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Transport, In Vivo Antihypertensive Effect, and Pharmacokinetics of an Angiotensin-Converting Enzyme (ACE) Inhibitory Peptide LVLPGE
Abstract
The angiotensin-converting enzyme (ACE) inhibitory peptide LVLPGE provides outstanding antihypertensive effects in vivo, with a maximum systolic blood pressure (SBP) drop of 39 mmHg at a dose of 10 mg/kg. We evaluated the gastrointestinal digestion, transport, and in vivo antihypertensive effects of LVLPGE at different doses. LVLPGE was resistant to gastrointestinal enzymes with a stability of 97.8% and a permeability Papp of (5.09 ± 0.94) × 10-7 cm/s. LVLPGE was mainly transported through the Caco-2 cell monolayer by the peptide transporter PepT 1 and passive-mediated transport. LVLPGE at doses of 30 and 50 mg/kg had a positive antihypertensive effect in vivo; 30 mg/kg had a more significant effect than 50 mg/kg. After oral administration, the pharmacokinetics of LVLPGE showed that the Cmax was 4.65 ng/mL at 2 min. The blood pressure-lowering effect increased as the concentration of LVLPGE increased in the plasma of spontaneous hypertensive rats (SHRs).
... The main function of M pro is to hydrolyze pp1a and pp1ab from at least 11 conserved cleavage sites. These effects lead to the synthesis of nonstructural proteins, namely, membrane proteins, spike proteins, envelope proteins, nucleocapsid proteins, and hemagglutinin proteins (Ramajayam et al., 2011;Gentile et al., 2020). In particular, M pro is one of the potential therapeutic targets of SARS-CoV-2. ...
... In particular, M pro is one of the potential therapeutic targets of SARS-CoV-2. Its special properties do not create a homolog in the human body (Ramajayam et al., 2011;Kim et al., 2016). In this study, some inhibitors which can bind with M pro were screened and used as drug candidates. ...
... Samples from the basolateral chambers were collected and analyzed by high-performance liquid chromatography (HPLC). The apparent permeability coefficients (Papp, cm/s) were calculated based on formulas reported previously (Pei et al., 2021). ...
The main protease (Mpro) is essential for the replication of SARS-COV-2 and therefore represents a promising anti-viral target. In this study, we screened Mpro inhibitory peptides from Ulva prolifera protein on in-silico proteolysis. Cytotoxicity analysis using the online toxic prediction tool ToxinPred revealed that all the peptides were non-cytotoxic. The hexapeptide (SSGFID) exhibited high Mpro inhibitory activity in molecular docking and its IC50 value was 139.40±0.82 µmol/L in vitro according to fluorescence resonance energy transfer assay (FRET). Quantitative real-time (qRT-) PCR results show that SSGFID could stimulate the expression of mitosis-related factors, including nuclear factor-κB, cyclin D1, and cyclin-dependent kinase 4, to promote the proliferation of mice splenocytes. Stability study revealed that SSGFID showed resistance against pepsin and trypsin but lost D (Asp) after pretreatment at 121 °C for 15 min. Besides, SSGFID was mainly transported through the Caco-2 cell monolayer by the peptide transporter PepT1 and passive-mediated transport during the transport study. Unfortunately, the peptide was also degraded by Caco-2 intracellular enzymes, and the transfer rate of intact peptide was 4.2%. Furthermore, Lineweaver–Burk plots demonstrated that SSGFID possessed a mixed inhibitory characteristic with Mpro. Our study indicated the potential of Ulva prolifera as antiviral and immune-enhancing functional food ingredients and nutraceuticals.
... Numerous studies have successfully isolated, identified, and characterized several peptides possessing antihypertensive properties. The burgeoning field of peptide medicines in the international biotechnology arena holds great promise for medication research and development [5][6][7][8]. Quinoa is internationally recognized by nutritionists as an ancient "nutritional gold", a "super grain" and a "future food". It is also hailed as the "King of Vegetarianism" among vegan enthusiasts, making it one of the most promising foods for the future [9,10]. ...
... These findings indicate that FR-6 exhibits poor stability in plasma and is susceptible to enzymatic metabolism and degradation by various enzymes present [22][23][24]. To enhance its stability in plasma, we attempted to pre-add 10% H 2 SO 4 into whole blood during the experiment followed by thorough mixing [5], after which was obtained through centrifugation for subsequent. However, it was observed that while the addition of an appropriate amount of acid improved stability, it also had a detrimental effect on red blood cells, compromising their anticoagulant function and leading hemolysis. ...
The investigation of peptide drugs has become essential in the development of innovative medications for hypertension. In this study, a sensitive high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method was developed to determine the plasma concentration and stability of the antihypertensive peptide FR-6 in rats. An isotopically labeled peptide (with an unchanged sequence) was utilized as an internal standard (IS) for validation purposes. Subsequently, this assay was employed to examine the pharmacokinetics of different administration methods (tail vein and gavage) in Sprague Dawley (SD) rats. Extracted plasma samples underwent sample preparation through methanol protein precipitation, followed by elution of FR-6 on Wondasil C18 Superb column (4.6 × 150 mm, 5 μm), using a mobile phase consisting of formic acid (0.1%) in water (A) and formic acid (0.125%)-ammonium formate (2 mM) in methanol (B). Ion pairs corresponding to FR-6 and IS were monitored via multiple reaction monitoring (MRM) under positive ion mode: m/z 400.7 → 285.1 for FR-6 and m/z 406.1 → 295.1 for IS detection respectively. The method exhibited excellent linearity with respect to FR-6 concentrations. In addition, the inter-day and intra-day precision were 0.61–6.85% and 1.76–11.75%; the inter-day and intra-day accuracy were −7.28–0.13% and −7.20–2.28%, respectively. In conclusion, the matrix effect, extraction recovery, and stability data were validated according to FDA recommended acceptance criteria for bioanalytical methods. This validated method serves as a reliable tool for determining the concentration of antihypertensive peptide FR-6, and has been successfully applied in pharmacokinetic studies involving rats.
... The results suggested the antibacterial component may comprise protein macromolecules, the thermal stability of which may be unremarkable. Moreover, after digested by trypsin and papain the significant decrement in the inhibitory ability of the supernatants suggests that the protein macromolecule surface may contain Lys residues or Arg residues (Dang et al., 2021). Comparison between the treatments of pepsin and proteinase K indicates that the C terminal of Phe, Tyr, Leu, and Trp residues may be hidden inside the protein macromolecule (Dang et al., 2021;Ren, Faas, & de Vos, 2020). ...
... Moreover, after digested by trypsin and papain the significant decrement in the inhibitory ability of the supernatants suggests that the protein macromolecule surface may contain Lys residues or Arg residues (Dang et al., 2021). Comparison between the treatments of pepsin and proteinase K indicates that the C terminal of Phe, Tyr, Leu, and Trp residues may be hidden inside the protein macromolecule (Dang et al., 2021;Ren, Faas, & de Vos, 2020). Fig. 3 showed the adhesion of the five LAB strains to GES-1 cells and their abilities excluding H. pylori cells from GES-1 cells. ...
With the advantages of superior antibacterial activity and probiotic performance, lactic acid bacteria have been attracting considerable attention in the inhibition of Helicobacter pylori. Here, five Lactiplantibacillus plantarum strains were isolated by a multi-step method and characterized in cell adhesion, β-glucosidase activity, antibiotic susceptibility and hemolytic activity. The five strains supernatants can reduce the viable counts of Helicobacter pylori from 7.4 × 10⁸ CFU/mL to 1.5 × 10⁴–2.0 × 10⁵ CFU/mL after treating for 8 h. The five stains supernatants also showed a better inhibitory effect in the urease activity than the other strains, with the decreased activity of 84.3–90.2% and 73.2–84.0% when treated with the supernatants and the strains for 6 h, respectively. The adhesion of Iso05 to GES-1 cells was up to 9.1%, significantly superior to that of the other four strains, adhesion rate of which ranged from 2.1% to 6.1%. Furthermore, the five strains can decrease the adhesion of Helicobacter pylori by 66.0–89.7%, and the β-glucosidase activity of the five strains reached 0.10–0.14 U/g wet cells. Finally, the five strains were safe with nonhemolytic activity. This study contributes to the isolation of lactic acid bacteria with anti-Helicobacter pylori ability and the development of antibiotics-free anti-Helicobacter pylori foods.
... Therefore, the passive paracellular transport via TJ was involved in the transport process of LDF. A large number of water-soluble short peptides were transported by paracellular pathway, such as LVLPGE (Pei et al., 2021), KYI-PIQ (Lin et al., 2020), IQW andLKP (Xu et al., 2017). In this study, LDF was consistent with the above reported peptides. ...
