Highest Angiotensin-converting Enzyme Inhibition Research Articles

Antihypertensive mechanism of the medicine food homology compound solution with high ACE inhibition rate based on network pharmacology and molecular docking

Certain instances of medicine food homology (MFH) have an antihypertensive effect, which has a therapeutic effect on hypertension, but their mechanism in treating hypertension and improving blood pressure is still unclear. The objective of this study is to analyze the potential bioactive substances and the hypotensive mechanism by which the MFH compound solution (Hawthorn:Lycium barbarum:Cassia = 4:1:1) with a high angiotensin-converting enzyme (ACE) inhibition rate. This will be achieved through the use of network pharmacology and molecular docking techniques, which will be further validated through experimental testing. The key components in the MFH compound solution were obtained by constructing the component-disease target network, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to explore the pathways of the MFH compound solution participating in anti-hypertension. The content of the main active ingredients in the MFH compound solution was identified by high-performance liquid chromatography (HPLC). The main active components were quercetin, beta-sitosterol, stigmasterol, kaempferol, and isorhamnetin, while the identified core genes were AKT1 and TP53. Through pathway analysis, the mechanisms of the MFH compound solution against hypertension may be Lipid and atherosclerosis, Calcium signaling pathway, PI3K-AKT signaling pathway, etc. Moreover, the molecular docking of five key compounds and the top five targets verified the reliability of network pharmacology results. HPLC analysis revealed that these five active substances were detected in the MFH compound solution, where kaempferol was the most abundant. This study revealed that the MFH compound exerted a hypotensive effect through multiple targets and pathways.

Anti-Hypertensive and Anti-Hypercholesterolemic Effects of Protein Hydrolysates from (Phaseolus vulgaris) L. in Functional Beverage

The study aimed to formulate a functional beverage from common bean seeds, isolate the proteins and evaluate their anti-hypertensive and anti-cholesterolemic properties. White common beans (Phaseolus vulgaris L.) mature seeds were used to prepare the beverage. Proteins isolated from the beverage were subjected to digestion with pepsin and combined enzymes including trypsin, thermolysin, and chymotrypsin. The unhydrolyzed beverage and protein hydrolysates were subsequently tested for Angiotensin Converting Enzyme (ACE) inhibition and cholesterol micellar solubility inhibition. The results showed that both unhydrolyzed and hydrolyzed proteins exhibited blood pressure and cholesterol-lowering properties, with high ACE inhibition (77.60%) and cholesterol micellar solubility inhibition (27.38%). The formulated functional beverage from white common bean seeds has potential for preventing hypertension and hypercholesterolemia. This study offers a theoretical foundation for the formulation of functional beverages or bean-based food products by food companies.

Potential antihypertensive activity of novel peptides from green basil leaves

Hypertension is among the risk factors of death globally. Novel antihypertensive peptides are alternative choices of antihypertensive assistance. This study aimed to discover novel antihypertensive peptides from green basil leaves. Two bioactive peptides with high angiotensin-converting enzyme inhibition (Asp-Leu-Ser-Ser-Ala-Pro; peptide 1) and antioxidant (Asp-Ser-Val-Ser-Ala-Ser-Pro; peptide 2) activities were gavaged to male Wistar rats induced with NG-nitro-l-arginine methyl-ester (L-NAME). L-NAME-treated rats (HT) had decreased body weights and levels of nitrite and nitrate, which are metabolites of nitric oxide. The levels of their glucose and liver function indicators increased as compared to normal rats. HT rats receiving antihypertensive drugs (HTD) showed higher low-density lipoprotein and low-density lipoprotein/high-density lipoprotein levels than HT rats. Peptide 1 seems to benefit the rat lipid profiles, liver functions, antioxidant, nitrite, nitrate, and angiotensin II peptide levels but not peptide 2. In conclusion, our findings indicate the antihypertensive potential related to vasodilation of peptides from green basil leaves.Graphical

Identification and Effects of Skim Milk-Derived Bioactive Antihypertensive Peptides

