Polyphenolic Composition and in Vitro Antihypertensive and Anti-Inflammatory Effects of Cuphea lindmaniana and Cuphea urbaniana.

The present study investigates the chemical composition, anti-inflammatory, and antihypertensive activities, in vitro, from extracts of Cuphea lindmaniana and Cuphea urbaniana leaves. The extraction was performed ultrasound-assisted, and UHPLC/MS analysis was in positive mode ionization. The anti-inflammatory activity of the extracts and miquelianin were assayed at concentrations 0.001-10 µg/mL by chemotaxis on rat polymorphonuclear neutrophils. The antihypertensive activity was performed by angiotensin-converting enzyme (ACE) inhibition. From the nineteen proposed compounds, six of them are described for the first time in this genus. The extracts displayed antichemotactic effect with a reduction of 100 % of the neutrophil migration, in vitro, in most concentrations. The ACE-inhibition presented results ranging from 19.58 to 22.82 %. In conclusion, C. lindmaniana and C. urbaniana extracts contain a rich diversity of flavonoids and display in vitro anti-inflammatory and antihypertensive potential. Thus, this study could serve as a scientific baseline for further investigation, on developmental novel products with therapeutic actions.

Potential of green and roasted coffee beans and spent coffee grounds to provide bioactive peptides.

Protein extracts from green and roasted coffee beans and from spent coffee grounds (SCG) were evaluated as bioactive peptides sources. The in silico approach revealed a high frequency of the occurrence (A) of dipeptidyl peptidase-IV (DPP-IV) (0.62) and angiotensin I-converting enzyme (ACE) inhibitor peptides (0.44) in the 11S coffee globulin, which could be released after digestion. After in vitro digestion of the protein, the green bean and SCG proteins were more susceptible to proteolysis, releasing smaller polypeptides (3.4 kDa), which showed higher anti-hypertensive potentials (IC50 = 0.30 and 0.27 mg soluble protein/mL). However, the antioxidant capacity only increased for the roasted coffee and SCG extracts due to antioxidant groups formed during roasting. The heat treatment applied during coffee brewing increased the sensitivity of the SCG extract to proteolysis, leading to their high anti-hypertensive and antioxidant potentials. Therefore, the 11S coffee globulin is a precursor of a series of bioactive peptides.

Identification of Angiotensin I-Converting Enzyme-Inhibitory and Anticoagulant Peptides from Enzymatic Hydrolysates of Chicken Combs and Wattles.

Peptides from protein hydrolysate of a mixture of chicken combs and wattles (CCWs) were obtained through enzymatic hydrolysis, and their anticoagulant and inhibitory effects on angiotensin I-converting enzyme (ACE) were investigated. The protein hydrolysate exhibited anticoagulant capacity by the intrinsic pathway (activated partial thromboplastin time) and potent ACE-inhibitory activity. The peptides were sequenced by LC-MS to identify those with higher inhibitory potential. From the pool of sequenced peptides, the following three peptides were selected and synthesized based on their low molecular weight and the presence of amino acids with ACE-inhibitory potential at the C-terminus: peptide I (APGLPGPR), peptide II (Piro-GPPGPT), and peptide III (FPGPPGP). Peptide III (FPGPPGP) showed the highest ACE-inhibitory capacity among the peptides selected. In conclusion, a peptide (FPGPPGP) of unknown sequence was identified as having potent ACE-inhibitory capacity. This peptide originated from unconventional hydrolysates from poultry slaughter waste, including combs and wattles.

Antithrombotic Activity of Brewers' Spent Grain Peptides and their Effects on Blood Coagulation Pathways.