In this study, Ulva prolifera protein was used for preparing angiotensin-I converting enzyme (ACE)-inhibitory peptide via virtual gastrointestinal digestion and in silico screening. Some parameters of the obtained peptide, such as inhibition kinetics, docking mechanism, stability, transport pathway, were explored by Lineweaver-Burk plots, molecular docking, in vitro stimulate gastrointestinal (GI) digestion and Caco-2 cells monolayer model, respectively. Then, a novel anti-ACE peptide LDF (IC50, (1.66 ± 0.34) µmol/L) was screened and synthesized by chemical synthesis. It was a no-competitive inhibitor and its anti-ACE inhibitory effect mainly attributable to four Conventional Hydrogen Bonds and Zn701 interactions. It could keep activity during simulated GI digestion in vitro and was transported by peptide transporter PepT1 and passive-mediated mode. Besides, it could activate Endothelial nitric oxide synthase (eNOS) activity to promote the production of NO and reduce Endothelin-1 (ET-1) secretion induced by Angiotensin II (Ang II) in Human Umbilical Vein Endothelial Cells (HUVECs). Meanwhile, it could promote mice splenocytes proliferation in a concentration-dependent manner. Our study indicated that this peptide was a potential ingredient functioning on vasodilation and enhancing immunity.
... ACE inhibitory peptides with in vivo anti-hypertensive effect have been identified from multiple food sources by using spontaneously hypertensive rats (SHRs), including peptides QIGLF, TNGIIR from egg white [4,5], peptide LRW from pea [6], peptide WGAP from rabbit meat [7], and peptide LVLPGE from broccoli [8]. However, the in vivo anti-hypertensive mechanism of most ACE inhibitory peptides has not been fully clarified, thereby greatly limiting their development and application [9,10]. ...
... Pentapeptide VPLVM from broccoli hydrolysate with an IC 50 value of 99.68 µM for DPP-IV inhibitory activity showed remarkable potential in reducing blood glucose after 30 min administration in healthy C57BL/6 female mice models [146]. In another study, the ACE inhibitory peptide LVLPGE (the IC 50 value of 13.5 µM) is known as a product after simulated digestion from peptide LVLPGELAK (the IC 50 value of 184 µM) derived from broccoli hydrolysate [147]. Hexapeptide LVLPGE had a positive antihypertensive effect in spontaneous hypertensive rat (SHRs) models at doses of 30 mg/kg. ...
Bioactive peptides with high potency against numerous human disorders have been regarded as a promising therapy in disease control. These peptides could be released from various dietary protein sources through hydrolysis processing using physical conditions, chemical agents, microbial fermentation, or enzymatic digestions. Considering the diversity of the original proteins and the complexity of the multiple structural peptides that existed in the hydrolysis mixture, the screening of bioactive peptides will be a challenge task. Well-organized and well-designed methods are necessarily required to enhance the efficiency of studying the potential peptides. This article, hence, provides an overview of bioactive peptides with an emphasis on the current strategy used for screening and characterization methods. Moreover, the understanding of the biological activities of peptides, mechanism inhibitions, and the interaction of the complex of peptide–enzyme is commonly evaluated using specific in vitro assays and molecular docking analysis.
... Although the most recent literature shows a positive antihypertensive in vivo effect when the ACE-inhibitory peptides are used at doses of 3.8-52.5 mg/kg [66,67], an analytical quantification of the bioactive peptides in fortified ricotta cheese is needed to make further considerations. Moreover, in vivo and human studies are necessary to elucidate the dose-effect and the mechanisms involved in the activity of these sequences. ...
Aiming at valorizing the ricotta cheese exhausted whey (RCEW), one of the most abundant by-products from the dairy industry, a biotechnological protocol to obtain bioactive peptides with angiotensin-I-converting enzyme (ACE)--inhibitory activity was set up. The approach was based on the combination of membrane filtration and fermentation. A Lactobacillus helveticus strain selected to be used as starter for the fermentation of the ultrafiltration protein-rich retentate (R-UF) obtained from RCEW. The fermented R-UF was characterized by a high anti-ACE activity. Peptides responsible for the bioactivity were purified and identified through nano-LC–ESI–MS/MS. The sequences identified in the purified active fractions of the fermented R-UF showed partial or complete overlapping with previously reported κ-casein antihypertensive fragments. The fermented R-UF was spray-dried and used to enrich ricotta cheese at different fortification level (1 and 5% w/w). An integrated approach including the assessment of the microbiological, chemical, functional, textural, and sensory properties was used to characterize the fortified products. A significantly higher anti-ACE activity was found in the ricotta cheese fortified with fermented R-UF as compared to the control and to the samples obtained with the unfermented R-UF fraction at the same levels of fortification. In particular, a 100 g portion of the ricotta cheese produced at 5% fortification level contained circa 30 mg of bioactive peptides. The fortification led to a moderate acidification, increased hardness and chewiness, and decreased the milk odor and taste of the ricotta cheese as compared to the control, while flavor persistence and sapidity improved.
Bioactive oligopeptides have gained increasing attention due to their diverse physiological functions, which can be transported to the interior of intestinal epithelial cells via transcellular and paracellular pathways. Among these,...
This study aimed to identify angiotensin I-converting enzyme (ACE) from in vitro digestion products of pork sausage with partial substitution of NaCl by KCl (PSRK). Peptides from in vitro digestion products of PSRK were identified through liquid chromatography with tandem mass spectrometry analysis coupled with de novo sequencing. Subsequently, the ACE inhibitory peptides LIVGFPAYGH and IVGFPAYGH were screened based on PeptideRanker, in silico absorption, molecular docking, and the determination of ACE inhibitory activity. In addition, the ACE inhibitory peptides LIVGFPAYGH and IVGFPAYGH were mixed-type inhibitors; these peptides' ACE inhibitory activities were expressed as the 50% inhibitory concentration (IC50) values in vitro, which were 196.16 and 150.88 μM, respectively. After 2 h of incubation, LIVGFPAYGH and IVGFPAYGH could be transported through Caco-2 cell monolayers with paracellular passive diffusion. Furthermore, LIVGFPAYGH and IVGFPAYGH significantly increased the levels of ACE2 and nitric oxide while decreasing the levels of ACE, angiotensin II, and endothelin-1 in Ang I-treated human umbilical vein endothelial cells, indicating the ACE inhibitory effect of LIVGFPAYGH and IVGFPAYGH. In summary, LIVGFPAYGH and IVGFPAYGH from PSRK can be used as functional foods with antihypertensive activity.
Food-derived α-glucosidase inhibitory peptides have gained significant interest in treating type 2 diabetes mellitus (T2DM) owing to their favorable safety profiles. Molecular docking combined with molecular dynamics simulation was performed to screen α-glucosidase inhibitory peptides from Ginkgo biloba seed cake (GBSC), and two novel peptides (Met-Pro-Gly-Pro-Pro (MPGPP) and Phe-Ala-Pro-Ser-Trp (FAPSW)) were acquired. The results of molecular docking and molecular dynamics simulation suggested that FAPSW and MPGPP could generate stable complexes with 3wy1, and the electrostatic and van der Waals forces played contributory roles in FAPSW and MPGPP binding to 3wy1. The α-glucosidase inhibition assay corroborated that FAPSW and MPGPP had good α-glucosidase inhibition capacity, with IC50 values of 445.34 ± 49.48 and 1025.68 ± 140.78 μM, respectively. In vitro simulated digestion results demonstrated that FAPSW and MPGPP strongly resisted digestion. These findings lay a theoretical foundation for FAPSW and MPGPP in treating T2DM.
The moth bean is a high-protein legume food. This study aims to produce, screen, and identify natural ACE-I inhibitory peptides derived from moth bean seed protein hydrolysates. The extracted protein was hydrolysed using alcalase, chymotrypsin, flavourzyme, papain, pepsin and trypsin respectively. Alcalase achieved the greatest degree of hydrolysis and ACE inhibition. The highest ACE-I inhibitory activity was exhibited by the peptide with the lowest molecular weight i.e. <3 kDa (IC50 11.19 ± 0.15 μg/mL). This was further separated by FPLC, followed by mass spectrometry. Molecular docking analysis showed that the peptides IAWDFR and ADLPGLK bind to the active sites whereas DKPWWPK and AVIPNAPNLR to the non-active sites of the ACE molecule. In vivo administration of MBP hydrolysate to dexamethasone-induced hypertensive rats reduced their systolic blood pressure (125 ± 0.76 mmHg) compared with the positive control (155 ± 3.13 mmHg). Hence, moth bean protein (peptides) exhibit therapeutically relevant functional nutritional properties.