Bioactive peptides are generated during milk fermentation or enzymatic hydrolysis. Lactobacillus (L) helveticus is commonly used to produce some types of fermented milk products. Fermented milk derived bioactive peptides are known to be beneficial in human health. Anti-hypertensive peptides play a dual role in the regulation of hypertension through the production of the vasoconstrictor angiotensin II and its inactivation of the vasodilator bradykinin. MALDI MS/MS, nano-LC/MS/MS and RP-HPLC were used to isolate peptides showing angiotensin converting enzyme inhibition (ACE-I) from 12% fermented skim milk using a combination of L. helveticus and Flavourzyme®. The fermentation procedure facilitated the identification of 133 anti-hypertensive peptides and 75% short chain amino acids, and the three with the highest ACE-I activity reduced blood pressure in a rat model of hypertension. The freeze- dried extract was supplemented in rodent chow. In this study 14-week-old male spontaneously hypertensive rats were fed for 10 weeks with the identified peptides added to chow and compared to controls supplemented with skim milk powder. Blood pressure (BP) decreased significantly (p < 0.05) from 6 to 10 weeks of FS groups (120/65 mmHg) compared with the NFS control groups, where the BP increased significantly (220/150 mmHg) (p < 0.05). The F6 fraction provided bioactive peptides with stronger antihypertensive properties than other fractions. Skim milk fermented by L. helveticus and Flavourzyme® generates several bioactive peptides which have a blood pressure lowering effect in hypertensive disease.

Bioactivity and peptide profile of whey protein hydrolysates obtained from Colombian double-cream cheese production and their products after gastrointestinal digestion

Peptides obtained from whey proteins have been associated with different biological properties, but most peptides are usually degraded during the digestive process. In this work, hydrolysates were prepared from a whey protein concentrate obtained by ultrafiltration of Colombian traditional cheese whey and subsequent enzymatic hydrolysis using alcalase, chymotrypsin and flavourzyme. The antioxidant and angiotensin-converting enzyme (ACE) inhibitory properties were evaluated, and peptide profile was determined by ultra-high pressure liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Changes in the above biological properties and peptide profile after simulated gastrointestinal digestion were then investigated. Before enzymatic hydrolysis, the alcalase hydrolysate showed higher 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity, whereas an inhibition greater than 85% of ACE activity was observed for the alcalase and chymotrypsin hydrolysates. In both tests, the flavourzyme hydrolysates showed lower activities. Different changes in the above biological activities were observed after gastrointestinal digestion of the alcalase and chymotrypsin hydrolysates: ABTS radical scavenging ability increased, whereas ACE inhibitory capacity decreased significantly. The alcalase hydrolysate obtained from ultrafiltrated whey protein concentrate showed high antioxidant and ACE inhibition capacities and higher survivability of peptides after in vitro gastrointestinal digestion.

Assessment of Techno-Functional and Nutraceutical Potential of Tomato (Solanum lycopersicum) Seed Meal.

Tomato (Solanum lycopersicum) is a widely consumed fruit all around the world. The industrial exploitation of tomato generates a lot of waste. Most of the utilization of tomato seeds waste is focused on animal feeding, as well as a food ingredient aimed to increase the protein content, and raw material for some organic bioactive component extraction. The aim of this work was to evaluate the techno-functional properties of tomato seed meal (TSM) and its nutraceutical properties after applying defatting processing (TSMD), and to evaluate the nutraceutical properties after a fermentation processing (TSMDF) by Lactobacillus sp. The results showed that, at alkaline conditions (pH 8–9), the techno-functional properties for TSM and TSMD improved. In comparison with TSM, TSMD showed higher water holding capacity (WHC ≈32%), higher oil holding capacity (OHC ≈13%), higher protein solubility (49–58%), more than 10 times foaming activity (FA), more than 50 times foam stability (Fst), as well as an improved emulsifying activity (EA) and emulsion stability (Est) wich were better at pH 9. Regarding the nutraceutical properties, after 48 h of fermentation (TSMDF), the antioxidant activity was doubled and a significant increase in the iron chelating activity was also observed. During the same fermentation time, the highest angiotensin-converting enzyme inhibition (ACEI) was achieved (IC50 73.6 μg/mL), more than 10 times higher than TSMD, which leads to suggest that this fermented medium may be a powerful antihypertensive. Therefore, the strategy proposed in this study could be an option for the exploitation of tomato wastes.