Antithrombotic activity of brewers' spent grain peptides before and after simulated gastrointestinal digestion and their effects on blood coagulation pathways were evaluated. Two hydrolysates were produced using sequential enzymatic systems: alkaline protease + Flavourzyme (AF) and neutral protease + Flavourzyme (PF). Simulation of gastrointestinal digestion of AF and PF hydrolysates was made using porcine pepsin and pancreatin enzymes, obtaining the corresponding digested samples: AFD and PFD, respectively. Peptides were fractionated by ultrafiltration using a 1 kDa cut-off membrane. Hydrolysates had peptides with medium and low molecular weights (2100 and 500 Da, respectively), and Glu, Asp, Leu, Ala, and Phe were the most abundant amino acids. Gastrointestinal digested hydrolysates presented high proportion of small peptides (~500 Da), and higher amount of Val, Tyr, and Phe than hydrolysates. Mass spectrum (HDMS Q-TOF) of AFD-ultrafiltered fraction <1 kDa exhibited peptides from 500 to 1000 Da, which are not present in AF. PFD showed the generation of new peptides from 430 to 1070 Da. All samples showed thrombin inhibitory activity. However, no effect was observed on prothrombin time. Peptides <1 kDa from hydrolysates and digested samples delayed thrombin and thromboplastin time respect to the control (~63%). Also the samples showed thrombin inhibitory activity at common pathway level. Thus, brewers' spent grain peptides exerted their antithrombotic activity by inhibiting the intrinsic and common pathways of blood coagulation. This is the first report to demonstrate that brewers' spent grain peptides are able to delay clotting time after simulated gastrointestinal digestion.

Identification, In Vitro Testing and Molecular Docking Studies of Microginins' Mechanism of Angiotensin-Converting Enzyme Inhibition.

Cyanobacteria are able to produce a wide range of secondary metabolites, including toxins and protease inhibitors, with diverse biological activities. Microginins are small linear peptides biosynthesized by cyanobacteria species that act against proteases. The aim of this study was to isolate and identify microginins produced by the LTPNA08 strain of Microcystis aeruginosa, as well as to verify their potential to inhibit angiotensin-converting enzyme (ACE; EC. 3.4.15.1) using in vitro and in silico methods. The fractionation of cyanobacterial extracts was performed by liquid chromatography and the presence of microginins was monitored by both LC-MS and an ACE inhibition assay. Enzyme inhibition was assayed by ACE with hippuryl-histidyl-leucine as the substrate; monitoring of hippuric acid was performed by HPLC-DAD. Isolated microginins were confirmed by mass spectrometry and were used to carry out the enzymatic assay. Molecular docking was used to evaluate microginin 770 (MG 770) and captopril (positive control), in order to predict similar binding interactions and determine the inhibitory action of ACE. The enzyme assay confirmed that MG 770 can efficiently inhibit ACE, with an IC50 equivalent to other microginins. MG 770 presented with comparable interactions with ACE, having features in common with commercial inhibitors such as captopril and enalaprilate, which are frequently used in the treatment of hypertension in humans.

Fetopathies associated with exposure to angiotensin converting enzyme inhibitor from Tropaeolum majus L.

The prevalence of the use of herbal medicines is on the rise across the world, especially amongst pregnant women. A fact that draws attention is that many species commonly used by pregnant women, including the Tropaeolum majus L. (Tropaeolaceae), also present inhibitory activity on the angiotensin-converting enzyme (ACE). Herein, we have investigated the effects of T. majus extract (HETM) on fetal development, evaluating its relationship with possible ACE inhibitory activity. Pregnant Wistar rats were treated with different HETM doses (3, 30 and 300 mg/kg/day) from gestational days 8-20. Rats were sacrificed on the day 20 of pregnancy and the following parameters were evaluated: clinical symptoms of maternal toxicity; maternal body weight; feed and water intake; maternal liver, kidney, and ovary weights, maternal ACE activity and aldosterone levels, live fetuses mean; dead fetuses percentage, fetus weight, and fetal malformation. All pregnant rats treated with high HETM doses showed significant reduction in plasma ACE activity accompanied by a decrease in serum aldosterone levels. Moreover, significant changes in fetal development were observed, including growth retardation and renal damage after 20 days of gestation. Thus, data presented demonstrate the significant effects of the use of HETM on fetal development during pregnancy.