YPVEPF (Tyr-Pro-Val-Glu-Pro-Phe) is an outstanding sleep-enhancing peptide derived from casein. This study aimed to evaluate the bioavailability of YPVEPF in vitro and in vivo and to explore its structure-activity relationship through a sleep test and cheminformatics. Our results showed that YPVEPF was unstable against gastrointestinal enzymes and almost totally degraded to YPVEP in vitro. However, the pharmaco-kinetics results in vivo showed that the Cmax of YPVEPF was 10.38 ± 4.01 ng/mL at 5 min, and YPVEPF could be detected in the stomach, intestine, and brain at 12.89 ± 0.55, 10.26 ± 0.23, and 2.47 ± 0.55 ng/g, respectively. The main metabolites including YPVEP, YP, PVEPF, and PVEP were identified. We first explored whether the fragment YPVEP also had a strong sleep-enhancing effect, and the sleep-enhancing effects of PVEPF and PVEP (lacking a Tyr residue) significantly decreased compared with those of YPVEPF and YPVEP. Moreover, molecular docking and quantum calculations revealed that the N-terminus Tyr played a dominant role in YPVEPF and YPVEP. They had distinctive self-folding structures and varying electron-withdrawing properties of the groups at the N terminus, allowing different binding modes and electron/proton transfer.
In the present study, Ulva prolifera, an edible alga, was used to prepare angiotensin-I converting enzyme (ACE) inhibitory peptide. The algae protein was isolated and later hydrolyzed by five commercial enzymes (alcalase, papain, pepsin, trypsin, neutral protease), either individually or in combination. Hydrolysate, with the highest in vitro ACE inhibitory activity, was processed using the Sephadex-G100, ultrafiltration, HPLC-Q-TOF-MS, ADMET screening and molecular docking, respectively. The ACE inhibitory peptide DIGGL with a IC50 value of 10.32 ± 0.96 μM was then identified. The peptide against ACE by a non-competitive mode and mainly attributable to the three Conventional Hydrogen Bonds. It could activate Endothelial nitric oxide synthase activity in NO generation and reduce Endothelin-1 secretion induced by Angiotensin II in Human umbilical vein endothelial cells. Meanwhile, DIGGL could promote mice splenocytes proliferation, which was also effective when co-incubated with Con A or LPS, respectively. Besides, the anti-ACE peptide could remain active during the digestion of gastrointestinal proteases (pepsin-trypsin) in vitro.
Hypertension or elevated blood pressure is a serious medical condition that significantly increases the risks of cardiovascular disease, heart disease, diabetes, stroke, kidney disease, and other health problems, that affect people worldwide. Thus, hypertension is one of the major global causes of premature death. Regarding the prevention and treatment of hypertension with no or few side effects, antihypertensive peptides (AHTPs) obtained from natural sources might be useful as nutraceuticals. Therefore, the search for alternative/novel AHTPs in food or natural sources has received much attention, as AHTPs may be functional agents for human health. AHTPs have been observed in diverse organisms, although many of them remain underinvestigated. The identification of peptides with antihypertensive activity in the laboratory is time- and resource-consuming. Alternatively, computational methods based on robust machine learning can identify or screen potential AHTP candidates prior to experimental verification. In this paper, we propose Ensemble-AHTPpred, an ensemble machine learning algorithm composed of a random forest (RF), a support vector machine (SVM), and extreme gradient boosting (XGB), with the aim of integrating diverse heterogeneous algorithms to enhance the robustness of the final predictive model. The selected feature set includes various computed features, such as various physicochemical properties, amino acid compositions (AACs), transitions, n-grams, and secondary structure-related information; these features are able to learn more information in terms of analyzing or explaining the characteristics of the predicted peptide. In addition, the tool is integrated with a newly proposed composite feature (generated based on a logistic regression function) that combines various feature aspects to enable improved AHTP characterization. Our tool, Ensemble-AHTPpred, achieved an overall accuracy above 90% on independent test data. Additionally, the approach was applied to novel experimentally validated AHTPs, obtained from recent studies, which did not overlap with the training and test datasets, and the tool could precisely predict these AHTPs.
Umami peptides can help reduce the salt content in foods while still maintaining a savory taste. Few studies have reported the bioactivity of umami peptides after consumption. We studied the bioactivities of 12 umami peptides after gastrointestinal digestion. Three umami peptides exhibited Angiotensin I converting enzyme (ACE) inhibitory and antioxidant activity after digestion. Six novel peptides were identified from digestion solutions of the peptides using HPLC-MS/MS. Among them, CC, CCNK, and HCHT had both ACE inhibitory activity (IC50 values were 9.81, 9.00 and 114.99 μM respectively) and antioxidant activity (strong DPPH and ABTS free radical scavenging activities). AHSVRF had strong ACE inhibitory activity. These peptides increased the nitric oxide (NO) concentration and decreased the content of endothelin-1 (ET-1) in a medium of human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner. Experiments with damaged HepG2 cells showed that peptides CC, CCNK, and HCHT have antioxidant activity through their cytoprotective effects and by reducing the reactive oxygen species (ROS) content. The results indicated that umami peptides may provide many health benefits after consumption.
The remarkable growth of therapeutic peptide development in the past decade has led to a large number of market approvals and the market value is expected to hit $25 billion by 2018. This significant market increase is driven by the increasing incidences of metabolic and cardiovascular diseases and technological advancements in peptide synthesis. For this reason, the search for bioactive peptides has also increased exponentially. Many bioactive peptides from food and nonfood sources have shown positive health effects yet, obstacles such as the need to implement efficient and cost-effective strategies for industrial scale production, good manufacturing practices as well as well-designed clinical trials to provide robust evidence for supporting health claims continue to exist. Several other factors such as the possibility of allergenicity, toxicity and the stability of biological functions of the peptides during gastrointestinal digestion would need to be addressed.
Marine red alga Gracilariopsis lemaneiformis is the main cultured seaweed in China with potent economic and ecological value. In this paper, the algal protein was hydrolyzed using trypsin, flavourzyme, papain and alkaline protease. Among them, the trypsin hydrolysate exhibited the highest angiotensin-I-converting enzyme (ACE) inhibitory activity and was fractionated into three molecular weight of >10 kDa, 3–10 kDa and <3 kDa. The <3 kDa fraction showed the highest ACE inhibitory activity of 78.15 ± 1.56% (2.0 mg/mL) and was used for further purification. An ACE inhibitory peptide was isolated from the <3 kDa fraction by Sephadex G-25, G-15 gel chromatography and ÄKTA pure system. The molecular mass and amino acid sequence of the purified peptide were identified as Gln-Val-Glu-Tyr (QVEY; MW, 537.57 Da) by MALDI-TOF/TOF–MS and MALDI-TOF/TOF–MS/MS, respectively. The peptide showed an IC50 value of 474.36 μM (0.255 mg/mL). The present study indicated that the marine red alga G. lemaneiformis can provide good protein sources, and the hydrolyzed bioactive peptides could be a potential source of functional food ingredients against hypertension.
Our previous studies showed that several sipholane triterpenes, sipholenol A, sipholenone E, sipholenol L and siphonellinol D, have potent reversal effect for multidrug resistance (MDR) in cancer cells that overexpressed P-glycoprotein (P-gp/ABCB1). Through comparison of cytotoxicity towards sensitive and multi-drug resistant cell lines, we identified that the semisynthetic esters sipholenol A-4-O-acetate and sipholenol A-4-O-isonicotinate potently reversed P-gp-mediated MDR but had no effect on MRP1/ABCC1 and BCRP/ABCG2-mediated MDR. The results from [3H]-paclitaxel accumulation and efflux studies suggested that these two triterpenoids were able to increase the intracellular accumulation of paclitaxel by inhibiting its active efflux. In addition, western blot analysis revealed that these two compounds did not alter the expression levels of P-gp when treated up to 72 h. These sipholenol derivatives also stimulated the ATPase activity of P-gp membranes, which suggested that they might be substrates of P-gp. Moreover, in silico molecular docking studies revealed the virtual binding modes of these two compounds into human homology model of P-gp. In conclusion, sipholenol A-4-O-acetate and sipholenol A-4-O-isonicotinate efficiently inhibit the P-gp and may represent potential reversal agents for the treatment of multidrug resistant cancers
To determine types and frequency of side effects of antihypertensive drugs in patients with diabetes mellitus (DM) type 2 and hypertension.
We performed a prospective study of 79 patients with DM type 2 and hypertension, randomly selected by systematic sampling, who were followed over a period of six months. Patients were assessed at baseline and once a month measuring following parameters: types of used antihypertensive drugs and frequency of side effects, the values (mmHg) of systolic (SBP) and diastolic blood pressure (DBP).