New sauces produced by koji fermentation of kamaboko show acceptable sensory characteristics, improved antioxidant activities, and high angiotensin-converting enzyme inhibition

In our previous study, kamaboko was fermented in koji to prolong its shelf life and to increase its health-promoting effects. After fermentation, the texture of the kamaboko became cheese- or tofuyo-like. In the present study, sauces were produced by the fermentation of kamaboko in fermentation beds of wheat (WS), rice (RS), brown rice (BS), or soybean koji (SS), and their sensory qualities examined. WS, RS and BS had similar qualities to commercial oyster sauce. Fried cabbage with RS had significantly better overall acceptance than fried cabbage with oyster sauce. SS had significantly higher ash, protein and fat contents, and significantly lower carbohydrate contents than WS, RS, and BS. Free amino acid contents increased following fermentation for all sauces, and were highest in SS. The sugar contents of WS, RS, and BS were significantly higher than that of SS. SS had the highest phenolic content followed by BS, WS and RS. Antioxidant activity and angiotensin-converting enzyme (ACE) inhibition were highest in SS. All the new sauces had significantly higher free amino acid contents than the equivalent fermentation beds without kamaboko.

Structural and molecular bases of angiotensin-converting enzyme inhibition by bovine casein-derived peptides: an in silico molecular dynamics approach

The angiotensin-converting enzyme (ACE) plays a key role in blood pressure regulation process, and its inhibition is one of the main drug targets for the treatment of hypertension. Though various peptides from milk proteins are well-known for their ACE-inhibitory capacity, research devoted to understand the molecular bases of such property remain scarce, specifically for such peptides. Therefore, in this work, computational molecular docking and molecular dynamics calculations were performed to enlighten the intermolecular interactions involved in ACE inhibition by six different casein-derived peptides (FFVAPFPEVFGK, FALPQYLK, ALNEINQFYQK, YLGYLEQLLR, HQGLPQEVLNENLLR and NAVPITPTLNR). Two top ranked docking poses for each peptide (one with N- and the other C-terminal peptide extremity oriented towards the ACE active site) were selected for dynamic simulations (50 ns; GROMOS53A6 force field), and the results were correlated to in vitro ACE inhibition capacity. Two molecular features appeared to be essential for peptides to present high ACE inhibition capacity in vitro: i) to interact with the S1 active site residues (Ala354, Glu384, and Tyr523) by hydrogen bonds; ii) to interact with Zn2+ coordinated residues (His383, His387, and Glu411) by short-lenght hydrogen bonds, as observed in the cases of ALNEINQFYQK (IACE = 80.7%), NAVPITPTLNR (IACE = 80.7%), and FALPQYLK (IACE = 79.0%). Regardless of the temporal stability of these strong interactions, they promoted some disruption of Zn2+ tetrahedral coordination during the molecular dynamics trajectories, and were pointed as the main reason for the greatest ACE inhibition by these peptides. On the other hand, peptides with intermediate inhibition capacity (50% < IACE < 45%) interacted mainly by weaker interactions (e.g.: electrostatic and hydrophobic) with the Zn2+ coordinated residues, and were not able to change significantly its tetrahedral coordination structure. These findings may: i) assist the discrimination in silico of “good” and “bad” ACE-inhibitory peptides from other food sources, and/or ii) aid in designing de novo new molecules with ACE-inhibitory capacity. Communicated by Ramaswamy Sarma

In vitro antioxidant and anti-inflammatory activity of chaya extracts (Cnidoscolus aconitifolius (Mill.) I.M. Johnst)