Non-disulfide-bridged peptides from Tityus serrulatus venom: Evidence for proline-free ACE-inhibitors.

The present study purifies two T. serrulatus non-disulfide-bridged peptides (NDBPs), named venom peptides 7.2 (RLRSKG) and 8 (KIWRS) and details their synthesis and biological activity, comparing to the synthetic venom peptide 7.1 (RLRSKGKK), previously identified. The synthetic replicate peptides were subjected to a range of biological assays: hemolytic, antifungal, antiviral, electrophysiological, immunological and angiotensin-converting enzyme (ACE) inhibition activities. All venom peptides neither showed to be cytolytic nor demonstrated significant antifungal or antiviral activities. Interestingly, peptides were able to modulate macrophages' responses, increasing IL-6 production. The three venom peptides also demonstrated potential to inhibit ACE in the following order: 7.2>7.1>8. The ACE inhibition activity was unexpected, since peptides that display this function are usually proline-rich peptides. In attempt to understand the origin of such small peptides, we discovered that the isolated peptides 7.2 and 8 are fragments of the same molecule, named Pape peptide precursor. Furthermore, the study discusses that Pape fragments could be originated from a post-splitting mechanism resulting from metalloserrulases and other proteinases cleavage, which can be seen as a clever mechanism used by the scorpion to enlarge its repertoire of venom components. Scorpion venom remains as an interesting source of bioactive proteins and this study advances our knowledge about three NDBPs and their biological activities.

Phytochemical and in vitro and in vivo biological investigation on the antihypertensive activity of mango leaves (Mangifera indica L.).

AIMS: The aim of this study was to investigate the antihypertensive effect of leaves Mangifera indica L. using in vitro and in vivo assays. METHODOLOGY: The ethanol extract of leaves of M. indica was fractionated to dichloromethanic, n-butyl alcohol and aqueous fractions. The chemical composition of ethanolic extract and dichloromethanic fraction were evaluated by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Antioxidant activity was evaluated in the DPPH scavenging activity assay. Angiotensin-converting enzyme (ACE) inhibitory activity was investigated using in vitro and in vivo assays. The chronic antihypertensive assay was performed in spontaneously hypertensive rats (SHRs) and Wistar rats treated with enalapril (10 mg/kg), dichloromethanic fraction (100 mg/kg; twice a day) or vehicle control for 30 days. The baroreflex sensitivity was evaluated through the use of sodium nitroprusside and phenylephrine. Cardiac hypertrophy was evaluated by morphometric analysis. RESULTS: The dichloromethanic fraction exhibited the highest flavonoid, total phenolic content and high antioxidant activity. Dichloromethanic fraction elicited ACE inhibitory activity in vitro (99 ± 8%) similar to captopril. LC-MS/MS analysis revealed the presence of ferulic acid (48.3 ± 0.04 µg/g) caffeic acid (159.8 ± 0.02 µg/g), gallic acid (142.5 ± 0.03 µg/g), apigenin (11.0 ± 0.01 µg/g) and quercetin (203.3 ± 0.05 µg/g). The chronic antihypertensive effects elicited by dichloromethanic fraction were similar to those of enalapril, and the baroreflex sensitivity was normalized in SHR. Plasma ACE activity and cardiac hypertrophy were comparable with animals treated with enalapril. CONCLUSIONS: Dichloromethanic fraction of M. indica presented an antihypertensive effect, most likely by ACE inhibition, with benefits in baroreflex sensitivity and cardiac hypertrophy. Altogether, the results of the present study suggest that the dichloromethanic fraction of M. indica leaves may have potential as a promoting antihypertensive agent.

New proline-rich oligopeptides from the venom of African adders: Insights into the hypotensive effect of the venoms.