Out of 79 patients, 48/79 (60.8%) were males and 31/79 (39.2%) were females. The median age in males was 53 years (IQR=48 to 55 years), in females was 53 years (IQR=49 to 56 years). There was no statistically significant difference in median age between males and females (P=0.368). There is a statistically significant difference in the values of SBP [χ2(5)=312.296, P<0.001] and DBP [χ2(5)=216.051, P<0.001] over a period of six months follow-up. The drug side effects were noted in 9/79 (11.4%) patients between 1-2 months, in 6/79 (7.6%) between 2-3 months, in 1/79 (1,3%) between 3-4 months. The most common side effect was cough (11/79 or 13.9%) associated with the combination of ACE inhibitor and thiazide diuretics. In 5/79 (6.3%) patients there were reports of: flushing, palpitations, headache, dizziness and leg edema associated with Ca blockers.
The most common side effect of antihypertensive treatment was cough (13.9%) associated with the combination of ACE inhibitor and thiazide diuretic.
CD146, a cell adhesion molecule, is found in normal and tumor tissues. The level of its expression has been found to directly correlate with tumor progression and metastatic potential. The objective of this study was to investigate the expression of CD146 in esophageal squamous cell carcinoma (ESCC) and its correlation with clinicopathological parameters. Tumor specimens were collected from 63 patients with ESCC who underwent complete resection. We analyzed the CD146 expression levels in ESCC by immunohistochemistry. The expression of CD146 was detected and it was observed to correlate with clinicopathological parameters. Sixty-three cases of normal squamous mucosa were included for comparison. CD146 expression was identified in 46.0% (29/63) of the ESCC samples, and no positive (weak to moderate or moderate to strong) expression was found in the normal squamous epithelium samples (χ(2)=27.248; P<0.0001). CD146 expression was associated with lymph node metastasis (χ(2)=5.117; P=0.024) and advanced clinical stage (χ(2)=4.661; P=0.031). CD146 expression was one of the significant predictors of survival (hazard ratio, 2.838; 95% confidence interval 1.102-7.305). The overexpression of the CD146 gene was one of the important phenotypes and characteristics in ESCC carcinomatous change. We found that CD146 expression was associated with lymph node metastasis and advanced clinical stage, and was an indicator of poor prognosis in ESCC patients. CD146 may prove to be an important tumor marker for the individualized treatment for ESCC.
Polyphenols, a group of complex naturally occurring compounds, are widely distributed throughout the plant kingdom and are therefore readily consumed by humans. The relationship between their chemical structure and intestinal absorption, transport, and first-pass metabolism remains unresolved, however.
Here, we investigated the intestinal absorption and first-pass metabolism of four polyphenol compounds, apigenin, resveratrol, emodin and chrysophanol, using the in vitro Caco-2 cell monolayer model system and in situ intestinal perfusion and in vivo pharmacokinetic studies in rats, so as to better understand the relationship between the chemical structure and biological fate of the dietary polyphenols.
After oral administration, emodin and chrysophanol exhibited different absorptive and metabolic behaviours compared to apigenin and resveratrol. The differences in their chemical structures presumably resulted in differing affinities for drug-metabolizing enzymes, such as glucuronidase and sulphatase, and transporters, such as MRP2, SGLT1, and P-glycoprotein, which are found in intestinal epithelial cells.
This study evaluated the blood pressure effects of administration of once daily oral benazepril hydrochloride, a new angiotensin-converting enzyme (ACE) inhibitor, for mild-to-moderate hypertension. After a 2 to 4 week placebo baseline period, patients with diastolic blood pressure between 95 and 114 mm Hg, were randomized to receive either placebo or benazepril hydrochloride, 5, 10, 20, or 40 mg, once daily in double-blind fashion for 28 days. Blood pressure was measured predose and at 1, 2, 3, 4, 6, 8, 12, 16, 20, and 24 hours after the dose during inpatient observation days at the end of the placebo baseline period, and on the first and last day of the double-blind treatment period; and 24 hours after the dose at weekly outpatient visits. All doses of benazepril hydrochloride resulted in clinically important reductions in diastolic and systolic blood pressures that lasted between 12 and 24 hours after both the first dose, and following the last dose after 4 weeks of treatment. The findings indicate that benazepril hydrochloride may be clinically useful as once-daily monotherapy in many patients with hypertension.
An angiotensin-converting enzyme inhibitory (ACEI) peptide with a median inhibitory concentration (IC50) of 1.26 mg/mL was purified from whey proteins resulting from a fermentation using Lactobacillus plantarum QS670. The peptide was subsequently derived from an αS1-casein, κ-casein, β-lactoglobulin, or serum albumin fraction. Analysis via liquid chromatography tandem mass spectrometry indicated that it had an amino acid sequence of Gly-Ala (GA). The GA dipeptide was also synthesized using an Fmoc solid-phase method. The GA dipeptide exhibited an IC50 of 1.22 mg/mL and was shown to be stable across both temperature (20 to 60°C) and pH (2 to12). Digestive enzymes including pepsin, trypsin, and chymotrypsin had negligible effects on activity. The whey exerted hypotensive effects when fed to spontaneously hypertensive rats (SHR), which exhibited a blood pressure drop of 2.33 kPa. A 4-wk gavage treatment resulted in greater decreases of 7.46 kPa. Results of this study indicate that milk fermented using Lb. plantarum QS306 has potential to be used as a functional food to help prevent or reduce hypertension-associated diseases.
To isolate bioactive broccoli peptides, crude proteins were flocculated from heated juice of broccoli stems and leaves and then hydrolyzed by proteases. Different proteases yielded different peptides with a significant effect on the bio-activities of broccoli peptides. Antioxidant activity of the broccoli peptides was investigated by measuring their DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals scavenging action in comparison to native antioxidants, reduced glutathione (GSH) and soybean peptides. Broccoli peptides (obtained by Neutrase® hydrolysis) at 5.0 mg/mL exhibited 72.8% of radicals scavenging rates, resembling GSH at 1.0 mg/mL (72.1%), and was 2.8 times than that of soybean peptides at 5.0 mg/mL (25.7%). Subsequently, the hypolipidemic activities were measured by oral gastric gavage of broccoli peptides in hyperlipemic golden hamster. Treatment with broccoli peptides (obtained by papain hydrolysis) significantly decreased the serum TC and LDL-C levels (P < 0.01) in experimental rats. The constitution of amino acid and the distribution of molecular weight analysis showed broccoli peptides contained sixteen amino acids and a great percentage of low molecular weight peptides (<1 kDa, 77.67%). By analyzing the amino acid compositions and bio-activities, our results indicate the high nutritive value and possible applications of broccoli peptides for human health.
In the present study, we purified and identified peptides from broccoli protein hydrolysates and evaluated their angiotensin-converting enzyme (ACE) inhibitory activity in vitro and hypotensive effect in vivo. Three ACE inhibitory peptides were isolated and identified as IPPAYTK, LVLPGELAK, and TFQGPPHGIQVER, and their inhibitory IC50 values were 23.5, 184.0, and 3.4 μM, respectively. We then investigated the effect of gastrointestinal digestion on ACE inhibitory activity. We detected almost two times the ACE inhibitory activity of the peptide LVLPGELAK following simulated digestion than prior to digestion. LVLPGE and LAK, two novel peptides exhibiting high ACE inhibitory activity, were discovered following digestion and possessed IC50 values of 13.5 and 48.0 μM, respectively. The hypotensive effect of the peptides was assessed after oral administration to spontaneous hypertensive rats (SHRs). We found that LVLPGE and LAK demonstrated a significant hypotensive effect in vivo. Protein from broccoli may thus constitute a potential antihypertensive peptide source.
Lactobacillus helveticus LB 10 proteinases immobilized with sodium alginate were used to hydrolyze whey protein to produce angiotensin-I-converting enzyme (ACE)-inhibitory peptides. The generated hydrolysates were tested for ACE-inhibitory activity and for their ability to be transported across Caco-2 cell monolayers. Using a response surface method, we determined that a proteinase concentration of 7.55 mg/mL, sodium alginate concentration of 2.03 g/100 mL, and glutaraldehyde concentration of 0.39% were found to be the optimal immobilization conditions. Compared with free proteinase, the immobilized proteinase had significantly higher pH, thermal and storage stability, and reusability. Whey protein hydrolysates were fractionated by gel filtration chromatography and ACE-inhibitory peptide mixtures were transported across Caco-2 cell monolayers in a human intestinal-absorption model. The di- and tripeptides KA, EN, DIS, EVD, LF, AIV, and VFK (half-maximal inhibitory concentrations (mean ± standard deviation) of 1.24 ± 0.01, 1.43 ± 0.04, 1.59 ± 0.27, 1.32 ± 0.05, 1.60 ± 0.39, 2.66 ± 0.02, and 1.76 ± 0.09 mmol/L, respectively) were detected on the basolateral side of the Caco-2 cell monolayer using ultra-performance liquid chromatography-tandem mass spectrometry. These results highlight that ACE-inhibitory peptides are present on the basolateral side of the Caco-2 cell model after transportation of whey protein hydrolysate across the Caco-2 cell membrane.
