrolisados de J. curcas poderiam ser incorporados na elaboração de alimentos funcionais e ser aplicados em tratamentos para pessoas com hipertensão por seu efeito inibitório sobre a ECA-I.

Angiotensina-(1-9) disminuye el remodelamiento cardiovascular hipertensivo independiente de los niveles de ECA y de angiotensina II / Angiotensin-(1-) reduces hypertensive cardiovascular remodeling independent of ACE and Ang II levels

Resumen: La enzima convertidora de angiotensina I (ECA2) a través de Angiotensina (Ang)-(1-9) más que Ang-(1-7) contrarresta los efectos deletéreos de ECA y Ang II. Se desconoce si Ang-(1-9) es efectiva en el tratamiento del remodelamiento cardiovascular (RMCV) hipertensivo, en ratas con polimorfismo del gen de la ECA. Objetivo: Determinar el efecto de Ang-(1-9) en el tratamiento del RMCV hipertensivo en ratas con niveles genéticamente determinados de ECA y Ang II. Métodos: Ratas normotensas homocigotas, Lewis (LL) y Brown Norway (BN), se les indujo HTA a través del modelo Goldblatt (GB, 2 riñones-1 pinzado). Después de 4 semanas, las ratas hipertensas se rando-mizaron para recibir Ang-(1-9) (602 ng/Kg min) o una coadministración de Ang-(1-9)+A779 (100 ng/Kg min, antagonista del receptor MAS de Ang-(1-7)) durante 14 días mediante una minibomba. Como controles se usaron ratas sometidas a operación ficticia (Sham). Se determinó masa corporal (MC), presión arterial sistólica (PAS), masa ventricular (MV), área de cardiomiocitos (AC), área y grosor de la túnica media (ATM, GTM), fracción volumétrica de colágeno total (FVCT) en el ventrículo izquierdo (VI), niveles proteicos de colágeno tipo I (Col I) en la aorta (Ao) y la infiltración de macrófagos en Ao y VI, por medio de su molécula especifica ED1 (ED1-Ao, ED1-VI). Resultados: La administración de Ang-(1-9) disminuyó significativamente PAS, MV, AC, FVCT, Col I, ATM, GTM, ED1-Ao (-) y ED1-VI, en las ratas hipertensas LL y BN respecto a las ratas GB sin tratamiento, respectivamente. Este efecto no fue inhibido por el antagonista A779. El polimorfismo de la ECA no modificó la respuesta al tratamiento. Conclusión: Ang-(1-9) redujo eficazmente la HTA y el RMCV secundario, independiente al polimorfismo en el gen de la ECA. Este efecto posiblemente es directo ya que no fue mediado por Ang-(1-7). Fondecyt 1100874.

Background: The angiotensin I converting enzyme 2 (ACE2) counteracts the deleterious effects of ACE and Ang II through angiotensin (Ang) -(1-9) rather than Ang-(1-7). In addition, it is not clear whether Ang-(1-9) is effective in the reversal of hypertensive cardiovascular remodeling (CVRM) in rats with ACE gene polymorphism. Objective: To determine the effect of Ang-(1-9) in the prevention of hypertensive CVRM in rats with genetically determined levels of ACE and Ang II. Methods: In normotensive homozygous Lewis (LL) and Brown Norway (BN) rats hypertension was induced by the Goldblatt 2 kidney-1 pinch model. After 4 weeks, rats were randomized to receive Ang- (1-9) (602 ng / Kg min) or the co administration of Ang- (19) + A779 (100 ng / kg min, a MAS receptor antagonist of Ang- (1-7)) for 14 days. Sham operated rats were used as controls. We determined body mass (BM), systolic blood pressure (SBP), ventricular mass (VM), cardiomyocyte area (CA), area and thickness of the aortic media (ATM, TTM), LV total collagen volume fraction (FVCT), type I collagen protein levels (Col I) in the aorta (Ao) and macrophage infiltration in LV and Ao, through its specific molecule ED1 (ED1-Ao, ED1-VI). Results: Continuous administration of Ang- (1-9) significantly decreased SBP, VM, CA, TCVF, Col I, TTM, and ED1 in the aorta and left ventricle of hypertensive rats. This effect was not inhibited by the antagonist A779. ACE polymorphism did not modify the response to treatment. Conclusion: Ang- (1-9) effectively reduced hypertension induced CVRM independent of ACE gene polymorphism. This effect was not mediated by Ang- (1-7).