BACKGROUND: The snakes from the Bitis genus are some of the most medically important venomous snakes in sub Saharan Africa, however little is known about the composition and effects of these snake venom peptides. Considering that the victims with Bitis genus snakes have exacerbate hypotension and cardiovascular disorders, we investigated here the presence of angiotensin-converting enzyme modulators on four different species of venoms. METHODS: The peptide fractions from Bitis gabonica gabonica, Bitis nasicornis, Bitis gabonica rhinoceros and Bitis arietans which showed inhibitory activity on angiotensin-converting enzyme were subjected to mass spectrometry analysis. Eight proline-rich peptides were synthetized and their potencies were evaluated in vitro and in vivo. RESULTS: The MS analysis resulted in over 150 sequences, out of which 32 are new proline-rich oligopeptides, and eight were selected for syntheses. For some peptides, inhibition assays showed inhibitory potentials of cleavage of angiotensin I ten times greater when compared to bradykinin. In vivo tests showed that all peptides decreased mean arterial pressure, followed by tachycardia in 6 out of 8 of the tests. CONCLUSION: We describe here some new and already known proline-rich peptides, also known as bradykinin-potentiating peptides. Four synthetic peptides indicated a preferential inhibition of angiotensin-converting enzyme C-domain. In vivo studies show that the proline-rich oligopeptides are hypotensive molecules. GENERAL SIGNIFICANCE: Although proline-rich oligopeptides are known molecules, we present here 32 new sequences that are inhibitors of the angiotensin-converting enzyme and consistent with the symptoms of the victims of Bitis spp, who display severe hypotension.

Scorpion venom components as potential candidates for drug development.

Scorpions are well known for their dangerous stings that can result in severe consequences for human beings, including death. Neurotoxins present in their venoms are responsible for their toxicity. Due to their medical relevance, toxins have been the driving force in the scorpion natural compounds research field. On the other hand, for thousands of years, scorpions and their venoms have been applied in traditional medicine, mainly in Asia and Africa. With the remarkable growth in the number of characterized scorpion venom components, several drug candidates have been found with the potential to tackle many of the emerging global medical threats. Scorpions have become a valuable source of biologically active molecules, from novel antibiotics to potential anticancer therapeutics. Other venom components have drawn attention as useful scaffolds for the development of drugs. This review summarizes the most promising candidates for drug development that have been isolated from scorpion venoms.

[The antihypertensive effect of fermented milks]. / El efecto antihipertensivo de las leches fermentadas.

There is a great variety of fermented milks containing lactic acid bacteria that present health-promoting properties. Milk proteins are hydrolyzed by the proteolytic system of these microorganisms producing peptides which may also perform other functions in vivo. These peptides are encrypted within the primary structure of proteins and can be released through food processing, either by milk fermentation or enzymatic hydrolysis during gastrointestinal transit. They perform different activities, since they act in the cardiovascular, digestive, endocrine, immune and nervous systems. Bioactive peptides that have an antihypertensive, antithrombotic, antioxidant and hypocholesterolemic effect on the cardiovascular system can reduce the risk factors for chronic disease manifestation and help improve human health. Most studied bioactive peptides are those which exert an antihypertensive effect by inhibiting the angiotensin-converting enzyme (ACE). Recently, the study of these peptides has focused on the implementation of tests to prove that they have an effect on health. This paper focuses on the production of ACEinhibitory antihypertensive peptides from fermented milks, its history, production and in vivo tests on rats and humans, on which its hypotensive effect has been shown.

El efecto antihipertensivo de las leches fermentadas / The antihypertensive effect of fermented milks