Hypertension is known as an important factor in cardiovascular diseases. Angiotensin-I-converting enzyme (ACE) inhibitor is one of the synthetic drugs that are widely used to control hypertension. Here, we have prepared and investigated the ACE inhibitory peptide from Ruditapes philippinarum fermented with Bacillus natto. The fermented product obtained under optimized fermentation conditions exhibited ACE inhibitory activity. The ACE inhibitory peptides were purified by ultrafiltration, gel filtration chromatography and RP-HPLC, sequentially. A novel peptide with high ACE inhibitory activity (IC50 of 8.16 μM) was isolated and the amino acid sequence was identified to be Val-Ile-Ser-Asp-Glu-Asp-Gly-Val-Thr-His (VISDEDGVTH) by LC-MS/MS. Line weaver-Burk plots suggested that VISDEDGVTH acts as a competitive inhibitor against ACE. Our In vitro study indicated the stability of VISDEDGVTH against gastrointestinal proteases. In vivo study in rats proved the significant anti-hypertension effect of the peptide. Furthermore, the cellular mechanism of VISDEDGVTH moderating hypertension was investigated. We found that VISDEDGVTH enhanced the release of NO, inhibited the secretion of EF-1, and scavenged ROS in human vascular endothelial cells. Our study suggests that VISDEDGVTH serves an anti-hypertension, anti-inflammatory drugs and as a beneficial ingredient in functional foods and pharmaceuticals.
Food derived angiotensin-I-converting enzyme (ACE)-inhibitory peptides are normally from products fermented by Lactobacillus helveticus but seldom by other lactic acid bacteria. In this study, a novel wild strain L. plantarum 69 was identified genetically and applied to ferment goat milk with high ACE-inhibitory activity, flourished bacterial population, and ideal flavor. The fermentation condition was optimized with the aid of response surface methodology (RSM). The optimal fermentation condition were temperature of 35 °C, CaCl2 concentration of 0.07%, and Tween-80 concentration of 0.04%. The ACE-inhibitory activity of the fermented product reach 88.91% which was approximately close to the predicted 91.68%. Purification was operated by ultrafiltration, macroporous resin DA201-C, gel chromatography, and reverse-phase high performance liquid chromatography (RP-HPLC), and finally exhibited the ACE-inhibitory activity of 91.62%. Goat milk fermented by L69 successfully survived in gastrointestinal tract and maintained high ACE-inhibitory activity.
Food-derived bioactive peptides are promising components for the prevention and treatment of cardiovascular diseases including hypertension. Recently, there has been an increased knowledge about the variety of complex and interrelated mechanisms for blood pressure regulation as well as the potential targets for peptides to exert their antihypertensive effects. Empiric and bioinformatics studies have provided large amounts of data regarding characteristics, structure–activity relationships and bioavailability of antihypertensive peptides through the use of in vitro assays, cell cultures, and animal studies. However, the scarce number of robust clinical trials to prove their efficacy in humans is the main reason of the limited use of antihypertensive peptides as functional foods for promoting health. Further research is needed to overcome the challenges for the application of food-derived antihypertensive peptides as functional ingredients with health benefits in the human body.
The objective of this study was to investigate the mechanisms of the transport of antihypertensive tripeptides LKP (Leu-Lys-Pro) and IQW (Ile-Gln-Trp) derived from egg white using a co-culture system of Caco-2 and HT29 cell monolayers. The results revealed that LKP and IQW have no cytotoxicity to the cell viability after 2 h-incubation, and could be transported intact across co-culture monolayers (apparent permeability coefficient: (18.11 ± 1.57) × 10-8 and (13.21 ± 1.12) × 10-8 cm/s, respectively), and were resistant to peptidase secreted by enterocytes. In addition, the transports were significantly inhibited by dipeptide Gly-Pro (P < 0.05), a competitive substance of peptide transporter 1 (PepT1). The transports from apical to basolateral side were significantly higher than that of the reverse direction (P < 0.05). These results suggest that PepT1 is involved in LKP and IQW transports. The transports were also significantly decreased by theaflavin-3′-O-gallate (P < 0.05), an enhancer of tight junction (TJ), and increased by cytochalasin D (P < 0.05), a disruptor of TJ, but no influenced by wortamanin, a transcytosis inhibitor, suggesting that passive paracellular route via TJs is also involved in LKP and IQW transports, but not transcytosis. In addition, siRNA was also used to knockdown the expression of PepT1, and significantly inhibited the transport (P < 0.05), confirming that PepT1 is involved in transport process. In conclusion, both passive paracellular route via TJ and active route via PepT1 coexist in the transport of antihypertensive LKP and IQW across Caco-2/HT29 co-culture monolayers.
Background:
Hypertension is the leading preventable cause of premature death worldwide. We examined global disparities of hypertension prevalence, awareness, treatment, and control in 2010 and compared secular changes from 2000 to 2010.
Methods:
We searched MEDLINE from 1995 through 2014 and supplemented with manual searches of retrieved article references. We included 135 population-based studies of 968 419 adults from 90 countries. Sex- and age-specific hypertension prevalences from each country were applied to population data to calculate regional and global numbers of hypertensive adults. Proportions of awareness, treatment, and control from each country were applied to hypertensive populations to obtain regional and global estimates.
Results:
In 2010, 31.1% (95% confidence interval, 30.0%-32.2%) of the world's adults had hypertension; 28.5% (27.3%-29.7%) in high-income countries and 31.5% (30.2%-32.9%) in low- and middle-income countries. An estimated 1.39 (1.34-1.44) billion people had hypertension in 2010: 349 (337-361) million in high-income countries and 1.04 (0.99-1.09) billion in low- and middle-income countries. From 2000 to 2010, the age-standardized prevalence of hypertension decreased by 2.6% in high-income countries, but increased by 7.7% in low- and middle-income countries. During the same period, the proportions of awareness (58.2% versus 67.0%), treatment (44.5% versus 55.6%), and control (17.9% versus 28.4%) increased substantially in high-income countries, whereas awareness (32.3% versus 37.9%) and treatment (24.9% versus 29.0%) increased less, and control (8.4% versus 7.7%) even slightly decreased in low- and middle-income countries.
Conclusions:
Global hypertension disparities are large and increasing. Collaborative efforts are urgently needed to combat the emerging hypertension burden in low- and middle-income countries.
Background:
The meat of Kacang goat has potential for production of a protein hydrolysate. Functional ingredients from protein hydrolysate of Kacang goat meat were determined by the consistency of ACE inhibitory activity and antihypertensive effect. This study examined the potency of Kacang goat protein hydrolysate in angiotensin converting enzyme (ACE) inhibition and antihypertensive activity.
Result:
Protein hydrolysates of Kacang goat meat were prepared using sequential digestion of endo-proteinase and protease complex at several concentrations and hydrolysis times. The highest ACE inhibitory activity resulted from a hydrolysate that was digested for 4 h with 5 g kg(-1) of both enzymes. An ACE inhibitory peptide was purified and a novel peptide found with a sequence of Phe-Gln-Pro-Ser (IC50 value of 27.0 µmol L(-1) ). Both protein hydrolysates and a synthesized peptide (Phe-Gln-Pro-Ser) demonstrated potent antihypertensive activities in spontaneous hypertensive rats.
Conclusion:
Protein hydrolysate of Kacang goat meat produced by sequential digestion with endo-proteinase and protease complex has great potential as a functional ingredient, particularly as an antihypertensive agent.
Ile-Trp (IW) and Trp-Leu (WL) are present in enzymatic hydrolysates of whey proteins and act as efficient inhibitors for angiotensin-converting enzyme (ACE) in vitro. Baseline plasma concentrations of IW and WL were analysed to 0.9 ± 0.3 nm for IW and 8.3 ± 1.3 nm for WL. Following administration of 50 mg IW or 100 mg WL to human volunteers (n = 3 for IW and n = 2 for WL, respectively), a significant increase in plasma concentrations to a maximum of 2.4 ± 0.5 nm for IW and 29-36 nm for WL after 0.5 h was observed, followed by rapid elimination. ACE activity in plasma decreased by 32% ± 8% following 50 mg IW administration. Administration of the corresponding amino acids had no effect on ACE activity. Thus, these tryptophan-containing dipeptides may serve as bioactive food additives with beneficial effects for the cardiovascular system.