Introduction: noncommunicable diseases (NCDs) are the main cause of death worldwide. Secondary metabolites from plant sources such as Cnidoscolus aconitifolius may be used as adjuvants in the prevention of diseases related to oxidative stress and inflammation such as NCDs. Objective: the in vitro antioxidant and anti-inflammatory activities associated with biologically active compounds in C. aconitifolius extracts were evaluated. Method: the contents of phenols, flavonoids, flavonones and hydroflavonoles were determined. The potential antioxidant activity was determined with 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, and angiotensin-converting enzyme (ACE) activity. For anti-inflammatory activity quantitative PCR and enzyme-linked immunosorbent assay (ELISA) tests were used in macrophages derived from THP-1 monocytes and stimulated with LPS. Results: the aqueous extract recorded the highest phenolic content (70.61  0.07 g/100 g of extract), and the ethanolic extract registered the highest content in flavonoids (47.76  4.84 g/100 g of extract), flavonones and dihydroflavonoles (70.10  7.29 g/100 g of extract). The acetone extract obtained the highest DPPH inhibition (49.85 ± 5.30%), while the ethanolic extract showed the highest ABTS inhibition (41.01 ± 3.81%). The etanolic and aqueous extracts had the highest ACE inhibition. The ethanolic extract had the highest anti-inflammatory activity, decreasing gene expression for TNF- by 39.78% and for IL-6 by 97.81%, and their production by 46% and 48.38%, respectively, in macrophages stimulated with LPS. Conclusion: these extracts demonstrated in vitro their antioxidant and anti-inflammatory potential due to their content of bioactive compounds.

Identification of Hypotensive Biofunctional Compounds of Coriandrum sativum and Evaluation of Their Angiotensin-Converting Enzyme (ACE) Inhibition Potential.

The aim of this study was to identify and characterize the bioactive compounds of Coriandrum sativum responsible for the treatment of hypertension and to explore their mechanism of action as angiotensin-converting enzyme (ACE) inhibitors. Bioactive fractions like alkaloids, flavonoids, steroids, and tannins were extracted and evaluated for their ACE inhibition potential. Among them, only flavonoid-rich fraction showed high ACE inhibition potential with IC50 value of 28.91 ± 13.42 μg/mL. The flavonoids were characterized through LC-ESI-MS/MS. Seventeen flavonoids were identified in this fraction of Coriandrum sativum in negative ionization mode which includes pinocembrin, apigenin, pseudobaptigenin, galangin-5-methyl ether, quercetin, baicalein trimethyl ether, kaempferol dimethyl ether, pinobanksin-5-methylether-3-O-acetate, pinobanksin-3-O-pentenoate, pinobanksin-3-O-phenylpropionate, pinobanksin-3-O-pentanoate, apigenin-7-O-glucuronoide, quercetin-3-O-glucoside, apigenin-3-O-rutinoside, rutin, isorhamnetin-3-O-rutinoside, and quercetin dimethyl ether-3-O-rutinoside, while six flavonoids including daidzein, luteolin, pectolinarigenin, apigenin-C-glucoside, kaempferol-3-7-dimethyl ether-3-O-glucoside, and apigenin-7-O-(6-methyl-beta-D-glucoside) were identified in positive ionization mode. The results of this study revealed that Coriandrum sativum is a valuable functional food that possesses a number of therapeutic flavonoids with ACE inhibition potential that can manage blood pressure very efficiently.

Angiotensin-converting enzyme (ACE) inhibitory potential of standardized Mucuna pruriens seed extract

Context: Mucuna pruriens Linn. (Fabaceae) is a tropical legume, traditionally used for controlling blood pressure. Inhibition of angiotensin-converting enzyme (ACE) is one of the successful strategies for controlling hypertension.Objective: The present study evaluated the ACE inhibition potential of the standardized extract of M. pruriens seeds.Materials and methods: Standardization of the extract and its fractions were carried out by RP-HPLC method [methanol and 1% v/v acetic acid in water (5:95 v/v)] using levodopa as a marker. The ACE inhibition activity of the extract and fractions was evaluated at different concentrations (20, 40, 60, 80, and 100 µg/mL) using the HPLC-DAD and the UV spectrophotometric method. The liberation of hippuric acid (HA) from hippuryl-l-histidyl-l-leucine (HHL) was estimated in the spectrophotometric method and RP-HPLC assay at 228 nm.Results: Methanol extract and aqueous fraction showed a maximum activity with IC50 values of 38.44 ± 0.90 and 57.07 ± 2.90 µg/mL (RP-HPLC), and 52.68 ± 2.02 and 67.65 ± 2.40 µg/mL (spectrophotometry), respectively.Discussion: The study revealed that the aqueous extract contains the highest amount of levodopa. Eventually the methanol extract showed highest ACE inhibition activity except levodopa alone. It was further observed that the inhibition was altered with respect to the change in the content of levodopa in the extract. Thus, it can be assumed that levodopa may be responsible for the ACE inhibition activity of M. pruriens seeds.Conclusion: It can be concluded that M. pruriens seed is a potential ACE inhibitor can be explored further as an effective antihypertensive agent.