Existe una gran variedad de leches fermentadas con bacterias lácticas, con propiedades que promueven la salud. Recientemente se ha comunicado que las proteínas de los alimentos pueden, además, ejercer otras funciones in vivo, por medio de sus péptidos con actividad biológica. Estos péptidos se encuentran encriptados dentro de la estructura primaria de las proteínas y pueden ser liberados por fermentación de la leche, hidrólisis enzimática, o bien durante el tránsito gastrointestinal. Las funciones que presentan son diversas, ya que pueden actuar en diferentes sistemas del cuerpo humano: el cardiovascular, el digestivo, el endocrino, el inmune y el nervioso. Los péptidos bioactivos que presentan un efecto en el sistema cardiovascular (antihipertensivo, antitrombótico, antioxidante o hipocolesterolémico) pueden reducir los factores de riesgo para la manifestación de enfermedades crónicas y ayudar a mejorar la salud humana. Los péptidos bioactivos más estudiados son aquellos que ejercen un efecto antihipertensivo a través de la inhibición de la enzima convertidora de angiotensina (ACE). Este documento se enfoca en la producción de péptidos antihipertensivos inhibidores de la ACE en leches fermentadas, en su historia, y en las pruebas in vivo realizadas en ratas y en humanos, donde se ha demostrado su efecto hipotensor.

There is a great variety of fermented milks containing lactic acid bacteria that present health-promoting properties. Milk proteins are hydrolyzed by the proteolytic system of these microorganisms producing peptides which may also perform other functions in vivo. These peptides are encrypted within the primary structure of proteins and can be released through food processing, either by milk fermentation or enzymatic hydrolysis during gastrointestinal transit. They perform different activities, since they act in the cardiovascular, digestive, endocrine, immune and nervous systems. Bioactive peptides that have an antihypertensive, antithrombotic, antioxidant and hypocholesterolemic effect on the cardiovascular system can reduce the risk factors for chronic disease manifestation and help improve human health. Most studied bioactive peptides are those which exert an antihypertensive effect by inhibiting the angiotensin-converting enzyme (ACE). Recently, the study of these peptides has focused on the implementation of tests to prove that they have an effect on health. This paper focuses on the production of ACEinhibitory antihypertensive peptides from fermented milks, its history, production and in vivo tests on rats and humans, on which its hypotensive effect has been shown.

El efecto antihipertensivo de las leches fermentadas / The antihypertensive effect of fermented milks

Existe una gran variedad de leches fermentadas con bacterias lácticas, con propiedades que promueven la salud. Recientemente se ha comunicado que las proteínas de los alimentos pueden, además, ejercer otras funciones in vivo, por medio de sus péptidos con actividad biológica. Estos péptidos se encuentran encriptados dentro de la estructura primaria de las proteínas y pueden ser liberados por fermentación de la leche, hidrólisis enzimática, o bien durante el tránsito gastrointestinal. Las funciones que presentan son diversas, ya que pueden actuar en diferentes sistemas del cuerpo humano: el cardiovascular, el digestivo, el endocrino, el inmune y el nervioso. Los péptidos bioactivos que presentan un efecto en el sistema cardiovascular (antihipertensivo, antitrombótico, antioxidante o hipocolesterolémico) pueden reducir los factores de riesgo para la manifestación de enfermedades crónicas y ayudar a mejorar la salud humana. Los péptidos bioactivos más estudiados son aquellos que ejercen un efecto antihipertensivo a través de la inhibición de la enzima convertidora de angiotensina (ACE). Este documento se enfoca en la producción de péptidos antihipertensivos inhibidores de la ACE en leches fermentadas, en su historia, y en las pruebas in vivo realizadas en ratas y en humanos, donde se ha demostrado su efecto hipotensor.(AU)

There is a great variety of fermented milks containing lactic acid bacteria that present health-promoting properties. Milk proteins are hydrolyzed by the proteolytic system of these microorganisms producing peptides which may also perform other functions in vivo. These peptides are encrypted within the primary structure of proteins and can be released through food processing, either by milk fermentation or enzymatic hydrolysis during gastrointestinal transit. They perform different activities, since they act in the cardiovascular, digestive, endocrine, immune and nervous systems. Bioactive peptides that have an antihypertensive, antithrombotic, antioxidant and hypocholesterolemic effect on the cardiovascular system can reduce the risk factors for chronic disease manifestation and help improve human health. Most studied bioactive peptides are those which exert an antihypertensive effect by inhibiting the angiotensin-converting enzyme (ACE). Recently, the study of these peptides has focused on the implementation of tests to prove that they have an effect on health. This paper focuses on the production of ACEinhibitory antihypertensive peptides from fermented milks, its history, production and in vivo tests on rats and humans, on which its hypotensive effect has been shown.(AU)

El efecto antihipertensivo de las leches fermentadas. / [The antihypertensive effect of fermented milks].