The aim of this study was to investigate the oral bioavailability and kinetics of the milk casein-derived peptide HLPLP, which had previously demonstrated antihypertensive effect in spontaneously hypertensive rats. HLPLP disposition after single intravenous (4 mg/kg body weight) and oral (40 mg/kg body weight) doses was studied in rats. Plasma concentrations of HLPLP [β-casein fragment f(134-138)], and two derived fragments found after HLPLP administration, LPLP [β-casein fragment f(135-138)] and HLPL [β-casein fragment f(134-137)] were determined by Ultrahigh Performance Liquid Chromatography (UPLC) coupled on line to a Q-TOF instrument. For HLPLP, the elimination half-lives (T1/2β) were 7.95 min after intravenous and 11.7 min after oral administration. The volume of distribution at steady state (Vss = 30.8 L/kg) suggests a considerable uptake of HLPLP into tissues. HPLPL was converted to the peptides, LPLP and HLPL. After HLPLP intravenous administration, the elimination half-lives (T1/2β) for these biotransformed peptides, LPLP and HLPL, were 8.38 and 10.9 min, respectively. After oral administration, HLPLP was rapidly absorbed with an absorption half-life (T1/2a) of 2.79 min. The oral bioavailability of HLPLP was found to be 5.18%. Our study suggest that HLPLP was rapidly absorbed and eliminated after oral administration, biotransformed into smaller fragments LPLP and HLPL, and distributed throughout the body by the circulation blood. The present pharmacokinetic information from a pre-clinical kinetic study in rats can to play an important role in designing future kinetic studies in humans for assessing HLPLP dose-response relationship.
Angiotensin converting enzyme inhibitors (ACE-I) are widely used, effective and well tolerated anti-hypertensive agents. The mechanisms by which those agents act can cause side effects such as decreased blood pressure, hyperkalemia and impaired renal function. ACE-I can induce cough in 5-35% and angioedema in up to 0.7% of the treated patients. Since cough and angioedema are considered class adverse effects, switching treatment to other ACE-I agents is not recommended. Angioedema due to ACE-I has a low fatality rate, although deaths have been reported when the angioedema involves the airways. Here, we review the role of bradykinin in the development of angioedema in patients treated with ACE-I as well as the incidence, risk factors, clinical presentation and available treatments for ACE-I induced angioedema. We also discuss the risk for recurrence of angioedema after switching from ACE-I to angiotensin receptor blockers (ARBs) treatment.
The purpose of this study was to investigate the transepithelial transport and cytoprotective effect of Gln-Ile-Gly-Leu-Phe (QIGLF), an ACE-inhibitory peptide derived from egg white ovalbumin, in human intestinal Caco-2 cell monolayers. The results showed that QIGLF could be absorbed intact though Caco-2 cell monolayers with Papp value of (9.11±0.19) ×10-7 cm/s (transport kinetic parameters: Km: 32.37±12.59 mM, Vmax: 1.23±0.49 μM/min cm2). The transport was not significantly decreased by sodium azide and Gly-Pro, an ATP synthesis inhibitor and a peptide transporter 1 (PepT1) substrate, respectively, suggesting that transport of QIGLF was not energy-dependent and carrier-mediated. In addition, wortmannin, a transcytosis inhibitor, had little effect on the transport, suggesting that endocytosis was not involved in the transport of QIGLF. However, the transport of QIGLF was increased significantly in the presence of cytochalasin D, a tight junction disruptor, suggesting that paracellular transport via tight junctions was the major transport mechanism for intact QIGLF across Caco-2 cell monolayers. Moreover, QIGLF was added to Caco-2 cells followed by addition of H2O2, and exhibited significant cytoprotective effect in Caco-2 cells against oxidative stress induced by H2O2.
This work evaluates, the presence of native antihypertensive peptides in five soybean-based infant formulas (SBIFs). SBIFs peptide extracts (< 10 kDa) and their sub-fractions (5–10 kDa, 3–5 kDa, and < 3 kDa) from a variety of samples were obtained by ultrafiltration and ACE inhibitory activity was determined. The highest activities were observed in the smaller (< 5 kDa) peptide fractions. A set of peptides present in various SBIFs were studied, and identified using HPLC-Q-ToF-MS. Despite ACE inhibitory activity decreasing after in vitro gastrointestinal digestion, it still remained at a high value (IC50 values of 18.2 ± 0.1 and 4.9 ± 0.1 μg/mL). Peptides resisting the action of gastrointestinal enzymes were identified and compared to previously identified peptides, highlighting the presence of peptide RPSYT. This peptide was synthesised, its antihypertensive and antioxidant activity were evaluated, and its resistance to in vitro gastrointestinal digestion and to high processing temperatures were studied.
Hen egg white lysozyme (HEWL) was hydrolysed with trypsin, papain and a combination of the two. The prepared hydrolysates exhibited ACE inhibitory activity. The hydrolysates were fractionated using ultrafiltration and reverse phase-high performance liquid chromatography (RP-HPLC). Three fractions, which showed the highest ACE inhibitory activities, were purified by RP-HPLC. They were the F7 (from papain–trypsin hydrolysate), F8 (from papain hydrolysate) and F3 (from trypsin hydrolysate) fractions. The IC50 values were 0.03, 0.155 and 0.23 mg/ml for F7, F8 and F3, respectively. The F7 fraction was the most potent ACE inhibitor peptide, and was composed of 12 amino acids, Phe-Glu-Ser-Asn-Phe-Asn-Thr-Gln-Ala-Thr-Asn-Arg (MW: 1428.6 Da). Lineweaver–Burk plots suggest that the F7 peptide acts as an uncompetitive inhibitor against ACE. The kinetic parameters (Km, Vmax, and Ki) for the F7 peptide were measured and compared to the control.
Haruan myofibrillar protein was hydrolysed with proteinase K and thermolysin to isolate Angiotensin converting enzyme (ACE) inhibitory peptides. The thermolysin hydrolysate of myofibrillar protein with the highest ACE inhibition activity (IC50=0.033mg/ml) was fractionated by ultrafiltration and size exclusion chromatography to three fractions. Fraction F2 with higher ACE inhibitory activity was separated into five fractions (A–E) using reversed-phased high performance liquid chromatography (RP-HPLC). Fraction C showed 81% inhibition activity and was subjected to HPLC coupled to electrospray ionisation-time-of-flight mass spectrometry (ESI-TOF MS/MS). Two peptide sequences for the most abundant fragments were identified as VPAAPPK (IC50=0.45μM) at 791.155m/z and NGTWFEPP (IC50=0.63μM) at 1085.841m/z. The presence of two proline residues at the C-terminal sequence is responsible for the high ACE inhibitory activity of these peptides. The results suggest that Haruan meat protein hydrolysate is a potent ACE inhibitor and may be used to decrease blood pressure.
According to the National Center for Health Statistics, of 2 471 984 total deaths in the United States in 2008, 616 828 were caused by heart disease and 134 148 were caused by cerebrovascular disease (Table 1). By these statistics, heart disease is the leading cause of death in the United States.1 Worldwide, the Global Burden of Disease study estimated that in 2001, 12.45 million of >56 million total worldwide deaths were caused by cardiovascular disease (CVD) and cerebrovascular disease. Ischemic heart disease was the leading cause of global mortality, accounting for 1.4 million deaths in the developed world and 5.7 million deaths in developing regions.2
View this table:
Table 1.
Leading Causes of Death, United States, 2008
These impressive statistics are used for the design and subsequent evaluation of health policies and interventions, and increasingly, attention is being drawn to the need to redistribute funding on the basis of disease and mortality burden.3 But how much do practitioners know about the strength of data such as these? Many cardiovascular clinicians and researchers consider mortality data to be the most basic type of data on which to make interventions and policy decisions. Although the conclusions drawn from various clinical trials may be challenged, it is generally taken for granted that CVD mortality data in developed countries are valid. But mortality data, like all data, are subject to limitations based on how the data are collected. Furthermore, as the cardiology community begins to focus its attention on the prevalence of CVD in developing countries, it is important to determine how best to assess CVD-associated mortality in settings where most people die at home without death certificates or prior health records. The purpose of this review is to elucidate how mortality statistics are currently collected in both developed and developing countries, the various limitations …
IRW is an ACE inhibitory peptide, derived from egg ovotransferrin. The purposes of the study were to evaluate the stability and transcellular transport of IRW in Caco-2 cell monolayers. The stability and transport of IRW was monitored in apical surface as well from apical (AP) to basolateral (BL) and from basolateral to apical. The results revealed that IRW is resistant against the intestinal peptidase up to 60 min. Transport of IRW was not affected by addition of wortamanin, a transcytosis inhibitor. However in the presence of cytochalasin D, a gap junction disruptor, transport of IRW was significantly increased, suggesting a possible passive transport from AP-BL then transcytosis. Interstingly absorption of IRW from BL-AP was higher than AP-BL suggesting a carrier mediated absorption. Moreover in the presence of glycine sarcosine, a substrate for peptide transporter, transport of IRW was reduced. The above observations showed atypical absorption of IRW in Caco-2 cell monolayers. Henceforth IRW may be used as a possible therapeutic bioactive peptide in food formulations for controlling hypertension.