Discovery of new angiotensin converting enzyme (ACE) inhibitors from medicinal plants to treat hypertension using an in vitro assay

Background and purpose of the studyAngiotensin converting enzyme (ACE) inhibitors plays a critical role in treating hypertension. The purpose of the present investigation was to evaluate ACE inhibition activity of 50 Iranian medicinal plants using an in vitro assay.MethodsThe ACE activity was evaluated by determining the hydrolysis rate of substrate, hippuryl-L-histidyl-L-leucine (HHL), using reverse phase high performance liquid chromatography (RP-HPLC). Total phenolic content and antioxidant activity were determined by Folin-Ciocalteu colorimetric method and DPPH radical scavenging assay respectively.ResultsSix extracts revealed > 50% ACE inhibition activity at 330 μg/ml concentration. They were Berberis integerrima Bunge. (Berberidaceae) (88.2 ± 1.7%), Crataegus microphylla C. Koch (Rosaceae) (80.9 ± 1.3%), Nymphaea alba L. (Nymphaeaceae) (66.3 ± 1.2%), Onopordon acanthium L. (Asteraceae) (80.2 ± 2.0%), Quercus infectoria G. Olivier. (Fagaceae) (93.9 ± 2.5%) and Rubus sp. (Rosaceae) (51.3 ± 1.0%). Q. infectoria possessed the highest total phenolic content with 7410 ± 101 mg gallic acid/100 g dry plant. Antioxidant activity of Q. infectoria (IC50 value 1.7 ± 0.03 μg/ml) was more than that of BHT (IC50 value of 10.3 ± 0.15 μg/ml) and Trolox (IC50 value of 3.2 ± 0.06 μg/ml) as the positive controls.ConclusionsIn this study, we introduced six medicinal plants with ACE inhibition activity. Despite the high ACE inhibition and antioxidant activity of Q. infectoria, due to its tannin content (tannins interfere in ACE activity), another plant, O. acanthium, which also had high ACE inhibition and antioxidant activity, but contained no tannin, could be utilized in further studies for isolation of active compounds.

Response surface optimization of angiotensin converting enzyme inhibition of milk protein concentrate hydrolysates in vitro after ultrasound pretreatment

Abstract Studies were conducted on ultrasound pretreatment of milk protein concentrate (MPC) before enzyme hydrolysis in order to produce hydrolysates with potent angiotensin converting enzyme (ACE) inhibitory activity. The effects of three independent variables of ultrasound pretreatment time (min), hydrolysis time (h) and enzyme-to-substrate ratio (%) on ACE inhibition as determined by central composite rotatable design were investigated in vitro. Optimization was achieved by response surface method. All the independent variables showed significance at 95% confidence level in contributing to ACE inhibition. According to response surface analysis, the optimum conditions for producing hydrolysates with the highest ACE inhibition were ultrasound pretreatment time, hydrolysis time and enzyme-to-substrate ratio of 4.11 min, 2.32 h and 2.33%, respectively. Under these optimal conditions, the theoretical ACE inhibition was 0.044 mg mL− 1. Model validation yielded satisfactory results indicating relevance of the model to explain ACE inhibition while ultrasound pretreatment showed strongest effect on ACE inhibition of MPC hydrolysates. Industrial relevance Milk protein concentrate has reportedly produced inferior bioactive compounds when compared to other milk proteins such as whey protein concentrate and sodium caseinate. Through the use of ultrasound pretreatment, milk protein concentrate can be used to produce more potent ACE inhibitory fractions comparable to those from non-aggregated milk protein sources. The use of short ultrasound pretreatment time offers an attractive route for industrial production of bioactive compounds from milk protein concentrate and other complex protein sources.