There is a great variety of fermented milks containing lactic acid bacteria that present health-promoting properties. Milk proteins are hydrolyzed by the proteolytic system of these microorganisms producing peptides which may also perform other functions in vivo. These peptides are encrypted within the primary structure of proteins and can be released through food processing, either by milk fermentation or enzymatic hydrolysis during gastrointestinal transit. They perform different activities, since they act in the cardiovascular, digestive, endocrine, immune and nervous systems. Bioactive peptides that have an antihypertensive, antithrombotic, antioxidant and hypocholesterolemic effect on the cardiovascular system can reduce the risk factors for chronic disease manifestation and help improve human health. Most studied bioactive peptides are those which exert an antihypertensive effect by inhibiting the angiotensin-converting enzyme (ACE). Recently, the study of these peptides has focused on the implementation of tests to prove that they have an effect on health. This paper focuses on the production of ACEinhibitory antihypertensive peptides from fermented milks, its history, production and in vivo tests on rats and humans, on which its hypotensive effect has been shown.

Defatted Jatropha curcas flour and protein isolate as materials for protein hydrolysates with biological activity.

Jatropha curcas L. protein hydrolysates were produced by treatment of a non-toxic genotype with Alcalase as well as the digestive enzymes pepsin and pancreatin. The J. curcas protein hydrolysate produced with the pepsin-pancreatin system from protein isolate had the highest TEAC value and was shown to undergo single-electron transfer reactions in the ABTS(+) reduction assay, demonstrating its antioxidant capacity. Testing of antimicrobial activity in the J. curcas protein hydrolysates against seven bacterial pathogens showed no growth inhibitory effect in Gram-negative and Gram-positive bacteria. More ACE-I inhibitory active peptides were produced in the Alcalase hydrolysates obtained from J. curcas protein isolate. The protein hydrolysate obtained with Alcalase from defatted J. curcas flour as well as from the protein isolate showed the highest inhibitory effect of ADP-induced aggregation of human platelets in platelet-rich plasma. It is expected that the information collated will facilitate new applications of proteins present in Jatropha plant.

Yeasts from Colombian Kumis as source of peptides with Angiotensin I converting enzyme (ACE) inhibitory activity in milk.

This study investigated the possibility of using yeast strains in fermented milks to obtain products with high Angiotensin I-converting enzyme (ACE) inhibitory activity and low bitter taste. Ninety-three yeast strains isolated from Colombian Kumis in different geographic regions were molecularly identified, and their milk fermentation performances were determined. Molecular identification evidenced that Galactomyces geotrichum, Pichia kudriavzevii, Clavispora lusitaniae and Candida tropicalis, were the dominant species. Eighteen out of 93 strains produced fermented milk with ACE-inhibitory (ACEI) activity values ranging from 8.69 to 88.19%. Digestion of fermented milk samples by pepsin and pancreatin demonstrated an increase in ACEI activity, with C. lusitaniae KL4A as the best producer of ACEI peptides. Moreover, sensory analysis of the products containing the major ACE-inhibitory activity pointed out that P. kudriavzevii KL84A and Kluyveromyces marxianus KL26A could be selected as potential adjunct starter cultures in Kumis, since they made a considerable contribution to the ACE inhibitory activity and produced fermented milk without bitter taste. In this study we observed that Colombian Kumis can be an excellent vehicle for the isolation of yeasts with a potential to enhance bioactive peptides produced during milk fermentation.

Overexpression of a modified protein from amaranth seed in Escherichia coli and effect of environmental conditions on the protein expression.