A commercial casein hydrolysate, which contains peptides RYLGY and AYFYPEL as active molecules, has shown antihypertensive effects after acute and long-term administration. This study examines transepithelial absorption of RYLGY and AYFYPEL and derived digestion fragments using Caco-2, HT29-MTX−6 and co-culture 75 % Caco-2/25 % HT29-MTX−6 as predictive models and RP-HPLC–MS as analytical tool. Peptides RYLGY and AYFYPEL were absorbed intact through cell monolayers, although RYLGY was partly hydrolyzed by intestinal peptidases. Co-culture 75 % Caco-2/25 % HT29-MTX−6 exhibited intermediate properties, with regard to transepithelial electrical resistance, peptide hydrolysis, and absorption of the studied peptides, between Caco-2 and HT29-MTX−6 pure cultures. Interestingly, mucus layer that covered completely HT29-MTX−6 and co-culture monolayers was not a barrier for the absorption of the studied peptides. The apparent permeability values for absorptive transport across Caco-2 monolayers for RYLGY (0.22 × 10−6 cm/s) and AYFYPEL (0.26 × 10−6 cm/s) were similar. These findings highlight that in vivo absorption of antihypertensive peptides RYLGY and AYFYPEL may occur partially as intact peptides.
The angiotensin I-converting enzyme (ACE) inhibitory activities of protein hydrolysates prepared from heads and viscera of sardinelle (Sardinella aurita) by treatment with various proteases were investigated. Protein hydrolysates were obtained by treatment with Alcalase(®), chymotrypsin, crude enzyme preparations from Bacillus licheniformis NH1 and Aspergillus clavatus ES1, and crude enzyme extract from sardine (Sardina pilchardus) viscera. All hydrolysates exhibited inhibitory activity towards ACE. The alkaline protease extract from the viscera of sardine produced hydrolysate with the highest ACE inhibitory activity (63.2±1.5% at 2mg/ml). Further, the degrees of hydrolysis and the inhibitory activities of ACE increased with increasing proteolysis time. The protein hydrolysate generated with alkaline proteases from the viscera of sardine was then fractionated by size exclusion chromatography on a Sephadex G-25 into eight major fractions (P1-P8). Biological functions of all fractions were assayed, and P4 was found to display a high ACE inhibitory activity. The IC50 values for ACE inhibitory activities of sardinelle by-products protein hydrolysates and fraction P4 were 1.2±0.09 and 0.81±0.013mg/ml, respectively. Further, P4 showed resistance to in vitro digestion by gastrointestinal proteases. The amino acid analysis by GC/MS showed that P4 was rich in phenylalanine, arginine, glycine, leucine, methionine, histidine and tyrosine. The added-value of sardinelle by-products may be improved by enzymatic treatment with visceral serine proteases from sardine.
Copyright © 2008 Elsevier Ltd. All rights reserved.
A pilot-scale production was developed to enhance the value of proteins from corn gluten meal (CGM). Corn protein isolate (CPI) with high protein content (90.68%) was obtained through heat treatment of CGM (150 kg) in aqueous alkaline solution. Two-step enzymatic hydrolysis and multistage separation were applied to enrich corn oligopeptides (COP) with low molecular weights, 96.77% of which were less than 1000 Da. The greatest antihypertensive effect of COP treatment in spontaneously hypertensive rats (SHR) was observed at a dose of 0.45 g/kg. One major ACE-inhibitory peptide, Ala-Tyr, was identified and quantified (9.16 ± 0.08 mg/g) from COP. The ACE inhibitory activity of Ala-Tyr (IC50 = 0.037 mg/ml) was over 27 times higher than that of COP (IC50 = 1.020 mg/ml). The results indicate that COP may be a source of natural antihypertensive compounds that could be used for drugs or functional food ingredients.
Peptide inhibitors of angiotensin I-converting enzyme (peptidyldipeptide hydrolase, EC 3.4.15.1) were produced by digesting gelatin with bacterial collagenase. The inhibitors were isolated from the digests with a combination of alcohol fractionation, treatment with Amberlite CG-50 column, gel filtration through Sephadex G-25, and Dowex 50 column and paper chromatography. Nine peptide fractions were purified to apparent homogeneity judging by thin-layer and ion-exchange column chromatography, and amino acid composition.Amino acid sequences of the peptides were determined: 2 were found to be mixtures of peptides and the sequence of another was only partially determined.Six of the peptides were potent inhibitors of the converting enzyme, while the other three were less active. 6 peptides were substrates for the enzyme. The enzyme released a dipeptide, Ala-Hyp from one peptide and was strongly inhibited by this dipeptide. The remainder of the parent peptides was a less effective inhibitor.
Several animal studies have showed that gelatin may be effective for minimizing bone loss in OVX rats with established osteopenia. To gain insight into how cod bone gelatin administration affects bone loss after ovariectomy, studies were carried out focusing on bone quality and the molecular mechanisms. Eighty-four female rats were ovariectomized, 12 sham-operated, divided into six groups of 12 each and treated one week after ovariectomy either with vehicle or cod bone gelatin (0.375, 0.75, 1.5, 3, 6 mg/kg body weight) for 90 days. Bone densitometry, microCT analysis, real-time PCR analysis and biochemical analysis were used at the end of the study. After 90 days, BMD of proximal tibia and femoral neck decreased in OVX rats, whereas the loss of BMD in those regions was prevented at 3 g/kg (P<0.05). However, the BMD of midshaft femurs showed no significant differences. BV/TV, Tb.N. and Tb.Th. in the 3 g/kg group were, respectively, 30.4% (P<0.05), 145.5% (P<0.05) and 81.5% (P<0.05) higher than in the OVX group. A significant decrease was detected in urine CTX, NTX and DPD, suggesting decreased bone resorption. Treatment with 3 g/kg and 6 g/kg cod bone gelatin attenuated the increase in serum IL-1beta, IL-6 and TNF-alpha observed in the OVX group. Real-time PCR showed significantly decreased levels of mRNA expression for RANKL at the dosage of 6 g/kg and the RANKL/OPG mRNA ratio in the 3 g/kg and 6 g/kg group significantly decreased compared to the OVX group (P<0.05). In conclusion, our data confirmed that the cod bone gelatin treatment at 3 g/kg is effective in the prevention of estrogen deficient bone loss by modulating the expression of RANKL and OPG and suppressing the release of proinflammatory cytokines.
When a new drug is developed, one of the first requirements is to establish the correct dose. Unfortunately, in dose-determination studies, not enough lessons have been learned from the past. Pilot studies are often planned without sufficient statistical power, due to an insufficient number of patients and highly variable blood pressure measurements. In the development of the new angiotensin converting enzyme (ACE) inhibitor benazepril, crossover trials were used to obtain useful information. At the end of phase II of the benazepril development, a double-blind crossover study was carried out with 25 patients, and the results made it possible to redefine the 12- and 24-h effects of benazepril in comparison with placebo. Moreover, the crossover trial allowed an investigation of the biological effects of the treatment. In further work, the efficacy of 10 mg benazepril, administered once a day, was confirmed in comparison with captopril and enalapril, with a beta-risk of less than 20%. Since this crossover study yielded reliable data, and there was no carryover effect, a similar crossover design was used to study the interaction between benazepril and nifedipine. In the past, mistakes were made and many antihypertensive drugs were administered in high doses, with no further beneficial effect on blood pressure and an increased risk of side effects. Work described in this paper shows that fewer but better designed and implemented studies can improve the efficiency and value of dose-finding studies for antihypertensive drugs.