Angiotensin Converting Enzyme Inhibitory Effect of Standardised Extracts from Various Varieties of Ficus Deltoidea

Ficus deltoidea (Moraceae), Mas cotek, is a local medicinal plant which has been used for its health benefits including antioxidant, improving blood circulation and anti-hypertension effects. This study aims to determine the vitexin and isovitexin content in various varieties of F. deltoidea, and to study the extract’s inhibitory effect on angiotensin converting enzyme (ACE) activity as anti-hypertension marker. Five varieties were studied including F. deltoidea var deltoidea, F. deltoidea var. angustifolia, F. deltoidea var tranguensis, F. deltoidea var. Telinga Beruk, and F. deltoidea var. Tapak Itik. Five extracts were prepared; water, methanolic, ethanolic, 50% methanolic and 50% ethanolic, and ACE inhibitory effect was studied in vitro. Vitexin and isovitexin concentration was in the range 0.001–0.35% and 0.001–7.025% (w/w), respectively. The highest ACE inhibition was obtained from F. deltoidea var. Tapak Itik (FD-TI) extracts where the 50% ethanolic and 50% methanolic extracts showed the most promising results. A bivariate correlation analysis may indicate existence of relation between vitexin in FD extracts and the ACE inhibition (r = 0.58), whereas the isovitexin results do not show any relationship (r= -0.06). The median inhibitory concentration (IC50) of the 50% ethanolic extract of FD-TI was 22±3.8μg/ml, and that of vitexin and isovitexin was 3.1±0.5μg/ml, 18.6±1.3μg/ml, respectively. Our results showed the ACE inhibitory effect is partly due to existence of vitexin but not isovitexin, and the 50% ethanolic extract of the F. deltoidea var. Tapak Itik as a possible antihypertension candidate.

Activity-guided discovery of (S)-malic acid 1'-O-β-gentiobioside as an angiotensin I-converting enzyme inhibitor in lettuce (Lactuca sativa).

Angiotensin-converting enzyme (ACE), playing a crucial role in the renin angiotensin aldosterone system, is well-known to catalyze the conversion of the decapeptide angiotensin I into the physiologically active octapeptide angiotensin II, triggering blood pressure increasing mechanisms. To meet the demand for natural phytochemicals as antihypertensive agents in functional food development, extracts prepared from a series of vegetables were screened for their ACE-inhibitory activity by means of a LC-MS/MS-based in vitro assay. By far the highest ACE inhibition was found for a lettuce extract, in which the most active compound was located by means of activity-guided fractionation. LC-MS, NMR spectroscopy, and hydrolysis experiments followed by ion chromatography led to the unequivocal identification of the ACE inhibitor as the previously not reported (S)-malic acid 1'-O-β-gentiobioside. This glycoside represents a novel class of ACE-inhibiting phytochemicals with a low IC(50) value of 27.8 μM. First incubation experiments in saliva and aqueous hydrochloric acid demonstrated the stability of (S)-malic acid 1'-O-β-gentiobioside against salivary glycosidases and stomach acid.

Effect of extrusion process on antioxidant and ACE inhibition properties from bovine haemoglobin concentrate hydrolysates incorporated into expanded maize products

Extrusion process has been widely used for the development of many functional foods. The aim of this study was to assess the effect of extrusion process on antioxidant and angiotensin-converting enzyme (ACE) inhibition properties from bovine haemoglobin concentrate (BHC) hydrolysates (P, FC, PF and FCF). Extrusion was carried out with a Brabender single screw extruder. The ACE inhibition and the antioxidant capacity (AC) were estimated by the inhibition of the ACE and ABTS+√ radical cation expressed as Trolox equivalent antioxidant capacity (TEAC), respectively. The ACE inhibition and TEAC values from hydrolysates were significantly higher than that from BHC. The highest ACE inhibition corresponded to P hydrolysate and the highest TEAC corresponded to PF and FCF hydrolysates. The ACE inhibition and AC from extruded products with added hydrolysates were higher than that from maize control; however, the extrusion process modified both ACE inhibition and AC formerly present in hydrolysates.