Amaranth seeds are considered as an excellent complementary source of food protein due to their balanced amino acid composition. Amarantin acidic subunit has the potential as a functional and nutraceutical protein, and it is structurally a good candidate for modification. The aim of this work was to improve its functionality, then the primary structure was modified into the third variable region of 11S globulins, by inserting antihypertensive peptides: four Val-Tyr in tandem and Arg-Ile-Pro-Pro in the C-terminal region. Modified protein was expressed in Escherichia coli Origami (DE3) and was purified. The culture conditions, including the culture media, temperature, agitation speed and air flow were tested in order to obtain an increased expression levels of the modified protein. A 2(3) factorial design was used for evaluate the effect of environmental conditions on modified protein production. The results indicated that the yield of modified protein could be increased by up 3-fold in bioreactor as compared with flask. In addition, the temperature, the agitation speed and the oxygen were significant factors on the expression of the antihypertensive protein. The maximum production was 99 mg protein-L(-1). The hydrolyzed protein showed a high inhibitory activity of the angiotensin converting enzyme (IC50=0.047 mg mL(-1)).

Hancornia speciosa Gomes induces hypotensive effect through inhibition of ACE and increase on NO.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Hancornia speciosa Gomes are popularly used in Brazil to treat diabetes and hypertension. Cardiovascular diseases are the main cause of death worldwide and their incidences are increasing in Brazilian population. The present study aimed to investigate the hypotensive effect and the mechanism of action of Hancornia speciosa Gomes. METHODS: A fraction of the ethanolic extract of leaves from Hancornia speciosa (SFH) was obtained and standardized by its content on rutin, bornesitol and quinic acid. Systolic blood pressure (SBP) of normotensive mice was measured by tail plethysmography. SFH was given orally and SBP was monitored for 5h. Angiotensin-converting enzyme (ACE) inhibitor activity of SFH (1mg/kg) or captopril (10mg/kg) was measured by colorimetric methods. Serum nitrite levels were measured by spectrophotometry. RESULTS: SFH induced a dose-dependent hypotensive effect in normotensive mice. The serum activity of ACE and the level of angiotensin II were significantly reduced by SFH and by captopril. Administration of SFH induced a significant increase on plasmatic level of nitrites and the systemic inhibition of nitric oxide synthase by L-NAME (20mg/kg) reduced the hypotensive effect of SFH. CONCLUSIONS: The present work demonstrated that Hancornia speciosa has a potent hypotensive effect in normotensive mice. The inhibition of ACE leading to reduction on angiotensin II and increase on NO levels might account for the hypotensive effect. These results support the use of Hancornia speciosa by traditional medicine as antihypertensive.

Short communication: Assessing antihypertensive activity in native and model Queso Fresco cheeses.

Hispanic-style cheeses are one of the fastest growing varieties in the United States, making up approximately 2% of the total cheese production in this country. Queso Fresco is one of most popular Hispanic-style cheeses. Protein extracts from several varieties of Mexican Queso Fresco and model Queso Fresco were analyzed for potential antihypertensive activity. Many Quesos Frescos obtained from Mexico are made from raw milk and therefore the native microflora is included in the cheese-making process. Model Queso Fresco samples were made from pasteurized milk and did not utilize starter cultures. Water-soluble protein extracts from 6 Mexican Quesos Frescos and 12 model cheeses were obtained and assayed for their ability to inhibit angiotensin-converting enzyme, implying potential as foods that can help to lower blood pressure. All model cheeses displayed antihypertensive activity, but mainly after 8 wk of aging when they were no longer consumable, whereas the Mexican samples did display some angiotensin-converting enzyme inhibitory action after minimal aging.

Bj-PRO-5a, a natural angiotensin-converting enzyme inhibitor, promotes vasodilatation mediated by both bradykinin B2and M1 muscarinic acetylcholine receptors.

Bradykinin-potentiating peptides (BPPs) or proline-rich oligopeptides (PROs) isolated from the venom glands of Bothrops jararaca (Bj) were the first natural inhibitors of the angiotensin-converting enzyme (ACE) described. Bj-PRO-5a (