In a double-blind, placebo controlled, crossover study 12 patients with essential hypertension received single doses of 5, 10 and 20 mg of cilazapril, a new angiotensin converting enzyme (ACE) inhibitor. All doses similarly and significantly (P less than 0.05) reduced supine and erect blood pressure without increasing heart rate. The hypotensive effect was evident within 1 h, maintained for up to 8 h, with a maximal effect at 6 h. There was no discernible effect on blood pressure at 24 h after dosing. Plasma ACE activity was markedly inhibited to the same extent after all doses, with a peak inhibition of 94-96% at 2-3 h. At 24 h residual inhibition of ACE was 49-54%. Plasma renin activity increased in a dose-dependent manner with a peak at 6 h, and returned to baseline at 24 h. No correlation was found between the reduction in blood pressure and plasma renin activity, either at baseline or following cilazapril. There were no significant changes in plasma noradrenaline and the responses to upright posture and to dynamic exercise were preserved. There was no evidence of impaired exercise performance. Cilazapril is a potent ACE inhibitor with a rapid onset and a prolonged duration of action. These results suggest that peak ACE inhibition is achieved by 5 mg and that lower doses may be useful in clinical practice.
Whey protein was digested with one of seven kinds of proteases at 37 degrees C (trypsin, proteinase K, actinase E, thermolysin, or papain) or at 25 degrees C (pepsin or chymotrypsin) for 24 h. The digested samples were assayed for the inhibitory activity of angiotensin-converting enzyme and for changes in the systolic blood pressure caused in spontaneously hypertensive rats after gastric intubation. The strongest depressive effect on the systolic blood pressure (-55 mm Hg) was observed at 6 h after gastric intubation of the whey protein that was digested by proteinase K. Finally, six peptides were chromatographically isolated from the proteinase K digest by a combination of hydrophobic reversed-phase HPLC and gel filtration. The amino acid sequences and their origins were clarified as follows: Val-Tyr-Pro-Phe-Pro-Gly [beta-casein (CN); f 59-64], Gly-Lys-Pro (beta 2-microglobulin; f 18-20), Ile-Pro-Ala (beta-lactoglobulin; f 78-80), Phe-Pro (serum albumin; f 221-222; beta-CN, f 62-63, f 157-158, and f 205-206), Val-Tyr-Pro (beta-CN; f 59-61), and Thr-Pro-Val-Val-Val-Pro-Pro-Phe-Leu-Gln-Pro (beta-CN; f 80-90). Chemical synthesis of these six peptides confirmed that all peptides, except an undecapeptide, have antihypertensive activity in spontaneously hypertensive rats. The synthetic tripeptide Ile-Pro-Ala, originating from beta-lactoglobulin, showed the strongest antihypertensive activity (-31 mm Hg).
Seven kinds of ripened cheeses (8-mo-aged and 24-mo-aged Gouda, Emmental, Blue, Camembert, Edam, and Havarti) were homogenized with distilled water, and water-soluble peptides were prepared by C-18 hydrophobic chromatography. The inhibitory activity to angiotensin I-converting enzyme and decrease in the systolic blood pressure in spontaneously hypertensive rats were measured before and after oral administration of each peptide sample. The strongest depressive effect in the systolic blood pressure (-24.7 mm Hg) and intensive inhibitory activity to angiotensin I-converting enzyme (75.7%) were detected in the peptides from 8-mo-aged Gouda cheese. Four peptides were isolated by HPLC with reverse-phase and gel filtration modes. Their chemical structures and origins, clarified by combination analyses of protein sequencing, amino acid composition, and mass spectrometry, were as follows: peptide A, Arg-Pro-Lys-His-Pro-Ile-Lys-His-Gln [alpha(s1)-casein (CN), B-8P; f 1-9]; peptide B, Arg-Pro-Lys-His-Pro-Ile-Lys-His-Gln-Gly-Leu-Pro-Gln (alpha(s1)-CN, B-8P; f 1-13); peptide F, Tyr-Pro-Phe-Pro-Gly-Pro-Ile-Pro-Asn (beta-CN, A2-5P; f 60-68); and peptide G, Met-Pro-Phe-Pro-Lys-Tyr-Pro-Val-Gln-Pro-Phe (beta-CN, A2-5P; f 109-119). Peptides A and F, which were chemically synthesized, showed potent angiotensin I-converting enzyme inhibitory activity with little antihypertensive effects.
The age-specific relevance of blood pressure to cause-specific mortality is best assessed by collaborative meta-analysis of individual participant data from the separate prospective studies.
Information was obtained on each of one million adults with no previous vascular disease recorded at baseline in 61 prospective observational studies of blood pressure and mortality. During 12.7 million person-years at risk, there were about 56000 vascular deaths (12000 stroke, 34000 ischaemic heart disease [IHD], 10000 other vascular) and 66000 other deaths at ages 40-89 years. Meta-analyses, involving "time-dependent" correction for regression dilution, related mortality during each decade of age at death to the estimated usual blood pressure at the start of that decade.
Within each decade of age at death, the proportional difference in the risk of vascular death associated with a given absolute difference in usual blood pressure is about the same down to at least 115 mm Hg usual systolic blood pressure (SBP) and 75 mm Hg usual diastolic blood pressure (DBP), below which there is little evidence. At ages 40-69 years, each difference of 20 mm Hg usual SBP (or, approximately equivalently, 10 mm Hg usual DBP) is associated with more than a twofold difference in the stroke death rate, and with twofold differences in the death rates from IHD and from other vascular causes. All of these proportional differences in vascular mortality are about half as extreme at ages 80-89 years as at ages 40-49 years, but the annual absolute differences in risk are greater in old age. The age-specific associations are similar for men and women, and for cerebral haemorrhage and cerebral ischaemia. For predicting vascular mortality from a single blood pressure measurement, the average of SBP and DBP is slightly more informative than either alone, and pulse pressure is much less informative.
Throughout middle and old age, usual blood pressure is strongly and directly related to vascular (and overall) mortality, without any evidence of a threshold down to at least 115/75 mm Hg.
The incidence of bovine spongiform encephalopathy has resulted in marine collagen hydrolysate (low-molecular-weight gelatin) being sold as supplements and cosmetics in Japan. Shark skin collagen is one of the important sources of marine collagen. We examined the effect of shark skin gelatin in an osteoporosis model animal.
Shark skin gelatin was orally administered to ovariectomized rats with a low-protein diet. Bone mineral density of the right femur was measured. Collagen and glycosaminoglycan in the tibial end were extracted and analyzed by western blotting and cellulose acetate membrane electrophoresis, respectively.
Administering collagen to the ovariectomized rats resulted in the bone mineral density of the femur epiphysis being higher than that in the sham-operated rats. The contents of type I collagen and glycosaminoglycan in the epiphysis were increased by administering shark skin gelatin.
These results indicated that shark skin gelatin would be useful as a dietary supplement for treating osteoporosis.
Angiotensin converting enzyme (ACE) inhibitory peptides are biologically active peptides that play a very important role in blood pressure regulation. In previous experiments, we obtained an ACE inhibitory peptide Val-Leu-Pro-Val-Pro (VLPVP) by DNA recombinant technology. The purpose of this study was to examine the bidirectional transport of VLPVP by using the human intestinal Caco-2 monolayers. The permeability coefficient ( P app) values of VLPVP over 4-8 mmol/L ranged from 7.44 x 10(-8) to 1.35 x 10(-6) cm/s for apical (AP) to basolateral (BL) transport, while the P app values for BL to AP flux were significantly lower than those for the AP to BL flux, with efflux ratio values of 0.74-0.13 over 4-8 mM. Preincubation of the paracellular transport enhancer (sodium deoxycholate), the inhibitor of multidrug resistant protein (MK-571), or sodium azide stimulated efflux of VLPVP significantly ( p < 0.01); these results indicate that the transport of VLPVP across Caco-2 monolayers was involved in paracellular diffusion and MRP2 transport.
Enzyme (ACE) Inhibitory and Antioxidant Activity of Umami Peptides after In Vitro Gastrointestinal Digestion
- I Angiotensin
- Converting
Angiotensin I Converting Enzyme (ACE) Inhibitory and Antioxidant
Activity of Umami Peptides after In Vitro Gastrointestinal Digestion.
J. Agric. Food Chem. 2020, 68, 8232−8241.
Using Caco-2 and HT29 Coculture Monolayers
Using Caco-2 and HT29 Coculture Monolayers. J. Agric. Food Chem.
2017, 65, 7406−7414.
Diurnal blood perssure in patients with mild-to-moderate hypertension treated with once-daily benazepril
- W Weinberger
- B Henry
- L Keneth
- L George
- M Catherine
- P Arturo
- Z Philip
- D Jacqueline
- G Lyn
- B David
- W John
Weinberger, W.; Henry, B.; Keneth, L.; George, L.; Catherine,
M.; Arturo, P.; Philip, Z.; Jacqueline, D.; Lyn, G.; David, B.; John, W.
Diurnal blood perssure in patients with mild-to-moderate hypertension treated with once-daily benazepril. Clin. Pharmacol. Ther.
1990, 47, 608−617.