Preparation and antihypertensive activity of peptides from Porphyra yezoensis

This research was to develop a antihypertensive peptide, an efficient angiotensin converting enzyme (ACE) inhibitor (ACEI), from Porphyra yezoensis. Seven commercial enzymes were screened and then enzymatic hydrolysis conditions were optimised. The results showed that alcalase was the most effective for hydrolysis and its optimum conditions for achieving the highest antihypertensive activity of peptide were 1.5% substrate, 5% alcalase, pH 9.0, and temperature of 50 °C at a hydrolysis time of 60 min. The antihypertensive peptide produced under the optimum conditions had a high ACE inhibition rate of 55.0% and a low IC 50 value of 1.6 g/l and remained at high stability at temperatures of 4, 25, and 37 °C, pH values of 2.0 and 8.0, and after pepsin and trypsin treatments. Major proteins from P. yezoensis were glutelin, albumin, and gliadin. The albumin and glutelin had higher hydrolysis rates than the gliadin, but the IC 50 value of glutelin was the lowest, which indicated that the antihypertensive peptide from glutelin was more functional.

Production and characterization of angiotensin converting enzyme (ACE) inhibitory peptides from apricot (Prunus armeniaca L.) kernel protein hydrolysate

Six different proteases (Flavourzyme®, Neutrase®, Protamex®, Alcalase® 2.4L, Proleather® FG-F, and papain) were employed to hydrolyze apricot kernel protein (AKP). Alcalase® is an inexpensive and non-specific protease that has been shown to be useful for the generation of bioactive peptides from AKP. Alcalase® 2.4L was selected for further study on enzymatic preparation of ACE inhibitory peptide from AKP. After 60-min hydrolysis, the highest ACE inhibition was 82 ± 0.14%. Results of molecular weight distribution revealed that most of ACE inhibition activity was probably attributed to low-molecular weight peptide fraction ranging from 200 to 900 Da. Ultrafiltration on membranes with several molecular weight cutoffs (MWCFs) demonstrated that most of the ACE inhibitory activity was due to peptides with a less than 1,000 Da molecular weight: the IC50 value of the 1-kDa ultrafiltrate was 0.15 ± 0.007 mg mL−1, while it was 0.378 ± 0.015 mg mL−1 before ultrafiltration. Additionally, further separation and purification of the ACE inhibitory peptides were carried out using gel filtration and C18 RP-HPLC. The result of research can be used to optimize AKP enzymatic hydrolysis for producing ACE inhibitory peptides which could be used for food industry and nutraceuticals.

천마추출물의 성분분석 및 in vitro 생물활성에 관한 연구

본 연구는 천마의 성분과 생리활성을 규명하기 위하여 성분분석과 다양한 생리활성 (암세포 생육 저해효능, 항균력, <TEX>${\alpha}$</TEX>-glucosidasege활성 저해효능, angiotensin converting enzyme 저해효능, glutathion S-transferase 활성)을 검토하였다. 천마의 일반성분은 조단백질 5.4%, 조회분 2.6%, 조지방 3.6%, 조섬유 3.3%, 수분 8.1%, 전당이 77%이었으며, 무기질함량은 칼륨(1,150mg/100g) > 인(300mg/100g) 순이었다. 천마추출물의 암세포(간암; Hep3B, 유방암: MCF-7, 폐암; A549, 위암; AGS)에 대한 생육 저해능은 천마추출물 시료농도가 증가함에 따라 증가하는 경향을 보여 1.0mg/ml에서 위암세포(AGS)에 대한 생육 저해능이 83%로 가장 높았다. 천마추출물의 항균활성은 Bacillus subtilis와 Pseudomonas aeruginosa에 대하여 미약한 활성을 나타내었으며, 그 이외의 피검균에 대하여는 항균활성이 거의 없었다. <TEX>${\alpha}$</TEX>-glucosidase효소 활성 저해능은 천마추출물 시료가 1.0mg/ml일때 64%의 높은 저해능을 보였다. ACE활성 저하능은 시료가 <TEX>$0.2{\sim}1.0mg/ml$</TEX>의 농도 범위에서 <TEX>$63{\sim}89%$</TEX>이었고, 1.0mg/ml일 때 89%로 높은 저해능을 보였다. Glutathion S-transferase(GST) 활성능은 추출물 농도가 1.0mg/ml일 때 221%의 높은 활성을 나타내었다. 이상의 결과로부터 천마는 건강식품이나 기능성 식품의 소재로서 활용이 가능할 것으로 판단되었다. A hot water extract was prepared from the artificially grown Gastrodia elata to investigate its chemical composition and various in vitro biological activities as an effort to develop G. elata as health/functional food materials. The contents of crude protein, ash, fat, fiber, moisture and total sugar were 5.4, 2.6, 3.6, 3.3, 8.1 and 77% (w/w), respectively. The extract of G. elata had greater amount of potassium (1,150 mg/100 g) than phosphorus (300 mg/100 g). Dose-dependence against human carcinoma (Hep3B, MCF-7, A549 and AGS) were observed from 0.2 mg/ml to 1.0 mg/ml. Especially, the treatment of 1.0 mg/ml extracts showed the highest cytotoxicity with 83% against gastric carcinoma (AGS). The extracts showed weak antimicrobial activities against Bacillus subtilis and Pseudomonas aeruginosa, but practically no antimicrobial activity against the other microorganisms tested. The effect of <TEX>${\alpha}$</TEX>-glucosidase inhibition was 64% at the concentration of 1.0 mg/ml. The inhibitory effect of angiotensin converting enzyme (ACE) of the extract in the range of <TEX>$0.2{\sim}1.0mg/ml$</TEX> showed <TEX>$63{\sim}89%$</TEX>, and the highest ACE inhibition was 89% at the concentration of 1.0 mg/ml of extracts. The highest activity of glutathion S-transferase (GST) was 221 % at the concentration of 1.0 mg/ml of the G. elata extracts. These results suggest that G. elata may be used as health/functional food materials.