Menores niveles tisulares de la enzima convertidora de angiotensina I homologa (ECA-2) y angiotensina-(1-9) están asociados a mayor remodelamiento de la pared aórtica de ratas hipertensas / Lower tissue levels of homologous angiotensin I converting enzyme (ACE-2) and angiotensin 1-9 are associated to increased remodeling of the aortic wall of hypertensive rats

Antecedentes: Recientemente hemos propuesto en un modelo experimental de infarto al miocardio una significativa interregulación entre los niveles de la enzima convertidora de angiotensina I (ECA) y su homóloga (ECA-2), junto con que angiotensina (Ang)-(1-9) más que Ang-(1-7) actuaría como uncontrarregulador de Ang II. Sin embargo tal relación no se ha investigado en el remodelado aórtico hipertensivo. Objetivo: Determinar la expresión de ECA y ECA-2, los niveles de Angs I, II, (1-7) y (1-9) y los parámetros de remodelado de la pared aórtica de ratas hipertensas. Métodos: Ratas normotensas Lewis (n=18) fueron randomizadas a hipertensión (HTA) por sobrecarga de presión (modelo Goldblatt, GB, 2 riñones-1 pinzado, n=9). Ratas pseudo-operadas se usaron como controles (S, n=9). A las 6 semanas post cirugía, se determinó la masa cardíaca relativa (MCR) y la presión arterial sistólica (PAS). En la aorta torácica se determinó el grosor de la túnica media (GTM), área de la TM (ATM), niveles de mRNA de ECA y ECA-2, factor de crecimiento transformante tipo beta (TGF-beta), inhibidor del activador de plasminógeno (PAI-1) y de la proteína quimioatractante de monocitos (MCP-1) por RT-PCR. La actividad y niveles proteicos de ECA y ECA-2 por fluorimetría y Western blot y los niveles de Angs I, II, (1-7) y (1-9) por HPLC y radioinmunoensayo. Resultados: La MCR y la PAS aumentaron significativamente (p<0,05) en el grupo GB respecto a su control S. Las ratas hipertensas mostraron un aumento significativo (p<0.05) del GTM (18 por ciento), ATM (31 por ciento), niveles de mRNA de ECA (164 por ciento), TGF-beta (105 por ciento), PAI-1(51 por ciento), MCP-1 (53 por ciento) junto con mayor actividad (89 por ciento), niveles proteicos de ECA (130 por ciento) y Ang II (48 por ciento). Esos efectos se asociaron a una significativa disminución del mRNA, los niveles proteicos y actividad...

Background: In experimental models of myocardial infarction we have recently proposed a significantinter-regulation between levels of Angiotensin I converting enzyme (ACE) and its homologous, ACE-2; in addition, we have proposed that Angiotensin 1-9 (Ang-(1-9)) rather than Ang-(1-7) counter regulates Ang II. These relations have not been investigated in hypertensive aortic wall remodeling. Aim: To measure de expression of ACE and ACE-2, the aortic wall levels of Ang I, Ang II, Ang-(1-7) and Ang-(1-9), along with parameters of aortic wall remodeling in hypertensive rats. Methods: 18 Lewis rats were randomized to Goldblatt (2 kidneys, 1 clamped) induced hypertension (n=9) or sham operation (controls, n=9). Six weeks after surgery, relative cardiac mass (RCM), systolic blood pressure (SBP), medial layer aortic wall thickness (MLT) and ML area (MLA) were measured. The aortic wall levels of ACE and ACE-2, tissue growth factor beta (TGF- beta), plasminogen activator inhibitor (PAI-1) and monocyte chemoattractant protein (MCP-1) were determined by RT-PCR. Activity and protein levels of ACE and ACE-2 were measured by fluorometry and Western Blot and ANG I, Ang II, Ang-(1-7) and Ang-(1-9) levels were determined using HPLC and radioimmunoassay. Results: RCM and SBP increased significantly in hypertensive as opossed to sham operated rats...