ACE inhibitors in heart failure: an update.

Angiotensin-converting enzyme (ACE) inhibitors are now accepted as part of the routine management of patients with heart failure. Their use has been mandated in all the new major mortality trials to test the efficacy of beta-blockers in heart failure. Morbidity and mortality remain high in those with heart failure even with the benefits proven for both these groups of agents. In spite of the evidence for benefit of ACE inhibitors they are persistently used in lower doses in clinical practice than tested in the large-scale trials. This was so prevalent as to allow the conduct of a substantial study, the ATLAS trial, to compare high and low dose ACE inhibition. Its equivocal findings have allowed different interpretations. Clinical experience would suggest that starting with a low dose is appropriate but the dose should be titrated then without undue delay to the levels used in the trials wherever possible. The evidence for benefit with these drugs had been obtained largely in patients with impaired systolic function. However the AIRE study selected patients with clinical evidence of heart failure after myocardial infarction rather than with impaired systolic function. A substantial and long-term benefit was found from ACE inhibition. A cohort of patients had ventricular function assessed and as anticipated almost one half had preserved systolic function. Whilst the absolute benefit in lives saved was greater in the higher risk/low ejection fraction group, the relative risk reduction was not significantly different between those with preserved or impaired systolic function. The publication of the HOPE trial, although not a study of patients with heart failure, has clarified the situation considerably for those taking day to day care of patients. The HOPE study selected patients on the basis of high cardiovascular risk excluding those with known impaired systolic function. Although not an entry requirement for the study, ejection fraction was measured in a substantial majority and was above 40% indicating preservation of systolic function. The ACE inhibitor ramipril markedly reduced the combined end-point of cardiovascular death, stroke and myocardial infarction. Importantly there was a highly significant 20% risk reduction in the rate of myocardial infarction, a prospectively defined end-point, over the average four and a half year follow-up. Taken together with the retrospectively derived evidence from the heart failure trials there is now compelling evidence that the ACE inhibitors prevent myocardial infarction. The majority of patients with clinical heart failure have underlying ischaemic heart disease. Prevention of myocardial infarction and control of blood pressure are two key factors in the management of these patients irrespective of systolic ventricular function. The ACE inhibitors like the beta-blockers therefore have a pivotal role in their management. A challenge to current clinical trials is to determine whether these properties are shared to the same degree by the angiotensin antagonists or if even further gains in benefit can come from their combination. The neutral findings of the ELITE II study comparing the angiotensin antagonist, losartan, with the ACE inhibitor, captopril, have heightened interest in the on-going trials addressing these issues.